Neuro Flashcards
What is a TIA?
ischaemic neurological event with symptoms lasting <24h
Causes of TIA
atherothromboembolism
cardioembolism (post-mi etc)
hyperviscosity (polycythaemia, sickle-cell anaemia, myeloma)
vasculitis (rare, non-embolic cause)
assessing risk of stroke: what does the ABCD2 score stand for?
A- age >60 (1pt) B- BP>140/90mmHg (1pt) C-clinical features (unilateral weakness 2pt, speech disturbance without weakness 1pt) D-duration (>60min 2pt) D- diabetes (1pt)
Factors for high risk of stroke
ABCD2 score>4
atrial fibrillation
>1 TIA in a week
TIA whilst on anticoagulant
what is amaurosis fugax
renal artery is occluded causing unilateral progressive vision loss (like curtain descending)
investigations for TIA
bloods CXR ECG carotid doppler CT angiography
management of TIAs
- control CV risk factors
- antiplatelet drug = aspirin 300mg for 2 weeks then switch to clopidogrel 75mg
- carotid endarterectomy to remove plaque build up in carotid
Causes of stroke
- thrombus in situ
- cardiac emboli
- atherothroboembolism
- CNS bleeds
risk factors for stroke
- high BP
- smoking
- DM, heart disease, peripheral vascular disease
clinical manifestations of stroke
- worst at onset
- pointers to bleeding = meningism, severe headache, coma
- pointers to ischaemia = carotid bruit, AF, past TIA, IHD
signs of cerebral infarcts
- depends on site
signs of brainstem infarcts
- varied
- quadriplegia, visual/gaze disturbance, locked-in syndrome (aware but unable to respond)
where are lacunar infarcts and what are the 5 syndromes associated?
- basal ganglia, internal capsule, thalamus, pons
- 5 syndromes= ataxic hemiparesis, pure motor, pure sensory, sensorimotor, dysarthria/clumsy hand
signs of MCA occlusion
motor weakness, hemiplegia (paralysis of one side of body)
sensory disturbances
receptive and affective aphasia
signs of ACA occlusion
frontal lobe, drowsiness, changes in logical thinking and personality
signs of PCA occlusion
contralateral hemianopia
differential diagnosis for stroke
head injury
hypo/hypercalcaemia
subdural haemorrhage
tumours, migraine
investigations for stroke
- FAST
- CT/MRI
- ECG (AF)
- CXR (LV hypertrophy)
- Carotid doppler US (stenosis of carotid)
treatment for ischaemic stroke
- thrombolysis = IV alteplase
- aspirin 2 weeks then switch to clopidogrel
- rehab and modify risk factors
treatment for haemorrhagic stroke
- control BP = beta blocker (atenolol)
- surgery = clot evation
acute management of stroke
- protect airway
- maintain homeostasis
- CT/MRI within 1h
- antiplatelets (aspirin 300mg) and thrombolysis (IV alteplase) once haemorrhagic stroke excluded
primary prevention of strokes
control risk factors
lifelong anticoagulant in AF and prosthetic heart valves
what does aspirin do
- blocks cyclooxygenase (COX)
- anti-platelet
what does clopidogrel do
- anti-platelet
- makes platelets less ‘sticky’
causes of subarachnoid haemorrhage
- rupture of berry aneurysm
- arterio-venous malformations
- encephalitis, vasculitis, tumour invading blood vessels, idiopathic
what is a berry aneurysm
arise at site of bifurcations around Circle of Willis and may rupture causing subarachnoid haemorrhage
risk factors for subarachnoid haemorrhage
- previous aneurysm
- smoking/alcohol
- hypertension
- bleeding disorders
- polycystic kidneys, aortic coarctation, Ehlers-Danlos syndrome = associated with berry aneurysm
clinical presentation of subarachnoid haemorrhage
- thunder-clap headache
- precipitated by exertion
- mat be LOC or instant death
- symptoms = vomiting, collapse, seizures, come/drowsiness, photophobia
signs of subarachnoid haemorrhage
- neck stiffness
- Kernig’s sign (stiffness of hamstrings - cant straighten leg when hip flexed)
- retinal, sub-hyaloid, vitreous bleeds
investigations for subarachnoid haemorrhage
- urgent CT
management of subarachnoid haemorrhage
- re-examine CNS often
- keep well hydrated
- nimodipine (CCB) reduces vasospasm so reduces ischaemia
- mannitol to reduce ICP
- surgery = endovascular coiling or surgical clipping
complications of subarachnoid haemorrhage
- re-bleeding
- cerebral ischaemia due to vasospasm
- hydrocephalus due to blockage of arachnoid granulations (needs lumbar drain)
- hyponatraemia
what can skull fractures cause
- may cause contusions and haematomas
- base of skull fracture = LCN palsies or CSF discharge from nose or ear
what are cerebral contusions, what causes them and what can they cause
- bruises on brain surface
- from brain suddenly moving in cranial cavity and being crushed
- causes oozing of blood into brain parenchyma and can cause cerebral oedema and raised ICP
what is a subdural haemorrhage
- between dura and arachnoid mater
- bleeding from bridging veins between cortex and venous sinuses
- blood spreads freely in subdural space so crescent shape
- starts to break down weeks later causing increase in oncotic pressure leading to water being pulled in and growing in size
causes of subdural haemorrhage
minor trauma up to 9 months prior
dural metastases, lowered ICP
symptoms and signs of subdural haemorrhage
- fluctuating consciousness
- physical/intellectual slowing
- sleepiness, headache, personality change, unsteadiness
- raised ICP
- seizures
differential diagnoses for subdural haemorrhage
- dementia
- stroke
- CNS masses
investigations for subdural haemorrhage
- CT/MRI
- crescent shaped collection of blood over one hemisphere
management of subdural haemorrhage
- reverse clotting abnormalities
- IV mannitol to reduce ICP
- surgical removal
what is an extradural haemorrhage
- bleeding from middle meningeal artery after fracture of squamous temporal bone. (temple)
- accumulation of blood is slow
- characteristic lucid period
- any tear in a dural venous sinus can also cause
Clinical presentation of extradural haemorrhage
- appear well for several hours/days then deteriorate quickly
- low GCS from rising ICP
- increasingly severe headache, vomiting, confusion, seizure
- ipsilateral pupil dilates, coma deepens, bilateral limb weakness, breathing becomes deep and irregular
differential diagnosis for extradural haemorrhage
- epilepsy
- carotid dissection
- carbon monoxide poisoning
management for extradural haemorrhage
- urgent surgery
- IV mannitol
- care of airway
what is epilepsy
recurrent tendency to spontaneous episodes of abnormal electrical activity within the brain which manifests as seizures
what are partial seizures (simple and complex)
- localised part of one hemisphere
- simple = consciousness is not affected
- complex = consciousness is impaired
what are generalised seizures
- no features referable to one hemisphere
- consciousness always impaired
- absence seizures
- tonic-clonic (LOC with stiffening then jerking movements)
- myoclonic (sudden jerking)
what are focal seizures
- one hemisphere, often with underlying structural disease
- without LOC
- with LOC = usually from temporal lobe, postictal confusion
- evolving to a bilateral, convulsive seizure (turns into generalised seizure)
presentation of temporal lobe seizure
emotional disturbances, dysphagia, hallucinations, bizzare associations
presentation of frontal lobe seizure
motor features (peddling movements), motor arrest, dysphagia or speech arrest, post-ictal Todd’s palsy (limb paralysis for hours after)
presentation of parietal lobe seizure
sensory = tingling, numbness, pain
motor
presentation of occipital lobe seizure
visual phenomena = spots, lines, flashes
investigations for seizure
- look for provoking causes
- EEG
- MRI for structural lesions
- drug levels
what AED (anti-epileptic drug) is used for focal seizures
carbamazepine
what AED for generalised seizures (tonic-clonic, abscence, myoclonic, tonic)
sodium valproate
management of epilepsy
- monotherapy or combination therapy with AEDs
- epilepsy surgery = vagal nerve stimulator = palliative treatment
what is Parkinson’s disease
-neurodegenerative hypokinetic movement disorder characterised by parkinsonism, neuronal loss and Lewy bodies concentrated in substantia nigra
pathology of parkinsons
- normal = neurones from substantia nigra connect to the putamen and globus pallidus where they release dopamine and control movement
- lack of dopamine release and loss of dopaminergic neurones in SN
- other parts of nervous system involved
- most are sporadic but can be many genetic loci
clinical manifestation of parkinsonism (classical triad)
1) tremor = worse at night
2) rigidity = hypertonia
3) bradykinesia (parkinsonism) = slow to initiate movement = shuffling, pitched forward gait
- autonomic dysfunction, cognitive/behavioural disturbance, sleep disfunction (rapid eye movement sleep disorder)
what may patients with parkinsons develop
- dysphagia
- depression
- dementia
investigations for parkinsons disease
- clinical
- clinical response to dopaminergic therapy is supportive
- signs worse on one side
- MRI = atrophy of substantia nigra
management of parkinsons disease
- dopaminergic drugs (eg levodopa) for symptom easing but longterm use can cause seveer dyskinesias
- co-careldopa = levodopa + carbidopa
- dopamine receptor agonists = pramiprexole
- tremor management with anti-cholinergics (amantadine)
what is Huntington’s chorea
- inherited autosomal dominant neurodegenerative disorder caused by mutation of the HTT gene
genetics of Huntingtons chorea
- HHT gene mutation on chromosome 4
- > 36 trinucleotide repeats (CAG) = higher the number, the fuller the penetrance and earlier the onset.
- anticipation = expansion of repeats in each successive generation
pathology of huntingtons
- huntingtin = protein coded by HHT, expressed in all cells but highest concentration in brain and testis.
- mutated huntingtin is cytotoxic to certain cells = neurones in caudate nucleus and putamen
- atrophy and neuronal loss of striatum and cortex.
- loss of neurotransmitters
what neurotransmitters are lost in huntingtons
- GABA, ACh, glutamate
clinical manifestations of huntingtons
- chorea (uncontrolled, random , jerky movements) caused by decrease of GABA and unbalanced dopamine
- motor, neuropsychiatric and cognitive decline
what does huntingtons chorea always result in
dementia
differential diagnoses for huntingtons
SLE
MS
investigations for huntingtons
- clinical
- abnormal eye movements
- chorea = random, unpredictable movements
- often parkinsonism = regidity and slowness of fine finger movements
management of huntingtons
- chorea and aggression= risperidone (dopamine receptor antagonist)
- depression = sertraline (selective serotonin reuptake inhibitors)
- psychosis = haloperidol (neuroeptics)
primary headaches
migraine, cluster, tension
secondary headaches
- meningitis
- subarachnoid haemorrhage
- giant cell arteritis
- idiopathic intracranial hypertension
- medication overuse headache
what symptoms of headache need urgent referral
- thunderclap
- seizure or new headache
- suspected encephalitis
- red eye (acute glaucoma)
- headache and new focal neurology (papilledema)
headache red flags
new onset and history of cancer
papilledema
cluster headache
headache exam
fever
altered consciousness
neck stiffness/ kernig’s sign
focal neurology signs
clinical presentation of migraine
- unilateral, throbbing headache +/- aura
- nausea/vomiting
- sensory disturbances
diagnostic criteria for migraine
> 5 headches lasting 4-72h + nausea + unilateral/pulsating/ impairs routine activity
management of migraines
- propranolol (beta blocker) to reduce frequency (prophylactic).
- oral triptan (severe) + NSAID/paracetamol during attack
- non-pharmaceutical therapies = cold packs etc
what is a tension headache
- very common
- bilateral, tightening, mild/moderate pain, not aggravated by physical activity, no nausea
cause of tension headache
missed meals, conflict, stress, clenched jaw, overexertion, lack of sleep, depression
clinical manifestations of cluster headache
- rapid onset of excruciating pain around one eye that may become watery, bloodshot, lid swelling, lacrimation, facial flushing.
- unilateral
- last 15 min - 3h (once/twice a day)
- clusters last 4-12 weeks and are followed by pain free periods of months to years
management of cluster headaches
- treatment = 100% oxygen for 15 min + sumatriptan sc 6mg
- preventative = avoid triggers, corticosteroids short term, verapamil (CCB)
how do triptan drugs work
- used for migraines and cluster headaches
- serotonin receptor agonists
- vasoconstriction of pain sensitive intracranial vessels
what is the criteria for a drug overuse headache
- > 15 days/month
- use of drug for >3months (ergotamine, triptans, opioids)
what is the treatment for drug overuse headache
withdraw drug
what is giant cell arteritis
vasculitis of medium/large vessels mostly head and neck arteries in >50s
clinical manifestations of giant cell arteritis
- over weeks/months with fever, anorexia, weightloss
- temporal artery = headache, scalp tenderness, jaw claudication
- ocular vessels = blindness
- aortic involvement = thoracic or abdominal aortic aneurysm formation
investigations for giant cell arteritis
- positive temporal artery biopsies (lymphohistiocytic infiltrate and giant cells)
- ESR/CRP raised, raised platelets, low Hb
- criteria = >50y/o, new headache, temporal artery tenderness and decreased pulsation, ESR>50, abnormal biopsy
management of giant cell arteritis
- prednisolone PO immediately or IV methylprednisolone if evolving vision loss
main cause of death = long term steroid treatment