Neuro Flashcards
How is SAH confirmed
CT head
- acute blood (hyperdense/bright on CT)
- CT is negative for SAH in 7% of cases
LP used to confirm SAH if CT negative
- perform at least 12 hours following onset of symptoms to allow the development of xanthochromia (helps distinguish true SAH from traumatic tap)
- as well as xanthochromia, CSF findings consistent with subarachnoid haermorrhage include a normal or raised opening pressure.
REFER TO NEUROSURG as soon as SAH confirmed.
Tx of SAH
After spontaneous SAH is confirmed, the aim of investigation is to identify a causative pathology that needs urgent treatment:
- CT intracranial angiogram (to identify a vascular lesion e.g. aneurysm or AVM)
- +/- digital subtraction angiogram (catheter angiogram)
Most intracranial aneurysms are now treated with a coil, but a minority require craniotomy and clipping by neurosurgeon
Vasospasm is prevented using a 21 day course of nimodipine (CCB targeting brain vasculature)
What is Lambert Eaton syndrome
Seen in association with small cell lung cancer or as an autoimmune disorder.
Antibody against presynaptic voltage gated calcium channels in the PNS
- repeated muscle contractions lead to increased muscle strength (as opposed to myaesthenia)
- limb girdle weakness
- hyporeflexia
- autonomic symptoms
Tx - underlying cancer
- immunosuppression
Myaesthenia Gravis vs Lambert Eaton?
MG - increased fatiguability with exercise
LES - weakness improves with exercise
What is a vestibular schwannoma and how does it present?
How to investigate?
Also known as acoustic neuroma, is a cerebellopontine tumour that affects the (8th) vestibulocochlear nerve. may also affect the trigeminal and facial nerve during the late stages.
Unilateral sensorineural hearing loss (most common symptom), tinnitus and dizziness.
Trigeminal and facial nerve involvement may manifest as unilateral facial pain (absent corneal reflex too) and unilateral facial weakness respectively.
bilateral vestibular schwannomas are associated with Neurofibromatosis type 2
1st line Ix: audiogram and gadolinium-enhanced MRI head scan. urgent referral to ENT
Common adult brain tumours?
Metastases
- often multiple and not treatable with surgical intervention
- tumours that commonly spread to brain include: lung, breast, bowel, skin (melanoma), kidney
Meningioma - 2nd most common
- typically benign
- arise form the dura mater of the meninges, cause their symptoms via compression rather than invasion
- CT will show contrast enhancement. Tx can be either observation, radiotherapy or surgical resection
GBM
- most common primary tumour in adults
- v poor prognosis
- imaging: solid tumours with central necrosis and a rim that enhances with contrast. BBB disrupted to associated with vasogenic oedema
- surgery with post op chemo/radio. dex for oedema
Acute and chronic management of migraine
Acute:
- oral triptan + NSAID or oral triptan + paracetamol
Prophylaxis: topiramate or propranolol
(in women of childbearing age propranolol is preferred as topiramate may be teratogenic)
Stroke management acutely
If <4.5 hours - thrombolysis (alteplase) AND thrombectomy
- acute ischaemic stroke and confirmed occlusion of the proximal anterior circulation
- obvi exclude haemorrhagic
within 6 hours but >4.5 - thrombectomy
- acute ischaemic stroke and confirmed occlusion of the proximal anterior circulation
- potential to salvage brain tissue
Within 24 hours of symptom onset, and once haemorrhagic excluded - 2 weeks aspirin 300mg then long term clopidogrel (aspirin + MR dipyridamole if aspirin not tolerated)
statin if cholesterol >3.5mmol (many delay 48 hours due to risk of haemorrhagic transformation)
don’t lower BP unless acute complications e.g. hypertensive encephalopathy
What nerve is at risk with fracture of surgical neck of humerus?
Axillary nerve winds around the bone at the neck of the humerus. The Axillary nerve is also at risk during shoulder dislocation
Erbs vs Klumpke palsy?
Erbs palsy - injury to upper group of arms nerves, specifically brachial trunks c5-6
Klumpke - involves brachial trunks C8-T1. involvement of T1 may cause a Horner’s syndrome
Localising features of focal seizures
Temporal - hallucinations, epigastric rising/emotional, automatisms (lip smacking, grabbing, plucking), deja vu/dysphasia post ictal)
Frontal (motor) - head/leg movements, posturing, post ictal weakness, jacksonian march
Parietal (sensory) - paraesthesia
Occipital (visual) - floaters/flashes
Cluster headache management
acute: 100% O2, subcut triptan
prophylaxis: verapamil
Neurofibromatosis vs tuberous sclerosis? what the hell is going on here please learn
no fucking clue mate
Investigations for mysathenia gravis?
single fibre electromyography
Ct thorax to exlude thymoma (present in 15%)
CK is normal
autoantibodies - to ACh in around 85-90%, in the remaining, 40% for anti-muscle-specific tyrosine kinase abs
Tensilon test (not commonly used)
Mx myasthenia Gravis
Long-acting acetylcholinesterase inhibitors - PYRIDOSTIGMINE is first line.
Prednisolone is added as adjunctive treatment if pyridostigmine does not resolve her symptoms well enough.
down the line - cyclosporine, mycophenolate mofetil
thymectomy
Crisis - plasmapharesis, IVIg
Stroke associated effects with the sites of the lesions
Anterior cerebral artery
- contralateral hemiparesis and sensory loss
- lower extremity > upper
Middle cerebral artery
- Contralateral hemiparesis and sensory loss, upper extremity > lower
- Contralateral homonymous hemianopia
- Aphasia
Posterior cerebral artery
- contralateral homonymous hemianopia with macular sparing
- visual agnosia
Lacunar strokes
- either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia
- strong association with hypertension
- common sites - basal ganglia, thalamus, internal capsule
Guillain-Barre syndrome features
Ix
rapidly progressive peripheral neuropathy with lower motor neurone signs (hyporeflexia)
Often follows a diarrhoeal illness, esp campylobacter
- around 65% patients get back/leg pain in initial stages
- weakness is classically ascending
proximal muscles usually affected before distal ones - reflexes reduced or absent
- sensory symptoms tend ot be mild
IX:
- LP: rise in protein + abnormal WCC in 66%
- nerve conduction may be performed
Parkinson’s plus syndromes?
do this answer lol