Neurology Flashcards
What is a transient ischemic attack?
Ischemia, without infarction which resolves within 24 hours
Which artery supplies the anterior circulation and which the posterior of the brain?
- Anterior = internal carotid
- Posterior = vertebral arteries
Which circulation do the majority (90%) of TIAs affect?
Anterior circulation (embolism travels through internal carotid)
What are some risk factors for stroke (8)?
- Old
- Smoking
- T2DM
- Hypertension
- Obesity
- Hypercholestrolaemia
- AF
- VSD + other heart defects
What deficit is seen in an occluded anterior cerebral artery?
Weak/ numb contralateral leg
What deficits are seen in an occluded middle cerebral artery (2)?
- Weakness/ numbness contralateral body/ face
- Dysphasia (can’t speak properly -temporal)
What deficits are seen in an occluded posterior cerebral artery (1)?
Contralateral visual changes
What part of the vision is often spared and why during a PCA occlusion?
Macular sparring - macular is represented at the occipital pole and can receive collateral blood flow from middle cerebral artery
What deficits are seen in an occluded vertebral artery (2)?
- Cranial nerve lesions (3-12)
- Limb ataxia (clumsiness)
What is amaurosis fugax?
Transient vision loss in one or both eyes
When would amaurosis fugax occur (3)?
- Vascular origin (ophthalmic artery blocked - comes off internal carotid)
- Occular origin
- Neurological origin (nerve lesion)
How is a TIA investigated?
- Clinically by symptoms, usually quite obvious, resolves within 10-15 minutes (can’t differentiate from stroke till after recovery)
- CT head - rule out haemorrhagic stroke
How is TIA treated?
- Acutely = aspirin 300mg
- Long term prophylaxis = clopidogrel + atorvastatin
What is a stroke?
Focal neurological deficit lasting 24+ hours with infarction
What percentage of strokes are ischemic?
85%
Which “brain bleeds” are considered strokes?
- Intracererbal
- Subarachnoid
(Sub/epi dural not considered strokes)
What are some risk factors for an ischemic stroke (9)?
- Old
- Smoking
- T2DM
- Hypertension
- Obesity
- Hypercholestrolaemia
- AF
- VSD + other heart defects
- TIA
What are the symptoms of a stroke?
Same as TIA
What is a lacunar stroke?
Block in arteries that supply deep brain structures e.g. thalamus, pons
What are the symptoms of a lacunar stroke (1)?
Weakness/ lack of coordination on one side of body
How is an ischemic stroke diagnosed?
- CT head
How is an ischemic stroke treated?
- If within 4.5 hours –> thrombolytic
- Aspirin for 2 weeks
- Prophylactic clopidogrel + atorvastatin
What thrombolytic is given for ischmemic strokes?
Alteplase
How does alteplase break down clots?
Tissue plasminogen activator (activates plasminogen to plasmin)
What are some risk factors for intracerebral bleeds (5)?
- Trauma
- Hypertension
- Aneurisms
- Tumours
- Anticoagulants (e.g. warfarin)
How is a haemorrhagic stroke investigated generally (2)?
- CT head - midline shift, high ICP
- Lumbar puncture - if CT negative
What are some signs/ symptoms of intracerebral bleed (4)?
- Seizures
- Weakness
- Vomiting
- Reduced consciousness
What scale accesses conciseness?
Glasgow coma scale (3-15)
How is intracererbal haemorrhage treated?
Neuro referal - usually surgery
What are the layers of the skull and brain?
Skin –> periosteum –> cranium –> dura –> arachnoid –> pia
Where is CSF located in the meninges?
Sub-arachnoid space
Which vessels lie in the subarachnoid space?
Circle of willis
What is a berry aneurysm?
Round out pouching of an artery at the base of the brain (in the circle of willis)
What is the most common site for a berry aneurysm?
Anterior communicating artery
What are some risk factors for subarachnoid haemorrhages (7)?
- Marfans/ EDS
- Hypertension
- PKD
- Trauma
- Older
- Family history
- Alcohol/ cocaine
What are the signs/ symptoms of subarachnoid headache (5)?
- Thunderclap headache (sudden occipital)
- Meningism
- N + V
- Reduced GCS
- CN 3/6 palsies
What sometimes occurs before a subarachnoid haemorrhage?
Sentinel headache - days/ weeks before rupture
How is subarachnoid haemorrhage investigated (3)?
- CT head - shows bleed
- Lumbar puncture
- CT angiogram - localise point of bleeding
What shape is a subarachnoid haemorrhage?
Spider web in centre of brain
What is performed if the CT head is negative for bleeding in a SAH?
Lumbar puncture
What would a lumbar puncture show if there was a subarachnoid haemorrhage (2)?
- Xanthochromia (bilirubin in CSF due to breakdown of RBCs)
- Raised RBC count
How is a subarachnoid haemorrhage treated?
Neurosurgey
What is a common surgical treatment for subarachnoid haemorrhage?
Endovascular coiling (catheter through arterial system)
What medication is used to prevent vasospasm in subarachnoid haemorrhage?
Nimodipine (CCB)
The rupture of which vessel is the most common cause of subdural haemorrhage?
Bridging veins
What are 2 risk factors/ causes of subdural haemorrhage?
- Trauma
- Atrophy of brain - e.g. in dementia (weakens vessels and widens subdural space)
What are the signs/ symptoms of subdural haemorrhage (4)?
- Headache that keeps getting worse
- N + V
- Lower GCS
- High ICP symptoms
Is a subdural haemorrhage fast or slow onset and why?
Slower because bridging vein is lower pressure than arteries
What are some symptoms/ signs of high ICP (3)?
- Cushings triad
- Papilloedema
- CN3/6 palsy
What are the three parts of Cushing’s triad?
- Bradycardia
- Increased pulse pressure
- Irregular breathing
What shape is a subdural haemorrhage on a CT?
Banana shape
How can you tell on CT if a subdural haemorrhage is acute, subacute or chronic?
- Acute = hyperdense
- Subacute = isodense (same colour as brain tissue)
- Chronic = hypodense
How is subdural haemorrhage treated?
Surgery (craniotomy/ burr hole) to allow swelling
What medication is used to treat high ICP?
Mannitol
Rupture of which vessel often causes extradural haemorrhage?
Middle meningeal artery
What age does extradural haemorrhage typically affect?
Younger adults (20-30)
dura more firmly adhered in older people
Why does risk of extradural haemorrhage decrease as you age?
Dura more firmly adhered to the skull
What is the cause of most extradural haemorrhage?
Trauma
What are some signs/ symptoms of extradural haemorrhage?
- Headache that keeps getting worse
- N + V
- Lower GCS
- High ICP symptoms
What is a typical presentation after trauma for people who develop extradural haemorrhage?
They feel fine –> then ICP builds up and they feel acutely unwell
How does a haematoma result in increased ICP?
Clot haemolysed –> becomes osmotically active –> water moves into brain + swells
How can high ICP lead to respiratory arrest?
Cerebellar tonsil herniation –> compression of respiratory centre in PONS
What shape does an extradural haemorrhage form on a CT?
Lemon shaped (biconvex)
How is an extradural haemorrhage treated (2)?
- Surgery
- Mannitol
Give 3 types of primary headaches?
- Tension
- Migraine
- Cluster
Give 6 causes of secondary headaches?
- Giant cell arteritis
- Infection
- Sub-arachnoid haemorrhage
- Trauma
- Cerebrovascular diseases (e.g. strokes, aneurysms)
- ENT problems
What is the most common type of recurrent headache?
Migraine
Which gender is most commonly affected by migraines?
Females
What age range is most commonly affected by migraines?
< 40
What are the 3 stages in the development of a migraine?
Prodrome –> Aura –> Throbbing headache
What is prodrome in the development of a migraine?
Change in mood before attack
What is an aura in the development of a migraine?
Visual/ sensory changes minutes before an attack
What are some symptoms of migraines (5)?
- Unilateral moderate-severe throbbing pain
- Motion sickness
- N + V
- Photophobia/ phonophobia
- Facial weakness
As well as presence of symptoms, what is also important to be done for a diagnosis of migraine?
Negative neurological examination
How are migraines treated acutely (2)?
- Triptan (serotonin receptor agonists)
- Other analgesics
How are migraines treated prophylactically (2)?
- Propanolol (topiramate in asthmatics)
- TCA e.g. amitriptyline = 2nd line
What is important to check in women of child bearing age with migraines?
Take them off oral contraceptive pill (increases risk of stroke)
Give some examples of triggers for migraines (5)?
- Over/under sleeping
- Caffeine
- Alcohol
- Dehydration
- Bright lights
What are some risk factors for cluster headaches (3)?
- Male
- Smoking
- Genetics/ family history
What sort of pain and where is it felt in a cluster headache?
Unilateral excruciating periorbital (around eye) pain
What are some other features of a cluster headache?
- Ptosis
- Red swollen watering eye
- Rinorrhoea (watery nose)
How frequently do cluster headaches attack and how long do they last, typically?
- 15 min - 3 hours
- 3-4 attacks a day then pain free period
How many cluster headache attacks are often required for diagnosis?
5 or more
How are cluster headaches treated?
- Acutely = triptan (serotonin receptor agonist)
- Prophylaxis = verapamil
What class of drug is verapamil?
CCB
What is the most common primary headache disorder?
Tension headache
What are 2 triggers for tension headaches?
- Stress
- Stagnant head/ neck position
What pain is felt in tension headaches?
Bilateral, tight, band like pain around forehead, temples and back of head/neck
Are other symptoms such as motion sickness and N+V present in those with tension headaches?
NOOOOOO
How are tension headaches treated?
Analgesics
What cause shooting/ stabbing pain in the face?
Trigeminal neuralgia
What are three risk factors for trigeminal neuralgia?
- Multiple sclerosis
- Older age
- Female
Where can trigeminal neuralgia affect?
Any combination of trigeminal nerve branches: ophthalmic (V1), mandibular (V3), maxillary (V2)
What medication is used to treat trigeminal neuralgia?
Carbamazepine (anticonvulsant)
What is another treatment for trigeminal neuralgia?
Surgery (decompression)
What type of disease is giant cell arteritis?
Large vessel vasculitis
What are some signs/ symptoms of giant cell arteritis (3)?
- Unilateral tender scalp/ temples
- Intermittent jaw claudication
- Amaurosis fugax
What features would be present in a biopsy positive for giant cell arteritis?
Granulomatous non-caseating inflammation of media + intima with skip lesions
What blood findings are common in those with GCA?
- Anaemia (normocytic, normochromic)
- High ESR/ CRP
How is GCA treated?
PREDNISOLONE
What is a seizure?
Transient episode of abnormal electrical activity in the brain?
What are 9 causes for seizures?
- Vascular
- Infection
- Trauma
- Autoimmune - e.g. SLE
- Metabolic
- Idiopathic
- Neoplasms
- Dementia/ drugs
- Eclampsia (pre-eclampsia + seizures)
What specific type of seizure is classed as epilepsy?
Idiopathic seizure
What is required for a diagnosis of epilepsy to be made?
2 seizures < 24 hours apart (without a cause)
What are two risk factors for epilepsy?
- Family history
- Dementia
What are three ways an epileptic seizure can be differentiated from a non-epileptic seizure?
In epileptic seizures…
* Eyes are often open
* Synchronous movements
* Happen at night
What is thought may be the cause of epilepsy?
Imbalances between GABA (inhibitory) and glutamate (stimulatory) - increased glutamate compared to GABA
How long does an epileptic seizure typically last?
< 2 minutes
What are the 4 phases of epileptic seizures?
Prodrome –> Aura –> Ictal event –> Post-ictal period
How does an aura before an epileptic fit often present (2)?
- Deja vu
- Lip smacking (automatism)
How are epileptic seizures classified depending on the part of the brain affected?
- Generalised - bilateral + loss of consciousness
- Focal - features confined to one region
What are 5 types of generalised epileptic seizures?
- Tonic-clonic (grand mal)
- Absence (petit mal)
- Tonic
- Myoclonic
- Atonic
What are the features of a tonic-clonic seizure (3)?
- Tonic phase (1st) = rigidity, fall to floor
- Clonic phase (2nd) = jerking of limbs
+ incontinence, tongue bitten
What is the main feature of an absence seizure?
Moment of staring off into space (seconds to minutes)
What age do absence seizures most commonly affect?
Children
What feature is seen on an EEG in absence seizures?
3 Hz spike
What is the main feature of tonic seizures?
Rigid body
What is the main feature of myoclonic seizures?
Just jerking limbs
What is the main feature of atonic seizures?
Sudden floppy limbs + muscles
What are the two types of focal seizure?
- Simple focal
- Complex focal
What is the difference between simple and complex focal seizures?
Simple maintain conciseness, complex loose conciseness
What are the symptoms of a focal seizure in each hemisphere of the brain?
- Temporal = aura + dysphasia
- Frontal = repeated muscle twitching/ paralysis
- Parietal = parenthesis in limbs
- Occipital = vision changes
What are two neurological phenomena that occur with frontal lobe seizure?
- Jacksonian marching (repeated twitching)
- Todds palsy (paralysis)
What extra brain structure is usually involved in complex focal seizures when the patient loses consciousness?
Basal ganglia
How is epilepsy investigated?
- MRI (check for structural issues)
- Bloods (check for metabolic/ infection causes)
What is the first line drug for generalised seizures?
Sodium valproate
What is the first line drug for focal seizures?
Carbamazepine
Who must sodium valproate not be given to?
Pregnant women (teratogenic - interferes with folic acid)
What epileptic drug is used for those who are pregnant?
Lamotrigine
What is a complication of epilepsy?
Status epilepticus
What is status epileptics defined as?
- Seizures > 5 minutes
- > 3 seizures in one hour
How is status epileptics treated?
- Lorazepam (benzodiazepine)
- If not worked, then phenytoin
What is the second most common neurodegenerative condition after dementia?
Parkinsons disease
What causes Parkinson’s disease?
Loss of dopaminergic neurones from the substantial nigra pars compactica
What are 3 risk factors for Parkinson’s disease?
- Family history
- Males
- Older age
What is protective against Parkinson’s disease?
SMOKING
Draw out the direct and indirect pathways in the basal ganglia
Direct: cortex (+) –> striatum (-) –> GPi and SNpr (-) –> thalamus (+) –> cortex
Indirect: cortex (+) –> striatum (-) –> GPe (-) –> STN (+) –> SNpr and GPi (-) –> thalamus (+) –> cortex
How does substantial nigra pars compactica affect the indirect/ direct pathways?
- Direct = stimulatory (via D1 neurones)
- Indirect = inhibitory (via D2 neurones)
What is the effect of the indirect and direct pathway on muscle movement?
- Direct = stimulator
- Indirect = inhibitory
Therefore a lack of dopaminergic neurones will increase or decrease muscle inhibition?
Increase muscle inhibition therefore more difficult to initiate movement
What are 4 typical features of parkinsons?
- Bradykinesia
- Unilateral resting tremor
- Rigidity
- Postural instability
What are some features of bradykinesia when walking (3)?
- Stooped posture
- Reduced arm swing
- Shuffling gait
Does Parkinson’s typically affect both or one side?
One side (particularly at the beginning)
How is parkinsons diagnosed?
Clinically, by a specialist
How is parkinsons treated when moderate-severe?
L-DOPA (levodopa)
How is parkinsons treated in more mild disease?
- Da agonist
- Monoamine oxidase - B inhibitors
What condition is often confused with parkinsons?
Benign essential tremor
What is a significant difference between benign essential tremor and parkinsons (in terms of the tremor)?
Bilateral in benign essential tremor
Which dementia often causes Parkinson like symptoms?
Lewy body dementia
What are the 4 main types of dementia?
- Alzheimers (60%)
- Vascular
- Lewy body
- Frontotemporal
How does Alzheimers cause dementia?
Beta amyloid proteins accumulate as plaques and tau neurofibrillary triangles –> death of brain cells
What are two risk factors for Alzheimers?
- Downs syndrome (inevitable due to gene mutation)
- Family history
What are some symptoms of Alzheimer’s (3)?
Affects whole brain
* Agnosia - can’t recognise
* Apraxia - can’t move
* Aphasia - cant speak
How is Alzheimers treated?
Cholinesterase inhibitors (e.g. galantamine)
What causes vascular dementia?
Lots of small (or big) infarcts of brain tissue
What is the pattern of deterioration in vascular dementia?
Stepwise - as more tissue damaged e.g. by TIA
What causes levy body dementia?
Lewy body accumulation in cortex
What is the main constituent of Lewy bodies?
Alpha synuclein
What are the symptoms of Lewy body dementia (2)?
- Cognitive decline
- Parkinsonism
The collection of what protein leads to fronto-temporal dementia?
Tau protein/ pick body
What sometimes causes frontotemporal dementia?
Autosomal dominant mutation in tau protein
What are the symptoms of frontotemporal dementia (2)?
- Frontal = thinking + memory affected
- Temporal = speech + language affected
What tool helps with dementia diagnoses?
Mini mental state exam (normal > 25)
What investigation is sometimes done I those with dementia?
MRI head
What other conditions can also cause dementia (4)?
- SLE
- Infection
- Neoplasm
- Hydrocephalus
Many others
What pattern is Huntington’s chorea inherited?
Autosomal dominant
What gene is affected in Huntington’s chorea?
HTT gene on chromosome 4
What is the mutation found in people with Huntingtons?
Trinucleotide repeat disorder of CAG
How many repeats of CAG are required for a person to develop huntingtons?
35 <
What changes in the development of huntingtons disease are seen from generation to generation?
Anticipation - symptoms present:
* Earlier
* More severely
How often is the genotype expressed in the phenotype for Huntington’s chorea?
100% FULL penetrance
What are the signs/ symptoms of Huntington’s chorea (5)?
- Chorea (limb jerking)
- Dementia
- Psychiatric issues
- Depression
- Dysphagia + dysarthria (speech problems)
How is Huntingtons chorea diagnosed?
- Family history + clinically
- Genetic testing (if wanted)
How can chorea be treated in those with huntingtons?
- Valproic acid
- Benzodiazepines (diazepam)
How can depression be treated in huntingtons?
SSRIs (fluoxetine)
How is psychosis treated in those with huntingtons chorea?
Risperidone
What is multiple sclerosis?
Chronic and progressive demyelination of neurones in the CNS
What are the two types of myelin producing cells?
- CNS = oligodendrocytes
- PNS = Schwann cells
Which type of cell does multiple sclerosis affect and which protein that is produced by this cell?
Oligodendrocytes (myelin basic protein)
What sort of hypersensitivity reaction is MS?
Type 4 (cell mediated)
What are some risk factors for MS (5)?
- Female
- Other autoimmune diseases
- Family history
- EBV
- 20-40
What are the four patterns of MS disease?
- Clinically isolated syndrome
- Relapsing-remitting
- Primary progressive
- Secondary progressive
What is the difference between primary and secondary progressive MS?
Secondary were initially presenting as relapsing-remitting at point of diagnosis
How are MS lesions/ progression of the disease often described?
Disseminated in time and space
What are the symptoms of MS (5)?
- Parasthesia
- Blurred vision
- Eye movement disorder
- Weakness
- Ataxia
What are some signs of MS (4)?
- Optic neuritis
- UMN signs
- Lhermittes sign
- Charcot neurological triad
What is Lhermittes sign?
Electric shock sensation with neck flexion (in MS)
What is Charcot neurological triad?
- Dysarthria
- Nystagmus
- Intention tremor
For MS
What is usually the first presenting sign/ symptom of MS?
Optic neuritis (blurred vision)
What diagnostic criteria is used for MS?
McDonald criteria
What investigations are often does for those with MS?
MRIs
How are relapses of MS treated?
Methylprednisolone
What medications are used for long term prophylaxis for MS?
DMARD/ biologic (e.g. beta interferon)
What are UMN lesion signs/ symptoms (4)?
- Hyper-reflexia
- Weakness
- Spasticity/ hypertonia
- Positive Babinski sign
What is Babinski sign?
Toes extend when foot stoked
What is spasticity?
Muscles rigid with movement
What are LMN lesion signs/ symptoms (5)?
- Hypo-reflexia
- Weakness
- Muscle waisting/ hypotonia
- Negative Babinski sign
- Fasciculations
What is a fasciculation?
Muscle twitching
What is motor neurone disease?
Progressive degeneration of upper and lower motor neurones (with a variety of causes, many unknown)
What is the main tract responsible for movement?
Corticospinal tract
What part of the brain is responsible for idea of movement?
Association cortexes e.g. premotor cortex
Where does activation of the upper motor neurone originate from?
Motor cortex
Which parts of the brain modulate motor control (2)?
- Basal ganglia - turn signals on/ off
- Cerebellum - fine control of movement
What are some risk factors for MND?
- Family history/ genetics (5-10% inherited)
- Male
What gene has been associated with MND?
SOD-1 gene mutation
What parts of the body/ functions are never affected by MND (3)?
- Eyes
- Sensory function
- Sphincters
What are 4 types of MND?
- ALS - 80% (amyotrophic lateral sclerosis)
- Progressive bulbar palsy
- Progressive muscular atrophy
- Primary lateral sclerosis
What are 3 features of amyotrophic lateral sclerosis?
- UMN + LMN lesions
- Can have corticobulbar involvement
- SOD-1 mutation (associated)
Which cranial nerves are affected in progressive bulbar palsy?
CN 9-12
(Upper + lower involvement)
What are the main symptoms of progressive bulbar palsy?
Breathing/ swallowing/ talking difficulties
What neurones are affected in progressive muscular atrophy?
Lower motor neurones - distal muscles affected first
Which neurones are affected in primary lateral sclerosis?
Upper motor neurones
How is MND diagnosed?
Clinically (electromyography shows fibrillation potentials - in muscles)
What medication can be used to slow the progression of motor neurone disease?
Riluzole
What is meningitis?
Inflammation of the meninges
What action do you need to take as a doctor if a patient has meningitis?
Notify public health England
What is the most common class of pathogen in infective meningitis?
Viruses
What are 3 viruses that infect the meninges?
- Enteroviruses
- Herpes simplex virus - 2
- Varicella zoster virus
What is an example of an enterovirus?
Coxsackie
What are 2 bacteria that infect the meninges the most in people over 3 months?
- S. pneumoniae
- N. meningitidus
What bacteria often infects the meninges of older (over 60) and younger (under 3 months)?
Listeria
What is the most common meningitis causing bacteria in neonates (0-3 months)?
Group B alpha haemolytic strep (s. agalactiae)
What 4 bacteria often causes meningitis in neonates?
- E. coli
- S. pneumoniae
- Group B alpha haemolytic strep
- Listeria
What bacteria has decreased in the prevalence of meningitis due to vaccinations?
H. influenzae
What sort of bacteria is N. meningitidus?
Gram -ve diplococcus
What sort of rash does N. meningitidus cause?
Non-blanching purpuric rash
What sort of bacteria is S. pneumoniae?
Gram + ve diplococcus in chains
What sort of bacteria is group b alpha haemolytic strep?
Gram +ve coccus in chains
Why is group b alpha haemolytic strep the most common cause of neonatal meningitis?
It colonises the maternal vagina
What sort of bacteria is listeria?
Gram +ve bacillus
What are the main 3 symptoms of meningitis?
- Headache
- Neck stiffness
- Photophobia
What are 3 signs of meningitis?
- Kernig sign
- Brudzinski sign
- Pyrexia
What is kerning sign?
Can’t extend knee when hip is flexed
What is brudzinski sign?
Knees + hips automatically flex when neck flexed
How is meningitis diagnosed?
Lumbar puncture + CSF analysis
Where is a lumbar puncture done?
L3/L4
When is a lumbar puncture contraindicated?
High ICP
What is the appearance of bacterial viral and fungal/TB meningitis?
- Bacterial = cloudy yellow
- Viral = normal
- Fungal/ TB = cloudy fibrous
What leukocytes are common in bacterial viral and fungal/TB meningitis?
- Bacterial = neutrophilia
- Viral = lymphocytosis
- Fungal/ TB = lymphocytosis
What is the protein levels in bacterial, viral and fungal/TB meningitis?
- Bacterial = high
- Viral = normal
- Fungal/ TB = high
Why is protein high in bacterial and fungal/ TB meningitis?
Waste product of those pathogens
What are the glucose levels in bacterial, viral and fungal/ TB meningitis?
- Bacterial = low
- Viral = normal
- Fungal/ TB = low
How is meningitis treated in hospital?
Ceftriaxone/ cefotaxime + steroids (dexamethasone)
What antibiotic is given for meningitis if listeria is suspected?
Amoxicillin
What antibiotic is given IM to people in the GP if meningitis is suspected?
Benzylpenicillin
What antiviral is used for the treatment of some meningitis?
Aciclovir
What prophylactic antibiotic is given to those deemed closed contacts of those diagnosed with meningitis?
Ciprofloxacin
What are some complications of meningitis (3)?
- Meningococcal septicaemia (DIC) - causes rash
- Hearing loss
- Adrenal insufficiency
What is the most common cause of encephalitis?
Viral infections
What are some other less common causes of encephalitis (3)?
- Parasitic
- Autoimmune
- Fungal
Rarely bacterial
What is a parasite that can cause encephalitis?
Toxoplasma gondii (toxoplasmosis - from CATS 🐱)
Who is most at risk of encephalitis?
Immunocompromised + very young/ old
What are some symptoms of encephalitis (4)?
- Fever
- Headache
- Focal neuropathy (e.g. aphasia)
- Seizures
How is encephalitis investigated (2)?
- Lumbar puncture = lymphocytosis
- MRI head
How is the viral cause of encephalitis found?
PCR testing of CSF
How is encephalitis treated?
Aciclovir
What are 4 types of brain tumour?
- Astrocytoma (90%)
- Oligodendrocytoma
- Meningioma
- Schwannoma
Which cancers most commonly metastasise to brain (3)?
- Lung cancers
- Breast cancer
- Melanoma
How are astrocytomas graded?
1-4 (by WHO)
What is grade 4 astrocytoma known as?
Glioblastoma
What is a glioma?
Cancer of glial cells (oligodendrocytes, microglial cells or astrocytes)
What are the signs/ symptoms of a brain tumour (5)?
- Cushing’s triad (high ICP)
- Seizures
- Lethargy + weight loss
- Focal neurology
- Occipital headaches (due to high ICP)
How is a brain tumour diagnosed?
MRI
How are brain tumours treated (3)?
- Surgery
- Chemo
- Steroids (reduce tumour size)
What are the three types of paralysis and what sort of lesion would cause them??
- Hemiplegia = lesion in the brain (half the body paralysed)
- Paraplegia = lesion in the spinal cord (legs paralysed)
- Quadriplegia = lesion in spinal cord (both legs + arms)
Where does the spinal cord end?
L1/2
What is found at the end and after the spinal cord (3 anatomical things)?
- Conus medularis
- Cauda equina
- Filum teminale
What are the main ascending tracts?
- DCML
- Spinothalamic
- Spinocerebellar
What does DCML carry?
- Fine touch
- Vibration
- Proprioception
Describe the pathway of the DCML?
- 1st order –> medulla (in gracile (T6 below legs) and cuneatus (arms) fasiculata)
- 2nd order –> decussate –> thalamus
- 3rd order –> sensory cortex
What does spinothalamic carry?
- Anterior = crude touch + pressure
- Lateral = pain + temperature
Describe the pathway of the spinothalamic tract?
- 1st order –> ipsilateral dorsal horn
- 2nd order –> decussate immediately –> contralateral thalamus
- 3rd order –> sensory cortex
What does the spinocerebellar tract carry?
Unconscious proprioception
What are the main descending tracts?
- Corticospinal
- Corticobulbar
What do the descending tracts carry?
Motor information
Describe the path of the corticospinal tract?
- Upper neurones - lateral tract (decussate in medulla); anterior tract (decussate just before point of synapse)
- Lower neurones - travel to muscle
What is the difference in terms of the muscles supplied by the lateral and anterior corticospinal tracts?
- Anterior = axial muscles
- Lateral = extremities
What is the corticobulbar tract?
The cranial nerves
Where does the knee jerk reflex go to in the spinal cord?
L3/4
Where does the big toe jerk reflex go to in the spinal cord?
L5
Where does the ankle jerk reflex go to in the spinal cord?
S1
What is brown squared syndrome?
Hemisection of the spinal cord
What are the symptoms of brown sequard syndrome?
- Ipsilateral motor control loss
- Ipsilateral proprioception + 2 point discrimination loss
- Contralateral pain + temp loss
What is myelopathy?
Spinal cord compression
What are two causes of myelopathy?
- Neoplasms
- Disco prolapse/ herniation
Lots of other spinal pathologies
What are some signs/symptoms of myelopathy?
- Progressive leg weakness
- UMN signs
- Sensory loss below lesions
How are myelopathies investigated?
MRI spine
How are myelopathies treated?
Surgery
What two surgical procedures are used to treat myelopathies?
- Microdiscectomy (removal of small part of disc)
- Laminectomy (removal of some of vertebral bone)
What is cauda equina syndrome?
Compression below conus medularis
What can cause cauda equina syndrome (4)?
- Herniated disc
- Tumours
- Trauma
- Abscess
What do the nerves of the cauda equina supply?
- Motor/ sensory function of lower limbs
- Parasympathetic to bladder and rectum
What are the signs/ symptoms of cauda equina (4)?
- Leg weakness
- LMN signs
- Saddle anaesthesia (perianal numbness)
- Bladder/ bowel dysfunction + sphincter involvement
How is cauda equina diagnosed?
MRI cord
How is cauda equina treated?
Treat underlying cause, e.g:
* Spinal fixation
* Microdiscectomy
What is peripheral neuropathy?
Nerve damage/ pathology outside of the CNS
What are the mechanisms that can damage nerves?
- Demyelination
- Axonal damage
- Nerve compression
- Infarction
- Wallerian degeneration
What is Wallerian degeneration?
Nerve lesion, dies distally
What is mononeuritis multiplex?
Several individual nerves affected
What are some causes of mononeuritis multiplex (4)?
- T2DM
- Vasculitis
- RA
- Infections
What is carpal tunnel syndrome?
Pressure on median nerve passing through the carpal tunnel
What are the nerve roots of the median nerve?
C6 - T1
What are some risk factors/ causes of carpal tunnel syndrome (5)?
- Hypothyroidism
- Acromegally
- Obesity
- RA
- Strain
What are the symptoms of carpal tunnel (3)?
- Hand weakness
- Thenar eminence waisting
- Parasthesia
How is carpal tunnel investigated?
- Tinsel test
- Phalen test
- Electymyography (EMG)
What is tinsels test?
Tapping wrist where median nerve is causes pain/ tingling
What is Phalens test?
Flexing wrist (wrists opposite of praying) causes numbness/ pain
How is carpal tunnel syndrome treated?
- Wrist splint at night (extent wrist)
- Steroid injections
- Surgery decompression
What would cause wrist drop?
Radial nerve palsy (C5 - T1)
Which muscles does the radial nerve innervate which causes wrist drop?
Extensor muscles
What causes claw hand?
Ulna nerve palsy (C8 - T1)
How are ulna and radial nerve palsy treated?
Splints
What is sciatica?
Irritation/ damage to sciatic nerve
What are the sciatic nerve roots?
L4 - S3
What can cause sciatica (4)?
- IV disc herniation/ prolapse
- Piriformis syndrome
- Tumours
- Trauma
What is piriformis syndrome?
Muscle in buttock spasms and irritates sciatic nerve
What are the symptoms/ signs of sciatica (2)?
*Shooting pain down from buttock to lateral leg
* Weakness in leg + foot
How is sciatica investigated?
- Clinically - can’t do strait leg raise
- MRI - check for possible causes
How is sciatica treated (3)?
- Analgesia + steroids
- Amitriptyline
- Surgery
Where do polyneuropathies typically affect?
Peripheries (glove and stocking distribution)
What causes a mostly motor polyneuropathy?
Guillain barre syndrome
What causes a mostly sensory polyneuropathy?
Diabetic neuropathy
What bacteria is a common cause of guillain barre syndrome?
Campylobacter jejuni
What is thought to cause diabetic neuropathy (2)?
- Microvascular disease
- Oxygen free radicals
What are some other causes of polyneuropathies (2)?
- Vasculitis
- Vitamin B12 deficiency (damage myelin sheaf)
GBS and diabetes on previous cards
What would a CN3 lesion present as (3)?
- Ptosis
- Down + out eye position
- Fixed dilated pupil
What would a CN4 lesion present as (1)?
Can’t look down (and inwards)
Rare, due to trauma
What would a CN5 lesion present as (3)?
- Jaw deviates towards affected side
- Loss of corneal reflex
- Trigeminal neuralgia
What would a CN6 lesion present as (1)?
Can’t abduct eye
Sign of high ICP
What would CN7 lesion present as (1)?
Drooping of one side of face (no forehead sparing)
What may cause a CN7 lesion?
Bells palsy
What would a CN8 lesion present as (2)?
- Hearing loss
- Loss of balance
What often causes a CN8 lesion?
Skull change - compression of internal acoustic meatus
What would a CN 9+10 lesion present as (2)?
- Impaired gag reflex
- Uvula deviation
What would CN11 lesion present as (1)?
Can’t shrug shoulders/ turn head against resistance
What would CN12 lesion present as (1)?
Tongue deviation towards side of lesion
What is myasthenia gravis?
Autoimmune response at neuro-muscular junction against post synaptic receptor
What type of hypersensitivity reaction is myasthenia gravis?
Type 2
Who is most commonly affected by myasthenia gravis (2 groups)?
- Women under 40
- Men over 60
What has myasthenia gravis been connected to?
Thyoma (thymus tumour) - stimulate production of auto-antibodies
What two types of antibodies are found in those with myasthenia gravis?
- Anti nicotinic Ach-R antibodies
- Anti MuSK (muscle specific kinase) antibodies
How do Anti Ach-R antibodies cause pathology in myasthenia gravis (2)?
- Competitively bind to Ach nicotinic receptors
- Activate compliment system –> receptor destruction
How do Anti MuSK antibodies cause pathology in myasthenia gravis?
- Activate compliment system –> receptor destruction
- MuSK helps synthesise Ach-R –> less Ach-R expression
When is myasthenia gravis worse in the day?
At the end of the day (worse with exertion - as more Ab binding)
Where do symptoms of myasthenia gravis usually begin?
Head and neck –> lower body
What are some signs/ symtpoms of myasthenia gravis (4)?
- Diplopia (due to eye muscle weakness)
- Ptosis
- Swallowing + speech difficulties
- Lopsided smile
How is myasthenia gravis diagnosed (2)?
- Serology (Ab presence detected)
- Edrophonium (tensilon) test
What is the edrophonium (tensilon) test - how does it work?
Edrophonium administered –> inhibits breakdown Ach-ase –> more Ach available –> weakness relieved
How is myasthenia gravis treated (2)?
- Ach-ase inhibitors (neostigmine)
- Immunosurpression (steroids)
What is an example of an ACH-ase inhibitor?
Neostigmine
pyridostigmine
What is a complication of myasthenia gravis?
Myasthenia crisis - muscle weakness –> resp failure
How is myasthenic crisis treated (2)?
- Plasma exchange
- IV Ig
both remove harmful Abs from circulation
What is a differential diagnosis of myasthenia gravis?
Lambert eaton syndrome
What are the differences between Lambert eaton syndrome and myasthenia gravis (3)?
Lambert eaton …
* Pre-synaptic Ca++ channel autoimmune pathology
* Improves with exertion
* Start at extremities
What is the treatment for Lambert eaton syndrome?
Similar treatment (steroids + immunosuppression)
What is Guillain barre syndrome?
Destruction of Schwann cells in PNS (basically MS in PNS)
What pathogens commonly cause GBS?
- Campylobacter jejuni (MOST common)
- CMV
- EBV
How does infection cause GBS?
Molecular mimicry (organism and schwann cell antigens similar)
What is the presentation of GBS (2)?
- Ascending symmetrical muscle weakness
- Reduced reflexes
What is a dangerous complication of GBS?
Respiratory failure
How is GBS investigated?
- Nerve conduction studies - reduced impulses
- CSF analysis
What is found in CSF analysis in GBS (2)?
- High protein levels (=inflammation)
- No WBC
How is GBS managed (3)?
- IV Ig (target schwann cell Abs)
- Plasma exchange
- Intubation if difficulty breathing
What is wernickes encephalopathy?
Lesions in the CNS caused by vitamin B1 (thiamine) deficiency
What causes wernickes encephalopathy?
High alcohol consumption
What are 3 classical symtpoms of wernickes encephalopathy?
- Ataxia
- Confusion
- Opthalmoplegia (lesions in eye movement nerves)
How is wernickes encephalopathy diagnosed (2)?
- Clinically
- Supported by microcytic anaemia + deranged LFTs
How is wernickes encephalopathy treated?
Pabrinex (vit B1 + others)
What is a complication of wernickes encephalopathy?
Korsakoff syndrome (irreversible damage - memory disorder)
How is duchennes muscular dystrophy inherited?
X-linked recessive
Pystrophin gene
What is the pathophysiology of DMD?
Muscle replaced with adipose tissue
Who is affected by DMD?
Almost exclusively boys
What are 2 symptoms of DMD?
- Difficulty getting up
- Skeletal deformities
How is DMD diagnosed?
Genetic testing (often prenatally)
What is charcot marie tooth syndrome?
Inherited autosomal dominant that causes sensory + motor polyneuropathy
What gene is affected by Charcot marie tooth syndrome?
Duplicated PUP 22 gene (chromosome 17)
What are the symptoms of Charcot Marie tooth syndrome (3)?
- Foot drop + weaknesses
- Thin calves
- Hammer toe!!!
How is charcot marie tooth diagnosed?
- Genetic testing
- Nerve biopsy
What sort of bacteria is clostridium tetani?
Gram +ve bacilli
How can you get tetanus?
Dirty soil + rusty metal
How does tetanus cause tetany?
Tetanospasmin toxin produced –> travels retrogradely up axons –> muscle spasms
How is tetanus prevented?
Vaccine !!!
What virus causes chicken pox?
Varicella zoster virus
What causes shingles?
Reactivation of varicella zoster virus (usually in adulthood)
What causes sensory defects in shingles?
Dorsal root of peripheral nerves attacked
What are the main symptoms of shingles?
- Painful erythromatous blistering rash (confined to dermatome)
- Tingling + pain in area of rash
How can shingles/ chicken pox be treated?
Aciclovir
What causes creutzfeldt Jakob disease?
Prions (misfiled proteins)
