Neuro Flashcards
What disease causes a rapidly progressive decline and what other features would you see?
Creutzfeldt-Jacob disease
prion infection causing spongiform encephaopathy
causes rapidly fata demetia - death within 1 year
myoclonic jerks and extra-pyramidal signs
causes - sporadic, infected hosipital infection, familial, blood transfusions in 1995
What is Huntington’s disease?
autosomal dominant disease with 100% peetrance - trinucleotide expansion repeat of CAG.
symptoms - cognitive decline –> progresses to subcortical dementia, personality change, choreinform involuntary movements, dysarthria, psychiatric disturbance.
genetic test - children must wait until old enough to decide
What is the pathophysilogy of HD?
reduced GABA (reduced inhibition) causing dopamine hypersensitvity and increase in dopamine transmission increased stimualtion at thalamus and cortex --> involuntary movements
Name 2 medical conditions that can cause psychiatric symptoms?
neurosyphilis - grandiosity, euphoria, mania, personality change
Wilson’s disease - copper excess leading to both neuro and psych changes, liver disease and kayser-fleischer rings
Name a potentially reversible cause of dementia?
Normal pressure hydrocephalus
triad of - ataxia, dementia and urinary incontinence
causes - idiopathic, SAH, head trauma, meningitis
tx with ventriculoperitoneal shunt
What are the features of an ataxc gait?
wide-based
falls
cannot walk heel-to-toe
often worse in the dark or with eyes closed
What are the 2 main causes of an ataxic gait?
- cerebellar problem
2. issue with proprioception
What are the cerebellar causes of an ataxic gait?
MS
posterior fossa tumour
alcohol
phenytoin toxicity
deficits are ipsilateral to cerebellar lesion
What are the features of cerebellar syndrome?
ataxia + nystagmus
What are the proprioceptive causes of an ataxic gait?
sensory neuropathies - low B12
inner ear problems affecting the vestibular system
How do you distinguish between a cerebellar and proprioceptive cause of ataxic gait?
walk normally with eyes open, problems start when eyes closed –> proprioceptive
problems exists all the time –> cerebellar
What are the features and causes of a circumduction (spastic) gait?
features - stiff gait, circumduction of the legs +/- scuffing of the toe of the shoes
cause - strone (hemiplegia)
What are the features and causes of a shufflinf (extra-pyramidal) gait?
features - flexed posture, shuffling feet, postural instability, slow to start
cause - Parkinson’s diease, PD+ syndromes, other causes of Parkinsonism such as antipsychotic medications
What are the causes of an antalgic gait?
AKA limping
MSK cause - painful limb
What are the features and causes of high stepping gait?
features - trip over often, struggle with dorsiflexion of the foot, lift ffeet high whilst walking to avoid tripping over
cause - foot srop (common peroneal nerve pasly)
What are the features and causes of Trendelenberg gait?
Features - unstable hip, sound side sags on Tredelenberg test
Causes - congenital hip dislocation, DDH, gluteus medius muscle weakness, superior gluteal nerve damage
What are the features and causes of an apraxic gait?
features - glued to the floor when attempting to walk, wide based unsteady gait with a tendency to fall (novice on ice)
causes - normal pressure hydrocephalus, multi-infarct states, Alzheimer’s disease
How does the onset of an episode of weakness help you assess the cause of it?
Sudden onset - likely to be a vascular event
medium onset - likely to be related to demyelination
insidious onset - slow-growing tumours etc
What are the patterns and distributions of muscle weakness?
- proximal weakness - muscle problem - hair, chair, stairs - struggle to do things close to their trunk
- distal weakness - nerve problem - nueropathy starts distally and works its way up - glove and stocking distribution
- symmetrical - genetic or metabolic cause eg. diabetes, muscular dystrophy
- asymmetrical - vasculitis or inflammatory
- mononeuropathy - entrapment
- polyneuropathy - systemic like diabetes
What are the features of peripheral neuropathy?
chronic and slowly progressive
length-dependent
sensnory, motor or both
glove and stocking distribution
How does mononeuritis multiplex present and what are some causes?
individually erves picked off randomly - wrist drop, leg numbness, foot drop
subacute presentation (months) inflammatory/immune-mediated
causes - inflammation of the vasa nervorum can block off the blood supply to the nerve causing sudden deficit
vasculitis (Wegner’s, PAN, RA), sarcoidosis
Give some examples of entrapment mononeuropathies.
Median nerve at wrist = carpal tunnel syndrome
ulnar nerve at elbow
radial nerve at axilla
common peroneal nerve in leg
What causes a myasthenic crisis?
infection
natural part of the disease
under or overdosing of medication
How should a myasthenic crisis be treated?
urgent neuro review
monitor breathing - serial FVC measurements
anaesthetic review
How does muscular dystrophy present and what clinical test can be done to demonstrate it?
presents in childhood with proximal muscle weakness
can have bulky muscles at first = pseudohypertrophy
then muscle wasting occurs
scoliosis is prominent later on
Gower test = positive
How is myopathy investigated?
creatinine kinase
EMG
ESR, CRP
+/- genetic (DMD, Becker)
+/- biopsy
What is the definition of coma/brain death?
unarousal unresponsiveness
What are the 3 domains used in assessing the Glasgow Coma Scale (GCS)?
- best eye opening response
- best verbal response
- best pain response
What are the 4 levels of best eye opening response?
- spontaenously
- to speech
- to pain
- None
What are the 5 levels to best verbal response?
- orientated in time/place/person
- confused
- inappropriate words
- incomprehensible sounds
- none
What are the 6 levels o best pain response?
- obeys commands
- localises pain
- normal flexion to pain (aka withdraws from pain)
- abnormal flexion to pain (decorticate response)
- extends to pain - decerebrate response
- none
What causes a fixed dilated pupil?
3rd nerve palsy
occulomotor nerve comes out of the brain stem and goes over the apex of the petrous part of the temporal bone as goes through the cavernous sinus to supply the eye. This means it’s susceptible to being damaged when the brain is swollen, bleeding, trauma, etc.
parasympathetic fibres’ job is to constrict the pupil so when they are damaged the pupil is fixed in the dilated position.
What is another differential for fixed dilated pupil?
blind eye
What are some metabolic causes of coma?
drugs, poisoning - alcohol, tricyclics, carbon monoxide
hypoglycaemia
hyperglycaemia - ketoacidotic or HONK (hyperglycaemic hyperosmotic non-ketotic coma)
hypoxia
CO2 narcosis (COPD) - when people are given too much oxygen, the hypoxic drive to breathe slows down, which means CO2 builds up and can lead to lethal hypercapnia
Septicaemia, hypothermia, myxoedema, Addisonian crisis, hepatic/uraemia encephalopathy due to kidney or liver failure
What are some neurological causes of coma?
trauma
infection - meningitis, encephalitis, HSV
vascular - stroke, SAH, hyptertensive encephalopathy
epilepsy - non-convulsive status epilepticus, post-ictal state
How is the unconscious patient managed?
ABCDE
IV access
stabilise cervical spine (esp in trauma)
control any seizures - phenytoin
tx potential causes - IV glucose, thiamine, naloxone if pinpoint pupils
brief collateral hx and exam
vital signs and pupils checked often
investigtions - blood, cultures, CXR, CT head
continually re-assess and plan investigations
What is the definition of vertigo?
An illusion of movement, often rotary, of the patient or their surroundings
spinning.tilting.veering sideways feeling
as if being pushed or pulled
always worse with movement
What are the causes of vertigo?
motion sickness
alcohol intoxication
benign paroxysmal positional vertigo - disturbance of crystals in the ear, worse when turning head or rolling over in bed
acute labyrinthitis - severe vertigo, acute onset, usually viral adn settles down
Meniere’s disease - triad of vertigo, hearing loss and tinnitus - abnormal fluctuations in endolymphatic fluid, attacks that come and go
Ototoxicity - aminglycoside antibiotics (gentamicin), thiazide diuretics, lithium
Acoustic neuroma - unilateral hearing loss and vertigo causes by Scwannoma in the brain
Traumatic damage involving petrous part of temporal boe
herpes zoster around the external acoustic meatus
Which medications are associated with ototoxicity that can present as vertigo?
aminogylcoside antibiotics like gentamicin
thiazide diuretics
lithium
What are some features in the history which would point you away from a diagnosis of vertigo?
feeling faint
light-headedness
loss of awareness during attacks
How would you investigate vertigo?
hx
tilt table test
MRI scan if suspecting acoustic neuroma
How is vertigo managed?
symptomatic tx for dizzinessin acute labyrinthitis - prochlorperazine (stemil)
antihistamines can help with dizziness - cinnarizine
How does a headache due to venous sinus thrombosis present?
subacute or sudden headache
papilloedema - do fundoscopy!!
What are the symptoms of a sinusitis headache?
dull, constan ache over frontal/maxillary sinuses, may also be felt right in the middle of the nose/forehead tenderness post-nasal drip pain worse when leaning forwards common with coryza pain lasts 1-2 weeks
How does acute glaucoma present?
elderly, long-sighted people
constant aching pain develops rapidly around one eye, radiating to the forehead
symptoms - markedly reduced vision, visual halos, nausea/vomiting
signs - red congested eye, cloudy cornea, dilated non-responsive pupil (may be oval shaped), decreased acuity
What sort of things can precipitate acute glaucoma?
dilating eye-drops
emotional upset
sitting in the dark (cinema)
How do you treat acute glaucoma?
immediate expert help
IV acetazolamide - a carbonic anhydrase inhibitor
How are migraines treated and prevented?
Tx - NSAID + triptan or paracetamol + triptan
Prophylaxis - topiramate or propranolol
How are cluster headaches treated?
acute attack - 100% oxygen for 15 mins + sumatriptan SC
prophylaxis - verapamil
How is trigeminal neuralgia treated?
Carbamazepine
What are the clinical features and treatment of giant cell arteritis?
exclude in all >50 with headache lasting a few weeks
tender, thickened, pulseless temporal arteries
jaw cluadication
ESR>40
tx - stat high dose methylprednisolone
What are the main signs of Parkinson’s disease?
- bradykinesia (cardinal sign)
- rigidity
- pill-rolling resting tremor
- shuffling gait
- loss of postural reflexes
What are some red flag symptoms which may lead you to believe that it’s not PD but instead a PD+ syndrome?
Early falls
ealy cognitive decline
early bladder and bowel dysfunction
both sides affected equally
What are the 4 PD+ syndromes?
- progressive supranuclear palsy (PSP)
- cortico-basal degeneration
- Multi-system atrophy
- Lewy body dementia
What are the features of progressive supranuclear palsy?
early falls early cognitive impairment occurs above the nuclei of C3, 4 and 6 difficulty moving the eyes ocular cephalic reflex will be present (caused by supranuclear issue) they tilt/turn their head to look at things rather than moving their eyes
What are the features of multi-system atrophy?
early bladder and bowel dysfunction
autonomic involvement i.e. casuing postural hypotension and falls
What are the features of Lewy Body dementia?
early visual hallucinations
clouding of consciousness
sleep behaviour disorder
What are the extra features of cortico-basal degeneration?
early myoclonic jerks
apraxia
agnosia
alien limb
What are the 3 types of tremor and what can cause them?
- intention - cerebellar issue
- resting - PD
- Postural - anxiety, increased adrenaline, slabutamol, valproate, lithium, benign essential tremor
What are some neurological causes of altered sensation?
MS
peripheral neuropathy due to DM
GBS - ascending paralysis and numbness
Spinal cord compression - legs, saddle anaesthesia
What are some causes of blackouts/LOC?
vasovagal - neruocardiogenic syncope situational syncope carotid sinus syncope epilepsy NEA drop attacks - cataplexy, hydrocephalus hypoglycaemia orthostatic hypertension anxiety - hyperventilation factitious blackouts choking
What are the vascular causes of unilateral vision loss?
amaurosis fugax
central retinal artery occlusion
central retinal vein occlusion
anterior ischaemic optic neuropathy (think GCA)
stroke affecting the occipital lobe
GCA
vitreous haemorrhage - diabetic retinopathy, CRVO, macular degeneration
What are the non-vascular causes of unilateral vision loss?
optic neuritis (MS) retinal detachment - flashes/floaters with decreased vision acute angle closure glaucoma - painul red eye, N&V
What investigations would you do in someone presenting with unilateral vision loss?
full eye exam - movements, acuity, fundoscopy
MRI
VEP - visual evoked potentials - helps dx optic neuritis
Fluorescecin angiography - central retinal vein occlusion
tonometry - measures intra-ocular pressure (glaucoma)
USS - ocular USS to look for vitreous haemorrhage/retinal detachment
LP - shows oligoclonal bands in MS
What can cause spinal cord compression?
malignancy or benign mass infection (epidural abscess) disc prolapse haematoma (esp if on warfarin) myeloma - rule out in anyone >50 with back pain
Secondary malignancy is the most common cause of cord compression. What are the 5 cancers which spread to the bone?
Breast Thyroid Prostate Kidney Lung
What is the ddx for cord compression?
transverse myelitis MS trauma dissecting aneurysm GBS
What causes dyarthria?
cerebellar disease
extrapyramidal disease i.e. stroke
pseudobulbar palsy - MND, severe MS
bulbar palsy - facial nerve palsy, GBS, MND
What is the difference between bulbar and pseudobulbar palsy?
pseudo - affects upper motor neurones
bulbar - affects te lower motor neurone (of C9, 10, 11, 12)
pseudobulbar dysarthria - slow, nasal, effortful “hot potato” voice
bulbar dysarthria - nasal speech due to paralysis of the palate
What causes dysphonia (reduced volume of speech due to weakness of respiratory muscles)?
Myasthenia gravis
Gullain Barre Syndrome
Parkinson’s disease (dysphonia + dysarthria)
How does Broca’s dysphasia differ from Wernicke’s dysphasia?
Broca’s - expressive - non-fluent speech produced with effort and frustration, malformed words, reading and writing are impaired but comprehension is intact.
Wernicke’s - receptive - empty, fluent speech, cannot respond to requests. Reading, writing and comprehension are impaired, replies are inappropriate