Neurology Flashcards
What are the meninges layers?
- Extra -dural space = minimal/narrow, associated meningeal vessels
- Dura mater = outermost, tough, fibrous, forms folds, encloses dural venous sinuses
- Sub-dural space = narrow, contains bridging veins
- Arachnoid mater = soft, thin, loose
- Subarachnoid space = contains CSF + cerebral vessels
- Pia mater = innermost, adhered to the surface of the brain and contributes to BBB
Recap - Outline the main roles of the
a) Frontal lobe
b) Temporal Lobe
c) Parietal Lobe
d) occipital lobe
Frontal - decision making, movement, executive function, personality.
Temporal - hearing (primary auditory cortex), memory and language, smell, facial recognition
Parietal - Sensory info
Occipital lobe - Vision
Recap - What are the main responsibilities for the
a) Brainstem
b) Cerebellum
brainstem - controls Heart and breathing rate, Blood pressure and GI function, as well as consciousness
Cerebellum - Muscle coordination, and balance
Recap - what are the two arteries that supply the brain?
Internal carotid
Vertebral arteries
What does the internal carotid artery branch off to supply?
branches off to create the Anterior cerebral artery, as well as posterior communicating artery to join the circle of Willis
After this the ICA continues on as the Middle cerebral artery, which supplies the lateral portions of the cerebrum.
After entering the cranium through the foramen magnum, what branches does the vertebral artery give off? What do the 2 vertebral arteries then go on to do?
Give off Spinal arteries, supply the entire length of spine
Gives off The Posterior Inferior cerebellar artery - supplies cerebellum
also gives off a menigeal branch
But after this two vertebral arteries converge to form the basilar artery
What arteries branch off the basilar artery?
Superior cerebellar artery (SCA)
Anterior inferior cerebellar artery (AICA) - Both to supply the cerebellum
The Pontine arteries
What are the layers of the cerebellum?
- moleucular layer
- purkinje cell layer (most important as only ouput)
- granule cell layer
- white matter
What does the posterior cerebral artery go on to supply? What is it a branch of?
Supplies occipital lobe, posteromedial temporal lobes, midbrain, thalamus,
It is the terminal branch of the basilar arteries,
What does the anterior cerebral artery supply?
ANTERIOR CEREBRAL ARTERY (supplies and runs over Corpus Callosum and supplies Medial aspects of Hemispheres (anteromedial aspects of the cerebrum)
What is the cause of an extra-dural haemorrhage?
Traumatic – typically caused by bleeding from the meningeal arteries as a result of skull fracture that tears the dura
Middle meningeal runs close to the pterion
What is the weakest part of the skull?
Pterion point
What is the clinical presentation of extra-dural haemorrhage?
Patient may have extensive traumatic injuries
In other cases, patient sustains a head injury but appears to be OK for a while (‘lucid period’)
Bleeding into the extradural space > rapid rise in intracranial pressure (ICP) > brain is compressed
Headache, drowsiness, rapid neurological deterioration
Death if not treated rapidly (neurosurgical emergency
What is the imaging look like for an Extra-dural haemorrhage?
Acute (fresh) bleed appears hyperdense on CT (bright white)
Convex; does not conform to surface of the brain as bleeding is limited by dural attachments to the skull (lemon shape)
Compression of the brain – midline shift (falx cerebri, lateral ventricles)
Skull fracture may be seen
What is the cause of a sub-dural haemorrhage?
Usually caused by trauma – typically a fall leading to bleeding from dural bridging veins
Low pressure bleeding
Gradual rise in ICP (over several weeks or months)
Most likely in patients with brain atrophy (elderly, dementia, history of excess alcohol intake) – bridging veins
WHat is the clincal presentation for sub dural haemorrhage?
Typical picture is of gradual cognitive deterioration
May be a history of a fall, maybe not
Patient may have old bruising on their head (or elsewhere) suggesting frequent / recent falls
What is the appearance of imaging for sub dural?
(banana shape)
Chronic (old) bleed appears hypodense on CT (dark)
Concave; conforms to surface of the brain as bleeding is not limited by dural attachments
Compression of the brain – signs include midline shift (falx cerebri, lateral ventricles)
What are the investigations for a SDH?
Immediate CT head
WHat is the cause of a sub-arachnoid haemorrhage?
Usually spontaneous from rupture of an aneurysm on a cerebral artery
Can be traumatic, but this is less common
What is the management for a SDH?
Drainage:
- small SDH are drained via a burr hole washout a small tube called
- large SDH requires a craniotomy which is when part of the skull bone is removed
What are the complications a the raised intercranial pressure in a SDH?
Supratentorial herniation: cerebrum is pushed against the skull or the tentorium, can compress the arteries that nourish the brain leading to an ischaemic stroke
Infratentorial herniation: cerebellum is pushed against the brainstem, can compress the vital area in the brainstem that control consciousness, respiration, and heart rate
WHat is the clinical presentation for subarachnoid?
Typically present with sudden onset severe ‘worst-ever headache’ (‘thunderclap’)
Patient may:
be conscious
have reduced GCS
be unconscious (poorer prognosis)
Can be rapidly fatal
What is the appearacne of a sub-arachnoid bleed?
Acute (fresh) bleed is hyperdense on CT (bright white)
Blood seen in fissures and cisterns +/- ventricles
(not a large mass like SD and ED)
Blood in the SA space:
irritates the meninges
irritates cerebral vessels and causes vasospasm > hypoxic injury
may track back into the ventricular system > hydrocephalus
(looks like spider)
What is the cause of an intra-cerebral haemorrhage?
- Spontaneous due to aneurysm or vessel rupture
- Small perforating vessels prone to rupture, especially if hypertensive
- Clinical presentation determined by the size of the bleed and brain region affected
E.g.
Coma
Weakness (facial, limbs)
Seizure
What is the appearance of a intra-cerebral bleed on imaging?
Acute (fresh) bleed is hyperdense on CT (bright white)
Blood seen in the substance of the brain
Mass effect seen if large (e.g. midline shift)
What is an epidural haemorrhage?
Bleeding above the dura matter
(same as extra dural haemorrhage)
Who is an EDH most common in?
They usually occur in young adults
What are the symptoms of a EDH?
Reduced GCS: loss of consciousness after the trauma due to concussion
- There might be a lucid interval after initial trauma if there is a slower bleed. This is followed by rapid decline.
Headaches
Vomiting
Confusion
Seizures
Pupil dilation if bleeding continues
What are the differentials for a EDH?
Epilepsy
Carotid dissection
Carbon monoxide poisoning
Subdural haematoma
Subarachnoid haemorrhage
What is the management for a EDH
Clot evacuation
Craniotomy: part of the skull bone is removed in order to remove accumulated blood below.
Followed by ligation of the vessel.
Which part of the brain do the middle, anterior and posterior arteries supply?
Anterior = front and midline
Middle = lateral lobes
Posterior = posterior part of brain
What is Broca’s and Wernicke’s area?
Broca - motor control of speech
Wernicke - understanding of speech
What artery and location of the primary motor cortex control upper and lower limb?
Lower limb - represented the medial surface of the cerebral hemisphere = anterior cerebral artery territory
Upper limb and face represented on the lateral surface = middle cerebral artery territory
What is the difference between CNS and PNS?
CNS = brain and spinal cord
PNS = cranial nerves, spinal nerves, ganglia
Where are motor neurones located in the spinal cord?
Ventral horn = motor neurones
Where are sensory neurones located in the spinal cord?
Dorsal root ganglion
What nerve fibres are carried in the spinal cord?
Sympathetic - smooth muscle, sweat glands
Somatic motor
Somatic sensory
What are the main ascending sensory tracts?
Dorsal columns
Spinothalamic tract
What is the main descending motor tract?
Lateral corticospinal tract
What is the route of the lateral corticospinal tracts? And consequence of lesion?
Descending motor control
decussate in the medulla
enter the contralateral lateral CST
UMN synapses with LMN in the ventral grey hron
axon leaves in the spinal nerve
lesions in cord = ipsilateral weakness
What sensations does the dorsal column pathway control?
Touch, proprioception, vibration
Cuneate fasciculus – info from the UL
Gracile fasciculus – info from the LL
What sensations does the spinoithalamic tract control?
pain and temperature
- ventrolateral
What is the route of the dorsal column pathway? And consequence of lesion?
1.Sensory primary axons ascend in the ipsilateral dorsal columns (cuneate or gracile fasciculus
2. Synapse with 2nd neuron in the cuneate (UL) or gracile (LL) nucleus
3. Axons decussate in the medulla then ascend
4. Synapse with 3rd neuron in thalamus
5. Axons project to the somatosensory cortex
Lesions in the cord: ipsilateral loss of / impaired fine touch and proprioception
What is the route of the spinothalamic tract? And consequence of lesion?
(travel up on opposite side)
Sensory primary axon synapses with 2nd neuron in the grey horn
Axons decussate then ascend
Synapse with 3rd neuron in thalamus
Axons project to the somatosensory cortex
Lesions in the cord: contralateral loss of / impaired pain and temp sensation
What is the difference between a dermatome and myotome?
Dermatome = area of skin supplied by a single spinal nerve
Myotome = muscles supplied by a single spinal nerve
What is the function of cranial nerve 1?
Olfactory
- sense of smell
- receptor in nasal cavity
- travel from cribriform plate > olfactory bulb > tracts > temporal lobe
What is the function of cranial nerve 2?
optic nerve
- Fibres travel from the retina to the primary visual cortex (calcarine sulcus, medial aspect of occipital lobe)
What is the function of cranial nerve 3?
Oculomotor nerve
- innervates eye muscles except from superior oblique + lateral rectus
- parasympathetic fibres = constrict the pupil
What is the function of the 4th nerve?
Trochlear
- Superior oblique muscle
(test by looking medially and down)
What is the function of 6th cranial nerve?
Abducens
Lateral rectus = abducts the eye
What is the function of 5th cranial nerve?
Trigeminal
Sensory and motor; 3 divisions:
Ophthalmic V1 > sensory
Maxillary V2 > sensory
Mandibular V3 > sensory plus motor to the muscles of mastication
What is the function of 7th cranial nerve?
Facial
Taste anterior 2/3 tongue
Muscles of facial expression:
Muscles of the upper face bilaterally innervated by the motor cortex
Muscles of lower face contralaterally innervated by the motor cortex
Parasympathetics to the lacrimal, submandibular and sublingual salivary glands
(stimulates secretion)
What is the function of the 8th cranial nerve?
Vestibulocochlear
- hearing + balance
WHat is the function of the 9th cranial nerve?
Glossopharyngeal
Taste posterior 1/3 of the tongue
General sensation: (touch, temp, pain)
Pharynx, posterior 1/3 of the tongue
Parasympathetics to parotid gland
What is the function of the 10th cranial nerve?
Vagus
General sensation - pharynx, larynx, oesophagus.
Motor - muscles of the soft palate, pharynx and larynx – vital for swallowing and speech
Parasympathetics: thoracic and abdominal viscera
What is the function of the 11th cranial nerve?
Accessory
Motor to sternocleidomastoid and trapezius
What is the function of cranial nerve 12?
Hypoglossal
Motor to the tongue muscles.
- Nerve lesion > ipsilateral tongue muscles are paralysed
(left deviation = left hypoglossal lesion)
What is Amaurosis Fugax?
A classical syndrome of painless short-lived monocular blindness.
It is a term usually reserved for transient visual loss of ischaemic origin.
What is the aetiology of Amaurosis Fugax?
- temporary reduction in the retinal, ophthalmic or ciliary blood flow leading to temporary retinal hypoxia
- transient obstruction from emboli of ophthalmic artery
- can occur in TIA
(other causes are giant cell arteritis and central retinal artery occlusion)
What is an ischaemic stroke?
An episode of neurological dysfunction caused by focal cerebral, spinal, or retinal infarction
(cell death due to lack of blood supply)
What is a stroke due to intracerebral haemorrhage?
Rapidly developing clinical signs of neurological dysfunction attributable to a focal collection of blood within the brain parenchyma or ventricular system not caused by trauma.
What is a stroke due to subarachnoid haemorrhage?
Rapidly developing signs of neurological dysfunction and/or headache because of bleeding into the subarachnoid space
(the space between the arachnoid membraneand the pia mater of the brain or spinal cord),
which is not caused by trauma.
What symptoms does a stroke in the dominant hemisphere cause?
(usually left hemisphere - right handed)
Language dysfunction
Expressive dysphasia
Receptive dysphasia
Dyslexia
Dysgraphia
What symptoms does a stroke in a non-dominant hemisphere cause?
Non-dominant hemisphere
(usually RIGHT hemisphere)
Anosognosia
- Neglect of paralysed limb (unaware of side of body)
- Denial of weakness
Visuospatial dysfunction
- Geographical agnosia
- Dressing apraxia
- Constructional apraxia
What are the symptoms of a anterior cerebral artery stroke?
Contralateral hemiparesis and sensory loss with upper limbs > lower limbs
Homonymous hemianopia
Aphasia: if the affecting dominant hemisphere 95% of right handed people this is the left side
Hemineglect syndrome if affecting the non-dominant hemisphere patients won’t be aware of one side
What are the symptoms of posterior cerebral artery strokes?
Contralateral homonymous hemianopia with macular sparing
contralateral loss of pain and temp due to spinothalamic damage
Unsteadiness
Visual disturbance
Slurred speech
Headache (MC in posterior)
Vomiting
Others e.g. memory loss, confusion
What are the symptoms of a vertebrobasilar artery stroke?
Cerebellar signs
Reduced consciousness
Quadriplegia (affects all 4 limbs + torso) or hemiplegia (one side of body)
What is Weber’s syndrome and what are the symptoms of it?
It is a midbrain infarct that leads to oculomotor palsy and contralateral hemiplegia (lack of control in one side of body)
What are the symptoms of lateral medullary syndrome (posterior inferior cerebellar artery occlusion)
ischaemia in lateral part of medulla oblongata
Ipsilateral facial loss of pain and temperature
Horner’s syndrome: miosis (constriction of the pupil), ptosis (drooping of the upper eyelid), and anhidrosis (absence of sweating of the face)
Ipsilateral cerebellar signs
Contralateral loss of pain and temperature
What is used to classify strokes and how does it do it?
The Bamford classification and it categorises strokes based on the area of circulation affected
What is used to identify strokes in the community?
F- Face
A- Arm
S- Speech
T- Time (this is a stupid one because it is not a symptom just there to make the word fast)
What is used to identify strokes in hospital?
Recognition of Stroke in the Emergency Room (ROSIER) scale.
What are the criteria for the ROSIER scale?
Loss of consciousness
Seizure activity
New, acute onset of:
- Asymmetric facial/arm/leg weakness
- Speech disturbance
- Visual filed defect
When would a stroke be possible using the ROSIER scale and what would happen as result?
A stroke is possible if they have any of the criteria and hypoglycaemia has been excluded
WOULD REQUIRE URGENT NON-CONTRAST CT
- Aspirin 300mg stat (after the CT)
What are key features of stroke symptoms?
Onset = abrupt (secs)
Nature of symptoms = Focal (localised to an area of the brain)
Quality = negative
Maximal deficit = at the start (symptoms are worse)
What are differential diagnosis for stroke?
Epileptic seizure = history + symptoms (unconscious)
Space occupying lesion (e.g. subdural, tumour, arteriovenous malformation) = gradual onset, headache, confusion, drowsiness, deterioration
Infection (MC in elderly - can unmask deficit from previous stroke) = gradual onset, fever
Metabolic (e.g. hyponatraemia, hypoglycaemia, hypercalcaemia, uraemia) = confusion, reduced consciousness, ataxia
Multiple sclerosis = young, sub acute progression
Functional neurological disorder (FND) = inconsistencies, ‘give way’ weakness
Migraine = history, previous attacks
Hepatic encephalopathy
What investigations are done for a stroke?
1st line: CT head (rule out anything serious like a tumour or bleed - often normal after a stroke)
GOLD: MRI brain with diffusion weighted imaging (can see ischaemia when a CT can’t)
- Blood tests (metabolites, electrolytes)
- ECG +- 72 hour tape
- carotid doppler
- ECHO
- CT or MR angiogram
What are the 4 categories for ischaemic stroke?
- large vessel disease (50%)
- small vessel disease
- cardioembolic
- cryptogenic/ rarities
What are the 2 categories of haemorrhagic stroke?
- primary intracerebral haemorrhage
- subarachnoid haemorrhage
What causes ischaemic stroke in large vessel iscahemia?
- atherosclerosis
- blood vessel occlusion, thrombus
- embolism
What causes small vessel ischaemic stroke?
- small deep perforator arteries blocked
- caused by high blood pressure, diabetes, smoking, age
- in situ microatheroma or lipohyalinosis
What are the causes of cardioembolic stroke?
Cardiogenic embolus:
Mural thrombus
Atrial fibrillation
Endocarditis (vegetation can embolise)
Atrial septal defect (
What is the most common cause of stroke in young people?
Dissection (carotid or vertebral)
Risk factors:
- trauma or cervical manipulation
- vigorous physical activity (eg weightlifting)
- vasculopathy (fibromuscular dysplasia, Marfan’s)
- sympathomimetic drug abuse
(can also be spontaneous)
What is a primary intracerebral haemorrhage stroke and its causes?
leakage of blood directly into brain tissues due to
- hypetension
- amyloidosis
- arteriovenous malformation
- aneurysm rupture
What is a secondary intracerebral haemorrhage?
NOT classed as a stroke
- due to trauma, warfarin or bleeding into a tumour
- but can cause similar symptoms as primary
What are the risk factors for developing an intracerebral stroke?
Head injury
Hypertension
Aneurysm
Brain tumour
Anticoagulant
What are the presentations of an intracerebral haemorrhage?
Sudden headache is a key feature
Weakness
Seizure
Vomiting
Reduced consciousness
What does a ‘thunder clap headache signify?
Subarachnoid haemorrhage
What are the investigations for a intracerebral haemorrhage?
CT/MRI to confirm size and location of the haemorrhage
Check FBC and clotting
Angiography to visualise the exact location of the haemorrhage
What is the management for a intracerebral haemorrhage?
Consider ICU and intubation and ventilation if there is reduced consciousness
Correct any clotting abnormalities
Correct severe hypertension but avoid hypotension
Drugs to relieve intercranial pressure mannitol
What are the surgeries that can be performed for an intracerebral haemorrhage?
Craniotomy = part of the skull bone is removed to drain any blood and relieve pressure
Stereotactic aspiration = aspirate off blood and relieve intracranial pressure guided by a CT scanner. Good for bleeding that is located deeper in the brain
What is the treatment for a ischaemic stroke?
Antiplatelets: aspirin given as soon as possible once haemorrhagic stroke is excluded
Thrombolysis: alteplase (tissue plasminogen activator)- given if to re-establish blood flow is <4.5 hours of symptom onset
Thrombectomy must score > 5 on NIH Stroke Scale/Score (NIHSS) and pre-stroke functional status < 3 on the modified Rankin scale
What should be performed before thrombectomy?
CT angiogram (CTA): identifies arterial occlusion
What are secondary stroke preventions?
- Antiplatelets agents = Clopidogrel (Warfarin/DOAC superior to aspirin in AF/mural thrombus)
- statins = stabilis atherosclerotic plaque
- long term BP lowering
- carotid intervention (remove blockage to prevent it happening again)
What can cause Subarachnoid Haemorrhage?
Trauma is a key factor
Atraumatic cases are referred to as spontaneous SAH
What is the most common cause of a spontaneous SAH?
Berry aneurysm- they account for 80% of cases.
Arise at points of bifurcation within the circle of Willis; the junction between the anterior communicating and anterior cerebral artery
They are associated with PKD, coarctation of the aorta, and connective tissue disorders (Marfan)
What are the risk factors for having a SAH?
Cocaine use
Sickle cell anaemia
Connective tissue disorders
Neurofibromatosis: tumours form on your nerve tissues
PKD
Alcohol excess
What can occur as a result of a subarachnoid haemorrhage?
Blood vessels that are bathing in a pool of blood can start to intermittently vasoconstrict (vasospasm).
If this occurs in the circle of Willis it will reduce the supply of blood flow to the brain causing further injury
Over time blood in the subarachnoid space can irritate the meninges and cause inflammation which leads to scarring of the surrounding tissue.
The scar tissue can obstruct the normal outflow of CSF causing fluid to build up leading to hydrocephalous
What are the signs of a SAH?
3rd nerve palsy- if the aneurysm occurs in posterior communicating artery
6th nerve palsy a non-specific sign which indicates raised intercranial pressure
Reduced GCS
What are the symptoms of a SAH?
Thunderclap headache during strenuous activity or sex. It’s like being hit really hard on the back of the head
Neck stiffness
photophobia
Vison changes
What are the initial investigations for SAH?
FBC
Serum glucose
Clotting screening
Urgent non-contrast CT of the head.
- Blood will cause ** hyperattenuation (this means becoming more dense on CT will show as white)** in the subarachnoid space
What tests would you perform if CT is negative but a SAH is still suspeccted?
Lumbar puncture: will show RBCs or xanthochromia (yellow pigmentation due to degradation of haemoglobin to bilirubin - so need to wait till 12 hours after SAH)
What is the management to prevent vasospasm?
Nimodipine is a CCB and prevents vasospasms
What is the management to stop the bleeding?
First line: Endovascular coiling of the aneurysm
Second line: surgical clipping via craniotomy
What are the complications of a SAH?
Rebleeding 22% risk at one month
Vasospasm: accounts for 23% of deaths; at highest risk for the first 2-3 weeks after SAH; treated with (induced) hypertension,hypervolemia andhaemodilution (triple-H therapy).
Hydrocephalus: acutely managed with external ventricular drain (CSF drainage into an external bag) or a long-term ventriculoperitoneal shunt, if required
Seizures: seizure-prophylaxis is often administered (e.g. Keppra)
Hyponatraemia: commonly due to syndrome of inappropriate antidiuretic hormone secretion (SIADH)
What is the treatment for a haemorrhagic stroke?
- Admit to neurocritical care: patients will need intensive monitoring
- If features of raised intracranial pressure:
consider intubation
with hyperventilation,
head elevation (30°)
and IV mannitol (reduce ICP) - Surgical intervention:decompression may be needed
What are the risk factors for developing a stroke
Hypertension
Smoking
AF
Vasculitis
Medication e.g. hormone replacement therapy
If the anterior cerebral artery is affected in a stroke where in the body will be affected?
Feet and legs
If the middle cerebral artery is affected in a stroke where in the body will be affected?
Hands and arms
Face
Language centres in the dominant hemisphere
If the posterior cerebral artery is affected in a stroke where in the body will be affected?
The visual cortex will be affected meaning the patient won’t be able to see properly
What is a TIA?
A transient episode of neurological dysfunction caused by focal brain, spinal cord or retinal ischaemia without acute infarction.
It usually resolves within 24 hours
What is the management for a TIA?
First line is antiplatelet initially with aspirin 300mg
Carotid endarterectomy: surgery to remove blockage of >70% on doppler
Manage cardiovascular risk with atorvastatin etc
What is a crescendo TIA?
Where there are two or more TIAs within a week. It carries a high risk of a stroke
How many people who have a TIA will go on to have a stroke
10% within 3 months
What are the two categories a haemorrhagic stroke can be split in to?
Intracerebral where the bleeding occurs within the cerebrum
Subarachnoid when bleeding occurs between the pia and arachnoid matter
What is meningitis?
Meningitis refers to inflammation of the pia and arachnoid mater. Micro-organisms infect the cerebrospinal fluid (CSF).
What are the 3 main features of ‘meningism’?
Stiffness of the neck
Photophobia
Severe headache
What other symptoms would present with bacterial or viral meningitis?
Fever
Feel unwell
Rash (characteristically haemorrhagic in meningococcal meningitis)
What are the viral causes of meningitis?
80% viral
- Enteroviruses (including Echo virus, Coxsackie virus)
- Herpes simplex virus
- Mumps virus
- varicella zoster virus
- Lymphocytic chorio meningitis virus
And historically, Poliovirus (also an enterovirus)
What are the main bacterial causes of meningitis for each age group?
Neonates = E.coli, Group B strep, Listeria monocytogenes
Infants = N.meningitis + H.influenza, Strep pneumoniae
Adults = N.meningitis + S.pneumoniae
Elderly = S. pneumoniae + N.meningitis + listeris monocytogenes
What are the causes of fungal meningitis?
Cryptococcus neoformans
Candida
What are some risk factors for developing meningitis?
Immunocompromised: such as being in the extremes of age, infection (HIV), and medication (Chemotherapy) Listeria monocytogenes
M. Tuberculosis
Non-immunised: at risk ofH. influenza, pneumococcal and meningococcal meningitis
Crowded environments: students living in halls of residence are a commonly affected demographic
What is encephalitis?
Refers to inflammation of the cerebral cortex
What are the main clinical symptoms of encephalitis?
Lethargy + fatigue
Decreased level of consciousness
Fever
Focal neurology
Occasionally there may be fits
What are the viral causes of encephalitis?
Herpes simplex virus
Varicella zoster virus
Parvoviruses
HIV
Mumps virus
Measles virus
Where are the signs of encephalitis?
Pyrexia (fever)
Reduced GCS
Aphasia
Hemiparesis
Cerebellar signs
–
What are some behavioural changes that occur in encephalitis?
Memory disturbance
Psychotic behaviour
Withdrawal or change in personality
What are some investigations for encephalitis?
Throat swab
HIV serology
MRI of head will show evidence of inflammation will be normal in 1/3 of cases
Lumbar puncture and CSF investigation including a PCR for HSV
What are some differentials for encephalitis?
Meningitis
Encephalopathy
Status epilepticus
CNS vasculitis
What is the treatment for encephalitis?
Aciclovir = should be given in all cases where it is suspected
Ganciclovirmay = be preferred in other herpesvirus infections, such as HHV-6
What lab investigations are done for enterovirus?
Nose + throat swabs
- plated out onto blood and chocolate agar
PCR
Stool
What lab investigations are done for S.pneumoniae and N.meningitidis?
Blood cultures
PCR
What CSF cell count results would signify a bacterial cause of infection?
- a neutrophil predominant leucocytosis
- a raised protein (from dying bacteria)
- reduced CSF glucose to serum glucose ratio (metabolically active bacteria, use up glucose as a source of energy)
What are the two tests to look for meningeal infection?
Kernigs Test
Brudzinski’s Test
What is Kernigs Test?
Involves patient lying on their back and flexing one hip and knee to 90 degrees and then slowly straightening the knee whilst keeping the hip flexed. This causes the meninges to stretch
A positive test will be where there is spinal pain or resistance to the movement
What is Brudzinski’s Test?
Involves lying a patient on their back and gently using your hands to lift their head and neck off the bed and flexing their chin to their chest
A positive test is when a patient involuntarily flexes their hips and knees
What is another classic sign of meningococcus meningitis?
non-blanching rash
- that everybody worries about as it indicates the infection has caused disseminated intravascular coagulopathy (DIC) and subcutaneous haemorrhages.
Other causes of bacterial meningitis do not cause this rash
What is the empirical antibiotic therapy used against bacterial causes of CNS infection in hospital?
IV cefotaxime or ceftriaxone
What medication should be prescribed alongside antibiotics for meningitis treatment?
IV dexamethasone (corticosteroids)
- reduce risk of long term neurological complications from some causes of meningitis
what medication should be given in primary care for meningitis?
IM benzylpenicillin
then admit the patient ASAP!!
What is the management for meningitis?
- Assess GCS
- blood culture
- broad spectrum antibiotics = Ceftriaxone or cefotaxime
- Steroids = IV dexamethasone
- lumbar puncture = definitive diagnosis
What are the contraindications for a lumbar puncture?
Abnormal clotting (platelets/coagulation)
Petechial rash
Raised intracranial pressure
GCS <9
Where is a lumbar puncture usually taken from?
Between L3/L4
Since spinal cord ends L1/2
When would you do a CT head before a lumbar puncture in meningitis?
Aged > 60
Immunocompromised
History of CNS disease
Seizures <1 week
GCS <14
Focal neurological signs
Papilloedema
Atypical history
What are close contacts of patients with meningitis offered?
Notified
Antibiotic prophylaxis = single dose of ciprofloxacin
What is the CSF count and culture characteristic for a viral meningitis infection?
Predominant lymphocyte response
Only moderately raised protein
CSF glucose more than 50% of the level of serum glucose
What antimicrobial agent is used to treat a viral meningitis or encephalitis infection?
IV aciclovir
How does an infection get into the brain?
- extra-cranial infection e.g. nasopharynx, ear, sinuses
- neurosurgical complications e.g. post op, infected shunts, trauma
- via blood stream e.g. bacteraemic
What is the pathophysiology of meningitis?
- bacteria in blood
- bacteria enter CSF and can be isolated from immune cells due to BBB
- replication
- blood vessels become leaky
- so WBCs can enter the CSF, meninges and brain
- meningeal inflammation +/- brain swelling
What types of meningitis are acute and which are more commonly chronic?
Bacterial and viral meningitis are usually acute
Fungal is more chronic
What will a lumbar puncture show for bacterial meningitis?
high pressure
cloudy
high WBCs
neutrophils
low glucose
high protein
What will a lumbar puncture show for viral meningitis?
normal or elevated pressure
clear
increased lymphocytes
high glucose
low protein
what will a lumbar puncture results show for fungal/TB meningitis?
elevated pressure
cloudy/fibrin web
Increased lymphocytes
low glucose
high protein
What are the common metastases for secondary brain tumours?
Lung
breast
melanoma
renal cell
GI
What are the symptoms of secondary brain tumours?
- Headache: worse in morning, when coughing or bending
- Focal neurological signs
- Ataxia
- Fits
- Nausea
- Vomiting
- Papilloedema (on fundoscopy)
What are the investigations for brain tumours?
CT/MRI
What is the management for brain tumours?
- steroids = dexamethasone (reduce cerebral oedema)
- Stereotactic radiotherapy/chemotherapy
- surgery if <75 years
- palliative care
What are mononeuropathies?
Lesions of individual peripheral or cranial nerves
- causes are usually local e.g. trauma or entrapment (tumour)
What are the features of a median nerve lesion in the wrist and anterior interosseous?
C6-T1 = nerve of precision grip + LOAF
Wrist = carpal tunnel syndrome, weakness of abductor pollicis brevis; sensory loss over the radial 3 1/2 fingers and palm
Anterior interosseous nerve lesions = weakness of flexion of the distal phalanx of the thumb and index finger
Proximal lesions = may show combined effects
What is the presentation of an ulnar nerve palsy/lesion?
C7-T1
Claw hand
(4th + 5th fingers ‘claw’ up)
- sensory loss over medial 1 1/2 fingers and ulnar side of the hand
- wasting of hypothenar eminence
What is the treatment for a ulnar nerve palsy?
Splint for elbow
simple analgesia
rest + avoid pressure on nerve
What is the presentation of a radial nerve palsy?
C5-T1
Wrist drop
Muscles involved = BEAST
Brachioradialis
Extensors
Abductor pollicis longus
Supinator
Triceps
What is the treatment for a radial nerve palsy?
Splint and simple analgesia
What are the causes of brachial plexus lesion?
- Trauma
- Radiotherapy
- Prolonged wearing of heavy rucksack
- Cervical rib
- Thoracic outlet compression
- Neuralgic amyotrophy
What are the signs of a brachial plexus lesion?
Pain/ paraesthesia and weakness in the affected arm in a variable distribution
What are the causes of a phrenic nerve lesion?
C3,4,5 keeps the diaphragm alive
- Lung cancer
- TB
- Paraneoplastic syndrome
- Myeloma
- Thymoma
- Cervical spondylosis/ trauma
- Thoracic surgery
- Infections e.g. HZV, HIV, Lyme disease
- Muscular dystrophy
What are the signs of a phrenic nerve lesion?
- Orthopnoea
- Raised hemi-diaphragm on chest x-ray
What nerve causes a ‘foot drop’?
Common peroneal nerve L4-S1
What are the effects of a tibeal nerve lesion?
L4-S3
- inability to stand on tiptoes, invert foot and flex the toes
- sensory loss over the sole
What is mononeuritis mulitplex? And causes?
- Involvement of two or more peripheral nerves
- Causes tend to be systemic: diabetes mellitus, connective tissue disorders, vasculitis, sarcoidosis, amyloidosis, leprosy
- Electromyography helps define the anatomic site of lesion
What are the signs of cranial nerve 1 lesion?
- Reduced taste and smell
- Ammonia taste remains as it stimulates the pain fibres carried in the trigeminal nerve
What are the causes of a cranial nerve lesion?
- Trauma
- Frontal lobe tumour
- Meningitis
- fracture
- Raised ICP
- Diabetes
- hypertension
What are the signs of cranial nerve 2 lesion?
- Visual field defects:
- Start as small areas of visual loss (scotomas).
- Monocular severe sight impairment: lesions of one eye or optic nerve
- Bilateral severe sight impairment
- Bitemporal hemianopia
- Homonymous hemianopia: loss of the same half (left or right) of the visual field of both eyes, on the opposite side to the lesion (eg, a right side lesion causes loss of the left side of the visual field of both eyes).
- Pupillary abnormalities
- Optic neuritis
- Pain on moving the eye
- Loss of central vision
- Afferent pupillary defect
- Papilloedema
- Optic atrophy
- Pale optic discs
- Reduced acuity
What are the signs of cranial nerve 3 lesion?
- Fixed dilated pupil which doesn’t accommodate
- Ptosis
- Complete internal ophthalmoplegia
- Unopposed lateral rectus causes outward deviation of the eye
- If the ocular sympathetic fibres are also affected behind the orbit, the pupil will be fixed but not dilated.
What are the signs of cranial nerve 4 lesion?
- Diplopia due to weakness of downward and inward eye movement (pure vertical diplopia)
- Compensation by tilting the head away from the affected side
What are the signs of cranial nerve 5 lesion?
- Reduced sensation or dysasthesia over the affected area
- Weakness of jaw clenching and side-to-side movement.
- If LMN lesion, the jaw deviates to the weak side when the mouth is opened
- May be fasciculation of temporalis and masseter
What are the causes of sensory CN5 lesions?
Trigeminal neuralgia
HSV
Nasopharyngeal carcinoma
What are the signs of cranial nerve 6 lesion?
- Inability to look laterally
- Eye is deviated medially because of unopposed action of the medial rectus muscle
What are the signs of cranial nerve 7 lesion?
- Facial weakness
- LMN lesion:
- Forehead is paralysed - the final common pathway to the muscles is destroyed
- UMN lesion:
- Upper facial muscles are partially spared because of alternative pathways in the brainstem
What is Bell’s palsy/
Neurological condition that presents with rapid onset of unilateral facial paralysis
Why is the top half of the face sometimes spared in Bell’s palsy?
The lower half of the faces only has contralateral innervation
Top half has bilateral. forehead sparing
How can you tell between an UMN and LMN Bell’s palsy?
UMN injured: means the contralateral side is weak but the forehead is not
LMN - weakness of all the muscles on the ipsilateral side of the face
What are the signs of cranial nerve 8 lesion?
- Unilateral sensorineural deafness
- Tinnitus
- Slow-growing lesions seldom present with vestibular symptoms as compensation has time to occur
What are the signs of cranial nerve 9 lesion?
- Unilateral lesions do not cause any deficit because of bilateral corticobulbar connections (wasting and deviation of tongue)
- Bilateral lesions result in pseudobulbar palsy
What are the causes of a CN9/CN10 lesion?
Jugular foramen lesion
What are the signs of cranial nerve 10 lesion?
- Palatal weakness:
- Nasal speech
- Nasal regurgitation of food
- Palate moves asymmetrically when the patient says ‘ahh’
- Recurrent nerve palsy:
- Hoarseness
- Loss of volume
- Bovine cough (non- explosive cough of someone unable to close their glottis)
What are the signs of cranial nerve 11 lesion?
Weakness and wasting of sternocleidomastoid and trapezius muscles
What are the signs of cranial nerve 12 lesion?
- LMN lesion:
- Wasting of the ipsilateral side of the tongue, with fasciculation
- Attempted protrusion of tongue causes deviation towards the affected side
What are conditions that may affect cranial nerves?
- Diabetes mellitus
- Stroke
- MS
- Tumours
- Sarcoid
- Vasculitis (e.g. polyarteritis nodosa)
- Systemic lupus erythematosus (SLE)
- Syphilis
- Chronic meningitis (malignant, TB, or fungal)
How do you get a tetanus infetion?
Inoculation through skin with Clostridium tetani spores (found globally in soil)
Clostridium tetani - gram positive anaerobe with spores
e.g. stepping on a nail, dirty wounds
What toxins does a tetanus infection produce?
Tetanolysin (tissue destruction)
Tetanospasmin (clinical features )
What are the symptoms of tetanus?
Unopposed flexion of limbs
spasm of muscles
What is the management of tetanus?
Prevention = vaccinate!!
Supportive
Muscle relaxants
Paracetamol/cooling
Immunoglobulin to mop up toxin
Metronidazole to clear any residual bacteria
How do you become infected with Rabies?
Inoculation through skin withsaliva of rabid animal(dogs, cats, foxes etc)
e.g. lick, bite, splash
Travels retrogradelyalong nerves
What is the clinical manifestation of Rabies?
Incubation depends on site and size of inoculation
symptoms can first present within Min 2 weeks to Max years!
Paraesthesia at bite site
Reaches CNS…
Furious or paralytic presentation
What is the management for rabies?
Once symptomatic invariably fatal (>99.9%)
Managed with sedatives ++++
PROPHYLAXIS IS KEY!!!
pre-exposure prophylaxis(vaccination)
post-exposure prophylaxis (vaccination and immunoglobulin)
What are polyneuropathies?
Motor and/or sensory disorder of multiple peripheral or cranial nerves
Usually symmetrical, widespread and worse distally (glove and stocking distribution)
What are the classification of polyneuropathies?
- Chronicity e.g. acute or chronic
- Function e.g. sensory, motor, autonomic or mixed
- Mostly motor e.g.
- Guillain-Barre syndrome
- Lead poisoning
- Charcot-Marie-Tooth syndrome
- Mostly sensory e.g.
- Diabetes mellitus
- Renal failure
- Leprosy
- Mostly motor e.g.
- Pathology e.g. demyelination, axonal degeneration or both
What are the causes of polyneuropathies?
- Metabolic: diabetes mellitus, renal failure, hypothyroidism, hypoglycaemia, mitochondrial disorders
- Vasculitides: polyarteritis nodosa, rheumatoid arthritis, GPA
- Malignancy: paraneoplastic syndromes, polycythaemia rubra vera
- Inflammatory: Guillain-Barre syndrome, sarcoidosis
- Infections: leprosy, HIV, syphilis, lyme disease
- Nutritional: decreased; vit B12, B1, B6, E
- Inherited syndromes: Charcot-marie-tooth, porphyria, leucodystrophy
- Drugs/toxins: lead, arsenic, alcohol, vincristine, cisplatin, metronidazole, isoniazid, phenytoin, nitrofurantoin
- Other: paraproteinaemias, amyloidosis
What are the differential diagnoses for epilepsy?
- postural syncope
- migraine
- hypoglycaemia
- benign paroxymal positional vertigo
- dystonia
- cataplexy
- TIA
- parasomnia
- cardiogenic syncope
- non-epileptic seizure
- hyperventilation
Define epilepsy?
A neurological disorder in which a person experiences recurring seizures.
(needs to have at least 2 seizures to be diagnosed as epilepsy)
What are the main excitatory and inhibitory neurotransmitters? And their function?
main excitatory neurotransmitter = glutamate
- binds to NMDA (primary receptor)
- opens ion channels that cause calcium and sodium influx.
main inhibitory neurotransmitter = GABA
- binds to GABA receptors
- inhibits the signal by opening channels that cause a chloride influx
What are the different types of seizure?
- Generalised:when both hemispheres are affected always a loss of consciousness
- Focal : when the affected area is limited to one half of the brain or sometimes even smaller like a single lobe can progress to bilateral
What are the different subtypes of generalised seizure?
Tonic
Atonic
Clonic
Tonic-clonic
Myoclonic
Absence
What are the two types of focal seizure?
Simple (without impaired awareness)
Complex (with impaired awareness)
What are the general clinical manifestations of seizures for each stage?
Prodromal phase:
Confusion, irritability or mood disturbances
Early-ictal phase:
Aura: warning felt before a seizure. These can include sensory, cognitive, emotional or behaviour changes.
Ictal phase:
Will vary depending on seizure type
Post-ictal phase:
Confused, drowsy and irritable during recovery
What is a tonic, clonic and tonic-clonic seizure?
Tonic seizure: the muscles become stiff and flexed which will cause the patients to fall backwards
Clonic seizures: violent muscle contractions (convulsions)
Tonic-clonic: there is loss of consciousness and tonic (muscle tensing) and clonic (muscle jerking episodes).
Typically the tonic phase comes before the clonic phase. (tongue biting, incontinence, groaning and irregular breathing.
After the seizure there is a prolongedpost-ictal periodwhere the person is confused, drowsy and feels irritable or depressed.
What is the medication for generalised tonic-clonic seizures?
1st line:Sodium valproate
2nd line:LamotrigineorCarbamazepine
What is an Atonic seizure
Known as drop attacks. This is where the muscles suddenly relax and become floppy which can cause the patient to fall usually forward.
They don’t usually last longer than 3 minuets. They typically begin in childhood. They may be indicative ofLennox-Gastaut syndrome.
What is the management for an Atonic seizure?
First line: sodium valproate
Second line: Lamotrigine
What is a myoclonic seizure?
They present as sudden brief muscle contractions like a sudden jump. The patient usually remains awake during the episode.
They occur in various forms of epilepsy but typically happen in children as part of juvenile myoclonic epilepsy.
What is the management for a myoclonic seizure?
First line: sodium valproate
Other options: lamotrigine, levetiracetam or topiramate
What is an absence seizure?
Impaired awareness or responsiveness. Patient becomes blank and stares into space before returning to normal. Motor abnormalities are either absent or very minor e.g. eyelid flutters or repetitive lip smacking.
Common in children. Most patients (> 90%) stop having absence seizures as they get older.
What is the management for an absence seizure?
First line: sodium valproate or ethosuximide
What are infertile spasms?
Known as West syndrome.
- It is a rare (1 in 4000) disorder starting in infancy at around 6 months of age.
- It is characterised by clusters of full body spasms.
- There is a poor prognosis: 1/3 die by age 25, however 1/3 are seizure free.
What is a simple focal seizure (focal aware seizure)?
No loss of consciousness
The patient is aware and awake
Will have uncontrollable muscle jerking
What is a complex focal seizure (focal impaired awareness seizure)?
There is loss of consciousness
Patient is unaware
What is the most common region of the brain affected in a focal seizure?
Temporal lobe
What are the features of a temporal lobe seizure?
They affect hearing, speech, memory and emotions:
- Hallucinations
- Memory flashbacks
- Déjà vu
- Doing strange things on autopilot
Can also include audio symptoms such as buzzing, ringing and vertigo
What are the features of a frontal lobe seizure?
Motor symptoms: pelvic thrusting, bicycling and tonic posturing
Bizarre behaviour
Vocalisations
Sexual automatisms
What are the features of a parietal focal seizure?
Paraesthesia
Visual hallucinations
Visual illusions
More subjective and difficult to diagnose than other areas
What are the features of a Occipital focal seizure?
Visual hallucinations
Transient blindness
Rapid and forced blinking
Movement of head or eyes to the opposite side
What can happen if a focal seizure spreads?
Focal to bilateral tonic-clonic: a focal seizure may spread to affect a wider network of neurons involving both hemispheres.
Traditionally termed a secondary generalised seizure.
What is the medication for focal seizures?
1st line: Carbamazepine or Lamotrigine
2nd line: Sodium valproate or Levetiracetam
What is the management for infantile/west syndrome seizures?
Prednisolone
Vigabatrin
What is the mechanism of Carbamazepine?
sodium channel blocker; prevents repetitive and sustained firing of action potentials
What are the side effects of Carbamazepine?
- Reduce effect of Oral Contraceptive Pill
(by CYP450 induction > faster metabolism) - leucopenia, thrombocytopenia, hydronatraemia + liver dysfunction
Can you take Carbamazepine when pregnant?
DONT STOP
- risk of harm from seizures is greater than risk of foetal malformations (very low risk)
- immediately start taking folic acid
What is the mechanism of sodium valproate?
increases the activity of GABA, which has a relaxing effect on the brain, teratogenic
What are the investigations for seizures?
urinalysis or urine cultures, blood cultures (exclude sepsis, encephalitis, or meningitis)
CT scan
Blood: blood glucose (rule out hypoglycaemia)
ECG (to exclude a heart problem)
EEG (only useful while having a seizure to track electrical patterns in brain, won’t visualise much afterwards)
What are the other treatments for epilepsy?
Vagus nerve stimulation = send electrical stimulations to left vagus nerve to calm down irregular electrical brain activity
Surgery:
Temporal lobe resection MC
Corpus callosotomy = cut callosum to stop epilepsy spreading to other side of brain
Lesionectomy
Hemispherectomy or hemispherotomy
Ketogenic diet
- high fat, low carbs, controlled protein protein diet
- brain use ketone bodies instead of glucose
Which anti-epileptic medication is teratogenic?
sodium valproate
- drugs which cause structural/functional malformations in a developing fetus
What is required for a diagnosis of epilepsy?
Must have had 2 or more seizures more than 24 hours apart
MRI/CT: examine the hippocampus look for underlying cause
EEG: 3H2 wave absence
Bloods: rule out metabolic/infection
What are the different causes of seizures? (pneumonic)
VITAMIN DE
- Vascular
- Infection
- Trauma
- Autoimmune- SLE
- Metabolic
- Idiopathic
- Neoplasms
- Dementia and drugs (cocaine)
- Eclampsia
What is the medical emergency associated with epilepsy?
Status Epilepticus
How do you treat status Status Epilepticus?
ABCDE
Give IV lorazepam 4mg and repeat 10 minuets after if it doesn’t work
If seizure persist then give IV phenobarbital or phenytoin
What are the driving rules for a seizure?
Adults who present with an isolated seizure:
Should stop driving for6 months, providing no cause is found on brain imaging and there is no epileptiform activity on EEG
If the above conditions are not met or the patient has known epilepsy:
Patients must be seizure-free for12 monthsbefore they may qualify for a driving license
If seizure-free for 5 years, a ‘til 70 licence is usually reinstated
What is Multiple Sclerosis?
An autoimmune cell-mediated demyelinating disease of the central nervous system
What is the epidemiology of MS?
More common in women
20-40 most common age for diagnosis
More common in white
More common in northern latitudes
Symptoms will improve in pregnancy and post-partum period
What are some risk factors for developing MS?
Vitamin D deficiency
Family history: HLA-DR2 is implicated; 30% monozygotic twin concordance
EBV infection: the virus with the greatest link to MS
Smoking
Obesity
Describe the pathophysiology of MS
(don’t fully know the cause)
T-cells get through the blood brain barrier and are activated by myelin. The T-cell then changes the BBB to allow more immune cells to get in the brain
MS is a type IV hypersensitivity reaction: T-cells release cytokines and these recruit more immune cells whilst also damaging the oligodendrocytes (+ axones)
B-cells will make antibodies that will destroy the myelin of the oligodendrocytes. leaving behind areas of plaque/sclera
How does MS progress over time?
In early disease, re-myelination can occur and symptoms can resolve. (thin myelin forms so conduction reduced in heat)
In the later stages of the disease, re-myelination is incomplete and symptoms gradually become more permanent.
A characteristic feature of MS is that lesions vary in their location over time, meaning that different nerves are affected and symptoms change over time
MS lesions change location over time is that they are “disseminated in time and space”.
What are the different types of MS?
Relapsing-remitting:
Secondary progressive
Primary progressive
Progressive relapsing
Clinically isolated syndrome (kind of counts)
What is Relapsing-remitting: MS?
The most common pattern 85% of cases
Episodic flare-ups separated by periods of remission. There isn’t full recovery after flare ups so disability increases over time.
60% will develop secondary within 15 years
What is secondary progressive MS?
Initially, the disease starts with a relapsing-remitting course, but then symptoms get progressively worse with no periods of remission
What is primary progressive MS?
Symptoms get progressively worse from disease onset with no periods of remission
Accounts for 10% of cases and is more common in older patients
What is Progressive relapsing MS?
One constant attack but there are bouts superimposed during which the disability increases even faster
What is clinically isolated syndrome MS?
This describes the first episode of demyelination and neurological signs and symptoms.
- MS cannot be diagnosed on one episode as the lesions have not been “disseminated in time and space”.
- Patients with clinically isolated syndrome may never have another episode or develop MS. If lesions are seen on MRI scan then they are more likely to progress to MS
What are the signs and symptoms of MS?
Optic nerve affected:
Optic neuritis
Eye movement abnormalities- double vision VI nerve
Spinal cord affected:
Focal weakness (incontinence, limb paralysis, Bells palsy)
Focal sensory symptoms ( numbness, pins and needles, Lhermitte’s sign is an electric shock sensation that travels down the spine and into the limbs when flexing the neck.)
Cerebellar white matter affected
Ataxia
Cerebral hemispheres:
- large variety but can be silent
Medulla + pons
- dysarthria, double vision, vertigo, nysatgmus
Uhthoff’s phenomenon: worsening of symptoms following a rise in temperature, such as a hot bath
What is optic neuritis?
Demyelination of the optic nerve which present with:
- Unilateral reduced vision
- Central scotoma (enlarged blind spot)
- Pain on eye movement
- Impaired colour vision (red)
What is the primary investigation for MS and what would it show?
MRI of brain and spine:
- Will show demyelinating plaques called Dawson’s fingers
- High signal L2 lesions
- Old lesions will not enhance with contrast, whereas newer lesions will. This provides evidence of dissemination of lesions in time and space which is required for a diagnosis of MS
What other investigations are done for MS?
Lumbar puncture
- can detect oligoclonal IgG bands in the CSF
Nerve conduction studies
- delayed conduction speeds
Evoked Potentials (VEP)
- measures speed of messages along nerves
What is the diagnostic criteria used to diagnose MS?
McDonald criteria
What is the McDonald criteria based on?
2 or more relapses and either:
- Objective evidence of two or more lesions
- Objective evidence of one and a reasonable history of a previous relapse
‘Objective evidence’ is defined as an abnormality on neurological exam, MRI or visual evoked potentials
What is used to treat a MS relapse?
Oral or IV methylprednisolone
(reduce time to recover from illness but don’t treat illness)
Plasma exchange: to remove disease-causing antibodies
What is used for maintenance of MS?
Disease-modifying drugs-
Beta-interferon: decreases the level of inflammatory cytokines
Monoclonal antibodies e.g. alemtuzumab (anti-CD52) and natalizumab (anti-α4𝛃1-integrin)
Glatiramer acetate: immunomodulator drug which acts as a ‘decoy’
Fingolimod: a sphingosine-1-phosphate receptor modulator that keeps lymphocytes in lymph nodes so they can’t cause inflammation
Why is stem cell transplant used in MS?
- use chemotherapy to kill off all their immune cells
- and give them a stem cell transplant
- MS is a inflammatory disease so new immune cells should not attack myelin
- doesn’t improve demyelination as damage is already done but stops the disease progressing
What are some complications of MS?
Genitourinary: urinary tract infections, urinary retention and incontinence
Constipation
Depression: offer mental health support if required
Visual impairment
Mobility impairment: offer physiotherapy, orthotics and other mobility aids
Erectile dysfunction
What is Guillain-Barré syndrome?
An acute paralytic polyneuropathy. It is an autoimmune, rapidly progressive demyelinating condition of the peripheral nervous system
What are the risk factors for developing Guillain-Barré syndrome?
Male
Age 15-35 and 50-75
Malignancies
Vaccines (flu)
Infections
What are the most common infections that trigger Guillain-Barré syndrome?
Campylobacter jejuni (most common)
Cytomegalovirus
EBV
What causes Guillain-Barré syndrome?
A pathogenic antigen resembles myelin gangliosides in the peripheral nervous system.
The immune system targets the antigen and attacks the myelin sheath of sensory and motor neurones
It occurs in patches along the length of the axon so is called segmental demyelination
What antibodies are found in 25% of people with Guillain-Barré syndrome?
Anti-ganglioside antibodies (anti-GMI)
Describe the disease course of Guillain-Barré syndrome?
Symptoms usually start within 4 weeks of the preceding infection. The symptoms typically start in the feet and progresses upward.
Symptoms peak within 2-4 weeks, then there is a recovery period that can last months to years.
What are the signs and symptoms of Guillain-Barré syndrome?
Symmetrical ascending weakness (starting at feet and moving up the body)
Reduced reflexes
Loss of sensation and pain
Cranial nerve involvement such as facial nerve weakness
Autonomic features (sweating, raised pulse)
Struggling to breathe
What is used to diagnose Guillain-Barré syndrome?
A clinical diagnosis that is evidenced by progressive weakness and hyporeflexia in the weaker limbs.
The Brighton criteria is used for diagnosis.
What are the differentials of Guillain-Barré syndrome?
Myasthenia gravis
Transverse myelitis
Polymyositis
What is the treatment for Guillain-Barré syndrome?
IV immunoglobulins IV IG
Plasma exchange (alternative to IV IG)
Venous thromboembolism prophylaxis (PE is the leading cause of death)
What is the prognosis for Guillain-Barré syndrome?
80% will fully recover
15% will be left with some neurological disability
5% will die
What is Parkinson’s disease (PD)
A neurodegenerative disorder characterised by the loss of dopaminergic neurons within the substantia nigra pars compacta (SNPC) of the basal ganglia.
What are the risk factors for developing PD?
Age: prevalence is 1% in 60-70 and 3% in those above 80
Gender: men are 1.5 times more likely than females to develop PD
Family history
Describe the pathophysiology of PD
- progressive loss of dopamine-producing neurons meaning there is a reduction in the amount of dopamine produced at the substantia nigra
- Loss of these neurons results in reduction in action of the direct pathway and a resultant increase in the antagonistic indirect pathway which has a restrictive action on movement.
- Therefore bradykinesia and rigidity are key symptoms
- There is also formation of protein clumps Lewy bodies
What are the 3 key presentations of PD?
Bradykinesia
Tremor
Rigidity
PD symptoms usually start unilaterally and then become bilateral later in the disease course.
What does the bradykinesia look like in PD?
Handwriting gets smaller
Only take small steps (shuffling gait)
Difficulty initiating movement
Difficulty turning around when standing
Reduced facial movements and expressions
What does the tremor look like in PD?
A unilateral resting tremor. Described as pill rolling tremor looks like they are rolling pill between thumb and finger
The tremor is worse at resting and when they are distracted like using the other hand
Frequency of 4-6 times a second
What is the difference between an essential and Parkinson’s tremor?
Essential - active tremor + worsens with movement
Parkinson’s - pill rolling, resting tremor
What is the rigidity like in PD?
If you take their hand and passively flex and extend their arm at the elbow you will feel tension in their arm that gives way to movement in small increments (little jerks)
Described as cogwheel
What are some other symptoms of PD?
Depression
Sleep disturbance and insomnia no REM
Loss of sense of smell
Postural instability
Cognitive impairment and memory problems
What are the differences between a PD tremor and a benign essential tremor?
PD= asymmetrical BET= symmetrical
PD= frequency= 4-6 BET= 5-8
PD= worse at rest BET= better at rest
PD= improves with intentional movement BET= worse
PD= no change with alcohol BET= better with alcohol
What is used to diagnose PD?
PD is a clinical diagnosis and should be suspected in a patient with bradykinesia and at least one of the following:
- Tremor
- Rigidity
- Postural instability
What is the management for PD?
Motor symptoms not affecting quality of life:
A choice of one of the following:
- Dopamine agonist(non-ergot derived)
- Pramipexole, ropinirole - Monoamine oxidase B inhibitor
- Selegiline, rasagiline
- Stop breakdown of circulating dopamine
Motor symptoms affecting the quality of life:
- L.Dopa
Synthetic dopamine levodopa given with a drug that stops it being broken down.
- These are peripheral decarboxylase inhibitors. Carbidopa and benserazide.
Co-benyldopa (levodopa and benserazide)
Co-careldopa (levodopa and carbidopa)
What is the prognosis for PD?
PD is a chronic and progressive condition with no cure.
Overall, life expectancy is reduced with the mortality being 2-5 times higher for those aged 70-89 years old. Also, the risk of dementia is up to 6 times higher in PD patients.
What is Huntington’s disease?
An autosomal dominant genetic neurodegenerative condition that causes a progressive a progressive deterioration in the nervous system.
What causes HD?
- It is a trinucleotide repeat disorder that involves a genetic mutation in the HTT gene on chromosome 4
- There is a repeat of CAG which codes for glutamine 36 times in a row so patients have 36 glutamine in a row on the Huntington protein
- These mutated proteins aggregate within neuronal cells of the caudate and putamen causing neuronal cell death.
- This leads to decreased ACh and GABA synthesis.
- This leads to dopamine increase leading to excessive movement
What is anticipation and how is it linked to HD?
It is a feature of trinucleotide repeat disorders. 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.
This leads to successive generations having more repeats in the gene resulting in:
- Early age of onset
- Increased severity of the disease
What are the symptoms of HD?
Patients will be asymptomatic until 30-50.
Symptoms:
- Begin with Cognitive, psychiatric or mood problems
- Chorea (involuntary, abnormal movements)
- Eye movement disorders
- Dysarthria: speech difficulties
- Dysphagia: swallowing difficulties
- Dementia
How is diagnosis of HD made?
Made at a specialist genetic centre that looks for the number of CAG repeats.
This will involve pre and post test counselling
What is the treatment for HD?
No treatment
- supporting person and family
- maintaining quality of life = OT + PT
- speech and language therapy
- genetic counselling
- end of life care planning
What medications are given for symptoms relief in huntington’s?
Medications that can suppress the disordered movement:
Antipsychotics (e.g. olanzapine)
Benzodiazepines (e.g. diazepam)
Dopamine-depleting agents (e.g. tetrabenazine)
Describe the epidemiology of Alzheimer’s Disease?
Most common form of dementia
More than 500,000 people with it in the UK
More common in women
What are the risk factors for developing AD?
Age
CVD
Depression
Low educational attainment
- Low social engagement and support
- head trauma, learning difficultie
What genes put you at risk of AD?
APP and presenilin genes (PSEN1, PSEN2)
- APP on chromosome 21, so increased risk for people with down syndrome
alleles of apolipoprotein E4 = not as good at clearing beta plaques
What are the amyloid beta plaques and how do they contribute to AD?
- Senile plaques deposits of beta amyloid aggregate.
- Amyloid precursor protein is found on neurons (helps it to grow and repair after injury).
- If it is broken down normally by alpha secretase and gamma secretase it is soluble and easy to remove
- However if it is broken by beta secretase the leftover fragment isn’t soluble and creates a monomer called beat amyloid.
- These are sticky and can in between neurones and their signalling, They also increase inflammation which damages surrounding neurones
What are neurofibrillary tangles and how do they contribute to AD?
- Neurons held together by cytoskeleton = is made up of microtubules a protein ‘tau’ makes sure they stay together.
Beta amyloid build-up outside the neurones initiates pathways which leads to the activation of kinase.
This leads to the phosphorylation of tau
The tau protein changes shape, stops supporting the microtubules, and clumps up with other tau proteins, forming neurofibrillary tangles
Neurones with tangles and non-functioning microtubules can’t signal as well, and sometimes end up undergoing apoptosis.
As neurones die, the brain starts to atrophy.
What are some of the symptoms of AD?
- Agnosia- can’t recognise things
- Apraxia can’t do basic motor skills
- Aphasia speech difficulties
Cognitive impairment
Agitation and emotional lability
Depression and anxiety
Sleep cycle disturbance: Motor disturbance: wandering is a typical feature of dementia
How can the activities of daily life be affected in AD?
Loss of independence: increasing reliance on others for assistance with personal and domestic activities:
- Early stages: problems with higher level function (e.g. managing finances, difficulties at work)
- Later stages: problems with basic personal care (e.g. washing, eating, toileting) and motor function (e.g. walking, transferring)
What is the diagnostic criteria for AD?
Functional ability: inability to carry out normal functions
Impairment in 2 or more cognitive domains
Differentials excluded
What imaging is used for AD?
CT/MRI:
exclude other diagnosis
help determine type of dementia;
will show medial temporal lobe atrophy
What is the definitive diagnosis for AD?
Brain biopsy after autopsy
What are the two cognitive assessments that can be performed to asses AD?
Mini mental state examination (MMSE)
Montreal cognitive assessment scale (MoCA)
Primary care: 6 Cognitive Impairment Test (6CIT)
What is assessed in the cognitive assessments?
Attention and concentration
Recent and remote memory
Language
Praxis (planned motor movements)
Executive function
Visuospatial function
What are the different score on the MMSE and MoCA and what do they represent?
Mild: MMSE 21-26, MoCA 18-25, CDR 1
Moderate: MMSE 10-20, MoCA 10-17, CDR 2
Severe: MMSE <10, MoCA <10, CDR 3
What is the treatment for AD?
Non-pharmacological:
programmes to improve/maintain cognitive function
Mild to moderate AD:
acetylcholinesterase inhibitors e.g., Donepezil and rivastigmine
Moderate to severe AD:
N-methyl-d-aspartic acid receptor antagonist memantine (anti-glutamate transmitter)
What is frontotemporal dementia?
A neurodegenerative disorder characterised by focal degeneration of the frontal and temporal lobes.
It is a heterogenous condition with various subtypes e.g., Pick’s disease
What are the genes associated with FTD?
- C9ORF72 gene: found on chromosome 9. Most common genetic cause of inherited FTD. Also implicated in hereditary motor neuron disease.
- MAPT (microtubule associated protein)- found on chromosome 17
- Granulin precursor(GRN): found on chromosome 17.
Describe the pathophysiology of FTD?
In Pick disease 3R isoforms of the tau protein become hyperphosphorylated.
- This means they change shape and stop being able to tie together the tubulins in the neurones cytoskeleton.
These proteins start to clump together forming tangles of tau proteins known as pick bodies
What are the frontal lobe effects of FTD?
Personality and behaviour change:
- Disinhibition
- Loss of empathy
- Apathy
- Hyperorality(e.g. dietary changes, attempt to consume non-edible products, eat beyond satiety)
- Compulsive behaviour(e.g. cleaning, checking, hoarding)
What are the temporal lobe effects of FTD?
Language problems:
- Effortful speech
- Halting speech
- Speech sound errors
- Speech apraxia
- Word-finding difficulty
- Surface dyslexia or dysgraphia: mispronouncing difficult words (e.g. yacht)
How would you diagnose FTD?
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
What are the pharmacological treatments for FTD?
Serotonin reuptake inhibitors (SSRI) = used for difficult behavioural symptoms. Have been shown to decrease disinhibition, anxiety, impulsivity and repetitive behaviours.
Atypical anti-psychotics = can help with agitation and behavioural symptoms.
What is the epidemiology of vascular dementia?
Makes up 20% of dementias
It is the second most common form
What can cause vascular dementia?
Ischaemic stroke
Small vessel disease
Haemorrhage
Other: cerebral amyloid, which is a cause of small vessel disease. Deposition of amyloid in small arteries. CADASIL, which is due to mutation in the NOTCH3 gene and leads to arterial thickening and occlusion.
Normal Physiology - how much of the hearts cardiac output goes to the brain?
What is unique about the brain’s metabolism?
The brain uses around 20-25% of oxygen
Neurons can only function in aerobic conditions and don’t have long term energy stores so need a constant supply
Describe the pathophysiology of VD?
- Once blood supply to the brain falls below the demands to the tissue, it’ considered an ischaemic stroke.
- The tissue damage is permanent because the dead tissue liquifies in a process called
*liquefactive necrosis** - Brain tissue necrosis leads to a loss of mental function in the area where the loss has occurred
How do the symptoms of VD appear?
They appear suddenly and the brain function decline is STEP-WISE e.g. it decreases with each stroke
Symptoms will vary depending on which vessels are affected in stroke/atherosclerosis
What is Lewy body dementia?
A type of dementia characterised by fluctuating cognitive impairment, visual hallucinations and parkinsonism
What % of dementia does Lewy Body Dementia make up?
15-25%
What causes LBD?
- Neurons contain a protein called alpha synuclein and in LBD this proteins is misfolded within the neurons
- This misfolded protein aggregates to form Lewy bodies that deposit inside the neurones particularly in the cortex and the substantia nigra.
What other disease are Lewy bodies seen?
Parkinson’s
Multiple system atrophy
What are the early symptoms in LBD?
Alzheimer’s like cognitive ones:
Difficulty focusing
Poor memory
Visual hallucinations
Disorganized speech
Depression
What are the later symptoms of LBD?
Later symptoms are typically motor ones (Parkinson’s-like)
Resting tremors
Stiff and slow movements
Reduced facial expressions
Some patients may have sleep disorders e.g. sleep walking or talking in their sleep
What is the management for 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 symptoms
What drugs should be avoided in LBD?
Antipsychotics as they can have harmful side effects
What are primary headaches and give some examples?
No underlying cause relevant to the headache:
- Migraine
- Cluster
- Tension
- (Trigeminal Neuralgia)
What are red flags for headaches in regard to the features of the headache?
Sudden-onset reaching worse severity within 5 minuets (subarachnoid haemorrhage)
New-onset over 50 (GCA/ space occupying lesion)
Progressive/persistent headache or one that has changed dramatically (space-occupying lesion/ subdural haematoma)
What are red flag precipitating factors for headaches?
Recent head trauma within 3 months (subdural haematoma)
Headache worse lying down (raised ICP)
Headache worse on standing (CSF leak)
Household contacts with similar symptoms (CO poisoning)
What are red flag associated symptoms of headaches?
Fever, photophobia or neck stiffness (meningitis or encephalitis)
New neurological defect (raised ICP/stroke)
Visual disturbance (GCA/ acute closure glaucoma)
Vomiting (raised ICP, brain abscess and CO poisoning)
What is an important investigation to carry out for a headache?
fundoscopy = (look at retina at back of eye) look for papilledema which indicates a raised intracranial pressure + idiopathic intracranial hypertension
What are the features of idiopathic intracranial hypertension?
females
- headache, intermittent, generalised
- worse lying down
- visual obscurations
- usually high BMI
- papillodema
I = normal CT
T = modify risk factors, acetazolamide/diuretics/topiramate
What are the risk factors for migraines?
Family history
Female gender 3 times more common
Obesity
Triggers
What are some triggers for migraines?
CH- Chocolate
OC- Oral contraceptive
OL- alcohOL
A- anxiety
T- travel
E- exercise
CHOCOLATE
Other triggers can be red wine, bright lights and menstruation
What are the different types of migraine?
Migraine without aura
Migraine with aura
Silent migraine (just the aura without the headache)
Hemiplegic migraine
What causes migraines?
- Headache is thought to be due to neuronal hyperexcitability.
- This leads to trigeminal nerves initiating an inflammatory response with dilation of meningeal blood vessels and sensitisation of surrounding nerve fibres leading to pain
- Aura is thought to occur due to cortical spreading depression which is a propagating wave of depolarisation across the cerebral cortex causing the brain to become hypersensitive to certain stimuli
What are the headache symptoms of a migraine?
Last between 4-72 hours:
- Pounding or throbbing in nature
- Usually unilateral (can be bilateral more common in children)
- Photophobia
- Phonophobia (loud noises)
- Aura
- Nausea and vomiting
What is aura?
Aura is the term used to describe the visual changes associated with migraines symptoms can be:
- Sparks in vision
- Blurring vision
- Line across vision
- Loss of different visual fields
What is a hemiplegic migraine?
They can mimic a stroke. Need to rule out if patient has symptoms:
- typical migraine
- Sudden onset
- Hemiplegia
- Ataxia
- Change in consciousness
What are the 5 stages of a migraine?
- Prodromal stage subtle symptoms such as yawning, fatigue or mood changes
- Aura
- headache
- Resolution the headache can fade away and be relieved by vomiting or sleeping
- Postdromal stage
What is the diagnostic criteria for migraines with aura?
At least TWO headaches filling criteria:
One or more typical fully reversible aura symptoms including:
- Visual symptoms such as zigzag lines and/or scotoma
visual aura is the most common type of aura.
- Sensory symptoms such as unilateral pins and needles or numbness.
- Speech and/or language symptoms such as dysphasia.
At least three of the following:
- At least one aura symptom spreads gradually over at least 5 minutes.
- Two or more aura symptoms occur in succession.
- Each individual aura symptom lasts 5-60 minutes.
- At least one aura symptom is unilateral.
- At least one aura symptom is positive.
- The aura is accompanied, or followed within 60 minutes, by headache. (can be confused with stroke until headache starts)
What is the diagnostic criteria for migraines without aura?
FIVE attacks fulfilling this criteria
Duration = Headache lasting 4–72 hours in adults or 2–72 hours in adolescents.
Headache with at least TWO of the following characteristics:
- Unilateral location (more commonly bilateral in children).
- Pulsating quality — may be described as ‘throbbing’ or ‘banging’ in young people.
- Moderate or severe pain intensity.
- Aggravation by, or causing avoidance of, routine activities of daily life (for example walking or climbing stairs).
Headache with associated symptoms including at least one of:
- Nausea and/or vomiting.
- Photophobia (sensitivity to light) and phonophobia (sensitivity to sound).
What is the management for migraines?
Analgesia (avoid opioids)
Oral triptan ( 500mg sumatriptan) as the headache starts
Antiemetics metoclopramide
What are triptans?
They 5HT (serotonin) receptor agonists and they cause:
- smooth muscle contraction in arteries
- Peripheral pain receptors to inhibit activation of pain receptors
- Reduce neuronal activity in the central nervous system
What are the medications used for migraine prophylaxis?
Propranolol
Topiramate (don’t use in pregnancy as it is teratogenic and can cause cleft lip)
Amitriptyline
What are the non-pharmacological treatments for migraines?
Acupuncture: if bothpropranololandtopiramateare ineffective or unsuitable
Riboflavin (vitamin B2): **may be effective in some people, but avoid in pregnancy
What is a tension headache?
The most common form of a primary headache
- Can be episodic (<15 days/month) or chronic (>15 days a month for at least 3 months)
What are the causes of tension headaches?
Missed meals
Stress
Overexertion
Lack of sleep
Depression
What are the symptoms of tension headaches?
Bilateral with a pressing/tight sensation of mild-moderate intensity
Nausea or vomiting
Photophobia
Phonophobia
What is the main risk factor for a tension headache?
stress
What are cluster headaches?
Severe unilateral headaches often periorbital that come in clusters of attacks
What is the typical presentation for cluster headaches?
A typical patient with cluster headaches in your exams is a 30 – 50 year-old male smoker.
- Attacks can be triggered by things like alcohol, strong smells and exercise.
How long can a cluster headache last?
Patient may suffer 3 – 4 attacks a day for weeks or months followed by a pain-free period lasting 1-2 years.
Attacks last between 15 minutes and 3 hours.
What are the symptoms of a cluster headache?
Severe and intolerable pain
unilateral
Red swollen watering eye
Pupil constriction
Eyelid dropping
Nasal discharge
Facial sweating
What is the acute management of cluster headaches?
Triptans (6mg sumatriptan subcut)
High flow oxygen 100%
What are the prophylaxis for cluster headaches?
Verapamil (CCB)
Lithium
Prednisolone (a short course for 2-3 weeks to break the cycle during clusters)
What are the risk factors for Trigeminal Neuralgia?
females
50-60
increases with age
unilateral
MS
What are the causes of Trigeminal Neuralgia?
Normally due to compression of the trigeminal nerve by a vascular loop often the superior cerebellar artery
What are triggers for TGN?
Light touch
Washing
Shaving
Talking
Cold weather
What is the headache like in Trigeminal Neuralgia?
Electric Shock Pain that lasts for seconds to minutes across the face
90% unilateral
10% bilateral
What is the diagnostic criteria for trigeminal neuralgia?
Clinical Dx
3 or more attacks with characteristic unilateral facial pain and Symptoms
MRI - exclude secondary causes/other pathology
What is the treatment for TGN?
- First line: Carbamazepine
- Second line: microvascular decompression or ablative surgery may be considered in refractory patients
What is spinal cord compression SCC?
Results form processes that compress or displace arterial, venous and cerebrospinal fluid spaces as well as the cord itself.
What is the main cause of SCC?
Metastatic cancer lesions
Where are the metastasis most commonly from the cause SCC?
Breast
Lung
Prostate
Thyroid
Kidney
Myeloma
Lymphoma
What area of the spine is most commonly affected by metastasis in SCC?
Thoracic 60%
Lumbar 30%
Cervical 10%
What are some other causes of SCC?
Disc herniation
Disc prolapse
Primary spinal cord tumour
Infection
Haematoma
What are the symptoms of SCC?
Back pain
Progressive weakness of legs with UMN signs
Sensory loss 1-2 cord segments below level of lesion
UMN signs below level of lesion
LWN signs at the level of the lesion
What is a late sign of SCC?
Bladder and anal sphincter involvement: hesitancy, frequency and painless retention
What are the nerve routes for the ankle Jerk reflex?
S1/S2
What are the nerve routes for the Knee jerk reflex?
L3/L4
What are the nerve routes for the Big toe reflex?
L5
What would the features of a complete spinal cord compression be?
Loss of all motor and sensory function below the level
What would be the features of an anterior spinal cord compression?
Disruption of the anterior spinal cord:
- Loss of motor function below the level
- Loss of pain and temperature sensation
- Preservation of fine touch and proprioception
What would be the features of a posterior spinal cord compression?
Disruption of posterior spinal cord or posterior spinal artery (rare)
- Loss of fine touch and proprioception (posterior column)
- Preservation of pain and temperature sensation (anterior column)
What are the features of brown-sequard syndrome?
Hemi section of spinal cord:
- Ipsilateral paralysis
- Ipsilateral loss of vibration and proprioception
- Contralateral loss of pain and temperature
What is the primary investigation if suspecting a Spinal cord compression?
MRI of spinal cord
Biopsy/surgical exploration
What is the treatment for SCC?
Surgical decompression
- Laminectomy: removal of the lamina/spongy tissue between the discs to relieve pressure
- Microdiscectomy: removal of the herniated tissue from the disc
What is sciatica?
L4/S3 lesion Sensory loss and pain in the back of the thigh and lateral aspect of little toe
What nerves are branches of the sciatic nerve?
Common peroneal
Tibial
What are the symptoms of sciatica?
Unilateral pain from the buttock radiating down the back of the thigh to below the knee or feet
Paraesthesia numbness and motor weakness
What are the main causes of sciatica?
Herniated/prolapsed disc
Tumours
Spinal stenosis
Piriformis syndrome
What is bilateral sciatica a red flag for?
Cauda equina syndrome
What is the main treatment for sciatica?
Physiotherapy + Analgesia:
Amitriptyline
Duloxetine
What is cauda equina syndrome?
It is a neurosurgical emergency which occurs when the bundle of nerves below the end of the spinal cord are compressed
What are the causes of CES?
Lumbar disc herniation: the most common cause of CES
Trauma
Spinal tumour
Lumbar spinal stenosis: narrowing of the spinal cord may result in CES. This can be congenital or acquired e.g. spinal osteoarthritis (spondylosis), rheumatoid arthritis, and a slipped vertebra (spondylolisthesis)
Epidural abscess or haematoma
What are the key presentations of CES?
Saddle anaesthesia = (loss of sensation in the perineum) can you feel wiping after poo
Loss of sensation in bladder and rectum (not knowing when they’re full)
Urinary retention or incontinence
Faecal incontinence
What are the investigations for CES?
Examinations: PR exam, knee and ankle reflexes
MRI spine is gold standard
Bladder ultrasound: to determine whether there us urinary retention
What is the treatment for CES?
Emergency decompressive laminectomy: surgery should be performed within24-48 hoursof symptom onset.
The incidence of thromboemboli in patients with CES is remarkably high, therefore patients require adequate thromboprophylaxis
What is the main differential of CES?
Conus medullaris
What is motor neurone disease?
Motor neurone disease is an umbrella term that encompasses a variety of specific diagnoses. They are neurodegenerative diseases that affect both upper and lower motor neurones but sensory neurons are spared
What is the most common cause of Motor Neurone Disease?
Amyotrophic lateral sclerosis (ALS) accounts for 50% of cases
What are some other causes of MND?
Progressive muscular atrophy: LMN only
Primary lateral sclerosis: UMN only
Progressive bulbar palsy: affects muscles of talking and swallowing (second most common) LMN only
ALS: affects both UMN and LMN
What gene is implicated in some cases of ALS?
SOD1
What are the risk factors for MND?
Increasing age (over 60)
Male
Pesticides
Heavy metals
Rugby
What are the general symptoms of MND?
- Progressive weakness of the muscles throughout the body affecting the limbs, trunk, face and speech.
- The weakness is often first noticed in the upper limbs. There may be increased fatigue when exercising.
- They may complain of clumsiness, dropping things more often or tripping over. They can develop slurred speech (dysarthria).
What are the signs of LWN disease?
Muscle wasting
Reduced tone
Reduced reflex
Fasciculations
Loss of power
Babinski reflex negative
What is the cause of LMN injury?
motor neurone - MND< spinal muscular atrophy, polio infection
motor nerve roots - radiculopathy, guillain barre
motore nerves - neuropathies
Neuromuscular junction - myasthenia gravis
Muscles disorder - myositis, myopathies
What are the signs of a UMN lesion?
Increased tone (no UMN to stop actions of LMN)
Brisk reflexes
Rigidity + spasticity
Babinski reflex positive
What is never affected in MND?
Eye muscles (oculomotor movements)
Sensory function and sphincters (onuf’s nucleus)
What are the symptoms of MND?
Progressive weakness
Fatigue - nocturnal respiratory insufficiency (so wake up in night when CO2 builds up)
Falls
Speech and swallow issues
What are the investigations for MND?
MND is a clinical diagnosis
Electromyography: in MND there will be evidence of fibrillation potentials
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
What are some differentials for MND?
MS
Polyneuropathies
Myasthenia gravis
GBS
What is the management for MND
No treatment - large amount of neurones have died before symptoms present
Riluzole prolongs survival by 2-4 months by protecting motor neuron damage form glutamate
Respiratory support: patients with reduced FVC can use non-invasive ventilation at home, usually BiPAP; prolongs survival by 7 months
Supportive treatment:
Antispasmodics: such as baclofen
What is the main cause of death in motor neurones disease?
death 75-80% within 5 years
- most commonly due to respiratory failure
What is spinal muscular atrophy?
- genetic condition that makes the muscles weaker + causes problems with movement
- gets worse over time
- unstable SMN protein produced
- muscle weakness appears symmetrical + proximal
What is Myasthenia Gravis?
A chronic autoimmune disorder of the postsynaptic membrane at the neuromuscular junction of skeletal muscle
When does Myasthenia Gravis affect men and women?
Symptoms peak in women in 20/30s
Symptoms peak in men 50/60s
What are the risk factors for developing Myasthenia Gravis?
Female 2x as common
Autoimmune: linked to rheumatoid and SLE
-Thymoma or thymic hyperplasia: 10-15% have a thymoma and 70% have thymic hyperplasia
Describe the normal physiology of a neuromuscular junction
Axons of motor nerves are situated across a synapse from from the post-synaptic membrane on the muscle cell
The axons release a neurotransmitter from the pre-synaptic membrane. This neurotransmitter is acetylcholine.
ACh travels across the synapse and attaches to nicotinic receptors on the post-synaptic membrane stimulating muscle contraction
What is the main cause of disease in Myasthenia Gravis?
Acetylcholine receptor antibodies present (85%)
These bind to the receptors on the post-synaptic membrane and prevent ACh from binding and causing muscle contraction
The problem is worsened during exercise as more of the receptors become blocked up. So the more the muscles are used the weaker they get. Gets better with rest
These antibodies also activate the complement system which damages cells further making the problem worse
What are the two other antibodies that can cause MG and how do they do it?
Muscle specific kinase (MuSK)
low-density lipoprotein receptor-related protein 4 (LRP4).
They are both proteins that are important for making the acetylcholine receptor. These antibodies lead to inadequate acetylcholine receptors causing MG
What are the signs of MG?
Proximal muscle weakness: often affecting the face and neck
Ptosis (drooping eyelid)
Complex ophthalmoplegia: cannot be isolated to one cranial nerve
Head drop: a rare sign due to weakness of cervical extensor muscles
Myasthenic snarl: a ‘snarling’ expression when attempting to smile
What are the symptoms of MG?
Muscle weakness that gets worse throughout the day
Diplopia: double vision
Slurred speech
Fatigue in jaw while chewing
What is are the investigations for MG?
Look for presence of autoantibodies:
- Acetylcholine receptor (ACh-R) antibodies (85% of patients)
- Muscle-specific kinase (MuSK) antibodies (10% of patients)
- LRP4 (low-density lipoprotein receptor-related protein 4) antibodies (less than 5%)
CT/MRI of thymus gland to look for thymoma
What is another test that can be performed if unsure about MG?
Edrophonium test:
patients given IV Edrophonium chloride (neostigmine). Will prevent breakdown of ACh by cholinesterase enzymes and improve symptoms temporarily
What are the treatments for MG?
First-line: Reversible acetylcholinesterase inhibitors (neostigmine/pyridostigmine)
Second-line: Immunosuppressants: prednisolone/azathioprine
Consider monoclonal antibodies (rituximab)
Thymectomy can also improve symptoms.
What is the main complication of MG?
Myasthenic crisis often triggered by another illness such as respiratory tract infection . Causes an acute worsening of symptoms and can lead to respiratory failure
What is the treatment for a Myasthenic crisis?
Patients may require non-invasive ventilation with BiPAP or full intubation and ventilation.
Medical treatment of myasthenic crisis is with immunomodulatory therapies such as IV immunoglobulins and plasma exchange.
What is the main differential for MG?
Lambert-Eaton myasthenic syndrome
What drugs should be avoided in MG?
Antibiotics;
- aminoglycosides (e.g. gentamicin)
- fluoroquinilones (e.g. ciprofloxacin)
- Macrolides (e.g. azithromycin)
- tetracyclines (e.g. doxycycline)
- quinolones
Neuromuscular blocking agents
Magnesium sulfate
penicillamine
Cardiac drugs - BB
neurological - lithium + phenytoin
What is Lambert-Eaton myasthenic syndrome?
Lambert-Eaton myasthenic syndrome has a similar set of features to myasthenia gravis. It causes progressive muscle weakness with increased use as a result of damage to the neuromuscular junction. The symptoms tend to be more insidious and less pronounced than in myasthenia gravis.
What causes Lambert-Eaton myasthenic syndrome?
Typically occurs in patients with SCLC.
- It is a result of antibodies produced by the immune system against voltage gated calcium channels in SCLC but this also targets the pre-synaptic terminal
These channels are responsible for assisting the release of ACh at the synapse
What is the presentation of Lambert-Eaton myasthenic syndrome?
Proximal muscle weakness that develops more slowly
All other same symptoms really e.g., double vision ptosis, jaw tiredness, slurred speech
What is the difference clinically between Lambert-Eaton myasthenic syndrome and MG?
Lambert Eaton Syndrome symptoms tend to improve following a period of strong muscle contraction.
Post Tetanic Potentiation
What is the treatment for Lambert Eaton Syndrome?
Amifampridine
- allows more ACh to be released in the neuromuscular junction synapses by blocking voltage gated potassium channels
What are some other treatments for Lambert Eaton Syndrome?
Immunosuppressants (e.g. prednisolone or azathioprine)
IV immunoglobulins
Plasmapheresis
What is syncope?
A term used to describe the event of temporarily losing consciousness due to disruption in blood flow.
Known as vasovagal episodes
What are the causes of primary syncope?
Dehydration
Missed meals
Extended standing in warm environment
Vasovagal response to stiumli
What are the causes of secondary syncope?
Hypoglycaemia
Anaemia
Hypovolaemia e.g. due to haemorrhage, GI bleeding, ruptured aortic aneurysm
Infection
Anaphylaxis
Arrhythmias
Valvular heart disease
Hypertrophic obstructive cardiomyopathy
Pulmonary embolism: causing hypoxia
What are some risk factors for syncope?
Elderly
Pregnant women
Certain medications such as - that block vasoconstriction e.g. calcium channel blockers, beta blockers, alpha blockers, and nitrates
Affect the volume status e.g. diuretics
That prolong the QT interval e.g. antipsychotics and antiemetics
What is a vasovagal episode (neurocardiogenic) syncope?
Caused by problems with the autonomic nervous system regulating blood flow to the brain
When the vagus nerve receives strong stimulus it causes an increase in parasympathetic activation which causes vasodilation and reduction in BP and blood flow to brain leading to the loss of consciousness
What is Carotid sinus hypersensitivity?
This occurs when mild external pressure on the carotid bodies in the neck is enough to induce this reflex response.
- Mild pressure could be due to shaving, neck turning, tight collar etc
What is s orthostatic hypotension syncope?
- A drop of blood pressure of more than 20mmHg or a reflex tachycardia of more than 20 beats. When a person goes from lying down to standing
- It occurs when there’s a delay in constriction of the lower body veins, which is needed to maintain an adequate blood pressure when changing position to standing.
As a result, blood pools in the veins of the legs for longer and less is returned to the heart, leading to a reduced cardiac output.
What are the prodrome symptoms for syncope?
Hot or clammy
Sweaty
Heavy
Dizzy or lightheaded
Vision going blurry or dark
Headache
What is loss of consciousness defined as?
Suddenly losing consciousness and falling to the ground
Unconscious on the ground for a few seconds to a minute as blood returns to their brain
Twitching, shaking or convulsion activity, which can be confused with a seizure
What are the primary investigations for syncope?
Clinical Hx and examination
Ix to rule out pathological causes:
Bloods - infection
FBC - anaemia
ECG- arrythmia
Glucose - Hypoglycaemia
B-hCG - ectopic pregnancy
What is a mononeuropathy?
A process of nerve damage that affects a single nerve
What is polyneuropathy?
Disorders of peripheral or cranial nerves whose distribution is usually symmetrical and widespread
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?
WARDS PLC
- Wegner’s granulomatosis
- AIDS
- Rheumatoid arthritis
- Diabetes
- Sarcoidosis
- Polyarteritis nodosa
- Leprosy
- Carcinoma
What is peripheral neuropathy?
Nerve pathology outside of the CNS that affects the peripheral nerves
What are the mechanisms that cause peripheral neuropathy?
Demyelination
Axonal damage
Nerve compression
What can cause peripheral neuropahty?
ABCDE
A- Alcohol
B- B12 deficiency
C- Cancer and CKD
D- Diabetes and drugs
E- Every vasculitis
What drugs can cause peripheral neuropathy?
amiodarone
isoniazid
vincristine
nitrofurantoin
metronidazole
What are the main symptoms of peripheral 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 fee
What is carpal tunnel syndrome?
Compression of the median nerve as it travels through the carap tunnel in the wrist
What two things can cause carpal tunnel syndrome?
Swelling of the contents e.g. swelling of tendons putting pressure on nerve
Narrowing of the tunnel
Who is more commonly affected by carpal tunnel syndrome?
Females due to narrower wrists so more likely to have compression
Over 30s
Where does the median nerve provide sensory innervation for in the hand?
The palmar aspects and full fingertips of the:
- Thumb
- Index and middle finger
- The lateral half of the ring finger
Note that the palmar cutaneous branch of the median nerve provides sensation to the palm. However, this branch originates before the carpal tunnel and does not travel through the carpal tunnel. Therefore, it is not affected by carpal tunnel syndrome.
Where does the median nerve provide motor function for in the hand?
The three thenar muscles which make up the muscular budge at the base of the thumb:
- Abductor pollicis brevis (thumb abduction)
- Opponens pollicis
- Flexor pollicis brevis (thumb flexion)
The other muscle that controls thumb movement is the adductor pollicis (thumb adduction). However, this is innervated by the ulnar nerve.
What are the causes of carpal tunnel syndrome?
Most cases are idiopathic but can be caused by:
- Repetitive strain
- Obesity
- Perimenopause
- RA
- Diabetes
- Acromegaly
- Hypothyroidism
If it is bilateral then think underlying cause
What are the sensory symptoms of carpal tunnel syndrome?
Numbness
Paraesthesia (pins and needles or tingling)
Burning sensation
Pain worse at night wakes from sleep
This occurs in areas innervated so most of the palmar aspects of everything but little finger. Patients may shake hand to relieve pain
What are the motor symptoms of carpal tunnel syndrome?
Weakness of thumb movements
Weakness of grip strength
Difficulty with fine movements involving the thumb
Weakness of the thenar muscles
What are the two tests for carpal tunnel syndrome?
Phalen’s test
Tinel’s test
Durkan’s test
What is Phalen’s test?
Involves fully flexing the wrist and holding it in this position. Often this is done by asking the patient to put the backs of their hands together in front of them with the wrists bent inwards at 90 degrees.
The test is positive when this position triggers the sensory symptoms of carpal tunnel, with numbness and paraesthesia in the median nerve distribution.
What is Tinel’s test?
Involves tapping the wrist at the location where the median nerve travels through the carpal tunnel. This is in the middle, at the point where the wrist meets the hand.
The test is positive when this position triggers the sensory symptoms of carpal tunnel, with numbness and paraesthesia in the median nerve distribution.
What is the management for carpal tunnel syndrome?
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 (last resort)
What are the nerve roots of the radial nerve?
C5-T1
What is the classical presentation of a radial nerve palsy?
wrist drop
What can cause wrist drop?
Damage to the radial nerve e.g. mid shaft fracture of humerus or compression of radial nerve at humerus
What is the classical presentation of an ulnar nerve palsy?
Claw hand (4th/5th fingers claw up)
What is the sign of a Sciatic/Common peroneal nerve Palsy?
Foot drop
What is Charcot-Marie-Tooth disease?
A group of diseases that affect the peripheral motor and sensory nerves
What are the most common forms of Charcot-Marie-Tooth disease?
CMT1 and CMT2
What inheritance pattern are CMT1 and CMT2?
Autosomal dominant
What causes CMT1?
Caused by mutations in the PMP22 and MPZ genes which encode proteins that are part of the myelin sheath made by Schwan cells.
Loss of myelin slows down the transmission of nerve impulses. Over time Schwann cells try and replace myelin.
As a result, under a microscope, there’s often onion bulb formation - the axon is surrounded by layers of new myelin with underlying damaged layers of myelin.
What causes CMT2?
Caused by mutations in MFN2 gene which encodes for a protein in neuronal mitochondria.
When the protein is defective mitochondrial function is disrupted leading to neuronal death
What are the affects of CMT1 and CMT2?
When motor neurones are affected muscles begin to atrophy.
When sensory neurones are affected it first affects the feet and toes as those are the longest axons and most sensitive to damage
What are the signs of CMT1 and CMT2?
Pes cavus: high foot arches
Hammer toes
Distal muscle wasting
Hand and arm muscle wasting
Thickened palpable nerves
What are the symptoms of CMT?
Weakness in the lower legs, particularly loss ofankle dorsiflexion
Foot drop
High-stepped gait
Weakness in the hands
Reduced tendon reflexes
Reduced muscle tone
Peripheral sensory loss
Tingling and burning sensations in the hands and feet
May be neuropathic pain
What are the investigations for CMT?
Nerve conduction studies: measures ability of nerves to conduct impulses
Neurologists and geneticists make the diagnosis by looking for mutations
What is Duchenne’s muscular dystrophy?
A genetic condition that cause gradual weakening and wasting of muscles.
What is another type of muscular dystrophy?
Becker’s
What is the inheritance pattern of Duchenne’s muscular dystrophy?
X-linked recessive
What causes Duchenne’s muscular dystrophy?
There is a mutation which codes for the dystrophin protein which is used to stabilise the muscle fibres. Without it the sarcolemma wilts and becomes unstable.
Overtime cellular proteins e.g. creatinine kinase starts escaping the damaged cell and calcium starts to enter the cell leading to its death
In the short term there is muscle regeneration resulting in muscle fibres of different sizes but in the long term the muscles atrophy and are infiltrated by fat and fibrotic tissue making them really weak
What will a muscle biopsy in Duchenne’s muscular dystrophy show?
Biopsy of the tissue show changes in the muscle itself but not in the nerves which is used to distinguish it between neuropathies
What are the symptoms of Duchenne’s muscular dystrophy?
Symptoms usually present at around 3-5:
- Weakness is muscles around pelvis
- Walking late
- Waddling gait
- Enlarged calves
What is Gower’s sign?
Children with proximal muscle weakness use a specific technique to stand up from a lying position. This is called Gower’s sign.
To stand up, they get onto their hands and knees, then push their hips up and backwards like the “downward dog” yoga pose. They then shift their weight backwards and transfer their hands to their knees. Whilst keeping their legs mostly straight they walk their hands up their legs to get their upper body erect. This is because the muscles around the pelvis are not strong enough to get their upper body erect without the help of their arms.
What are the investigation for DMD?
High creatinine kinase level
Genetic testing looking for dystrophin mutations (can be diagnostic)
Muscle biopsy
Electromyogram: distinguish between neuropathic and myopathic pathology
What are the treatments for DMD?
Occupational therapy
Oral steroids have been shown to slow the progression of muscle weakness
Creatine supplementation can give an improvement in muscle strength
What are the complications of DMD?
Respiratory failure because of a weak diaphragm
Scoliosis
Dilated cardiomyopathy and arrhythmias: dystrophin protein is also expressed in heart muscle.
What is the life expectancy for DMD?
Duchenne’s muscular dystrophy: patients have a life expectancy of around 25 – 35 years with good management of the cardiac and respiratory complications.
Becker’s muscular dystrophy has a better prognosis
What are the different types of brain tumour?
Gliomas
Meningiomas
Pituitary
Hemangioblastoma
Acoustic neuroma
Accounts for less than 2% of all malignant tumours but 20% of childhood cases
What are glioblastomas?
They are tumours in the brain or spinal cord there are 3 types
What are the 3 types of glioblastoma?
Astrocytoma
Glioblastoma multiformeis the most common
Oligodendroglioma
Ependymoma
What is an astrocytoma?
Glioblastoma multiformeis the most common
Most commonly found in cerebral hemisphere
Histologically has pseudo-palisading pattern - peripheral tumour cells lined up around necrotic centre
Grade IV (most malignant)
What is an Oligodendroglioma?
Most common in 40s-50s
Adult oligodendrogliomas typically form in the frontal lobes
Categorised as grade II or III, slow-growing tumours,
Histologically, prominent features can vary from fairly small, round nuclei, surrounded by well-defined “halos” or thick white borders of cytoplasm giving them a “fried egg” appearabce
What is an Ependymoma?
Arise from ependymal cells (form the epithelial lining of the ventricles in the brain and the central canal of the spinal cord)
What is a Meningioma?
They grow from cells found in the arachnoid mater of the meninges
They are usually benign and this can lead to raised intercranial pressure and lead to the neurological symptoms
These tumours may also cause the formation of calcifications called psammoma bodies
What are the symptoms of brain tumours?
They are initially asymptomatic .
- As they develop they present with **focal neurological symptoms.
- Will show signs of raised ICP
What are the focal symptoms of a frontal lobe tumour?
Hemiparesis
personality change,
Broca’s dysphasia,
lack of initiative,
unable to plan tasks
What are the focal symptoms of a temporal lobe tumour?
Dysphagia
Amnesia
What are the focal symptoms of a parietal lobe tumour?
Hemisensory loss
Dysphasia
reduction in 2-point discrimination
astereognosis (unable to recognise object from touch alone
What are the focal symptoms of a cerebellum tumour?
DASHING -
- Dysdiadochokinesis (impaired rapidly alternating movement),
- Ataxia,
- Slurred speech (dysarthria),
- Hypotonia,
- Intention tremor,
- Nystagmus,
- Gait abnormality
What are the symptoms of raised ICP?
Headache
Vomiting
Visual field defect
Seizures
Papilloedema (on fundoscopy)
What are the investigations for a brain tumour?
CT/ MRI
Blood tests e.g. FBC, U&Es, LFT’s, B12
Tissue biopsy: to determine cancer grade and guide management
What is used to grade brain tumours?
Severity is classified by the World Health Organisation’s (WHO) scale
The scale goes from I to IV based on the morphologic and functional features of the tumour cells; a grade IV tumour being the most abnormal looking cells that also tend to be the most aggressive.
How common are secondary brain tumours?
Brain metastasis affects up to 40% of patients with cancer
10 times more common than primary brain tumours
What are the most common metastases of secondary brain tumours?
Lung
Breast
Melanoma
Renal cell
GI
What is ataxia?
problems with balance and coodination
- heterogenous group of disorders
- many different causes
- majority permanent and progressive
What are the types of ataxia?
Inherited
- autosomal dominant =SCA6 and EA2
- autosomal recessive = Friedreich’s ataxia,
- X-linked
- Mitochondrial
- metabolic
Acquired
- toxic/metabolic = alcohol, vitamin deficiencies
- immune mediated = paraneoplastic cerebellar degeneration, gluten related
- infective = post infectious
- degenerative = multi-system atrophy cerebellar variant
- structural
What are the symptoms of cerebellar dysfunction?
- dizzy
- falls, stumble
- difficulty focusing/double vision/’oscillopsia’ (
- slurred speech
- problems with swallowing
- tremor
- problems with dexterity/ fine motor skills
What are the clinical signs of cerebellar dysfunction?
- nystagmus
- dysarthria
- intention tremor/myoclonus
- dysmetria (under/overshoot of movements)
- heel - shin ataxia
- wide gait/limb/truncal ataxia
- tone/reflexes
What is the scale for ataxia?
Scale for the assessment and rating of ataxia (SARA)
- mild = mobilising independently or with one walking aid
- moderate = mobilising with 2 walking aids or walking frame
- severe = predominantly wheelchair dependent
What are the investigations for ataxia?
Blood = FBC, LFTs, ESR, CRP, Gluten, B12, HbA1c, folate
HLA typing for DQ2/DQ8
MRI brain = demonstrate cerebellar atrophy
CT if MRI contraindicated
What is the management of cerebellar ataxia?
no cure so tailored to the individual patient
- specialist services
What is the Cushing Relfex?
A physiological nervous system response to increased intracranial pressure
Triad:
1. Hypertension
2. Bradycardia
3. Irregular breathing
Explain the 3 stages of the Cushing Reflex
- Sympathetic stage = ICP -> sympathetic stimulation -> vasoconstriction -> hypertension
- parasympathetic stage = stimulate baroreceptors in aortic arch -> reduce heart rate
- ICP -> press on resp centre in brain stem -> irregular breathing
Why is there an increase in intracranial pressure after a TIA/stroke?
Ischaemia + necrosis of brain cells -> inflammation + swelling –> increase ICP –> press against blood vessels
Define tremor
involuntary, rhythmic oscillatory movement of a body part
what are the cause of tremors?
- physiological,
- drugs,
- metabolic (hyperthyroidism),
- essential tremor = puts hands out in front of them and can see tremor, carrying cup, faster then PD, family history (autosomal dominant), archimedes spiral (on axis, diagonal)
- dystonic tremor = jerky, variable axis, may be task specific, little finger hyperextended, head tremor
- functional tremor = distractibility (reduce tremor if asked to perform motor task), entrainability (Train tremor to follow rhythm if following someone else’s movement) , variability, unusual pattern, no 2 spirals are the same
Define dystonia
movement disorder characterised by sustained or intermittent muscle contractions causing abnormal, repetitive, movements, postures or both
What are the features and causes of dystonia?
Cause:
- Idiopathic
- Functional
- Genetic = usually starts in childhood in a lower limb
- Secondary
Can affect any part of the body or if after stroke can affect one side of body or focal (writers cramp, cervical,)
- Task specific
- Stop when they touch their face
- Spontaneous remission
- Exacerbation with stress
Define chorea
involuntary, irregular, flowing movement that doesn’t follow a pattern (figidity + restless)
e.g. Huntington’s
Define Tic
brief stereotyped movements or vocalisations that resemble voluntary actions
Define myoclonus
lightning fast, jerky involuntary movements
- Positive - movement contraction
- negative - loss of tone, in liver cirrhosis = asterixis
What is the difference between an organic and functional neurological movement?
Organic = follows a set pattern and fits the definition
Functional = more fluid and doesn’t fit a set definition, can’t be classed as one thing
WHat is the main medication for depression?
SSRI - Selective Serotonin Reuptake Inhibitors
e.g. fluoxetine
What is St John’s Wort and why does it need to be considered when prescribing medication?
Herbal medication
- potent inducer of cytochrome P450
- increases potency = SSRIs
- decreases effect = Contraceptive pill, warfarin, statins, digoxin, anticonvulsants, HIV medication
