neuro anki 2 Flashcards
What is the most common cause of a SAH
Head injury
What would you expect to see on a NCCT head of a patient with an SAH?
Hyperdense blood in basal cisterns/sulci
What would be seen on a LP of a patient with a SAH?
Xanthochromia: breakdown of RBC
What is the immediate treatment for a patient with a TIA?
Immediate antithrombotic therapy: aspirin 300mg unless CI
What is the most common blood vessel implicated in an extradural haemorrhage?
Middle meningeal artery-> thin skull at pterion
Usually arterial
What patient group is most commonly affected by an extradural haematoma?
Young patients with head injury-sports etc
What proportion of patients will have bilateral subdural haemorrhages?
15% adults
80% infants
Why are alcoholics and infants and the elderly more at risk of a subdural haemorrhage?
Brain atrophy
fragile/taut bridging veins
What kind of vessels are implicated in a subdural haemorrhage?
Rupture of bridging veins within subdural space
What proportion of strokes are ischaemic?
85%
15% haemorrhagic
What scoring system in used for those with a potential ischamic stroke?
ROSIER score->0 makes a stroke likely
When is thrombolysis contraindicated in a patient with an ischaemic stroke?
Previous haemorrhage
GI bleed
Recent surgery
Hypertension
Increased INR
When should thrombectomy be considered as a treatment for an acute ischaemic stroke?
If confirmed occlusion of proximal anterior circulation on CTA or MRA (with IV alteplase if <4.5 hours, on its own if 6-24 hours)
Consider: >24 hours: confirmed occlusion of proximal posterior circulation on MRA/CTA/potential to salvage brain tissue
What part of the brain is supplied by the posterior cerebral artery?
Posterior cerebral cortex:Occipital lobe, thalamus etc
What symptoms would you expect with a middle cerebral artery infarction?
Contralateral loss of sensation and motor control to face and UPPER limbs
Broca’s aphasia
What symptoms would you expect with an anterior cerebral artery infarction?
Contralateral loss of sensation and motor control to lower body
What symptoms would you expect with a posterior cerebral artery infarction?
Contralateral homonymous hemianopia
What symptoms would you expect with a basilar artery infarction?
Locked in syndrome-> bilateral loss of corticospinal tracts
What symptoms would you expect with an anterior inferior cerebellar artery infarction?
Contralateral loss of pain and temperature sensation
Lateral pontine syndrome
Ipsilateral:-CN3 palsy
-Vertigo/nystagmus/deafness-
Poor coordination/tone/balance
What vessels are implicated in Weber’s syndrome?
Upper basilar and posterior cerebral
What vessel is involved in a Wallenberg stroke?
Posterior inferior cerebellar artery
What is Horner’s syndrome?
Ptosis
Miosis
Anhidrosis
Damage to sympathetic nerve supply to the eye
What vessels are implicated in a total anterior circulation stroke?
Middle cerebral/anterior cerebral-> large cortical
What vessels are implicated in a partial anterior circulation stroke?
Only part of anterior circulation-> ACA/MCA
What parts of the brain are affected in a posterior circulation stroke?
Cortical
Cerebellum
Brainstem
Vertebrobasilar arteries
What will a CN3 palsy result in?
Occulomotor
Ptosis
‘down and out’ eye
Dilated fixed pupil
What will a CN4 palsy result in?
Trochlear
Defective downward gaze-> vertical diplopia
What is encephalitis?
Inflammation of the brain parenchyma
What part of the brain is most commonly affected by HSV1 encephalitis?
Temporal and inferior frontal lobes
What is meningitis?
Inflammation of the meninges (dura, arachnoid, pia)
Can be infective or non infective
What is the most common fungal cause of meningitis?
Cryptococcus neoformans
What is Waterhouse friedrichsen syndrome?
Adrenal insufficiency caused by intra-abdominal haemorrhage from DIC
Which bacteria is most likley to result in DIC and what does it look like under microbiology?
N.meningitidis
Gram egative diplococcus
What is neurofibromatosis?
Genetic condiiton that causes nerve tumours(neuromas) to develop in the nervous system
Benign but can cause neurological/structural problems
What is neurofibromatosis type 1 also called?
Von Recklinghausen’s syndrome
What is the inheritance pattern of neurofibromatosis type 2
Autosomal dominant
What is the main symptom/complication of neurofibromatosis type 2?
Bilateral acoustic neuromas
What is giant cell arteritis/temporal arteritis?
Vasculitis of unknown cause that affects medium-large sized vessel arteries, especially at the temples
Overlap with PMR
What would be seen on fundoscopy in a patient with giant cell arteritis?
Swollen pale disc and blurred margins
Why is there no forehead sparing in Bell’s palsy?
LMN palsy: affects facial nerve after its entered the brainstem
Contrast stroke: innervation from both hemispheres of the brain
When should patients with Bell’s palsy be referred to specialists?
Urgent ENT referral if no improvement after 3 weeks
Plastic surgery referral if long standing weakness(month)
What is essential tremore?
Common movement disorder characterised by a rhythmic postural or kinetic tremor primarily affecting the upper extremities
What is myasthenia gravis?
Autoimmune disease-> AChR(nicotinic ACH receptor antibodies)
What is the ice pack test for myasthenia gravis?
Measure degree of ptosis
Apply ice pack for a few minutes
Measure degreee of ptosis again
Positive if >2mm improvement
What is the edrophonium test for myasthenia gravis?
Administer small amount of edrophonium chloride(Tensilon): See effects
If rapid, transient increase in muscle strength; indicative of diagnosis
What is Meniere’s disease?
Inner ear disorder caused by increased fluid pressure in the endolymphatic spaces of the membranous labyrinth
What is trigeminal neuralgia?
Chronic pain condition characterised by severe sudden and brief bouts of shooting/stabbing pain that follow the distribution of one or more divisions of the trigeminal nerve, affecting the patients facial region
What is Guillain Barre syndrome?
Ascending inflammatory demyelinating polyneuropathy->acute onset of bilateral and roughly symmetric limb weakness
What might be seen on an LP of a patient with Guillain barre?
albuminocytological dissociation
Increased albumin without corresponding increase in white blood cells
What is the prognosis of Guillain Barre syndrome
Mostly full recovery
Can have residual weakness or fatigue
What is Miller Fisher syndrome?
Variant of GBS
Ophthalmoplegia, areflexia and ataxi(eye muscles affected first-descending paralysis)
Anti GQ1b antibodies in 90%
What is Huntington’s disease?
Genetic disorder that causes progressive breakdown of nerve cells in brain leading to motor, cognitive and psychiatric abnormalitis
What is meant by ‘anticipation’ with regards to genetics in Huntington’s disease
Number of CAG repeats directly correlated with disease severity and age of onset
Symptoms present earlier in excessive generations due to increase in number of repeats