Neuro Flashcards
Which medications to be avoided in PD?
Metoclopramide
Promethazine
Prochlorperazine
Holoperidol
Domperidone does not pass BBB
What is neurogenic shock?
Inadequate tissue perfusion from loss of sympathetic vasoconstrictive tone
Hypotension + bradycardia
What is spinal shock?
Complete flaccid paralysis immediately following spinal cord injury - may or may not be asscociated with circulatory shock
MRI head - what is the purpose of T1-weighted vs T2-weighted
T1: enhances acute haemorrhage
T2: enhances oedema, infarction, demyelination, chronic haemorrhage
Causes of cerebellar syndromes
Vascular lesions - demyelination - tumours etc.
Alcohol - hypothyroidism - phenytoin toxicity - metabolic disorders (eg Wilsons)
What is Kernig’s sign
hamstring spasm on trying to straighten leg
Normal lumbar puncture profile
Neut: 0
Lymphocytes: <5
Protein: <0.4
Glucose (ratio CSF/ serum): >0.6
Bacterial lumbar puncture profile
Neut: +++
Lymphocytes: +
Protein: >1
Glucose (ratio CSF/ serum): <0.4
Viral lumbar puncture profile
Neut: +
Lymphocytes: +++
Protein: 0.4-1.0
Glucose (ratio CSF/ serum): usually normal
TB lumbar puncture profile
Neut: +
Lymphocytes: +++
Protein: >1
Glucose (ratio CSF/ serum): <0.4
Describe internuclear ophthalmoplegia clinically
Lesion in medial longitudinal fasciculus will prevent ipsilateral adduction during conjugate gaze
(Convergence is normally fine)
Describe Lhermitte’s sign
Electric shock down spine on neck flexion
Types of MS
Relapsing-remitting
Primary progressive
Secondary progressive
Progressive relapsing
Management of tremor in MS
Clonazepam
What is GBS?
Autoimmune response causing demyelination
What causes GBS?
Infection (usually resp/ gastro) Malignancy Pregnancy Drugs Vaccination
Symptoms of GBS
Progressive ascending weakness, sensory loss, paraesthesia, pain
Dysphasia
Dysarthria
What is shown in CSF in GBS?
Increased protein
Causes of facial nerve palsy
Bell’s, acoustic neuroma, MS, infarcts, tumours, Lyme disease, sarcoidosis, Ramsay Hunt
Which facial muscles are preserved in UMN lesion
Frontalis
Orbicularis oculi
How to clinically help differentiate a facial nerve palsy due to sarcoid
Parotid enlargement/ tenderness
Which side more commonly affected in trigeminal neuralgia?
R
Triggers for trigeminal neuralgia
touching
but also talking, smiling, chewing, swallowing
Horner’s
Miosis - ptosis - anhidrosis
What is Horner’s syndrome?
Interrupted sympathetic innervation to the eye
Causes of Horners
CENTRAL: basal meningitis - demyelinating disease - CVA - basal skull tumours - pituitary tumour - intrapontintine haemorrhage - neck trauma - syringomyelia
PREGANGLIONIC: Pancoast’s - cervical rib - aortic aneurysm/ dissection - lesions of middle ear
POSTGANGLIONIC: Herpes Zoster - migraine - internal carotid dissection
DRUGS: chlorpromazine - levodopa - prochlorperazine - COCP
What is a Holmes-Adie pupil?
Normal variant - more common in women
Larger, irregular pupil. Slower (direct and consensual) constriction to light.
Often associated with absent deep tendon reflexes (Holmes-Adie syndrome)
What is an Argyll-Robertson pupil?
Miosis, irreg pupil. Absent light reflex (but consensual is intact)
Neurosyphilis - DM - MS - syringobulbia
Foot signs in Friedrich’s Ataxia
Hammer-toes
Clubfoot
What is subacute combined degeneration of the spinal cord?
B12 deficiency leading to degeneration of the posterior column and corticospinal tracts of the spinal cord
REPLACE B12 BEFORE FOLATE!
Presentation of syringobulbia
Dysfunction in cranial nerves
Presentation of syringomyelia
Slowly progressive
Loss of pain and temp - sometimes in shawl-like distribution
Muscle atrophy due to extension into anterior horns of spinal cord - begins in hands and p?rogresses proxinally
Lower limb LMN signs
Autonomic dysfunction
How does the botulinum toxin paralyse muscles
Prevents release of ACh from the terminal end bouton - so muscles can’t respond to nerve impulses
How does organophosphates cause death?
Prevent destruction of ACh - so muscles like the diaphragm remain depolarised, unable to return to their resting position
ANS neurotransmitters
All Ach
Except sympathetic postganglionic: NA
What causes RAPD?
What is the presentation?
Damage anywhere between the retinal ganglion cell layer to the lateral geniculate body
When light is shone on the unaffected eye, both eyes constrict fully and symmetrically
When light is shone in affected eye, both pupils will constrict but to a lesser degree
How to confirm a Horner’s syndrome?
4% cocaine drops - will dilate unaffected eye only
Causes third nerve palsies
Idiopathic (25%)
Microvascular
Vascular causes: extradural haematoma (pupil-sparing), posterior communicating artery aneurysm**
**posterior communicating artery runs adjacent to third nerve - may not be picked up on MR angiography (due to vasospasm) - should be repeated
Which cranial nerve most susceptible to trauma?
CN IV: long, slender, paratentorial course
Which cranial nerve defect might involve patient tilting head?
CN IV
tilted towards affected side
(part of Bielschowsky sign)
Causes sixth nerve palsies?
Microvascular disease
External compression: acoustic neuroma, raised ICP
Core symptoms of Meniere disease
vertigo - tinnitus - fluctuating hearing loss (should be confirmed on audiometry)
(aural fullness increasingly considered a fourth cardinal symptom)
How long do acute attacks of Menieres last?
Typically minutes - hours
Most commonly 2-3 hours
How to manage Menieres
May need admission - consider labyrinthine sedatives
For an acute attack: 7/7 prochlorperazine
Consider trial of betahistine prophylaxis
Presentation of labyrinthitis
SUDDEN onset severe vertigo with N&V
Sensorineural hearing loss + tinnitus
Symptoms may present for up to 72h
LESS LIKELY TO DESCRIBE AURAL FULLNESS
Investigations and management labrynthitis
Will need an audiogram
Advise to stand still and close eyes!
Causes recurrent/ bilateral Bells palsy
Sarcoid
Lyme Disease
GBS
HIV
What is Bell sign?
Eye rolls when they try to close it
Treatment of Ramsay Hunt
Aciclovir and steroids
Dose of prednisolone for Bells Palsy
Within 72h symptom onset: 25 mg BD for 10 days
When should recovery from Bell’s Palsy occur
within 6-9 months, usually no persistent damage
Triggers for analgesia overuse headaches
Triptans or opioids: >10 days/ month
Paracetamol or NSAIDs: >15 days/ month
Includes in combination
Migraine prophylaxis
If >2 attacks monthly
Propranolol or topiremate
Or acupuncture
Riboflavin or Mg supplements may help
Reduce caffeine/ other triggers
Tension headaches prophylaxis
TCA, eg amitriptyline - titrate down over time
Acupuncture
What meds are chronic paroxysmal hemicranias responsive to?
Indomethacin - cluster headaches dont respond
Differentials to cluster headache
Chronic paroxysmal hemicrania - occurs several times a day
SUNCT (short-lasting unilateral neuralgiform headache with conjunctival injection and tearing) - up to 100 times/ day - lamotrigine may help
Treatment of trigeminal neuralgia
Carbamazepine
Second-line: gabapentin, baclofen
Potential surgical mx
Primary care mx meningitis
IM benzylpenicillin
Initial empirical mx meningitis
IV ceftriaxone/ cefotaxime for at least 10 days
Add IV amoxicillin if over 50 (chloramphenicol if allergic)
Consider adding IV aciclovir.
Consider adding dexamethasone for 4/7 (with rules regarding when dose can be given/ amounts)
What prophylaxis for household contacts of meningitis?
Ciprofloxacin or rifampicin
Most common causative bug in encephalitis?
HSV1 (herpes simplex encephalitis)
Triad of encephalitis
fever, headache, altered mental state
Mx cerebral abscess
IV ceftriaxone and neurosurgial opinion
**STROKE CLASSIFICATION
p.221
When should LP be done in suspected SAH?
If CT negative
12h to allow red cell lysis to occur
Occular problems associated with raised ICP
Ptosis
Cranial nerve III and VI palsies
Papilloedema
Gait in normal pressure hydrocephalus
Magnetic - feet seemingly stuck to floor with small stride
What is Beck syndrome?
Anterior spinal artery syndrome/ vertebrobasilar occlusion
Ischaemic event causing decrease in blood flow to anterior two-thirds of spinal column.
Commonly caused by aortic pathology (eg aneurysm, dissection).
Brown-Sequard
Ipsilateral loss of proprioception and vibration sense at the level of the lesion
Contralateral pain/ temp loss below level of lesion
Sub-acute combined degeneration of the cord
Progressive demyelination of the dorsal columns
Signs of Multiple System Atrophy
Parkinsonism + cerebellar signs + autonomic dysfunction
Signs of Progressive Supranuclear Palsy
Parkinsonism + Speech Disturbance + Personality change/ dementia + Vertical gaze palsy
Imaging when difficult to diagnose Parkinsons
SPECT
Causes of sensory neuropathy
Diabetic (most common - may be painful) B12 deficiency Alcoholic Vasculitis Leporasy Meds: Isoniazid, vincristine - these are contraindicated in CMT
Causes of motor neuropathy
GBS
Hereditary sensory neuropathy
Lead poisoning
Most common pathogen associated with GBS
Campylobacter
Autoantibodies in Lambert-Eaton
Voltage-gated calcium channel blockers
Ice test
used in MG - will reduce ptosi if ice is held in a latex glove against patient eyes
