NEUROLOGY Flashcards
What are some risk factors for Alzheimer’s disease?
- Age: older age is a major risk for AD
- Genetics: most cases of AD are sporadic (95%). Small number of inherited causes exist (<5%, autosomal dominant inheritance). Inherited causes suggested by early-onset disease.
- Cardiovascular disease: smoking and diabetes increase risk.Exercise decreasesrisk.
- Depression
- Low educational attainment
- Low social engagement and support
- Others: head trauma, learning difficulties
Sedentary lifestyle, Hearing loss, Social isolation
What is the pathophysiology of AD - how do Amyloid Beta plaques form?
Amyloid Beta Plaques:
• Amyloid Precursor Protein (APP) - A channel protein in neurons.
• If it is broken down by the Beta secretase enzyme, the fragment is not soluble and becomes sticky, and will clump together
• ==> get in the way of neurones and their signalling
==> Plaques can trigger immune response, leading to inflammation
What is the pathophysiology of AD - What are neurofibrillary tangles? (NFTs)
Beta amyloid plaque build-up outside the neurone, lead to kinase enzyme activation in Neuron
This leads to phosphorylation of the tau protein, that helps hold microtubules in cell together.
When Tau is phosphorylated it stops supporting microtubules and clumps with other Tau proteins, forming forming neurofibrillary tangles
Neurones with tangles and non-functioning microtubules can’t signal as well, and sometimes end up undergoing apoptosis
What are some symptoms of Alzheimer’s disease?
Agnosia - cant recognise things
Apraxia - Cant do basic motor skills
Aphasia - Speech difficulties
- Cognitive impairment
- Poor memory
- Agitation and emotional lability
- Depression and anxiety
-
Sleep cycle disturbance
Motor disturbance: wandering is a typical feature of dementia
Poor memory
memory loss as the primary early symptom, followed by language, orientation, and personality changes.
Gradual Progression: Symptoms worsen steadily and continuously over time, with no clear breaks or abrupt changes (e.g., Alzheimer’s).
Stepwise Progression: Symptoms worsen in sudden, noticeable declines followed by periods of stability, often linked to specific vascular events like strokes (e.g., Vascular Dementia).
What investigations can you do for suspected Alzheimers?
Cognitive assessment: e.g. mini mental state examination (MMSE), looks at:
- Attention and concentration
- Recent and remote memory
- Language
- Praxis: planned motor movement (e.g. perform a task)
- Executive function
- Visuospatial function
- Bloods and other investigations e.g. ECG, virology, chest x-ray: exclude other pathologies
- Imaging
- CT/MRI: exclude other diagnosis and can help determine type of dementia; will show medial temporal lobe atrophy
What is some of the management you can offer for Alzheimer’s Disease?
- Non-pharmacological: programmes to improve/maintain cognitive function (e.g. structured group cognitive stimulation programmes). Also exercise, aromatherapy, therapeutic use of music/dancing, massage.
-
Pharmacological:
- Mild-to-moderate AD: acetylcholinesterase inhibitors (e.g. donepezil, rivastigmine).
- Moderate-to-severe AD: N-methyl-D-aspartic acid receptor antagonist (e.g. memantine).
- Advanced care planning
- End of life care
What is the prognosis for Alzheimer’s?
Estimated median survival after diagnosis is3-9 years (variable).
Development of delirium on a background of dementia is associated with more rapid progression.
- Mild: first 2 years
- Moderate: next 2-4 years
- Severe: 4-5 years onwards
What is frontal temporal dementia? What ages does it most likely affect?
Frontotemporal dementia is a neurodegenerative disorder characterised by focal degeneration of the frontal & temporal lobes.
- Typically affects patients at a younger age (< 65 years)
- The mean age of onset is 58 years old. The onset before 40 years old and after 75 years old is uncommon.
Rapid onset - Overall survival is 8-10 years from symptoms starting
outline the pathophysiology behind Frontal temporal dementia
3R isoforms of the tau protein get hyperphosphorylated. =====>As with AD, these can’t hold the tubulins together, and start clumping.
Affected Neurons won’t function well, and so neurons get damaged/undergo apoptosis
Large scale changes in brain -
- Brain atrophy: the gyri get narrower whereas the sulci get wider.
- The ventricles expand as the rest of the brain shrinks.
- The parietal and occipital lobes are spared.
What are some clinical manifestations of Frontaltemporal dementia/Pick’s disease?
- Frontal lobe effects: personality and behavior changes
- Disinhibition(e.g. socially inappropriate behaviour)
- Loss of empathy
- Apathy(losing interest and/or motivation)
- Compulsive behaviour
- Temporal lobe effects: language problems
- Effortful speech
- Halting speech
- Speech-sound errors
- Speech apraxia(i.e. difficulty in articulation)
- Word-finding difficulty
- As atrophy progresses
- Memory loss
- Lack of concentration
- Inability to learn new things
What are some investigations to do for Frontal temporal dementia?
- Diagnosis based on cognitive assessment
- Imaging:
- MRI: exclude other pathology; indicates changes in the frontal and temporal lobes
- Definitive diagnosis: brain biopsy after a person has died
Outline the pathphysiology behind what happens in Lewy- Body Dementia
neurones contain a protein called alpha synuclein. In LBD, this gets misfolded in neurons
misfolded alpha-synuclein aggregates to form Lewy bodies that deposit inside neurones, particularly in the cortex and the substantia nigra.
As the disease progresses, more and more neurones accumulate Lewy bodies and die.
Name 3 disease where Lewy bodies are seen
Lewy-Body dementia
Parkinson’s
Multiple System Atrophy
What are some symptoms of Lewy Body dementia
- Early symptoms are typically cognitive ones (Alzheimer’s-like)
- Difficulty focusing
- Poor memory
- Visual hallucinations
- Disorganized speech
- Depression
- Later symptoms are typically motor ones (Parkinson’s-like)
- Resting tremors
- Stiff and slow movements
- Reduced facial expressions
The clinical picture is often characterised by fluctuating cognition, Parkinsonism, and visual hallucinations.
- Some patients may have sleep disorders e.g. sleep walking or talking in their sleep
The criteria for diagnosing Lewy body dementia is the presence of dementia alongside two of the three core features: fluctuating attention and concentration, recurrent well-formed visual hallucinations, spontaneous Parkinsonism
What is the two treatments you can give to alleviate symptoms of Lewy body dementia?
What group of medications do you need to avoid in LBD?
- Dopamine analogue e.g. levodopa: for Parkinson’s like motor symptoms
- Cholinesterase inhibitors e.g. donepezil: increases acetylcholine availability, used for Alzheimer’s-like cognitive symptom
Antipsychotics should be avoided in patients with dementia due to adverse reactions and increased mortality in the elderly. In Lewy body dementia, severe antipsychotic sensitivity reactions have been reported in 50% of patients- these include rigidity, immobility, postural falls, and confusion. They may lead to irreversible parkinsonism, particularly risperidone and typical antipsychotics such as Haloperidol.
What vascular dementia?
How does it present
Vascular dementia is a chronic progressive disease of the brain caused by cerebrovascular disease, and a lack of oxygen being supplied to neurons
Vascular Dementia: Stepwise progression, often linked to stroke or cardiovascular issues; symptoms include impaired judgment, problem-solving, and movement difficulties early on.
Gradual Progression: Symptoms worsen steadily and continuously over time, with no clear breaks or abrupt changes (e.g., Alzheimer’s).
Stepwise Progression: Symptoms worsen in sudden, noticeable declines followed by periods of stability, often linked to specific vascular events like strokes (e.g., Vascular Dementia).
Outline the pathophysiology behind vascular dementia
Small vessel diseases eg Atherosclerosis, Ischaemic strokes, haemorrhage, amyloidosis = leads to lack of o2, and a gradual decrease in blood supply = chronic ischaemia
Tissue gets damaged = Liquefactive Necrosis
Brain necrosis leads to a loss of mental functions that are governed by that area.
What is some of the management you can do for Vascular dementia?
No cure
- Management of risk factors e.g. high BP, high cholesterol, diabetes, smoking.
- Acetylcholinesterase inhibitors e.g. donepezil: only used if mixed dementia as may have some benefit
Non-pharmacological: programmes to improve/maintain cognitive function (e.g. structured group cognitive stimulation programmes), exercise, aromatherapy, therapeutic use of music/dancing, massage
Outline what is assessed in the GCS - for motor
Motor response (M) - You should score the patient based on the highest scoring response you were able to elicit in any single limb
Obeys command 6 points
Localises to pain 5 points
Withdraws to pain (normal flexion) 4 points
Abnormal Flexion (decorticate posture 3 points)
Abnormal extension (decerebrate posture 2 points)
No response 1 point
need to record the best action done by the patient.
Patients with a GCS below 8 should be considered for both i) review by an anaesthetist and ii) intubation and ventilation
Outline what is assessed in GCS for Verbal
Verbal response (V)
Orientated 5 points
Confused conversation 4 points
Inappropriate words 3 points
Incomprehensible sounds 2 points
No response 1 point
Outline what is assessed in GCS for eyes
Eyes:
Eye-opening spontaneously 4 points
Eye-opening to sound 3 points
Eye-opening to pain 2 points
No response 1 point
need to record the best action done by the patient.
Patients with a GCS below 8 should be considered for both i) review by an anaesthetist and ii) intubation and ventilation
What principles should you remember when looking for a best motor response?
the pain stimulus should always be
applied within a cranial nerve distribution to ensure not eliciting a spinal reflex. The best site for
applying a pain stimulus is a point immediately below the ear between mastoid process posteriorly
and mandible anteriorly, applying the stimulus bilaterally, equally, and ultimately as hard as one can.
Patients with a GCS below 8 should be considered for both i) review by an anaesthetist and ii) intubation and ventilation
need to record the best action done by the patient.
Define Parkinson’s disease
Parkinson’s Disease (PD) is a neurodegenerative disorder characterised by loss of dopaminergic neurones within the substantia nigra pars compacta (SNPC) of the basal ganglia (nigrostriatal pathway)
Mutations of what genes have been implicated?
What are some causes of secondary Parkinson’s
Idiopathic condition but potentially related to genetics
Mutation in Parkin Gene, PINK1
Mutation in alpha-Synuclein gene
Secondary causes of Parkinsonism;
Vascular parkinsonism
Infections – Encephalitis
Toxin induced – Carbon monoxide, drugs, Pesticides
studies show smoking is protective for parkinson’s!!
Outline the basic pathophysiology of parkinson’s
Neurodegenerative loss of dopamine secreting cells from the pars compacta of the substantia nigra that project to the striatum 🡪 reduced striatal dopamine levels,
This means that Subthalamic nucleus will be less inhibited, so it will inhibited the Thalamus more.
Less dopamine means the thalamus will be inhibited resulting in PROBLEMS INITAIATING
MOVEMENT
What is the histological hallmark seen in Parkinson’s?
eosinophilic inclusion bodies - consisting of misfoldedα-synucleinin the dopaminergic neurones of the Pars Compacta, calledLewy bodies.
What are some motor symptoms of Parkinson’s disease?
Bradykinesia (hypokinesia/akinesia) – slowness or absence of movement
Resting tremor , 3-5 Hz
Rigidity – stiffness and Pain (20% initially present with pain), Increased tone in limbs and trunk - test at wrists
Postural instability - Impaired balance – especially when trying to turn
- Other features
- Micrographia (abnormally small, cramped handwriting)
- Hypomimia (reduced degree of facial expression)
Tremor is typically asymmetrical!
What are some non - motor symptoms of Parkinson’s Disease?
- Anosmia (smell blindness)
- Sleep disturbance: REM sleep is impaired
- Psychiatric symptoms
- Depression
- Anxiety
- Dementia: usually develops after motor symptoms, unlike in Lewy-body dementia
-
Constipation
Urinary incontinence not typical
What do you look for when making a clinical diagnosis of someone with Parkinson’s?
- PD is a clinical diagnosis: it should be suspected in a patient who has bradykinesiaand atleastoneofthe following:
- Tremor (asymetirical)
- Rigidity
- Postural instability
Tremor is typically asymmetrical!
What investigations can help diagnose someone with parkinson’s?
- MRI brain:may help exclude other causes of neurological disease but should not be used to diagnose PD - show substantia nigra atrophy
-
SPECT (DaT scan):single-photon emission computed tomography (SPECT) will show reduced dopamine uptake in the basal ganglia
DaT Scan reveals atrophy of basal ganglia/ ‘dots instead of commas
name some things that should NOT be present in Parkinson’s disease, at the beginnning.
Incontinence
Dementia
Symmetry
Early falls
Tremor in action
if these are present, think of differentails……
name 2 differentials for Parkinson’s disease, what you may see in them and how you would treat them.
Normal pressure hydrocephalus – increase in CSF 🡪 enlarged ventricles
Will See Magnetic gait - inability to lift the feet off the floor - also incontinence, and dementia
Treatment = Surgical correction
Shunt from the ventricles to the peritoneum
Benign Essential Tremor
see next card for manifestations
Very common, can run in families
Treat with Beta-blockers
Outline qualities of a tremor seen in Parkinsons
Parkinson’s Tremor
Asymmetrical
Worse at rest
Improves with intentional movement
May have other Parkinson’s features
No Change with alcohol
Lower frequency (4-6 hertz)
What is the main drug used in the management of Parkinson’s disease? When is it used?
1st line - Levodopa is the precurser to dopamine
It is used as a dopamine replacement agent
Should be started in all patients with significant functional impairment according to NICE guidelines
Typically combined with Carbidopa, (a Decarboxylase inhibitor) which decreases side effects and improves CNS bioavailability) oftern referred to as Co-careldopa
Other parkinsons treatments - give some examples of dopamine agonists, and when they are used, and side effects of them
Dopamine agonists
Examples include: Ropinirole, rotigotine, Apomorphine.
Are often used in early disease in those without functional impairment, or late in disease when dyskinesias and motor fluctuations secondary to levodopa is a problem.
may affect reward centres and lead to unwanted risk-taking behaviours such as gambling.
parkinosn treatment - what is MAO-B inhibitors
Examples include: Selegiline, Rasagiline.
Reduce dopamine breakdown peripherally & thus increase central update of levodopa. Often used in combination with levodopa later in disease.
Initial animal studies suggested a “neuroprotective effect” although this has not been seen in human studies.
Can cause serotonin syndrome.
What are some common side effects of L-Dopa?
- Dyskinesia:excessive involuntary movements related to levodopa use (excess dopamine)
- Dystonia: This is where excessive muscle contraction leads to abnormal postures or exaggerated movements.
- Chorea: These are abnormal involuntary movements that can be jerking and random.
- Athetosis: These are involuntary twisting or writhing movements usually in the fingers, hands or feet.
- hallucinations,
Excessive daytime sleepiness and sudden onset of sleep
Explain the difference between Dyskinesia and Dystonia
Dyskinesia is the involuntary movement of a body part or the entire body that you can’t control.
Dystonia is the involuntary stiffening or contraction of a muscle.
dyskinesia more often looks like jerky movements of an arm, leg, or face.
dystonia is a repetitive pattern of muscle movements that can appear across a much wider range of body parts, including the jaw, eyelids, hands, arms, feet, legs, face, and neck.
What is the issue with using levodopa to treat PD?
Initially works well but soon the Px becomes resistant to it and the effects wear off.
Therefore want to only use it when Sx are bad enough to prevent early resistance.
Levodopa can lead to overstimulation of neurones, leading to Chorea
Give Entacapone -makes the dopamine stay around longer
If a patient with Parkinson’s disease cannot take levodopa orally, they can be given a dopamine agonist patch as rescue medication to prevent acute dystonia
Parkinson differentials -
When would you see Parkinson’s Dementia?
What about Lewy Body Dementia/w Parkinsonism?
Parkinson Sx THEN dementia - PARKINSON’S DEMENTIA
Dementia Sx THEN Parkinson’s - LEWY BODY DEMENTIA W PARKINSONISM
What are some other things taht can cause parkinsonism?
Drugs - anti psychotics and antiemetics - would cause a symmetrical tremor
Vascular Parkinson
Dementia w Lewy Body’s
Normal Pressure Hydrocephalus
Severe Wilsons disease
progressive supranuclear palsy
multiple system atrophy
dementia pugilistica (secondary to chronic head trauma e.g. boxing)
What is
progressive supranuclear palsy
What are some features of it and how can you differentiate it from parkinsons?
rare neurodegenerative disorder characterized by problems with balance, eye movement, and cognition. caused by Tau protein in the brain
Parkinsonism: Stiffness, slowness, but poor response to levodopa.
Cognitive decline: Apathy, difficulty with planning, and speech changes.
PSP is often misdiagnosed as Parkinson’s but progresses more rapidly. There is no cure, and treatment is supportive.
What is multiple system atrophy and how is it different in its presentation to parkinsons disease?
rare, progressive neurodegenerative disorder affecting the autonomic nervous system and motor control. It is caused by the accumulation of alpha-synuclein protein in the brain.
MSA: Parkinsonism does not respond well to levodopa.
MSA: Autonomic dysfunction is early and severe, including significant orthostatic hypotension and bladder issues.
MSA: Cerebellar signs (ataxia, difficulty with coordination) are prominent, especially in the MSA-C subtype.
Symptoms often appear more suddenly and can be more widespread from the start.
Outline the qualities seen in an Essential tremor
Benign Essential Tremor
Symmetrical
Improves at rest
Worsens with intentional movement
No other Parkinson’s features
Improves Change with alcohol
Higher frequency (5-8 hertz)
What is the treatment for an essential tremor?
β-Blockers, most commonly propranolol, and primidone are the drugs of choice for treatment of ET
What is Motor Neuron Disease (MND)
Progressive neurodegenerative disease where both upper and lower motor neurons stop functioning but there is no effect on the sensory neurons.
What are the different types of MND?
Amyotrophic Lateral Sclerosis (ALS) - most common, 50% of cases
Primary Lateral Sclerosis (PLS) UMN
Progressive Muscular Atrophy (PMA) LMN
Progressive Bulbar Palsy (PBP)
What are the signs of progressive muscular atrophy?
Anterior horn cell lesion, so LMN signs only. Affects distal muscle groups before proximal. Better prognosis than ALS
In contrast to amyotrophic lateral sclerosis or primary lateral sclerosis, PMA is distinguished by the absence of:
brisk reflexes
spasticity
Babinski’s sign
^^ as lower MN lesion!
PMA is a diagnosis of exlcusion
What are the signs of Progressive bulbar palsy? What is affected?
UMN + LMN + Cranial Nerve IX, X, XI, XII signs
Lower cranial nerve nuclei affected causing dysarthria, dysphagia, nasal regurgitation of fluids, choking
- Worst prognosis
What are the signs of primary lateral sclerosis? What is affected?
UMN signs only. - Rare. Loss of Betz cells in motor cortex - marked spastic leg weakness and pseudobulbar palsy. No cognitive decline
Outline the pathophysiology of Amyotrophic lateral sclerosis.
Loss of motor neurons in motor cortex and the anterior horn of the cord, so combined UMN + LMN
What is the general pathology of MND?
Degenerative condition affecting motor neurons – mainly the anterior horn cells
There is relentless and UNEXPLAINED destruction of UMN and anterior horn cells in the brain and spinal cord
Causes both UMN and LMN dysfunction
UMN and LMN affected but no sensory or sphincter loss – distinguishes from MS
Never affects eye movements – distinguishable from myasthenia gravis
What are the signs of an Upper motor neuron (UMN) lesion, as seen in Motor Neurone disease
UMN – everything goes UP
Hypertonia
Rigidity + spasticity
Hyperreflexia
Extensor plantar responses (positive Babinski sign) stroke sole of foot, big toe goes up
Power:
Arms - Flexors > Extensors
Legs - Flexors < Extensors
If you see a patient with mixed upper and lower motor neurone signs, think Motor neurone disease!!
What are the signs of an lower motor neurone LMN lesion, as seen in Motor Neurone disease
Hypotonia
Flaccidity + muscle wasting
Hyporeflexia
Fasciculations
Babinski Reflex Negative - big toe goes down when stroking foot
Generally loss of power
If you see a patient with mixed upper and lower motor neurone signs, think Motor neurone disease!!
What are some general symptoms seen in motor neurone disease?
- Fasciculations (twitches in the muscles) especially on the tongue
- Dysarthria and dysphagia: particularly in progressive bulbar palsy
- Progressive weakness often first noticed in the upper limbs
- Clumsiness
- Fatigue
- Falls
- Speech and swallow issues: particularly in progressive bulbar palsy
If you see a patient with mixed upper and lower motor neurone signs, think Motor neurone disease!!
Outline the power gradings 0-5 seen in a neuro examination
0 - complete paralysis
1 - flicker of contraction possible
2 - movement is possible when gravity is excluded
3 - movement is possible against gravity
4 - movement is possible against gravity + some resistance
5 - normal power
Where is an UMN lesion?
Anywhere on a motor nerve between the pre-central gyrus to the anterior spinal cord
Where is a LMN lesion?
Anywhere on a motor nerve between the anterior spinal cord and the innervated muscle
What is NEVER affected in MND?
Eye muscles:
Affected in Multiple sclerosis and Myasthenia Gravis
Sensory Function and Sphincters:
Affected in MS and Polyneuropathies
How can you diagnose motor neurone disease?
- Definite: LMN + UMN signs in 3 regions
- Probable: LMN + UMN signs in 2 regions
- Probable with lab support: LMN + UMN signs in 1 region, or UMN sign in more than 1 region + electromyography (EMG) shows acute denervation in more than 2 limbs
What investigations can you do to help diagnose Motor neurone disease?
- Electromyography:in MND there will be evidence of fibrillation potentials - due to denervation of muscles due to LMN dysfunction - ( EMG is a technique for evaluating and recording the electrical activity produced by skeletal muscles.)
- Nerve conduction studies:may show modest reductions in amplitude
- MRI spine:imaging can help exclude spinal pathology which may mimic MND, such as cervical cord compression and myelopathy
- Lumbar puncture: to exclude inflammatory causes
- Pulmonary function tests:patients with MND are at risk of respiratory failure
Blood tests e.g. raised Creatinine Kinase (due to muscle destruction),
What are some differentials for MND?
- Multiple sclerosis
- Polyneuropathies
- Myasthenia gravis
- Diabetic amyotrophy
- Guillain-Barre syndrome
- Spinal cord tumours
What is some of the pharmological management used in MND?
Riluzole, anti-glutaminergic:an inhibitor of glutamate release and NMDA receptor antagonist = is thought to protect motor neurons from glutamate-induced damage, (only drug that can increase survival, 2-4 months)
Antispasmodics: such as baclofen
Respiratory support:patients with reduced FVC can use non-invasive ventilation at home, usually BiPAP; prolongs survival by 7 months
What is some of the non pharmological management of MND?
- Analgesia
- Feeding support: many patients require nutritional support, often with PEG (percutaneous gastronomy) tube
- Speech and language therapy
- Physiotherapy
- Advanced directivesto document the patients wishes as the disease progresses
- End of life careplanning
What are some complications of MND? What is the average prognosis?
- Aspiration pneumonia andbronchopneumonia
- Respiratory failure: often occurs in advanced disease when respiratory muscles have been affected
Most patients die within 3 years from the onset of their symptoms.
What are some risk factors for getting MND
Male
Family history of it
Increasing age
Genetic mutations - SOD1
What is transverse myelitis?
Transverse myelitis is a rare neurological condition. It’s caused by inflammation (swelling) of the spinal cord. The swelling damages the nerves and can leave permanent scars or lesions.
The scars or lesions interrupt the communication between the nerves in the spinal cord and the rest of the body.
What are some causes of transverse myelitis?
60% of cases, cause is idiopoathic
Can be seen in conidtions like MS, and Neuromyelitis optica
Infections - like HIV, TB, HSV, CMV, EBNV
What are some signs and symptoms of transverse myelitis?
muscle weakness in the legs, and sometimes the arms
mobility problems
unusual sensations and numbness
bladder problems
bowel problems
sexual problems
pain
back pain
A lesion of the thoracic segment (T1–12) will produce upper motor neuron signs in the lower limbs, presenting as a spastic paraparesis. This is the most common location of the lesion, and therefore most individuals will have weakness in the lower limbs
Lesions of the lower cervical region (C5–T1) will cause a combination of upper and lower motor neuron signs in the upper limbs, and exclusively upper motor neuron signs in the lower limbs.
What is the treatment for Transverse Myelitis?
If the patient is found to have idiopathic TM, no preventive therapy is required.
Therapy aimed at preventing future attacks is not required for single-event TM
There are no controlled trials of corticosteroids for TM, but the approach is extrapolated from treatment of acute multiple sclerosis (MS) attacks.
methylprednisolone: 1000 mg intravenously once daily for 3-5 days
What happens in multiple sclerosis?
Chronic progressive autoimmune, T-cell mediated inflammatory disorder of the CNS, against the myelin basic protein of oligodendrocytes
causes demyelination of CNS neurons (brain and spinal chord)
What are the risk factors for MS?
- Age: most commonly diagnosed in 20-40 year olds
- Female gender: MS is 3 times more common in females
- Smoking
- Vitamin D deficiency - due to lack of sunlight? so - Northern latitudes is also a risk factor
- Family history: HLA-DR2 is implicated
- Autoimmunity: patients often have a family history of other autoimmune disorders
- EBV infection: the virus with the greatest link to MS
Normal physiology - what does myelin do and what is it produced by in the CNS and PNS?
Myelin is the protective sheath that surrounds the axons of neurons, allowing them to quickly send electrical impulses.
This myelin is produced by oligodendrocytes in the CNS and by schwann cells in the peripheral nervous system
Outline the pathophysiology behind Multiple sclerosis. What happnes when the T cells get through the BBB, What is left behind on the myelin?
T Cells get through blood brain barrier, and get activated by Myelin = T cells can now change BBB (so has more receptors) to allow more immune cells to get through it
T cells release cytokines, damaging Oligodendrocytes, and B cells make antibodies and which allow macrophages to attack the oligodendrocytes,
Leaving behind areas of plaque/sclera on neurone
Pathophysiology behind MS - why do patients with this often get relapses?
regulatory T-cells can inhibit other immune cells, meaning at first there may be remyelination of damaged neurons - but over time this remyelination doesn’t keep up and permanent damage occurs.
A characteristic features of MS is that lesions vary in their location over time, meaning that different nerves are affected and symptoms change over time.
What is the most common type of Multiple sclerosis?
-
Relapsing-remitting:
- The most common pattern (85% of cases)
- Episodic flare-ups (may last days, weeks or months), separated by periods of remission. There isn’t full recovery after the flare-ups, so disability increases over time
- 60% of patients develop secondary progressive MS within 15 years
Secondary progressive
Primary progressive
What are some symptom of multiple sclerosis?
EYES:
Optic neuritis - most common presentation of MS - It involves demyelination of the optic nerve and loss of vision in one eye - PAIN WHEN LOOKING SIDEWAYS
Optic neurities involves - optic disc swelling, Phosphenes (floating things , unilateral pian, retero orbitral pain, and symptoms resolves over days from onset
Double Vision - due to lesions with the sixth cranial nerve (abducens nerve).
Plaques in sensory pathways from skin - Numbness, tingling, sensory loss, paraesthesia (tingling, itching burning sensation)
Plaques in autonomic nervous system- Bladder incontinence, sexual dysfunction
-
Trigeminal neuralgia: stimulation to face causes pain
Cognitive decline - Poor concentration, critical thinking, depression
Charcot’s triad due to Cerebellar white matter demyelination
Symptoms of MS - what is Charcots Neurological Triad?
Dysarthria – due to plaques in brainstem
Difficult or unclear speech – can affect eating, talking, swallowing
Intention tremor – due to plaques along motor pathways
Muscle weakness and spasms
Tremors
Ataxia
Paralysis
Nystagmus – due to plaques in nerves of eyes
Loss of vision
Optic neuritis
Painful eye movements
Double vision
what is
Uhthoff’s Phenomenon
Lhermitte’s phenomenon
SEEN IN MS
Uhtoff’s phenomenon: worsening of symptoms following a rise in temperature, such as a hot bath/sauna/exercise
Lhermitte’s phenomenon: electric shock sensation on neck flexion (bending neck forward), caused by stretching the demyelinated dorsal column.
Uhtoff explained - Although the myelin sheath does regenerate, the new myelin is less efficient and temperature dependent - When exposed to high heat – conduction through new myelin drastically decreases
How is a diagnosis for Multiple sclerosis made?
Diagnosis - neurologist based on the clinical picture and symptoms suggesting lesions that change location over time.
Often using the McDonald Criteria. - looking for symptoms/signs which demonstrate dissemination in space (i.e. different parts of the CNS affected) and time.
Other causes for the symptoms need to be excluded
What investigations can point a diagnosis of Multiple Sclerosis
MRI with contrast - Active Lesions will take up contrasts, Old ones will not ==> Can also see Demyelinated Plaques, known as Dawson’s Fingers
Lumbar puncture with CSF electrophoresis = inflammatory proteins found in the CSF, not serum - shows you that there’s an inflammatory response in the CNS eg Oligoclonal IgG bands = CNS inflammation -
Evoked vision potentials – tests how long it takes impulses to travel - delayed, but waveform preserved.
delayed, visual, brainstem, auditory, somatosensory potentials
E.g. stimulate optic nerve and measure time for impulse to go from eye to occipital cortex - measures visual evoked potential
As there is demyelination, conduction will be slower
Outline the McDonald Criteria
Criteria used to diagnose MS:
Uses symptoms/signs which demonstrate dissemination in space (i.e. different parts of the CNS affected) and time.
Diagnosis is based on:
- 2 or more relapses (disseminated in space and time AND EITHER
- Objective clinical evidence of 2 or more lesionsOR
- Objective clinical evidence of one lesionWITHa reasonable history of a previous relapse
- ‘Objective evidence’ is defined as an abnormality on neurological exam, MRI or visual evoked potentials
What is the management for Multiple sclerosis?
No cure
Acute attacks: (relapsing-remitting MS) – IV methylprednisolone 1000 mg intravenously once daily for 3 days
Plasma exchange: to remove disease-causing antibodies
Chronic
1st line (frequent relapse)
- Subcutaneous Interferon Beta
For spasticity
- Baclofen, and Botulinum toxin injections and Gabapentin
what are some side effects of high doses of steroids, and why do you need to give such high doses in MS?
Need to give high doses as harder to cross the BBB
- Immunosuppression - indeed, do a urine dipstick to rule out asymptomatic UTIs in MS, as these can be common in these patients
- Osteroporosis, and easier to fractrue - escpecially fibrosis necrosis
- Diabetes
Make you cushingoid
What is the management of MS, looking at symptom control?
Tremor – beta blocker
Mild to moderate muscle spasticity – oral medications e.g. diazepam, baclofen, gabapentin (GABA analogue that reduces Ca2+ influx)
Focal disabling muscle spasticity – peripheral nerve blocks, botulinum toxin - botox injections
Removal of trigger factors e.g. UTI, bed sores
Physical treatments e.g. physio, exercise to maintain strength.
Neuropathic pain – gabapentin
Depression - SSRIs
Name any biological DMARDs that are used in MS
Beta Interferon and Monoclonal antibodes eg atemuzmab (anti-CD52), natalizumab
Explain the genetics of DMD?
X linked Recessive condition.
Therefore mother with 1 faulty gene:
Daughters - 50% chance of being carrier
Sons - 50% chance of being affected
What is the pathophysiology of DMD?
Lack of Dystrophin gene (vital part of muscle fibre) means that the muscles are not protected from being broken down by enzymes
Therefore in DMD you get progressive wasting and weakness of muscle as they are broken down.
The muscle tissue is then replaced by fibrofatty tissue
Most Px in wheelchair by teenage years
What cardiovascular condition is associated with DMD?
Dilated cardiomyopathy
Dystrophin gene in heart muscle not present which is normally involved in membrane stability.
Therefore in DMD there is damage to the cellular mechanisms causing dilation of
ventricles due to wasting of the cardiac muscle causing cardiomyopathy
What are the symptoms of DMD? What tests could you do for it?
Child struggles to get up from lying down
(GOWER’S sign)
Skeletal deformities - scoliosis
Creatine Kinase will be raised in DND - Check this in any boy that is not walking by 18 months
What is Gower’s Sign?
an inability to lift the trunk without using the hands and arms to brace and push –
From the lying position, the patient rolls to the kneeling position, pushes on the ground with extended forearms to lift the hips and straighten the legs, so forming a triangle with hips at the apex and hands and feet on the floor forming the base.
The hands are then used to push on the knees and so lift up the trunk (climbing upon yourself).
Name some treatments for DND. What is life expectancy?
Phsyio, Braces, Corrective Sugery
Assisted Ventilation
Steroids, anticonvulsants to control seizures
The median life expectancy is 28–30;
Outline what is seen in Beckers Muscular dystrophy
similar to Duchennes, however the dystrophin gene is less severely affected and maintains some of its function. (It’s an inframe deleltion, not an outframe deletion)
What is Myotonic dystrophy?
It’s a type of muscular dystrophy, a group of genetic disorders that cause progressive muscle loss and weakness.
In DM, muscles are often unable to relax after contraction
Genetic anticipation occurs in this
What are some key features seen in Myotonic dystrophy?
Progressive muscle weakness
Prolonged muscle contractions
Cataracts
Cardiac arrhythmias/Heart problems
Can also see intellectual disability.
In men, there may be early balding and an inability to father children
Genetic anticipation occurs in this
Aka = unable to let go after shaking someones hand, or unable to release their grip on a doorknob after opening a door.
What is the treatment for myotonic dystrophy? What is the prognosis?
There is no cure.
Treatments may include braces or wheelchairs, pacemakers and non-invasive positive pressure ventilation.
The medications mexiletine or carbamazepine can help relax muscles
Pain, if it occurs, may be treated with tricyclic antidepressants and nonsteroidal anti-inflammatory drugs (NSAIDs)
Life expectancy in non-congenital late-onset or adult-onset DM1 is in the early 50s, with pulmonary complications being the leading cause of death, followed by cardiac complications
What is a myopathy?
Myopathy is a general term that refers to diseases that affect the muscles that connect to your bones (skeletal muscles). Myopathies may be passed on in families (inherited) or they may develop later in life (acquired)
What are some features of Myopathies?
Myopathies are diseases of muscle.
Like neuropathies, myopathies are characterised by:
muscle weakness
muscle atrophy
the pattern of muscle weakness seen in myopathies is usually proximal and symmetrical - this compares with a distal, or nerve or root distribution seen in neuropathies.
eg Difficuluty shaving, getting out of chair, climbing stairs
tone normal or reduced
reflexes normal or reduced
Sensory loss is not seen in myopathies.
What is the pattern of weakness typically associated with myopathies
proximal, and asymmetirical
What is Huntington’s Chorea (HD)?
an autosomal dominant genetic neurodegenerative condition that causes a progressive deterioration in the nervous system
What is the inheritance pattern of Huntingtons disease?
What type of genetic disease is Huntington’s, as where is this mutation?
autosomal dominant - SOMEONE WITH HD HAS 50% OF PASSING IT ONTO CHILDREN
It’s a “trinucleotide repeat disorder” that involves a genetic mutation in the HTT gene on chromosome 4., that codes for the huntingtin protein.
pathophysiology of huntingtons - what do mutated HTT proteins go on to do in the brain?
Mutated proteins aggregate within the neuronal cells of the caudate and putamen (dorsal striatum) of the basal ganglia causing neuronal cell death.
Specific neurons that die are the GABAergic and cholinergic neurones in the corpus striatum = decreased ACh and GABA synthesis. Without this, levels of dopamine increase leading to excessive movement - Chorea
Define anticipation
What does this mean for people with huntingtons?
A phenomenon in which the signs and symptoms of some genetic conditions tend to become more severe and/or appear at an earlier age as the disorder is passed from one generation to the next.
Anticipation is where successive generations have morerepeatsin the gene, resulting in:
- Earlier age of onset
- Increased severity of disease
Why does anticipation occur in Huntington’s?
What is the phenomena known as?
The expanded CAG not only causes the HTT protein to be mutated, but also interferes with DNA replication itself
When copying the HTT gene, DNA polymerase can lose track of which CAG it’s on and so add extra CAGs.
This is called repeat expansion and happens more frequently in the production of sperm than egg.
Therefore symptoms tend to present progressively sooner when Huntington’s disease runs in men
REPEAT EXPANSION
What is the penetrance of HD?
Full penetrance:
All genotypes of Huntington’s will express the phenotype
What are the physical manifestations of Huntington’s
- Chorea(involuntary, abnormal movements)
-
Eye movement disorders- Problems with initiating saccades
Broken pursuit - Dysarthria: speech difficulties
-
Dysphagia: swallowing difficulties
Ataxia - Problems with heel to toe walking
^^Due to caudate nucelus and putamen atrophy
Often additional touch of parkinsonism
Rigidity
Slowness of fine finger movements
When do symptoms of HD usually present?
Patients are usually asymptomatic until symptoms begin around aged 30 to 50. It presents with an insidious, progressive worsening of symptoms.
Sx present between 30-50 yrs
People with HD will have more severe symptoms typically around 60+ yrs
What are the psychiatric problems seen in Huntington’s?
Dementia
Memory problems
Psychiatric problems
Personality change
Depression
Psychosis
HD usually begins with these psychiatrics symptoms before advancing to physical symptoms.
What investigation is done for HD?
- Diagnosis is made in a specialist genetic centre using a genetic test for the faulty gene and identification of the number of CAG repeats.
- This involves pre-test and post-test counselling regarding the implications of the results.
What is the management for Huntington’s? Non pharmalogical
- Post-test counselling: to help patients cope with diagnosis
- Genetic counsellingregarding relatives, pregnancy and children
- Involvement ofMDTin supporting and maintaining their quality of life (e.g. occupational therapy, physiotherapy and psychology)
- Speech and language therapywhere there are speech and swallowing difficulties
- Advanced directivesto document the patients wishes as the disease progresses
What medical treatment is done in Huntington’s?
No cure, or treatment to stop progression.
Can provide Sx treatment for chorea:
- Antipsychotics (e.g. olanzapine)
- Benzodiazepines (e.g. diazepam)
- Dopamine-depleting agents (e.g. tetrabenazine)
- For depression
- Antidepressants
What is the prognosis of HD?
What would an MRI show of late-stage Huntingtons?
Progressive uncurable condition
Most common cause of death is due to Aspiration Pneumonia, due to swallowing difficulties
Life expectancy of 15-20 years post diagnosis
High rate of suicide
The MRI typically shows caudate nucelus and
putamen atrophy
Give some cause of Chorea
Genetic - huntingtins
HIV - leading to crytococal meningitis
Sydenham’s chorea occurs as a complication of streptococcal infection. Twenty percent (20%) of children and adolescents with rheumatic fever develop Sydenham’s chorea as a complication
Wilsons disease can cause chorea
Autoimmune diseases that affect white matter (aka BG) - SLE, Lupus Anticoagulant
Iatrogenic
Basal Ganglia lesions, ie from a Stroke/tumour, infection
What are some drugs that can cause chorea
Antipsychotics: Some antipsychotic medications, particularly older ones like haloperidol and chlorpromazine, can cause drug-induced chorea.
Antiepileptic drugs (AEDs): Certain AEDs, such as phenytoin and carbamazepine, have been reported to cause chorea in some cases.
Too much dopamine agonists - Levodopa used in Parkinson’s
Lithium: Lithium, commonly used for the treatment of bipolar disorder, can rarely cause chorea as a side effect.
Corticosteroids: High doses or prolonged use of corticosteroids can sometimes lead to chorea.
What is dystonia? How is it different to myoclonus?
Dystonia involves sustained or intermittent muscle contractions that cause abnormal postures or repetitive movements. (think of it as chorea that is slower and writhin)
Dystonia can affect specific body regions (focal dystonia), multiple regions (segmental dystonia), or the entire body (generalized dystonia).
myoclonus involves sudden, brief muscle jerks or twitches, whereas dystonia involves sustained or intermittent muscle contractions leading to abnormal postures or repetitive movements
What are some common causes of Dystonia?
Primary Dystonia: This refers to dystonia without an identifiable cause. The most common form of primary dystonia is cervical dystonia (also known as spasmodic torticollis),
Secondary Causes:
Parkinson’s disease: Dystonia can occur as a complication of Parkinson’s disease
Wilson’s disease:
Medication-induced dystonia: Certain medications, such as antipsychotics (e.g., haloperidol), can cause dystonia as a side effect, especially in susceptible individuals.
Stroke, and a Traumatic brain injury
Cerebral palsy:
Hereditary Dystonia: Some forms of dystonia have a genetic basis and may run in families. Examples include:
Dystonia musculorum deformans (DYT1): This is an inherited form of primary dystonia caused by mutations in the DYT1 gene.
Dystonia-parkinsonism: Certain genetic mutations can cause a combination of dystonia and parkinsonism
What is a brain abscess?
a pus-filled pocket of infected material in the brain
What are some common bacterial, fungal and parasitic causes of a brain abscess?
Streptococcus pyogenes/Strep milleri
Staph Aureus
Klebsiella pneumoniae,
Neisseria meningitides
Fungal
Aspergillus fumigates, Candida albicans
Parasitic
Toxoplasma gondii,
What are the key presentations of brain abscesses? x8
fever
headache
changes to mental state
focal neurological deficits
grand mal seizures
nausea
vomiting
neck stiffness
What symptoms are associated with rupture of a brain abscess?
suddenly worsening headache, followed by emerging signs of meningism
What are some investigations for a brain abscess?
FBC - rasied WCC
ESR and CRP raised
Blood Culutre may be postive
MRI
CT scan - abscess appears as a radiolucent space-occupying lesion
What is the management for brain abscesses?
Emperical antbx therapy, or for presumed Bacterial infection
Vancomycin + Metronizadole + Ceftriaxone
drain intracranial collection
administer effective antibiotic therapy (early treatment is essential)
Steriods
What is the most common cause of meningitis?
What is the most common form of chronic meningitis?
Viral infection is most common
Then bacterial infection
Can also be caused by fungal/parasite infection, as well as
Autoimmune (aka Lupus)
Medication injected into CSF (Intrathecal therapy)
Fungal infection is the most common form of chronic meningitis
What are the most common bacterial causes of meningitis in neonates?
Escherichia coli
Group B Streptococcus (Streptococcus agalactiae)
Listeria monocytogenes
only group where both Streptococcus Pneumoniae or Neisseria Meningitidis aren’t in the most common top 3
What are the most common bacterial causes of meningitis in infants
Neisseria meningitidis
Haemophilus influenzae (but less common now due to vaccination)
Streptococcus pneumoniae
if in doubt, just say Streptococcus Pneumoniae or Neisseria Meningitidis)
What are the most common bacterial causes of meningitis in young adults
Neisseria meningitidis
Streptococcus pneumoniae
if in doubt, just say Streptococcus Pneumoniae or Neisseria Meningitidis)
What are the most common bacterial causes of meningitis in the elderly
Streptococcus pneumoniae
Neisseria meningitidis
Listeria monocytogenes
if in doubt, just say Streptococcus Pneumoniae or Neisseria Meningitidis)
What are the common causes of viral meningitis?
-Enteroviruses (echoviruses, Coxsackieviruses, polioviruses)- most common
-Mumps in countries without routine childhood immunisation
-Herpes simplex virus
What are some signs of Meningitis?
- Kernig’s sign: extension of the knee when hip is flexed at 90 degrees causes neck pain
- Brudzinski sign: severe neck stiffness causes the hips and knees to flex when the neck is flexed
- Petechial or purpuric non-blanching rash: associated with meningococcal disease (N. meningitidis)
- Pyrexia
- Reduced GCS
What are some symptoms of meningitis?
FEVER
HEADACHE
NECK STIFFNESS – ‘MENINGISM’
Might not be able to touch chin to neck
Purpuric rash – only in BACTERIAL meningitis
Non-blanching plupurent rash = meningococcal septicaemia (meningitis caused by N. Menigitidis)
Photophobia and/or phonophobia
Papilloedema – swelling of optic disc on fundoscopy
Usually bilateral
What investigations do you do for meningitis?
INVESTIGATIONS AND TREATMENT SHOULD BE DONE IN PARALLEL
Treat first, investigate later – give IM benzylpenicillin
Assess GCS - if <8 then can’t maintain their own airway, 🡪 intubate
Blood cultures – BEFORE ANTIBIOTICS!!
Lumbar puncture - to obtain CSF - Diagnostic
Head CT – to exclude lesions e.g. tumour
Blood – blood cultures and PCR for S. pneumoniae and N. meningitidis.
Nose and throat swabs – are plated out onto blood and chocolate agar.
Stool – stool PCR can be used to detect enterovirus.
Serology – blood (to detect a convalescent rise in antibody).
What would you see on a Lumbar puncture for someone with bacterial meningitis?
CSF:
Appearance - Cloudy/Turbid
WCC - High neutrophils
Protein - High
Glucose - Low
Culture - bacterial organism
bacteria swimming in the CSF (cloudy) will release proteins (high) and use up the glucose (low). Immune response to bacteria is neutrophils
What would the results of an LP CSF sample analysis look like in Viral meningitis?
CSF:
Appearance - Clear
WCC - High Lymphocytes
Protein - Normal/Mildly raised
Glucose - Normal (2.8–4.2mmol/L., two thirds of blood glucose)
Culture - Negative
Viruses cant be seen (clear) don’t use glucose (normal) but may release a small amount of protein (normal/mild inc). Immune response to viruses are lymphocytes
Where is a lumbar puncture usually taken from?
What are some contraindications for a lumbar puncture?
Between L3/L4
Raised ICP
GCS <9
Focal Neurological signs
coagulopathy
Cardiovascular compromise (bradycardia and HTN),
Infection at the site of LP
What is the treatment for viral Meningitis?
Usually milder and so Supportive Tx
If HSV/VZV infection then Acyclovir
What is the treatment for bacterial meningitis in a hospital, for those <60 and not immunocompromised?
IV dexamethasone, ideally administered before or with the first dose of antibiotics once in hospital. Reduces mortality and likelihood of neurological sequelae.
ceftriaxone : 2 g intravenously every 12 hours
OR
cefotaxime : 2 g intravenously every 6 hours
What is the treatment for suspected meningitis w/ non-blanching rash present in the community?
Urgent/immediate IM Benzylpenicillin
Prior to immediate transfer to a hospital
What is the most common cause of fungal meningitis?
Cryptococcus Neoformans
Candida
Very rarely affects immune competent people
What is the treatment for bacterial meningitis in a hospital, for those >60 or immunocompromised?
intravenous dexamethasone, ideally administered before or with the first dose of antibiotics once in hospital. Reduces mortality and likelihood of neurological sequelae.
ceftriaxone : 2 g intravenously every 12 hours
OR
cefotaxime : 2 g intravenously every 6 hours
AND (for Listeria monocytogenes cover)
amoxicillin : 2 g intravenously every 4 hours
What is Encephalitis? Where does it most commonly affect?
infection of the brain leading to inflammation of the brain parenchyma
Most commonly affects frontal and temporal lobes of brain
What is the most common causes of Encephalitis?
Encephalitis is generally a viral infection and the viral causes are:
almost always Herpes simplex virus
but occasionally Varicella zoster virus (chickenpox), Parvoviruses, primary HIV, Mumps virus and Flaviviruses such as Japanese encephalitis virus and West Nile virus
What are some non viral causes of Encephalitis?
TB
Malaria
Neisseria meningitidis
- Fungal:
- Cryptococcus
- Parasitic:
- Toxoplasmosis - from cats
What are the symptoms of encephalitis?
Fever
Headache
Confusion
Seizures
Encephalopathy:
Behavioural changes
psychotic behaviour
mood changes
What are the signs of encephalitis?
- Pyrexia
- Reduced GCS
- Focal neurological deficit, such as:
- Aphasia
- Hemiparesis
- Cerebellar signs
- May also have signs of meningitis: meningo-encephalitis
What investigations would you do for Encephalitis?
What is Diagnostic
- Blood tests:FBC, CRP, U&Es and blood culture
- Throat swab:culture for viral organisms
- HIV serology: now routinely tested in the emergency department
CT/MRI Head: Bilateral medial temporal lobe involvement on MRI is strongly supportive of a diagnosis of encephalitis
Diagnostic - LP and CSF analysis, and PCR
CSF analysis:
Viraemia - increased lymphocytes, raised protein if viral aetiology
Consider PCR for confirmation
Cultures from CSF
Start aciclovir in all cases of suspected encephalitis
What is the treatment of encephalitis?
Aim to start acyclovir within 30min of the patient arriving (10mg/kg/8h IV over 1h)
if HSV or VZV
Start aciclovir in all cases of suspected encephalitis
Symptomatic treatment: eg phenytoin for seizures
What do you do as a GP if a patient presents to you w/ non blanching rash and you suspect meningococcal septicaemia?
What can you offer to families/close contacts of a relative with meningitis?
Give IM benzylpenicillin and do an immediate hospital referral
Can offer close contacts Ciprofloxacin
What are some causes of a raised ICP?
Head Trauma:
Brain Tumors:
Ischemic strokes/Haemorrhagic
Meningitis and Encephalitis: Infections of the brain and surrounding tissues can lead to inflammation and swelling, raising ICP.
Hydrocephalus: This condition occurs when there’s an accumulation of cerebrospinal fluid (CSF) within the brain, often due to obstruction in the flow or absorption of CSF.
Idiopathic Intracranial Hypertension (IIH): IIH is characterized by increased ICP without an obvious cause.
Cerebral Edema: Swelling of the brain tissue, which can occur due to various reasons such as metabolic disturbances, toxins, or as a secondary effect of other conditions like tumors or strokes.
How Can raised ICP present?
Headache - wrose in mornning, due to increased pressure while lying down and may worsen with activities like coughing, bending, or Valsalva maneuvers.
Nausea and Vomiting
Papilledema: Swelling of the optic disc
Cushing’s Triad: A late and critical sign of raised ICP, indicating brainstem compression. It consists of:
Hypertension (with widening pulse pressure)
Bradycardia
Irregular respirations
A sixth cranial nerve palsy (abducens nerve), causing double vision, is especially common due to its long intracranial course.
what are some investigations youd do for raised ICP?
Neuroimaging (CT or MRI):
Non-contrast CT scan: This is often the first-line investigation in acute settings to quickly assess for mass effect, bleeding, or hydrocephalus.
MRI brain
Lumbar Puncture (LP):
Generally avoided in cases of raised ICP due to the risk of herniation if there is a mass effect on imaging. However, it may be used cautiously in certain cases (like suspected idiopathic intracranial hypertension) after neuroimaging confirms there is no risk of herniation.
What is the management for raised ICP?
nagement
investigate and treat the underlying cause
head elevation to 30º
IV mannitol may be used as an osmotic diuretic
controlled hyperventilation
aim is to reduce pCO2 → vasoconstriction of the cerebral arteries → reduced ICP
leads to rapid, temporary lowering of ICP. However, caution needed as may reduce blood flow to already ischaemic parts of the brain
removal of CSF, different techniques include:
drain from intraventricular monitor (see above)
repeated lumbar puncture (e.g. idiopathic intracranial hypertension)
ventriculoperitoneal shunt (for hydrocephalus)
What is the main things thought to be often associated with Idiopathic intracranial hypertension?
Obesity: There’s a strong association between IIH and obesity, especially in younger women.
Female Gender: IIH predominantly affects women, particularly those of childbearing age.
Medications: Certain medications such as tetracycline antibiotics, growth hormone, oral contraceptives, and excessive vitamin A intake have been linked to IIH.
Endocrine Disorders: Conditions like polycystic ovary syndrome (PCOS) and hormonal imbalances may contribute.
Venous Sinus Thrombosis: Blood clots in the veins that drain blood from the brain can lead to increased intracranial pressure. - MR venogram
What is the treatment of IIH?
control is drainage of cerebrospinal fluid by lumbar puncture
- can be repeated if really necessary
acetazolamide - is a carbonic anhydrase inhibitor - reduces CSF production
Venous sinus stenting - if this is the cause, investigate with MRI
What is Cushings reflex, and when is it seen and what are the 3 things that make it up?
bradycardia, a reduced and irregular respiratory rate (Cheyne-Stokes breathing) and hypertension with a wide pulse pressure
- Blood pressure increases to force blood into brain against raised ICP
- In a reflex response to the high BP- baroceptors slow down HR
- Irregular breathing happens to brain stem compression - as respiratory centre in the pons gets squashed?
What is Guillain-Barre syndrome?
Guillain-Barré syndrome (GBS) is an autoimmune, rapidly progressive demyelinating condition of the peripheral nervous system, often triggered by infection
“Equivalent to MS for the PNS”
What bacteria/viruses can be known to trigger Guillain-Barre Syndrome?
What vaccine is associated with increased risk?
Campylobacter jejuni, cytomegalovirus, Zika virus, influenza virus, Epstein-Barr virus, hepatitis A, B, C, E, HIV, mycoplasma pneumoniae, Covid
association with the influenza vaccination (uncommon)
Outline the pathophysiology behind Guillian-Barre Syndrome.
GBS is believed to be caused by‘molecular mimicry’
- Thought that infectious organisms have the antigens that resemble myelin gangliosides on Schwann cells (PNS) 🡪 autoantibody mediated damage to myelin sheath
- Processinvolves the production ofanti-ganglioside antibodies(anti-GMI is positive in 25% of patients)
- The demyelination occurs in patches along the length of the axon, so it’s called segmental demyelination
- Early on, there is remyelination but over time, there’s irreversible damage
What are some signs to note seen in Guillian-Barre Syndrome?
- Reduced sensation in affected limbs: sensory findings on examination are usually mild
-
Symmetrical weakness in lower extremities first, progressing to the upper limbs: proximal muscles often affected earlier than distal muscles (trouble getting out of chairs)
Autonomic dysfunction: e.g. tachycardia, hypertension, postural hypotension, urinary retention (in severe disease)
Respiratory distress: shortness of breath,
Ataxia with hyporeflexia (or areflexia) in affected limbs - (Absence of neurologic reflexes such as the knee-jerk reaction)
What are some symptoms of Guillian-Barre Syndrome?
- Tingling and numbness in hands and feet: often precedes muscle weakness
- Symmetrical, progressive, ascending weakness
- Unsteady when walking
- Back and leg pain: common at some point in disease course
- Facial weakness and speech problems,
- Double vision (due to Affected Cranial nerves)
Outline features of the diagnostic criteria for GBS
What are some blood tests would you do to investigate Suspected Gullian-Barre Syndrome?
Clinical Dx of Hx of recent infection with progressive weakness and areflexia, in >1 limb, near symmetry of symptoms.
-
Bloods:exclude other causes
- U&Es: electrolyte abnormalities resulting in neuropathic symptoms
- B12 and folate: deficiency associated with neurological features
- TFTs: to exclude hypothyroidism as a cause of weakness
- Anti-ganglioside antibodies: can be used to differentiate GBS variants, e.g. anti-GQ1b antibody in Miller-Fisher syndrome, or Anti GMI
What other investigations can aid to confirm the diagnosis of Guillain Barre?
What do you see on lumbar puncture?
Nerve conduction studies: findings will typically be suggestive of demyelination, e.g. reduced conduction velocity
Lumbar puncture: raised protein, normal white cell count, normal red cell count, raised opening pressure, normal glucose
Spirometry: to monitor respiratory function as 20% of patients require mechanical ventilation at some stage
What are the two options for management seen in Gullian-Barre syndrome?
-
IV immunoglobulins (IVIg):5 day treatment course commenced within the first 2 weeks of symptom onset,
Contraindicated in patients with IgA deficiency as can cause severe allergic reactions
OR
- Plasma exchange: 5 treatments of 2-3L over 2 weeks commenced within the first 4 weeks of symptom onset
Don’t do Both. No role for steroids
What is some additional management seen in GBS?
- Thromboprophylaxis:to prevent venous thromboembolism - eg a direct oral anticoagulant, unfractionated heparin, or a low molecular weight heparin
- Physiotherapy:for those with impaired mobility or motor disturbance
- Intensive care support:for those who develop ventilatory failure (20%), intensive care and mechanical ventilation may be required
What is Peripheral Neuropathy?
What are the types of peripheral nerve disease?
Nerve pathology outside of the CNS that affects the peripheral nerves
Mononeuropathy: a process affecting a single nerve
Polyneuropathy: many nerves involved. Usually describes a symmetrical disease, and it usually begins distally. Can be sensory, motor or mixed.
What are some causes of peripheral nerve disease?
What malignancy
DAVIDE:
Diabetes
Alcohol
Vitamin B12 Deficiency
Infective - Guillain Barre/Charcot Marie Tooth
Drugs - isoniazid, phenytoin
Every vasculitis
Multiple Myeloma
What blood tests should you do for peripheral neuropathy?
B12, Folate
Blood sugar and Hba1c
Thyroid function tests
Liver Function tests? (for chronic alcoholism)
M Proteins, for multiple myeloma
What are some symptoms of periperhal neuropathy?
numbness and tingling in the feet or hands
burning, stabbing or shooting pain in affected areas
loss of balance and co-ordination
muscle weakness, especially in the feet
sphincter involvement - incontinence
LMN signs - areflexia
These symptoms are usually constant, but may come and go.
What does dibateic neuropahty affect mst commonly?
most commoonly affects Large fibres, May have a bit of small fibre involvmeent -little pain/numbenss or deadness
will be able to feel pin prick - or at least only a small relative loss
but not vibration w vibrating fork
trophic changes - abnormalities in the area of pain that include primarily wasting away of the skin, tissues, or muscle, thinning of the bones
eg hair loss, callous/ulcers, pigmentation of skin, deformed toe nails, due to bad arterial blood supply
Give some examples of Mononeuropathies. What is the most common?
- Carpal tunnel syndrome
- ‘Wrist drop’
- ‘Claw hand’
- ‘Foot drop’
Carpal tunnel syndrome is most common
What is carpal tunnel syndrome?
Carpal tunnel syndrome (CTS) is a collection of symptoms and signs caused by compression of the median nerve in the carpal tunnel.
What are the causes/risk factors of Carpal Tunnel Syndrome?
Mostly Idiopathic
Also: (HODPARAR)
Hypothyroidism
Obesity
Diabetes
Pregnancy - can resolve postpartum
Acromegaly
Rheumatoid Arthritis
Amyloidosis
Repetitive Strain Injury
Females due to narrower wrists so more likely to have compression
Over 30s
exam tip - if you see a patient with bilateral carpal tunnel syndrome, look for features that might suggest underlying rheumatoid arthritis, diabetes, acromegaly or hypothyroidism.
hat are the motor symptoms of Carpal Tunnel Syndrome?
Weakness of thumb movements
Weakness of grip strength
Difficulty with fine movements involving the thumb
Wasting of the thenar muscles (muscle atrophy)
Thenar Muscles
Flexor Pollicis Brevis
Abductor Pollicis
Opponens Pollicis
What are the tests to diagnose Carpal Tunnel Syndrome? What other investigation can be done?
Phalen Test
Tinel Test
Nerve conduction studies:
small electrical current is applied by an electrode (nerve stimulator) to the median nerve on one side of the carpal tunnel -
Recording electrodes over the median nerve on the other side of the carpal tunnel record the electrical current that reaches them
Tests for carpal tunnel syndrome - what is Phalen Test?
Phalen’s test - flex the wrists are far as possible and hold that position for a minute, this results in numbness in the areas of the hand innervated by the median nerve in people with carpal tunnel syndrome
Tests for carpal tunnel syndrome - what is Tinel’s Sign?
tap the transverse carpal ligament, this reproduces the symptoms of tingling or feelings of pins and needles in areas of the hand served by the median nerve
TOM TIP: I think of tapping a tin can (Tinel’s) to remember the difference between Phalen’s and Tinel’s test.
What are the management of carpal tunnel syndrome?
Management options for carpal tunnel syndrome are:
Rest and altered activities
Wrist splints that maintain a neutral position of the wrist can be worn at night (for a minimum of 4 weeks)
Steroid injections
Surgery
What can cause wrist drop?
Damage to the radial nerve
Compression of the radial nerve at the humerus
RADIAL NERVE SUPPLIES THE EXTENSOR MUSCLES OF THE WRIST
What is the classical presentation of an ulnar nerve palsy?
Claw hand (4th/5th fingers claw up)
What is the treatment of Wrist drop and Claw hand?
Splint
Analgesia
What are the nerve roots for the common peroneal nerve?
L4-S1
(Branch off the Sciatic nerve)
Give some causes of foot drop:
Common peroneal nerve palsy!1
muscle or spinal cord trauma
Toxins
More commonly: Diseases, such as:
Stroke, ALS,, Charcot Marie Tooth, MS, Cerebral Palsy, GBS
Axillary nerve - what does it do? When should you check its function
supplies motor and sensation to deltoid
Check sensation to the deltoid with a neuro tip if they’ve broken/dislocated their shoulder, for axillary nerve damage
What is Mononeuritis Multiplex?
A type of peripheral neuropathy where there is damage to several individual nerves due to systemic causes.
What are the causes of Mononeuritis Multiplex?
Systemic necrotizing vasculitis
* Polyarteritis nodosa
* ANCA-associated (Churg–Strauss syndrome, Granulomatosis with polyangiitis)
Vasculitis associated with connective tissue disorders
* Rheumatoid arthritis.
* Sjögren’s syndrome.
* SLE.
Hypersensitivity vasculitis
* Drug-induced vasculitis.
* Malignancy.
Infections
* Bacterial: Lyme disease, TB, syphilis.
* Viral: HIV, herpes zoster, CMV
What is shingles?
also known as herpes zoster virus, shingles is a disease which triggers a painful skin rash in a dermatomal distribution
What causes shingles?
human herpesvirus-3
primary infection usually occurs in childhood, producing chickenpox (varicella)
after this the virus lies dormant in the sensory nervous system but is susceptible to reactivation in patients over 50 years old and is associate with immunosuppressive illness, or psychological/physical trauma
What are the most common cancers to spread to the brain ?
Lung cancer, 48%
Breast cancer, 15%
Genitourinary tract cancers, 11%
Osteosarcoma, 10%
Melanoma, 9%
What are some symptoms of intracranail tumours?
Clinical features
- Symptoms and signs of raised ICP.
- Focal deficits.
- Seizures.
- Confusion.
- Sudden deterioration due to haemorrhage or vessel occlusion.
Rare to cause a headaches!
“Slowing down” - going off things, loss of interest, decline
What is an acoustic neuroma?
Acoustic neuromas are benign tumours of the Schwann cells surrounding the auditory nerve (vestibulocochlear nerve) that innervates the inner ear.
They are also called vestibular schwannomas, as they originate from the Schwann cells. Schwann cells are found in the peripheral nervous system and provide the myelin sheath around neurones.
Are acoustic neuromas normally unilateral or bilateral? What condidtion is normally assossicated with bilateral acoustic neuromas?
Acoustic neuromas are usually unilateral. Bilateral acoustic neuromas are associated with neurofibromatosis type II.
Bilateral acoustic neuromas almost certainly indicate neurofibromatosis type II. This is a popular association in exams, so worth remembering.
What is the presenation of an acoustic neuroma?
The typical patient is aged 40-60 years presenting with a gradual onset of:
Unilateral sensorineural hearing loss (often the first symptom)
Unilateral tinnitus
Dizziness or imbalance
A sensation of fullness in the ear
Cranial nerves V, VII and VIII are affected in vestibular schwannomas
This patient is presenting with symptoms affecting several of his cranial nerves. He has:
Vertigo and unilateral hearing loss indicating CN VIII involvement
Absent corneal reflex indicating CN V involvement
Unilateral facial numbness indicating CN VII involvement
They can also be associated with a facial nerve palsy if the tumour grows large enough to compress the facial nerve.
Whats the management of an acoustic neuroma? What is the risk of treatment?
Management
ENT specialist management options include:
Conservative management with monitoring may be used if there are no symptoms or treatment is inappropriate
Surgery to remove the tumour (partial or total removal)
Radiotherapy to reduce the growth
Notable risks associated with treatment are:
Vestibulocochlear nerve injury, with permanent hearing loss or dizziness
Facial nerve injury, with facial weakness
What is Bulbar Palsy
refers to a range of different signs and symptoms linked to impairment of function of the glossopharyngeal nerve (CN IX), the vagus nerve (CN X), the accessory nerve (CN XI), and the hypoglossal nerve (CN XII).
so called bulbar palsy because this region of the brain is sometimes called the ‘bulb’ of the brainstem
It is caused by a lower motor neuron lesion in the medulla oblongata,
What conditions can cause bulbar palsy?
MND
Guillain-Barre Syndrome
Polio
Brainstem tumours
Myasthenia gravis
Myotonic dystrophy
Toxic: botulism
Think - LMN and NMJ conditions!
What are some signs and symptoms of Bulbar palsy?
dysphagia (difficulty in swallowing).[1]
difficulty in chewing.
difficulty breathing (airway obstruction).[2]
dysphonia (defective use of the voice, inability to produce sound due to laryngeal weakness).
dysarthria (difficulty in articulating words due to a CNS problem) - Bulbar dysarthria – nasal speech due to paralysis of the palate
Drooling
flaccid paralysis, such as soft palate weakness (examined by asking the patient to say aah).
muscle atrophy, such as tongue atrophy with fasciculations.
The ocular muscles are spared and this differentiates it from myasthenia gravis.
What are the investigations for bulbar palsy? x5
electromagnetic articulography (EMA)
electropalatography (EPG)
pressure sensing EPG
routine bloods, brain/brainstem imaging, electromyography
What is the management for Bulbar palsy?
treatment is directed to underlying cause
postural changes can help with drooling of saliva and may prevent aspiration
supportive measures
support from SALT and dieticians
What is the difference between bulbar and pseudobulbar palsy?
What is Psudobulbar palsy usually caused by?
PSEUDO – affects the upper motor neurones
BULBAR – affects the lower motor neurones (of CN 9,10,11,12)
In contrast, pseudobulbar palsy is a clinical syndrome similar to bulbar palsy but in which the damage is located in upper motor neurons of the corticobulbar tracts in the mid-pons (i.e., in the cranial nerves IX-XII), that is the nerve cells coming down from the cerebral cortex innervating the motor nuclei in the medulla. This is usually caused by stroke.
What is the only cellular output later in the cerebellum? Degradation of it will lead to what?
The Purkinje cell layer - degradation of it will lead to ataxia
What is ataxia? What are the 2 main causes of an ataxic gait?
a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements,
Either
Cerebellar problem
Issue with proprioception
What test helps you distinguish between proprioceptive and cerebellar causes of ataxic gait?
If they can walk normally with their eyes open and the problem starts when they close their eyes – proprioceptive cause
If the problem is there all the time – cerebellar cause
What are some general features of ataxia?
Wide based gait
Falls
Cannot walk heel-to-toe
Often worse in the dark or with eyes closed
Gait abnormalities
nystagmus/jerky (saccadic) pursuit/hypo or hypermetropic saccades/optic atrophy/ptosis
dysarthria
intention tremors
dysmetria/past pointing/dysdiadochokinaesia
Heart problems
- decreased tone/reflexes
Give some cerebellar causes of ataxia
MS
Posterior fossa tumour
Alcohol
Direct injury
Gluten ataxia autoimmunity to Purkinje cells or other neural cells in the cerebellum
CNS vasculitis, multiple sclerosis, infection, bleeding, infarction, tumors, direct injury, toxins (e.g., alcohol), genetic disorders and neurodegenerative diseases
Deficit is on the SAME SIDE as the cerebellar lesion (i.e. If they are ataxic on the right, the problem is with the right side of the cerebellum) - UNLIKE IN CEREBAL LESIONS
What are the proprioceptive causes of an ataxic gait?
Sensory neuropathies – low b12
Inner ear problem – affecting the vestibular system
What is Friedrich’s ataxia?
Genetic, progressive, neurodegenerative movement disorder which typically presents at age 10-15 years old
What can you see in friedrichs ataxia? why does this happen?
Can lead to peripheral neuropathy, due to atrophy of the dorsal root ganglia and thinning of the dorsal roots
Name some blood tests used in ataxia diagnosis
- FBC, U&E, extended LFT’s
- HbA1c, B12, folate, TSH
- ESR, CRP
- gluten related serology* (can only be requested in sheffield)
What is MRI used for in ataxia? x2
to demonstrate cerebellar atrophy and/or dysfunction
to exclude cerebrovascular damage, primary tumours, hydrocephalus, demyelinating disorders, white matter disease, cerebellar dysgenesis/malformations
What are some generalised demyelinating peripheral neuopathies? other than GBS
Chronic inflammatory demyelinating peripheral neuropathy,
Multifocal motor neuropathy with conduction block,
Charcot Marie Tooth/Hereditary motor sensory neuropathy type I (can accept type III, IV or X-linked),
mitochondrial disorders (no need for specifics).
If say drug induced need to specify drug (e.g. amiodarone, chloroquine)
Define Cerebral Palsy
an umbrella term for a permanent disorder of movement and/or posture and of motor function due to a non-progressive abnormality in the developing brain.
Outline the different types of Cerebral Palsy
Spastic:
Dyskinetic
Ataxic:
Mixed
Outline what is Spastic and Ataxic cerebral palsy is
Spastic: hypertonia (increased tone) and reduced function resulting from damage to upper motor neurones
Ataxic: problems with coordinated movement resulting from damage to the cerebellum
Outline what is Dyskinetic and Mixed cerebral palsy is - what is Spastic and Dyskinetc CP also known as?
Dyskinetic: problems controlling muscle tone, with hypertonia and hypotonia, causing athetoid movements and oro-motor problems. This is the result of damage to the basal ganglia.
Mixed: a mix of spastic, dyskinetic and/or ataxic features
Spastic CP is also known as pyramidal CP. Dyskinetic CP is also known as athetoid CP and extrapyramidal CP.
Athetosis is a symptom characterized by slow, involuntary, convoluted, writhing movements of the fingers, hands, toes, and feet and in some cases, arms, legs, neck and tongue
Give some causes of Cerebral palsy
What about some risk factors
80% antenatal - hypoxia, infection, haemorrhage, ischaemia.
10% peri-natal - hypoxia, infection, haemorrhage.
High levels of unconjugated bilirubin can lead to kernicterus and then athetoid cerebral palsy
10% postnatal - hypoxia, infection e.g. meningitis, haemorrhage, encephalopathy, trauma.
A – Birth complications such as placental abruption and over conditions which disrupt the blood supply to
the foetus increase the risk of brain damage due to hypoxia.
C – Maternal infections result in cytokine release which can cause inflammation and damage of the
brain.
D – maternal thyroid dysfunction also increases the risk of brain damage associated with cerebral palsy.
The reason why is not currently fully understood but may be due to altering myelination, differentiation
and migration of nerve cells.
E – Prematurity increases the risk of bleeding and fluid accumulation in the brain, both of which can
result in brain damage
Macrosomnia alone is not a risk factor for cerebral palsy
What are the patterns of Cerebral palsy
Monoplegia
Hemiplegia
Diplegia
Quadriplegia
Patterns of CP - define Monoplegia and Hemiplegia
Monoplegia: one limb affected
Hemiplegia: one side of the body affected
Patterns of CP - define Diplegia and Quadriplegia
Diplegia: four limbs are affects, but mostly the legs
Quadriplegia: four limbs are affected more severely, often with seizures, speech disturbance and other impairments
What are some signs of Cerebral Palsy, that you may notice on examination?
Patients with cerebral palsy may have a hemiplegic or diplegic gait. This gait is caused by increased muscle tone and spasticity in the legs. The leg will be extended with plantar flexion of the feet and toes.
Hemiplegic gait - leg too long, leg is circumducted on bad side, with arm flexed inwards and elbow at 90 degrees
Diplegic - swinging gait on both sides, legs and hip bent and on tiptoes (Jeff) Arms less involved than in hemiplegic
They will have signs of an upper motor neurone lesion, with good muscle bulk, increased tone, brisk reflexes and slightly reduced power.
In CP, primitive reflexes, which facilitate the emergence of normal patterns of movement and which need to disappear for motor development to progress, may persist and become obligatory
Both Hemiplegic and Diplegic gaits are indicative of an upper motor neurone lesion
What are some symptoms/presenting features of cerebral palsy?
Failure to meet milestones
Increased or decreased tone, generally or in specific limbs
Hand preference below 18 months is a key sign to remember for exams
Problems with coordination, speech or walking
Feeding or swallowing problems
Learning difficulties
Walking with arms flexed and legs extended (as these are the dominant muscle groups in arms and legs)
What are the differentials for cerebral palsy?
Rett syndrome.
Acute poliomyelitis
Becker’s muscular dystrophy
Charcot-Marie-Tooth disease
What are some conditions also assossciated and seen with cerebral palsy?
Learning disability, ASD and ADHD
Epilepsy
Kyphoscoliosis
Muscle contractures
Hearing and visual impairment
Gastro-oesophageal reflux
Outline some people in and MDT that provide treatment to someone with CP
Physiotherapy is used to stretch and strengthen muscles, maximise function and prevent muscle contractures.
Occupational therapy is used to help patients manage their everyday activities, such as getting dressed and using the bathroom.
Speech and language therapy can help with speech and swallowing.
Dieticians can help ensure they meet nutritional requirements.
Orthopaedic surgeons can perform procedures to release contractures or lengthen tendons (tenotomy).
Social workers to help with benefits and support.
Charities and support groups
What are some medicines given to help the symptoms of CP
Muscle relaxants (e.g. baclofen) for muscle spasticity and contractures
Botox Injections as well^^
Anti-epileptic drugs for seizures
Glycopyrronium bromide for excessive drooling
Surgery - selective dorsal rhizotomy (a
proportion of the nerve roots in the spinal cord are
selectively cut to reduce spasticity),
What is Bells Palsy?
This is an idiopathic facial nerve palsy which causes lower motor neuron symptoms in the facial nerve (CN VII).
– It is an acquired condition which in more prevalent in pregnant women and is seen in the younger age group below the age of 40.
When would you give botox injections?, in cerebral palsy
Whenever the spastisctiy effect the qualtiy of life of the patient - this varies for each patient !
What are some causes/Known risk factors for Bells Palsy
Viral;
herpes simplex
herpes zoster
EBV
cytomegalovirus infections
rubella
Risk factors include diabetes, a recent upper respiratory tract infection, and pregnancy
HIV, sarcoidosis and Lyme disease (Borrelia Burgdoferi infection)
Obesity, Hypertension
What is the pathophysiology of Bell’s palsy?
the nerve that controls facial muscles passes through a narrow corridor of bone on its way to the face
in Bell’s palsy that nerve becomes inflamed and swollen - usually related to a viral infection
What are the key presentations of Bell’s palsy?
These have a very abrupt onset (can be overnight)
– Unilateral facial weakness of the whole face (including eyebrows)
– Ipsilateral numbness and pain around the ear
– Decreased taste –> due to damage to the chorda tympani
– Hypersensitivity to sounds –> stapedius palsy
How and why does Bell’s Palsy differ to a Stroke?
Bell’s Palsy is a peripheral nerve effect whereas a ischemic stroke is a central process. The forehead receives motor innervation from both hemispheres of the cerebral cortex.
A stroke that compromised motor innervation of the face would therefore only result in paralysis of the lower half of the face - the forehead is still receiving innervation from the unaffected hemisphere (as its a UMN lesion)
A peripheral lesion, such as Bell’s Palsy, interrupts the innervation after the motor commands from both hemispheres have joined, so that the forehead is paralyzed. (its a LMN lesion)
What are the differentials for Bell’s palsy?
Ramsay-Hunt syndrome - (inflammation of the geniculate ganglion of the facial nerve as a late consequence of varicella zoster virus (VZV).
Guillain-barre syndrome
Lyme disease
What is the management for Bell’s palsy?
steroids - prednisolone
eye-care - reduced eye closing can lead to dry eye and corneal damage
on going debate about whether to use antivirals - acyclovir
Night-time eyelid coverings - this is the correct answer. Care of the eye is very important in Bell’s palsy and cannot be understated. Paralysis of the facial nerve can leave the lid open during the night and dry the conjunctiva. Corneal damage or infection can result if not cared for properly.
Give some different types of causes of Proximal Muscle weakness
Inflammatory Myopathies: Conditions like polymyositis and dermatomyositis
Muscular Dystrophies:DMD, Beckers, Myotonic dystropy
Endocrine/metabolic conditions
Neurological Disorders: MS, or ALS
Medications
Trauma
inactivity
what endocrine/metabolic disorder can cause a proximal muscle weakness?
What medications can cause it
Hypothyroidism
Cushing’s
Hyperparathyroidism
Addisons
Steriods and statins
People on long term steriods - bone marrow trasnpalt, long term illness , cancer,
What are some common causes of distal muscle weaknesses?
Think LMN
Peripheral Neuropathy - so think alcohol, B12 deficiency
Charcot Marie Tooth Disease
ALS
Mystania Gravis
GBS
Nerve Compression/damage
What are polymyositis and dermatomyositis?
Autoimmune disorders where there is inflammation in the muscles.
Polymyositis refers to chronic inflammation of the muscles. Dermatomyositis is a connective tissue disorder where there is chronic inflammation of the skin and muscles
Leads to proximal muscle weakness and muscle pain
What is the key enzyme for diagnosing polymyositis and dermatomyositis?
other than in these conditions, when would you see it?
The creatine kinase blood test. It is an enzyme that is found inside muscle. Inflammation of the muscles can lead to the release of it.
It can also be raised in Acute kidney injury, Myocardial infarction, Statins
Strenuous exercise
Outline the pathophysiology behind Dermatomyostits and Polymyositis.
Molecular mimicry (often of a tumour protein) by Muscles cells, and also capillary endothelial cells in the skin.
What is the antibody found in polymyositis?
Anti-Jo-1 antibodies: polymyositis (but often present in dermatomyositis)
What is the management for polymyositis and dermatomyositis?
Patients should be assessed for underlying cancer
Corticosteroids are first line
Then immunosuppressants
Then infliximab - (targets TNF-a )
Recap - what does teh Spinothalamic tract convey?
Anterior spinothalamic tract is responsible for Crude touch/ or pressure
Lateral spinothalamic tract is responsible for Pain and temperature
Outlien the pathway of the spinothalamic tract
What will a lesion in the spinothalamic tract present as?
These pathways Decussate within the spinal cord and travel up to the brain
So lesion of the spinal cord will cause a contralateral loss of pain, crude touch, sensation (Generally speaking),
As nerve entering the Anterior lateral pathways tend to travel up 1 or 2 vertebral levels before Decussating
Spinothalamic and Dorsal Column medial lemniscal pathway synapses in the ventral posterio-lateral division (VPL) of the nucleus of thalamus.
Recap - what does the DCML tract convey?
These are responsible for FINE TOUCH AND TACTILE SENSATION, VIBRATION, PROPRIOCEPTION etc.
Signals from the lower limb (below T6) tend to travel in the Fasciculus Gracilis
(so they then Synapse in the Gracile Nucleus of the Medulla)
Signals from the upper limb (above T6) tend to travel in the Fasciculus Cuneatus
(so they then Synapse in the Cuneate Nucleus of the Medulla)
graciLis = L for Leg of Lower Limb
Outlien the pathway of the DCML tract
What will a lesion in the DCML tract present as?
- Afferent signals are carried along first order neurones to and up the Dorsal columns (from proprioception receptors) to then synapse in the medulla.
- 2nd order Neurones the decussate in the medulla and travel up to the thalamus where they synapse again.
- 3rd order neurones then travel through the internal capsule to the somatosensory cortex in the Parietal mode (postcentral gyrus)
THESE TRACTS RUN IPSILATERALLY THROUGH THE SPINAL CORD AND DECUSSATE IN THE MEDULLA OF THE BRAINSTEM = so damage to spinal cord here would lead to loss of Ipsilateral fine touch, tactile sensation, proprioception etc.
What info does the Corticospinal tract convey?
Carry signals down from the brain involved in Voluntary Movement
Outline the pathway of the corticospinal tract
After originating from the cortex, the neurones converge, and descend through the internal capsule
- this is particularly susceptible to compression from haemorrhagic bleeds
The fibres within the lateral corticospinal tract decussate
The anterior corticospinal tract remains ipsilateral, descending into the spinal cord.
From the ventral horn, the lower motor neurones go on to supply the muscles of the body.
What things can damage the spinal tracts/cause signs?
Corticopsinal damage - UPPER MOTOR NEURONE SIGN, AS SPINAL NERVES ARE UMN
Trauma
MS
Tummour/growth
Vascular suppkly of the spinal cord/spinal cord stroke?? - ANTERIOR SPINAL ARTERY STROKE INFARCTS CAN AFFECT TRACTS, —> can cause back pain as spine has pain receptors
Acute spinal chord and strokes can cause lower MN signs (spinal shock)
Syringomyelia - affects CRTS and STHAM - think this if see cape like distribution of weakness
Name some things that can cause neurally mediated syncope.
Vaso vagal,
situational syncope eg going for wee (can drop BP), carotid sinus syndrome
Shock
Dehydration
Sudden changes in posture
Hyperventilation
ALWAYS DO AN ECG IN ANY SYNCOPE/LOC, TO RULE OUT CARDIAC CAUSES - A 24 HOUR AMBULATORY ECG MAY BE NECESSARY!
Give some cardiac causes of syncope
Brugada syndrome - coved ST elevation in a young person
Aortic stenosis
Hypertrophic obstructive cardiomyopathy
Conduction issues
Long QTC, VT/Torsades de points
Bradycardia 2nd/3rd degree heart block
Tachycardia - particular broad VT complex
No prodromal phase in a cardiac syncope
ALWAYS DO AN ECG IN ANY SYNCOPE/LOC, TO RULE OUT CARDIAC CAUSES - A 24 HOUR AMBULATORY ECG MAY BE NECESSARY!
What are some features of a seizure that can point to it being a non epileptic seizure
Last longer, eyes closed and resistnace to opening eyes
Causes - can due to trauma history but be sensitive
They can remember what happens !
Head rocks from side to side
movements come and go
What are some features of a seizure that can point to it being an epileptic seizure
Tonic clonic (stiff then fall , and then rhythmic serizures)
Head veers off to one side
Very rhythmic, constant movements
Face goraning/croaking/throaty cry (gutteral cry) noise, before hand
Eyes open
What is the definition of febrile convulsions?
Febrile convulsions are a type of seizure that occurs in children with a high fever
.They are not caused by epilepsy or other underlying neurological pathology, such as meningitis or tumours
By definition, febrile convulsions occur only in children between the ages of 6 months and 5 years.
How do you go about diagnosing a febrile convulsion?
In order the make a diagnosis of a febrile convulsion, other neurological pathology must be excluded. The differential diagnoses of a febrile convulsion are:
Epilepsy
Meningitis, encephalitis or another neurological infection such as cerebral malaria
Intracranial space occupying lesions, for example brain tumours or intracranial haemorrhage
Syncopal episode
Electrolyte abnormalities
Trauma (always think about nonaccidental injury)
What is the management of a febrile convulsion?
Identify and manage the underlying source of infection and control the fever with simple analgesia such as paracetamol and ibuprofen.
Simple febrile convulsions do not require further investigations and parents can be reassured and educated about the condition. Complex febrile convulsions may need further investigation.
but a bacterial infection including meningitis should always be considered. The classical features of meningitis such as neck stiffness and photophobia may not be as apparent in children less than 18 months of age, so an infection screen (including blood cultures, urine culture, and lumbar puncture for cerebrospinal fluid) may be necessary.
What describes a complex febrile convulsion?
Febrile convulsions can be described as complex when they consist of partial or focal seizures, last more than 15 minutes or occur multiple times during the same febrile illness.
What is Giant Cell Arteritis (GCA)?
It is a granulomatous vasculitis of the medium and large arteries. It is the most common form of systemic vasculitis that affects and adults.
It usually affects branches of the carotid artery
Outline the pathophysiology of Giant cell arteritis, and what it leads to.
It is a granulomatous vasculitis. Arteries become inflamed and thickened and there is a narrowed vascular lumen and can obstruct blood flow.
Cerebral arteries are particularly affected.:
Superficial temporal: headache and scalp tenderness
Mandibular: Jaw claudication
Ophthalmic artery: visual loss due to retinal ischaemia
What are the symptoms of GCA?
Main symptom is headache that us unilateral and around forehead and temple.
Irreversible painless complete sight loss
Jaw claudication
Scalp tenderness may be noticed when brushing hair
What are the primary investigations of GCA?
1st line:
INCREASED ESR - ELEVATED IN 83% OF CASES
ANCA Negative
Temporal Artery biopsy - diagnostic
Fundoscopy
Picture - diagnostic criteria
What is the management for giant cell arthritis?
What may happen if a patient with GCA was to stop taking these medication immediately?
1st Line:
Corticosteroids - Oral Prednisolone
If you stop steroid doses abruptly, could cause an Adrenal crisis
What are some complications of GCA?
How should it be dealt with?
Amaurosis Fugax: Sudden painless vision loss of one eye (optic neuropathy)
Must be dealt with ASAP via high dose IV METHYL PREDNISOLONE
What is a migraine?
recurrent and throbbing headache, often preceded by an aura & associated with nausea, vomiting and visual changes
Name some risk factors, and potential triggers of a migraine
- Family history
- Female gender: migraines are three times more common in women
- Obesity
-
Triggers: CHOCOLATE
- Chocolate
- OralContraceptive
- Alcohol
- Anxiety
- Tumult - Loud noise
- Exercise
- Other important triggersinclude tiredness, lack of food, dehydration, menstruation, red wine and bright lights, under of over sleeping
What is the 4 diagnostic criteria for a migraine without aura?
4 diagnostic criteria
A – 5 attacks fulfilling B-D
B - attacks last 4-72 hours
C – Character, two of the following:
Unilateral, Pulsing, Moderate/severe, Aggravated by routine physical activity
D – during headache at least one of
Nausea and/or vomiting
Photophobia (light sensitive) and phonophobia (sound sensitive)
What is the diagnostic criteria for a migraine with aura?
3 diagnostic criteria for migraine with aura
A - at least 2 attacks fulfilling B and C
Time and character
B - Aura symptoms spread out gradually over 5 mins
Each symptom lasting 5-60 mins
Followed within 60 mins of headache
C ->1 reversible aura symptom
- Visual - zigzags, spots
- Speech - Asphasia
- Unilateral sensory
Motor weakness
Explain the progression of a Migraine?
Prodrome: Precedes headache by hours/days: yawning, cravings, mood/sleep change
Aura: last for 60mins
Vision changes minutes before attack (attack follows soon after)
ZigZag lines
Throbbing Headache: 4-72hrs
(Hemiplegic in some cases)
Resolution:
Headache fades away slowly
Recovery
What kinds of things are seen in auras? What are auras?
An aura is a perceptual disturbance that can occur before or during a migraine.
It is usually experienced as a visual phenomenon, such as flashing lights, zigzag lines, or blind spots. Other types of auras may include sensory disturbances, such as tingling in the arms and legs, or speech and language problems.
How are migraines diagnosed?
Clinical Dx unless pathology is suspected where you do tests to exclude DDx, investigating red flags:
CT/MRI red flags ie. Indications
- Worst/severe headache ie. Thunderclap
- Change in pattern of migraine
- Abnormal neurological exam
- Onset >50yrs
- Epilepsy
- Posteriorly located headache
Lumbar puncture indications
- Thunderclap headache
- Severe, rapid onset headache/ progressive headache/ unresponsive
headache
What are the treatments for Migraines?
Conservative - Avoid Triggers
ACUTE MANAGEMENT
Mild - Paracetamol/NSAIDs - ibuprofen
Severe - Triptans - sumatriptan
Anti-emetics - metoclopramide
ARB - Candesartan
Avoid use of Opiates
What are some preventative measures you can give to help stop migraines occurring?
Required if >2 attacks per month OR require acute meds >2x per week
Beta blockers eg. propranolol
TCAs eg. amitriptyline
Anti-convulsant eg. Topiramate
Propranolol is preferable to topiramate in women of childbearing age for migraine prophylaxis
Botox injections = generally used for the treatment of chronic migraines (15 or more days per month),
- CAS patient!
What are cluster headaches? What is a key trigger?
Cluster headaches are intensely painful, unilateral, periorbital headaches with associated autonomic dysfunction.
Alcohol can be a common trigger for them. Stress/aniexty dont tend to be, like they are for tension headaches and migraines
What are some clinical manifestations seen in cluster headaches?
- Unilateral, periorbital or temporal headaches lasting 15 minutes to 3 hours
- Ipsilateralautonomicsymptoms:
- Lacrimation (teary eye)
- Conjunctival injection (red eye due to enlargement of conjunctival vessels)
- Nasal congestion
- Rhinorrhoea (nasal discharge)
- Nausea and vomiting
- Photophobia, with agitation and restlessness
Horner’s Syndrome
- Ptosis (eyelid drooping)
- Miosis (excessive constriction of the pupil of the eye)
- Anhidrosis (Decreased sweating on on half of face)
5 similar attacks confirms diagnosis
What is the management of cluster headaches in acute attacks?
Acute attacks
Analgesics are unhelpful
15L 100% O2 for 15 mins via non-rebreather mask
Triptans eg. Sumatriptan
What are some preventive interventions given for cluster headaches?
Prophylaxis – Verapamil (CCB), Lithium, Prednisolone, Corticosteroids
What are Tension Headaches?
The most common form of a primary headache which has a characteristic rubber band feeling around the head.
What are some triggers of tension headaches?
STRESS - MAIN RISK FACTOR/TRIGGER
Sleep deprivation
Bad posture
Hunger
Eyestrain
Anxiety
Conflict
Overexertion
Depression
Clenched jaw
Noise
What is the some of the features of the typical diagnostic criteria seen in tension headaches?
Bilateral, mild to moderate intensity pain
Not aggravated by exercise
No nausea or vomiting (anorexia may occur)
No more than one of photophobia and phonophobia
What is the treatment for a Tension headache?
Stress relief
Avoid triggers
Simple analgesia:
Aspirin/Paracetamol
What a medication overuse headache, how it may present, and the management of it
Medication Overuse Headache (MOH): Headache caused by excessive use of acute headache medications (e.g., painkillers).
Presentation: Chronic, daily or near-daily headache in individuals frequently using analgesics or triptans.
Management: Gradual withdrawal of overused medication, supportive care, and preventive headache treatment.
Medication overuse is typically defined as:
Simple analgesics (e.g., paracetamol, NSAIDs): >15 days/month.
Combination analgesics, triptans, ergotamines, or opioids: >10 days/month.
What is Trigeminal Neuralgia?
A chronic, debilitating condition resulting in intense and extreme episodes of pain, due Compression of the trigeminal Nerve
What are some causes of Trigeminal Neuralgia?
Vein or artery compressing the trigeminal nerve
Local pathology pressing on trigeminal nerve (more common in younger people):
- Aneurysms
- Meningeal inflammation
- Tumour
- Infarction
Petrous bone – spreading middle ear infection
Multiple sclerosis
What are some key things in the diagnostic presentation of Trigeminal neuralgia?
3 attacks, with unilateral pain that is Severe intensity, Electric shock like, shooting, stabbing or sharp, Precipitated by innocuous stimuli to the affected side of the face
Occurs in one or more distributions of the trigeminal nerve, with no radiation beyond the trigeminal distribution
No neurological deficit
What investigations would you do in trigeminal neuralgia?
- Trigeminal neuralgia is a clinical diagnosis
- In patients where there is no obvious cause for the TN (e.g. herpes zoster of the trigeminal nerve, or recent trauma to the trigeminal nerve), neuro-imaging with MRI and MRA head should be performed to elucidate the underlying mechanism and rule out any concerning secondary causes (such as demyelination or a mass lesion). In classical TN, the MRI/MRA will demonstrate vascular compression with morphological changes to the trigeminal nerve root.
MRA = magnetic resonance angiogram of the head, is a type of MRI scan that uses radio waves and a magnetic field to create images of the blood vessels in the brain
What are the treatment options for trigeminal neuralgia?
First Line:
Carbamazepine (anticonvulsant)
Second Line:
Phenytoin/Gabapentin (analgesic targeted for neuropathic pain)
Surgery possible to decompress/intentionally damage nerve
similar to seizure meds?
Damage to what structure is likely to cause Horner’s syndrome?
Damage to the cervical sympathetic chain causes Horner’s syndrome by removing sympathetic innervation to the head and neck
= Lack of sympathetic innervation to the head and neck
What are some causes of Horner syndrome
Stroke
Multiple Sclerosis
Swelling
Syringomyelia (cyst in the spinal cord)
Tumour (Pancoast tumour)
Trauma
Thyroidectomy
Carotid aneurysm
Carotid artery dissection
Cavernous sinus thrombosis
Cluster headache
What are the investigations for Horner’s syndrome?
guided by suspected cause
CXR
CT/MRI
CT angiography/carotid USS
Pharmacological testing
What is the management for Horner’s syndrome?
Horner’s syndrome is a physical sign so management involves diagnosis of the underlying condition and treatment specific to diagnosis
Outline the key feautres in a presentation of carotid artery dissection
Neck Pain: Unilateral, sudden onset, can radiate to face/head.
Headache: Severe, often unilateral; may be occipital.
Neurological Symptoms: TIAs or stroke; weakness/numbness, speech difficulties (aphasia).
Horner’s Syndrome: Ptosis, miosis, anhidrosis on the affected side.
Visual Disturbances: Blurred vision or temporary visual loss.
Auditory Symptoms: Tinnitus possible.
Risk Factors: Recent neck trauma or spontaneous dissection in younger individuals.
Onset: Symptoms develop rapidly (hours to days) after an initiating event.
Outline the pathophysiology behind a relative afferent pupillary defect
Normally light shone into either eye should constrict both pupils equally
In RAPD - shine a light in the affected eye - and will only cause mild constriction of both pupils
- As afferent nerve from affected eye going towards brain isnt working (due to decreased response to light from the afferent defect)
Shine a light in the unaffected eye - both cause constriction -
as the unaffected eye’s afferent nerve is working, so signal can go to brain , and a signal from brain to the other eye can travel via the other eyes efferent nerve to make it constrict
Afferent neurons are sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain, while efferent neurons are motor neurons that carry neural impulses away from the central nervous systme and towards muscles to cause movement.
In what conditions might you see RAPD?
MS.
Glaucoma.
Severe retinal disease.
Optic nerve lesion.
What is the connsensual pupillary light reflex?
A consensual pupillary reflex is response of a pupil to light that enters the contralateral (opposite) eye.
what branch of the autonomic nervous system causes a dilated pupil and what branch causes a constricted pupil?
pupil constriction is mediated via parasympathetic activation, and dilation via sympathetic activation
a lesion on the parasympathetic nervous system of CN3 will lead to what kind of pupil? A lesion on the sympathetic chain innervating the eye will lead to what?
Lesion of parasympathetic - leads to a fixed dilated pupil (as only sympathetic innervation is received)
Lesion of sympathetic - Fixed constricted pupil, as only parasympathetic innervation is received - think in horners syndrome
What are some causes of 3rd nerve palsy?
eatures
eye is deviated ‘down and out’
ptosis
pupil may be dilated (sometimes called a ‘surgical’ third nerve palsy)
Causes
diabetes mellitus
vasculitis e.g. temporal arteritis, SLE
false localizing sign* due to uncal herniation through tentorium if raised ICP
posterior communicating artery aneurysm
cavernous sinus thrombosis
other possible causes: amyloid, multiple sclerosis
What are some of the differences in medical and surgical 3rd nerve palsy and why is this?
Since her right pupil is dilated and unreactive to light, the oculomotor nerve’s parasympathetic innervation to the iris sphincter muscles that constrict the pupils is affected, suggesting a ‘surgical’ cause i.e. there is something pressing against the oculomotor nerve (e.g. space-occupying lesions such as a bleed or tumour). This is because the parasympathetic fibres are located on the surface of the nerve, whereas the main constituents of the oculomotor nerve are within its core. Therefore structures compressing the surface lead to features of oculomotor nerve palsy and pupillary dilation, and medical causes such as multiple sclerosis affect the core, leading to oculomotor nerve palsy alone. This patient requires immediate brain imaging and a referral to neurosurgery.
What is meant by the term myelopathy? What are some broad causes?
describe any disorder or disease that affects the spinal cord
Causes can be
Trauma
Degenerative conditions
Inflammatory
Tumour
Vascular Myelopathy - disruption to blood supply of spinal cord
Infectious diseases
What is the difference between a myelopathy and a radiculopathy
Myelopathy may sometimes be accompanied by radiculopathy. Radiculopathy is the term used to describe pinching of the nerve roots as they exit the spinal cord or cross the intervertebral disc, rather than the compression of the cord itself (myelopathy).
Outline some degenerative and inflammatory disorders and infectious diseases that can cause myelopathy
!!The commonest cause of myelopathy is disc-osteophyte cord compression - bone spurs develop on vertebrae, compressing the intervertebral discs and exerting pressure on the nerve roots or even the spinal cord - see picture
Infectious Diseases: Tuberculosis, HIV-associated myelopathy, or viral infections
Degenerative Disorders: Cervical spondylosis (age-related changes in the spine), spinal stenosis (narrowing of the spinal canal), or herniated discs
Inflammatory Disorders: multiple sclerosis, transverse myelitis,
What are some symptoms of a Myelopathy
Proximal muscle weakness
‘Patient speak phrases’ reflecting loss of fine finger movements (clumsy hands)
struggling with keyboard, texting on mobile phone, handling coins, opening and closing buttons/zips
Also difficulty walking, legs feel ‘not my own’, ‘like lead boots, not doing what I tell them’ - Similar to peripheral neuropathy
Bowel/bladder symptoms and sexual dysfunction
Ask examples from how their life has changed
What are some signs of a Myelopathy?
LONG TRACT SIGNS - Also known as ‘upper motor neuron signs’, ‘pyramidal tract signs’ Corticospinal tract signs
Long tract signs (although often found for example in stroke, where the diagnosis is obvious from the
history) are PARTICULARLY USEFUL in screening for myelopathy (which may be asymptomatic or
with patient simply attending with neck pain)
eg
Babinski reflex
Clonus
Cross-adductors sign
Hoffman’s sign
Loss of fine finger movements - treacle hands
Hoffmans = an involuntary flexion movement of the thumb and or index finger when the examiner flicks the fingernail of the middle finger down.
What are some investigations for a myelopathy?
Because the term myelopathy describes a clinical syndrome that can be caused by many pathologies the differential diagnosis of myelopathy is extensive
The best way to visualize the spinal cord is magnetic resonance imaging (MRI)
CT and xrays
What is diabetic neuropathy? What are some symptoms?
What CN can be affected w Microvacular disease, such as diabetic neuropathy?
peripheral nerve damage as a result of diabetes mellitus
Commonly results in weakness; sensory symptoms such as numbness, tingling, or pain; or autonomic changes such as urinary symptoms.
These changes are thought to result from a microvascular injury involving small blood vessels that supply nerves (vasa nervorum).
Microvascular disease can involved CN IV in older patients with cardiovascular risk factors. The trochlear nerve innervates the superior oblique muscle which causes the eye to internally rotate and depress while adducted.
Vision worse going down stairs/looking downards? Think 4th nerve palsy
What are the 4 main components of diabetic neuropathy treatment?
control of blood sugar levels
lifestyle interventions, specifically diet and exercise
care for the feet to prevent complications
control of pain caused by neuropathy
What is a radiculopathy?
Radiculopathy, also commonly referred to as pinched nerve, refers to a set of conditions in which one or more nerves are affected and do not work properly
In a radiculopathy, the problem occurs at or near the root of the nerve, shortly after its exit from the spinal cord. However, the pain or other symptoms often radiate to the part of the body served by that nerve.
What are the main causes of radiculopathy?
changes in the tissues surrounding the nerve roots
aka intervertebral disk herniation (most commonly at C7 and then the C6 level)
osteoarthritis, ligamentous hypertrophy, spondylolisthesis
Cancer
Infections like Shingles, HIV, Lyme Disease
Proximal Diabetic neuropathy
What will the patient complain of in a radiculopathy?
99% patients have radiating limb pain, often in the pattern of the dermatome, sharp/shooting in character, - going down limbs
only a small proportion (about 5%) having associated neurologic symptoms such as dermatomal
sensory loss, and even less commonly myotomal muscle weakness.
What are the most common nerve roots affected in my radiculopathy, in the upper limb?
The two nerve roots usually affected for the upper limb are C6 and C7.
Thumb up - C6 nerve root - myotone - Biceps (6 letters
Middle finger - C7 - mytone - Triceps (7 letters)
What are the most common nerve roots affected in a radiculopathy, in the lower limb?
Therefore, what will be affected?
L5 Dorsum or top of foot/big toe Dorsiflexion (stand on
heels)
S1 - all the S’s - Side of foot sole of foot, Small (little) toe area
Plantar flexion (stand on toes)
Ankle jerk
What is the management of radiculopathy?
Medications, like nonsteroidal anti-inflammatory drugs, opioid medicines or muscle relaxants, to manage the symptoms
Weight loss strategies to reduce pressure on the problem area
Physical therapy to strengthen the muscles and prevent further damage
Steroid injections to reduce inflammation and relieve pain
Srugery to reduce pressure on nerve root
What is Spinal Cord Compression?
Compression of the spinal cord resulting in upper neurone signs and specific symptoms dependent on where compression is
This is a medical emergency as it can lead to paralysis.
What are some causes of spinal chord compression
Vertebral body neoplasms (most common cause)
-
Spinal pathology
-
Disc herniation
- When centre of disc (nucleus pulposus) has moved out through the annulus (outer part of disc) resulting in pressure on nerve root and pain
-
Disc herniation
-
Disc prolapse
- When nucleus pulposus moves and presses against the annulus - can cause a bulge in the disc
- Primary spinal cord tumour e.g. glioma, neurofibroma
- Infection e.g. epidural abscess
- Haematoma
Spinal chord compression causes - what metastasises from where most commonly cause spinal chord compression?
lung, breast, prostate, thyroid, kidney, myeloma, lymphoma
What are the symptoms of spinal cord compression?
- Sensory loss 1-2 cord segments below level of lesion
-
UMN signs below the level of lesion – everything goes up
Progressive weakness of legs (typically symmetrical) with UMN signs e.g. contralateral spasticity and hyperreflexia - LMN signs at level of lesion
Bladder sphincter involvement – hesitancy, frequency, painless retention
What are some Upper motor neurone signs?
Hypertonia - an abnormally high level of muscle tone or tension
Hyperreflexia - overactive or overresponsive bodily reflexes, twitching
Spasticity
Positive Babinski sign - extension of large toe when plantar surface of foot is stroked
What are some lower motor neurone signs?
Hyporeflexia/ areflexia - decreased or absent reflexes
Hypotonia/ atonia - loss of muscle tone
Flaccid muscle weakness or paralysis
Fasciculations – small involuntary muscle twitches,
Muscle atrophy
What would be the features of a complete spinal cord compression?
All motor and sensory function lost below the SCI level
What is the concern if there is sphincter involvement in spinal cord compression
This is a late and bad sign signalling a poorer prognosis
What investigation would you do in suspected spinal chord compression?
Do not delay investigations
- MRI: gold standard; identifies cause and site of compression
- Biopsy/surgical exploration may be required to identify the nature of any mass
- Screening blood tests: FBC, ESR, B12, U&E’s, syphilis serology, LFT, PSA
- Chest x-ray: to check for TB or lung malignancy
What is the treatment for spinal cord compression?
Neurosurgery to decompress cord
Dexamethasone to reduce inflammation
What is the cauda equina?
It’s a nerve bundle formed by the lumbar, sacral and coccygeal nerves, as they travel down the spinal canal together to reach their corresponding openings.
Distal to level of termination of spinal cord at L1/L2.
Cauda equina syndrome caused by damage to the peripheral nerves at the cauda equina
What functions do nerves in teh cauda equina have?
nerves in the cauda equina carry motor innervation for the genitals, both internal and external anal sphincter, detrusor vesicae, and muscles of the leg. They are also responsible for skin sensations in these regions.
What is cauda equina syndrome?
Cauda equina syndrome (CES) is a neurosurgical emergency which occurs when the bundle of nerves below the end of the spinal cord are compressed.
Name some causes of cauda equina syndrome
Herniation of lumbar disc – most commonly at L4/L5 and L5/S1
Spondylolisthesis – most commonly anterolisthesis (vertebra moves forward)
Trauma – car crash, gun shot, bleeding via haematomas
Tumours
Infection
Post-op haematoma
Causes of cauda equina syndrome - what is spondylolisthesis? What pathophysiological effects will be seen as a result of spondylolisthesis?
Spondylolisthesis is where one of the bones in your spine, called a vertebra, slips forward
most commonly anterolisthesis (vertebra moves forward)
Slippage of one vertebra over the one below
Nerve root comes out ABOVE the disc therefore root affected will be the one BELOW the disc herniation
E.g. L4/L5 herniation 🡪 L5 nerve root compression
What are some symptoms/signs of cauda equina syndrome
Saddle anaesthesia
Less bladder and bowel control – increased tone of anal sphincter and muscle wall of bladder
Erectile dysfunction (or other sexual dysfunction)
Lumbosacral pain
Leg weakness – flaccid and areflexic
Paraplegia
Bilateral symptoms
feeling like you need the toilet, and urethral sensation (feels like you are passing urine) - precursor to incontintence, is a red flag
Signs
Areflexia
Fasciculations
Loss of bowel/bladder control
Urinary retention
WILL SEE LOWER MOTOR NEURON SIGNS ONLY*
What are some investigations for cauda equina syndrome?
MRI spinal cord (diagnostic)
PR exam - feel for any abnormalities, and check anal tone
Testing nerve roots/reflexes
Knee flexion – test L5-S1
Ankle plantar flexion – test S1-S2
Straight leg raising – L5, S1
Femoral stretch test – L4
What is the management for cauda equina syndrome?
Management
Refer to neurosurgeon ASAP to relive pressure
Surgical decompression
High dose dexamethasone
Corticosteroids
What is the difference between cauda equina syndrome and spinal chord compression?
Spinal cord compression is more likely to be thoracic with neurology in the upper limbs with bladder & bowel changes being a very late sign.
Whereas in cauda equina, the lower limbs are classically affected with earlier bladder & bowel dysfunction and saddle anaesthesia.
What is anterior spinal chord syndrome? WHat is the main cause
Anterior spinal artery syndrome (also known as “anterior spinal cord syndrome”) is syndrome caused by ischemia of the anterior spinal artery, resulting in loss of function of the anterior two-thirds of the spinal cord
usually result of flexion/ compression injury
What things are affected in anterior spinal chord syndrome?
Therefore, what are its symptoms
The region affected includes the descending corticospinal tract, ascending spinothalamic tract, and autonomic fibers. It is characterized by a corresponding loss of motor function, loss of pain and temperature sensation, and hypotension.
What would you see on examination of someone with anterior chord syndrome?
Exam
lower extremity affected more than upper extremity
loss
Lateral cortical spinal (motor)
Lateral spinothalamic (pain, temperature)
preserved
DC (proprioception, vibratory sense)
What is meniere’s disease? What are the key triad of symptoms assossicated with it?
a long-term inner ear disorder, that causes recurrent attacks of vertigo, and symptoms of hearing loss, tinnitus and a feeling of fullness in the ear.
What is thought to cause menieres disease/why does it happen?
multifactoral causes
imbalance of sodium and potassium in the endolymph
excessive buildup of endolymph in the labyrinth of the inner ear, causing a higher pressure than normal and disrupting the sensory signals. This increased pressure of the endolymph is called endolymphatic hydrops.
What is the pattern of symptoms in Meniere’s disease? x4
acute attacks typically last mins-hrs
acute episodes may occur in clusters of around 6-11 per year
remission of symptoms may last several months
most patients develop unilateral symptoms initially with bilateral symptoms sometimes developing later
What is the management for menieres disease?
Reduce sodium intake aiming for a urinary sodium of less than 50 mmol/day. Thiazide diuretics eg bendroflumethiazide
motion sickness medications (meclizine, diazepam)
antinausea medications - (promethazine) - ) Oral betahistine
middle ear injections (gentamicin)
What procedures can be used treat Menieres disease?
endolymphatic sac procedure (help with decompression)
vestibular nerve section (helps to correct vertigo and maintain hearing)
labyrinthectomy (removal of labyrinth)
Outline what is seen in chronic fatigue syndrome
A complex, chronic medical condition affecting multiple body systems and of unknown cause which has many different presentations
Known as myalgic encephalomyelitis
What is the aetiology of myalgic encephalomyelitis?
Underlying cause is not well understood
Approximately 50-80% of people with ME start suddenly with a flu-like illness
Often found after infection suggesting an immunological dysfunction
Strong genetic predisposition
Life stressors
What are the key presentations of myalgic encephalitis?
Onset is usually abrupt, often following a psychologically or medically stressful event
viral-like illness with swollen lymph nodes, extreme fatigue, fever, and upper respiratory symptoms
Debilitating fatigue
Post-exertional malaise
Unrefreshing sleep or sleep disturbance
‘Brain fog’
Generalized pain
Significantly reduced ability to engage in occupational, educational, social or personal activities
What are some investigations you would do in ME/CFS?
The diagnosis of CFS is made by the characteristic history combined with a normal physical examination and normal laboratory test results
normal FBC, U+Es, Creatine, ESR, TFTs
What are some differentials for myalgic encephalitis?
Postural tachycardia syndrome
Hypothyroidism, diabetes, anaemia
Metabolic muscle disorders
Psychiatric illness
What is the management for ME?
Lifestyle advice - pace yourself, rest as needed, maintain health diet, work adjustments
CBT
graded exercise
Long-term graded exercise programs improve functional capacity.
Relaxation, rehabilitation, and physiotherapy may also help
No pharmacological agents have yet been proved effective for chronic fatigue syndrome
Define Wernicke’s Encephalopathy
is a neurological emergency resulting from thiamine deficiency with varied neurocognitive manifestations.
What is Korsakoff’s Syndrome? How is it related to Wernickes?
Hypothalamic damage & cerebral atrophy due to thiamine
(vitamin B1) deficiency (eg in alcoholics).
Wernicke’s encephalopathy is the acute, reversible stage of the syndrome, and if left untreated it can later lead to Korsakoff syndrome, which is chronic and irreversible.
What are some risk factors for developing Wernicke’s encephalopathy?
- Alcohol abuse
- Malnutrition
- Anorexia
- Malabsorption due to stomach cancer and IBD
- Prolonged vomiting e.g. due to chemotherapy, hyperemesis
Normal physiology - where is thiamine (vit B1) stored? Where is it absorbed?
What does it do in the brain?
Thiamine is typically stored in the liver and absorbed in the duodenum
in the brain thiamine helps maintain normal amino acid and neurotransmitter levels.
How can a lack of thiamine (vit B1) affect the brain?
- Thiamine deficiency impairs glucose metabolism and this leads to a decrease in cellular energy.
- The brain is particularly vulnerable to impaired glucose metabolism since it utilises so much energy.
What is the classical triad seen in Wernicke’s encephalopathy?
1 confusion
2 ataxia (wide-based gait; fig 2)
3 ophthalmoplegia (nystagmus,
lateral rectus or conjugate gaze palsies).
What does Wernicke - Korsakoff syndrome predominantly target? What symptoms does this cause?
- Mainly targets the limbic system, causing severe memory impairment:
- Anterograde amnesia: inability to create new memories
- Retrograde amnesia: inability to recall previous memories.
- Confabulation: creating stories to fill in the gaps in their memory which they believe to be true.
- Behavioural changes
What investigations would you do in suspected Wernicke’s encephalopathy?
- Diagnosis is typically made based on clinical presentation
- Bloods including LFTs: measure thiamine levels, measure blood alcohol levels, liver function may be deranged in alcoholism
- Red cell transketolase test: rarely done, thiamine is a co-enzyme to transketolases so transketolase activity will be low
- MRI/CT: can confirm diagnosis by showing degeneration of the mammillary bodies
Lumbar puncture to rule out other causes of the symptoms of wernickes
What is the management for Wernicke’s encephalopathy?
Urgent replacement to prevent irreversible Korsakoff’s syndrome (p718). Give thiamine (Pabrinex®) - (vitamins B and C:)
Oral supplementation (100mg OD) should continue until no longer ‘at risk’, give other B vitamins as well
Correct Magnesium deficiency as well
If there is coexisting hypoglycaemia, correct it
Why do you need to give Thiamine before you give glucose in a patient with Wernicke’s?
it’s important to normalise the thiamine levels first, because without thiamine pyrophosphate, most of the glucose will become lactic acid and that can lead to metabolic acidosis. (often the case in
this group of patients),
make sure thiamine is given before glucose, as Wernicke’s can be caused by glucose administration to a thiamine-deficient patient -
NOT GIVING THIAMINE AS YOU JUST THINK ITS HYPOGLYCAEMIA IS A COMMON MISTAKE DOCTORS MAKE
What is narcolepsy?
a chronic neurological disorder in which the brain loses its normal ability to regulate the sleep-wake cycle
What are the 2 types of narcolepsy?
Type 1 narcolepsy involves cataplexy and patients have low levels of orexin (also known as hypocretin) in their CSF
Type 2 does not involve cataplexy
What does Orexin (also known as hypocretin) do normally? What is thought to happen to it in type 1 narcolepsy?
It’s a neuropeptide that regulates arousal, wakefulness, and appetite
In type one narcolepsy, its thought that Mutations lead to loss of hypothalamic hypocretin-containing neurons, via autoimmune destruction.
95% are +ve for HLA DR2
What is cataplexy?
Cataplexy is bilateral loss of tone in antigravity muscles
provoked by emotions such as laughter, startle, excitement, or anger.
It is comparable to the atonia of rapid eye movement sleep but without loss of awareness
What are the features of a cataplexy attack? x5
- severity can vary e.g. from barely susceptible slackening of the facial muscles, dropping of the jaw or the entire head, to weakness at the knees or collapse onto the floor
- slurred speech and visual symptoms
- intact hearing, awareness and consciousness
- variable frequency
What are the key presentations of narcolepsy? x5
- excessive daytime sleepiness (EDS)
- disrupted nighttime sleep and/or vivid dreams
- cataplexy caused by muscle atonia
- hypnagogic/hypnopompic hallucinations
- sleep paralysis
what is the investigation of choice in narcolepsy
multiple sleep latency EEG
What are the differentials in narcolepsy diagnosis?
obstructive sleep apnoea
sleep deprivation
automatism
sleep paralysis
What is the management for narcolepsy? x6
- good sleep hygiene
- scheduled naps
- central nervous system stimulants (1st line: modafinil, or Methylphenidate
- antidepressants (for cataplexy) e.g. clomipramine, SSRIs, venlafaxine
- support and modifications (with school/work)
What is Myasthenia Gravis?
(Latin for “Grave Muscle Weakness”), its a Type 2 hypersensitivity reaction/autoimmune disease against nicotinic acetylcholine receptors (AChR) in the NMJ
Outline the pathophysiology behind Myasthenia Gravis
type II hypersensitivity reaction
B cells produce anti-AChR autoantibodies which interfere with the NMJ by binding to nicotinic AChR on muscle cells
When AChR are bound by the autoantibodies, they can’t be bound by ACh and don’t respond to “contract” signal from CNS
Results in muscle weakness
What autoantibodies are seen in Myasthenia Gravis?
What paraneoplastic syndrome is a risk factor with MG?
- anti-AChR autoantibodies (85%)
- Some people produce Muscle specific receptor tyrosine kinase (MuSK) antibodies which target proteins in muscle cells - (15%)
- Thymoma or thymic hyperplasia: 10-15% of patients have a thymoma, whilst up to 70% have thymic hyperplasia - thought that perhaps T cells made in thymus can lead to B cells creating autoantibodies
What are some signs/symptoms of MG?
Worse later in the day/on exertion
Lethargy
Muscle weakness that starts at head/neck and moves downwards
Weak eye muscles - diplopia, ptosis
Ptosis - sleepy hollow
Jaw fatigability - slurred speech/ chewing difficulties
- Dysphagia: difficulty swallowing
What are some differential diagnosis for MG?
Thyroid ophthalmology
MS
Myotonic dystrophy
Brainstem cranial nerve lesions
Lambert-Eaton myasthenic syndrome
What are some investigations for MG?
Serology - Ab testing:
serum acetylcholine receptor (AChR) antibody analysis (85%)
muscle-specific tyrosine kinase (MuSK) antibodies (15%)
Bedside tests - Count to 50 and as they reach higher numbers their voice becomes less audible
arm outstretched and ask patient to keep looking at it without lifting head up – after a few seconds they will unable to keep their eyes raises
Nerve Stimulation Tests - decrement in evoked potential after motor nerve stimulation
Serial measurements of forced vital capacity (FVC) - looking for pulmonary function, can be reduced in Myasthenic crisis
CT Thorax/MRI - look for Thymoma
What is the management of Myastenia gravis?
- First-line: pyridostigmine; an acetylcholinesterase inhibitor
- Second-line: prednisolone(to dampen down immune system)
Other: if symptoms remain uncontrolled, consider alternatives such as methotrexate orrituximab
Thymectomy:indicated if a thymoma is present on imaging,orin patients aged < 45 years old with positive serology;
What is a Myasthenic crisis: ? What is the management
weakening of the respiratory muscles and is often provoked by infections or medications. Patients present with increasing shortness of breath, which can deteriorate into respiratory failure
Monitor forced vital capacity. Ventilatory support (ie BiPAP) may be needed. Treat with plasmapheresis (removes AChR antibodies from the circulation) or IV immunoglobulin and identify
and treat the trigger for the relapse (eg infection, medications).
What are some common medications that you need to avoid if you have myasthenia gravis?
ciprofloxacin/Gentamicin. Erythromycin, Doxyclicne or certain other antibiotics,
beta-blockers like propranolol, atenolol, bisoprolol
calcium channel blockers,
Botox, muscle relaxants,
Lithium, magnesium,
verapamil
What is neurofibromatosis type one?
also known as von Recklinghausen’s disease
genetic disorder causing lesions in the skin, nervous system and skeleton
Autosommal dominant
What causes/pathophysiology of neurofibromatosis type 1?
a defect in the gene NF1
- neurofibromin, the gene product, is a ubiquitous nervous system protein and is believed to act as a tumour suppressor
- loss of neurofibromin leads to an increased risk of developing benign and malignant tumours but the effects of a mutation are very variable and can appear at any age due to a variety of mutations, differing penetration and mosaicism
What are some features of neurofibromatosis?
The diagnostic criteria for neurofibromatosis type 1 are based on the features, remembered with the “CRABBING” mnemonic:
C – Café-au-lait spots (more than 15mm diameter is significant in adults)
R – Relative with NF1
A – Axillary or inguinal freckling
BB – Bony dysplasia, such as Bowing of a long bone or sphenoid wing dysplasia
I – Iris hamartomas (Lisch nodules), which are yellow-brown spots on the iris
N – Neurofibromas (tumour of nerve sheath)
G – Glioma of the optic pathway
Scoliosis
What are some complications for neurofibromatosis type 1?
Complications
Migraines
Epilepsy
Renal artery stenosis, causing hypertension
Learning disability
Behavioural problems (e.g., ADHD)
Scoliosis of the spine
Vision loss (secondary to optic nerve gliomas)
Malignant peripheral nerve sheath tumours
Gastrointestinal stromal tumour (a type of sarcoma)
Brain tumours
Spinal cord tumours with associated neurology (e.g., paraplegia)
Increased risk of cancer (e.g., breast cancer and leukaemia)
TOM TIP: The two unique complications worth remembering for NF1 are malignant peripheral nerve sheath (MPNST) and gastrointestinal stromal tumours (GIST).
What happen in neurofibroatosis type 2?
The neurofibromatosis type 2 gene is found on chromosome 22. It codes for a protein called merlin, a tumour suppressor protein important in Schwann cells
Mutations in this gene lead to schwannomas (benign tumours of the Schwann cells).
What is a key finding that should make you think of type 2 neurofibromatosis? What is the inheritance of it?
Inheritance is autosomal domminant
TOM TIP: An exam patient with bilateral acoustic neuromas almost certainly has neurofibromatosis type 2.
What is hydrocephalus
Hydrocephalus describes cerebrospinal fluid (CSF) building up abnormally within the brain and spinal cord. This is a result of either over-production of CSF or a problem with draining or absorbing CSF.
Normal physiology - where is CSF found, and what creates it, and through what is it absorbed into the venous system?
The ventricles contain CSF. The CSF provides a cushion for the brain tissue. CSF is created in the four choroid plexuses (one in each ventricle) and by the walls of the ventricles. CSF is absorbed into the venous system by the arachnoid granulations, in the subarachnoid space
What are the types of hydrocephalus?
Communicating - there is communication between the ventricles and the subarachnoid space and the problem lies outside of the ventricular system (e.g. due to reduced absorption or blockage of the venous drainage system), may also be due to increased CSF production
Non-communicating/obstructive - the flow of CSF is obstructed within the ventricles or between the ventricles and the subarachnoid space
Normal pressure hydrocephalus is a condition with low-grade hydrocephalus with intermittently raised ICP.
What is normal pressure hydrocephalus (NPH)?
Its a form of communicating hydrocephalus in which excess cerebrospinal fluid (CSF) builds up in the ventricles, leading to normal or slightly elevated cerebrospinal fluid pressure.
What is the classic triad of symptoms in NPH?
DIG:
Dementia
Incontinence (urinary)
Gait Abnormality
wet, wobbly and whacky
4th Wentricle
What are the investigations for NPH?
neuroimaging - CT. Enlarged ventricles including temporal horns but with normal sulci.
high-volume lumbar puncture (LP) with removal of 30–50 ml of CSF. Gait and cognitive function are typically tested just before and within 2–3 hours after the LP to assess for signs of symptomatic improvement
What are the treatments of NPH?
The most common type used to treat NPH is ventriculoperitoneal (VP) shunts, which drain CSF fluid to the peritoneal cavity. Adjustable valves allow fine-tuning of CSF drainage. NPH symptoms reportedly improve in 70–90% of patients with CSF shunt
What are the two main imaging sequences of MRIs, and how is grey matter and white matter portrayed in them?
T1 sequences will have grey matter being darker than white matter. (Same as anatomy)
T2 weighted sequences, whether fluid attenuated or not, will have white matter being darker than grey matter.
On T1 and T2 weighted images, What are the brighter tissues,
T1 – ONE tissue is bright: fat
T2 – TWO tissues are bright: fat and water (WW2 – Water is White in T2)
T1 is the most ‘anatomical’ image (Figure 1). (hence why the outside grey matter is ‘Darker than the white matter (think - grey is darker than white)
Conversely, the cerebrospinal fluid (CSF) is bright in T2 due to its’ water content.
T2 is generally more commonly used in clinical disease/medicine, but T1 can be used as a reference for anatomical structures or to distinguish between fat vs. water bright signals.
What is a DWI MRI? What is it good at detecting?
DWI (Diffusion-weighted imaging )is an imaging modality that combines T2 images (that highlight both fat and water) with the diffusion of water.
DWI has a high sensitivity for water diffusion, thereby detecting the physiological changes that happen immediately after a stroke.
What other kind of imaging feature should always be sued with a T2 DWI MRI?
ADC (apparent diffusion coefficient) should be used alongside DWI in order to confirm whether there is true restricted diffusion and not simply “shine through” from T2. (as T2 also looks at water)
basically, DWI Measures abnormal diffusion of water (restricted diffusion) but ALSO combines it with the T2 image.
ADC Measures purely diffusion of water with no T2 combination, so by looking at it, it can Provides confirmation of true restricted diffusion in a DWI
before you do a lumbar puncture what must you always do
get imaging of the brain CT/MRI
Always ensure a patient is ‘stable’ before transferring a patient to the radiology department for a
scan, e.g., airway secure, vital signs are normal (i.e., any resuscitation is complete and respiratory
support is appropriate), scalp laceration is sutured.
Before performing a lumbar puncture, ensure prior appropriate cranial imaging, e.g., CT head.
What is a hounsfield unit?
CT scan raw data pixel values are given in Hounsfield units (Hu), an arbitrary scale, such that bone is +1000,
water is 0, and air is -1000, and that bears no relationship to any SI or Imperial units of radiation or energy.
This results in the following approximations:
Blood +60-70 Hu
Grey matter +40 Hu
White matter +30 Hu
CSF +7 Hu
Fat -100 Hu
Air -1000 Hu
As per the hounsfield scale, there are 2000 different types of grey, however humans can only reconginse about 30 shades of grey. - how do we get round this when looking at CT?
By convention for head CT scans, two settings of grey scale are looked at, ‘soft tissue window’ showing up
brain/blood/CSF and ‘bone window’ showing skull detail.
For any setting, the grey scale has a ‘centre’ (C) (or
level (L)) and a window (W), shown in the bottom left corner of the scan image.
For example, a soft tissue
window might be such to be centred on +40 Hu and have a range of 90 Hu, meaning that the whitest white is
+85 Hu and the blackest black is -5 Hu, with the grey scale in between thus easily allowing the soft
structures to be distinguished (this also explains why the fat in the orbits on a soft tissue window is black as
per the air in the adjacent nasal cavity)
This can be done on the software of the CT, the patient does not need to be scanned twice.
What are some 4 questions to ask for CT scan interpereation?
Q1 Is there an intracranial mass?
Is there hydrocephalus?
Is there intracranial blood?
What about skull and extracranial soft tissues?
what is syringomyelia?
What are some causes of it ?
describes a collection of cerebrospinal fluid within the spinal cord.
Causes include:
a Chiari malformation: strong association
trauma
tumours
idiopathic
What are some features of syringomyelia? What is the part of the tract affected
a ‘cape-like’ (neck, shoulders and arms)
loss of sensation to temperature but the preservation of light touch, proprioception and vibration
classic examples are of patients who accidentally burn their hands without realising
this is due to the crossing spinothalamic tracts in the anterior commissure of the spinal cord being the first tracts to be affected
spastic weakness (predominantly of the lower limbs)
neuropathic pain
upgoing plantars
As the syringomyelia progresses it will first cause compression of the spinothalamic tract as they decussate in the anterior white commissure
what is Subacute combined degeneration of the spinal cord due to, and what is affected in it?
due to vitamin B12 deficiency - see in poor diets, Recreational nitrous oxide inhalation, bariatric surgery due to impaired absorption of nutrients.
resulting in impairment of the dorsal columns, lateral corticospinal tracts and spinocerebellar tracts.
A helpful way of remembering the tracts affected is Subacute Combined Degeneration (SCD): Spinocerebellar tract, Corticospinal tract, and Dorsal columns.
what symptoms do you get in subacute degeneration of the spinal chord
dorsal/posterior column involvement =
distal tingling/burning/sensory loss is symmetrical and tends to affect the legs more than the arms
impaired proprioception and vibration sense
lateral corticospinal tract involvement
muscle weakness, hyperreflexia, and spasticity
upper motor neuron signs typically develop in the legs first
brisk knee reflexes
absent ankle jerks
extensor plantars
spinocerebellar tract involvement
sensory ataxia → gait abnormalities
positive Romberg’s sign
A positive Romberg’s sign occurs when a person sways, falls, or has difficulty maintaining balance when standing upright with their feet together, arms at their sides, and eyes closed. This test is used to assess balance and proprioception
