Neurological Flashcards
What would a patient with an oculomotor nerve palsy look like?
Unilateral complete ptosis
Eye down and out
Fixed dilated pupil in both direct and consensual light reflex (note opposite eye would dilate as consensual reflex still present)
If partial nerve palsy it would spare pupillary and lid parasympathetic nerves
Causes of optic nerve lesion
- optic/retrobulbar optic neuritis
Optic nerve compression eg pit tumour/aneurysm
Toxic/ischaemic/hereditary optic neuropathy
Vit B12 def
Trauma
infection
papilloedema
Causes of oculomotor nerve lesion
Aneurysm of posterior communicating artery
Internal carotid aneurysm
Microvascular infarction eg diabetes (spares pupil)
Midbrain infarction
Demyelination brainstem- MS
Myasthenia, orbital mass, inflammation
Causes of UMN facial palsy (spares forehead)
Stroke with hemiparesis on contralateral side Intracranial tumour MS Syphilis HIV
Causes of LMN facial palsy
Bells palsy Ramsey hunt syndrome Infection- lyme disease, TB otitis media skull # CPA tumours diabetes sarcoidosis Stroke- brainstem lesion demyelination-MS
Where is the damage in internuclear opthalmoplegia?
Damage to medial longitudinal fasciulus in brainstem and causes:
- disconjugate horizontal movements
- incomplete adduction of ipsilateral eye
- coarse jerky nystagmus of opposite abducting eye
Which nerves are affected in cavernous sinus syndrome and what are the symptoms?
Ipsilateral III, IV, VI, V1
Painful opthalmoplegia with fixed dilated pupil
Orbital congestion, chemosis, periorbital oedema
Proptosis
Sensory loss over V1 and possible horners
What causes cavernous sinus syndrome?
- tumours- nasopharyngeal/menigiomas
- pit apoplexy
- vascular- aneurysms of carotid, carotid sinus AV fistula, aseptic thrombosis
- infections
- granulomatous disease
What nerves are affected in Jugular foramen syndrome and what are the symptoms?
IX, X, XI Dysphagia, dysphonia Sensory loss of posterior 1/3 tongue, soft palate, larynx Sternocleidomasteoid/trapezius atrophy Absent gag reflex Headache/hydrocephalus/raised ICP
What nerves are affected in CPA syndrome? what are symptoms?
V, VII, VIII (less commonly VI, IV, X)
Facial sensory loss LMN facial weakness without hyperacusis Sensorineural hearing loss and tinnitus Nystagmus and gaze palsies If grows and puts pressure on cerebellum- ataxia
Which syndrome causes an ipsilateral 3rd nerve palsy and contralateral hemiparesis?
Weber’s syndrome
What are the differential diagnoses of stroke?
SOL: tumour, abscess, parasities Viral encephalitis Neuroinflammatory Metabolic Migraine Epilepsy- Todds paresis following a focal seizure Neuropsychiatric
What investigations would you do in a possible stroke?
Bloods: FBC, glucose, clotting, ESR, TFTs, ANA ECG- AF CT brain SALT review CXR- aspiration fasting glucose and lipids Thrombophilia screen MRI brain 24hr tape Carotid doppler
What is the acute management of stroke?
Confirm ischaemia
- Thrombolysis within 4.5hrs if no contraindications
- 300mg aspirin continued for 2 weeks
- If in AF wait 2 weeks until starting anti-coag
- Keep glucose 4-11mmol/L
- monitor BP- anti-hypertensives only given in hypertensive emergency eg encephalopthy, nephropathy, CCF
Who would be referred for hemicraniotomy?
Refer within 24hrs onset
Age <60yrs
Clinical deficits suggesting a MCA infarc with NIHSS score>15
Decrease in level of conciousness
Signs on CT of infarct of at least 50% MCA territory +/- additional territory of ant/post cerebral artery
Name some contraindications to thrombolysis?
Seizure at onset of stroke Symptoms suggestign SAH stroke/serious head injury in last 3 months Major surgery or trauma in last 2 weeks Previous intracranial haemorrhage Intracranial neoplasm AV malformation or aneurysm GI/urinary tract haemorrhage in last 3 weeks LP in preceeding week Current INR>1.7 Acute pericarditis Glucose <2.7 Preganancy
What are the acute and chronic complications of stroke?
Acute: raised ICP, haemorrhagic transformation, aspiration pneumonia
Chronic: pneumonia, contractures, DVT, pressure sores, UTI, constipation, depression, seizures, thalamic pain syndrome
What would you use in the secondary prevention of stroke?
Clopidogrel 75mg OD (if TIA on aspirin and dypyridamole)
Anticoagulation if in AF ( wait 2 weeks after stroke, start immediately if TIA)
Statin- aim to reduce non-HDL by 40%
Treat hypertension
LIfestyle- smoking, alcohol, exercise, diet
What score is used in strokes?
NIHSS (National institute for health stroke score)- used to assess severity of stroke and is scored out of 42.
Uses level of conciousness, gaze, visual field deficit, motor and sensory deficit, dysarthria, ataxia etc
WHat new interventional treatment for strokes is becoming available?
Mechanical thrombectomy- intra-arterial clot retrival via cannulation of femoral artery.
Used for people with proximal vessel occlusion.
NNT for 1 person to acheive functional independance is 2.6. Ideally done within 5hrs
How would you investigate and manage a patient with possible SAH?
- CT head- 95% accurate if done within 48hrs
- LP 12hrs later- xanthochromia
- Arterial imaging- CT/MR angiography
- supportive care- stabilise BP, ventilation, avoid hyperglycamia and hyperthermia
- stop anti-coagulation
- Commence nimodipine- reduce risk of vasospasm
- Liaise with neurosurgery- ? clipping/endovascular coiling
What are the clinical features of MS?
OPtic neuritis: pain behind eye on movement, reduction in visual acuity, colour desaturation, RAPD. Visual acuity reaches nadir at 2 weeks
Diplopia: VIth nerve palsy or INO
Spinal cord syndrome: sensory disturbance, paraparesis, bowel/urinary dysfunction
Weakness and spasticity =0 later
Cerebellar signs- unsual at presenations
Dysarthria, dysphagia, pain, trigeminal neuralgia
Lhermittes sign: electric shock on flexion of neck
Uhtoffs phenomonen: worsening symptoms with rise in body temp
What investigations would you request for a patient with possible MS?
ESR, ANA, ANCA, dsDNA, ENA, anti-phospholipid
MRI: classical peri-ventricular white matter lesions and involvement of corpus callosum. Other sites are juxtacortical white matter, brainstem, cerebellum, spinal cord
Visual and auditory evoked potentials
CSF- mild raised WCC, unmatched oligoclonal bands
What criteria can be used to diagnose MS without 2 episodes occuring?
Revised McDonald criteria using MRI evidence of active and previous lesion or further MRII showing new lesion 30 days apart