Neurology Flashcards
what is Lateral medullary syndrome, also known as Wallenberg’s syndrome
Lateral medullary syndrome, also known as Wallenberg’s syndrome, occurs following occlusion of the posterior inferior cerebellar artery (PICA)
Cerebellar features:
ataxia
nystagmus
Brainstem features:
ipsilateral: dysphagia, facial numbness, cranial nerve palsy e.g. Horner’s (mitosis, ptosis, anhydrosis)
contralateral: limb sensory loss
diagnosis multiple sclerosis
diagnosis is dependent on proof of demyelinating lesions separated by space AND time
MRI - high signal T2 images – of brain and spine
What is syringomyelia and how does it present?
cyst (syringe) forms in the spinal cord
compresses spinothalamic tract (responsible for pain, temperature, and crude touch)
Usually patients first notice a cape like (neck, shoulders and arms) loss of sensation to temperature but the preservation of light touch, proprioception and vibration - they might burn their hands without realising…
Loss of subtypes of sensation depends on how much of the spinothalamic tract fibres are damaged.
They might also get neuropathic pain
causes: idiopathic, trauma, tumours, chiari malformation
ix: MRI brain and spine
what is myotonic dystrophy?
genetic disorder (autosomal dominant)
affecting cardiac, smoothe and skeletal muscle
2 subtypes: DM1 and DM2
DM1
- chromosome 19
- Distal weakness more prominent
DM2
- chromosome 3
- Proximal weakness more prominent
features: ptosis, dysarthria, dysphagia, long face, heart block (long PR interval), cardiomyopathy, testicular atrophy, weakness of muscles
Miller-Fisher syndrome
Miller-Fisher syndrome, a variant of Guillain-Barre syndrome. The condition is classically associated with ophthalmoplegia, which normally develops first, a descending paralysis with areflexia and ataxia
EYE signs & descending are distinguishing,
Hemiballism
stroke damage to the subthalamic nucleus in basal ganglia –> involuntary “ballistic” movements on opposite side
patient jerk/ flinging/ ballistic movements
sometimes improve when sleeping
mx. haloperidol
trigeminal neuralgia signs and management
unilateral severe shooting pains in face (trigeminal nerve)
triggers- brushing teeth, combing hair
last a few seconds
mx. carbamazepine
wernicke’s vs broca and blood supply and regions of the brain
wernicke’s - understand - located in superior temporal gyrus, supplied by inferior division of the left MCA
broca - speech - - located in inferior frontal gyrus, superior division of the left MCA
conduction aphasia
affects connection between wenicke’s and broca’s known as the arcuate fasiculus
normal understanding
Speech is fluent but repetition is poor. Aware of the errors they are making
global aphasia
wenicke + broca + conduction (arcuate fasciculus)
Intracranial venous thrombosis investigation
MRI venography is the gold standard
stenosis cut off for Carotid endarterectomy
greater than 70% stenosis of the internal carotid artery.
distinguishing feature of serotonin syndrome vs neuroleptic malignant sydrome
serotonin syndrome has Myoclonus
Klumpke’s paralysis
T1 nerve palsy
cause: traumatic birth injury, or acute traction of the arm upwards
–> reduced power of the intrinsic hand muscles and over time can result in a ‘claw-like’ appearance
patchy haemorrhagic changes in the temporal lobe on MRI
herpes simplex encephalitis (HSE)
Drug options for reducing the risk of relapse in MS
natalizumab
ocrelizumab
drug for fatigue in MS
amantadine
Ramsay Hunt syndrome
reactivation of the varicella zoster virus in CN 7
oral aciclovir and corticosteroids are usually given
what anti-epileptic drug can worsen absence seizures?
Carbamazepine
(along with phenytoin, vigabatrin and gabapentin).
Baclofen mechanism of action
spasm
GABA receptor agonist
what is used to prevent vasospasm in aneurysmal subarachnoid haemorrhages
Nimodipine
what scale is used to determine ADL requirements in stroke patients?
The Barthel index is a scale that measures disability or dependence in activities of daily living in stroke patients
CT head showing temporal lobe changes
herpes simplex encephalitis
Miller-Fisher syndrome
Miller-Fisher syndrome is a variant of Guillain-Barré syndrome characterised by the triad of ophthalmoplegia, ataxia, and areflexia.
Treatment options for motor neurone disease
- Non-invasive ventilation at night if resp symptoms *greatest improvement on survival
- PEG feeding if needed
- Riluzole - prevents simulation of glutamate receptors
prolongs life by 3mo
drug treatment for idiopathic cranial hypertension?
carbonic anhydrase inhibitors
- acetazolomide
- topiramate (additional benefit of weight loss)
stroke secondary prevention antiplatelet choice
clopidogrel
(high dose aspirin is given first then stopped)
what typical feature of PD helps differentiate it from other causes of parkinsonism.
Asymmetrical tremor is unique to parkinsons disease
when to do lumbar puncture if suspecting Subarachnoid haemorrhage?
If subarachnoid haemorrhage is suspected but a CT head done within 6 hours of symptom onset is normal, do not do an LP as this is accurate, consider an alternative diagnosis instead
if CT head is done 6 hours after onset, could still have SAH so do lumbar puncture
Huntington’s disease
- inheritance pattern
- what trinucleotide repeat?
autosomal dominant condition,
chromosome 4
There is a repeat expansion of CAG trinucleotide in
Pathway of pupillary light reflex
afferent: retina → optic nerve → lateral geniculate body → midbrain
efferent: Edinger-Westphal nucleus (midbrain) → oculomotor nerve
eye is deviated ‘down and out’
Third nerve palsy
Brown-Sequard syndrome
caused by lateral hemisection of the spinal cord
Features
ipsilateral weakness below lesion
ipsilateral loss of proprioception and vibration sensation
contralateral loss of pain and temperature sensation
Urinary incontinence + gait abnormality + dementia
= normal pressure hydrocephalus
when to suspect multi-system atrophy
multi-system atrophy due to parkinsonism + classical history of poor response to levodopa, impotence, urinary retention and younger age group.
long-term prophylaxis of cluster headaches
Verapamil is used for long-term prophylaxis of cluster headaches
acute disseminated encephalomyelitis
Autoimmune neurological condition which occur typically a few weeks following a viral illness or vaccination . It can present with motor weakness, encephalopathy, seizures and coma. It is found on T2-weighted MRI imaging which reveals poorly-defined
hyperintensities in the subcortical white matter.
acute disseminated encephalomyelitis Management
Steroids and IV IG
down and in pupil
6th nerve palsy
what is narcolepsy associated with?
associated with HLA-DR2
it is associated with low levels of orexin (hypocretin),
what is horner’s syndrome?
ipsilateral ptosis, miosis, and anhidrosis (no sweat)
how to determine site of lesion in Horner’s syndrome presentation
anhydrosis determines site of lesion:
head, arm, trunk = central lesion: stroke, syringomyelia, multiple sclerosis, tumour
just face = pre-ganglionic lesion: Pancoast’s, cervical rib, trauma, thoidectomy
absent = post-ganglionic lesion: carotid artery, Carotid aneurysm, cluster headache
A slow-relaxing grip may be noticed on initial hand-shake with the patient
The slow-relaxing grip
typical of myotonic dystrophy
Nerve conduction studies (NCS) interpretation between axonal and demyelinating pathology
Axonal:
normal conduction velocity
reduced amplitude
Demyelinating:
reduced conduction velocity (myelin facilitates skip conduction)
normal amplitude
Tx. Meningeal tuberculosis
12 months RIPE
AND STEROIDS
What receptor does sumatriptan on & work MOA
Sumatriptan is a 5-HT1 receptor agonist
It works by constricting the blood vessels in the brain to relieve
Holmes ADIe
DIlated pupil, females, absent leg reflexes
What is the most likely cause for the patient’s hyponatraemia after subarachnoid haemorrhage?
SIADH
Subacute combined degeneration of the cord
impairment of the dorsal columns, lateral corticospinal tracts and spinocerebellar tracts..
SCD tracts
Features:
dorsal column involvement
- distal tingling/burning/sensory loss is symmetrical and tends to affect the legs more than the arms
- impaired proprioception and vibration sense
lateral corticospinal tract involvement
- muscle weakness, hyperreflexia, and spasticity
- upper motor neuron signs typically develop in the legs first
- brisk knee reflexes
- absent ankle jerks
- extensor plantars
spinocerebellar tract involvement
- sensory ataxia → gait abnormalities
- positive Romberg’s sign
Which type viral meningitis may be characteristically associated with a low cerebrospinal fluid glucose level?
MUMPS
Internuclear ophthalmoplegia
due to a lesion in the medial longitudinal fasciculus (MLF)
Features
impaired adduction of the eye on the same side as the lesion
horizontal nystagmus of the abducting eye on the contralateral side
causes: multiple sclerosis, vascular
where is the medial longitudinal fasciculus located?
paramedian area of the midbrain and pons
what medication is contraindicated in absence seizures?
carbmazepine
treatments for essential tremor.
Propranolol
if standard treatment options have failed which opioid is it most appropriate to consider starting for neuropathic pain?
Tramadol has a dual mechanism of action, acting as both a weak opioid agonist and a reuptake inhibitor of serotonin and norepinephrine.
What is Cushing reflex
The Cushing reflex is a physiological nervous system response to increased intracranial pressure (ICP) that results in hypertension and bradycardia
The classical history of vestibular schwannoma
The classical history of vestibular schwannoma includes a combination of vertigo, hearing loss, tinnitus and an absent corneal reflex. Features can be predicted by the affected cranial nerves:
cranial nerve VIII: vertigo, unilateral sensorineural hearing loss, unilateral tinnitus
cranial nerve V: absent corneal reflex
cranial nerve VII: facial palsy
post-herpetic neuralgia treatment
NICE recommend using amitriptyline, duloxetine, gabapentin or pregabalin first-line.
Wilson management
Penicillamine
which alzheimers drug can cause insomnia?
donepezil
Which antibiotic lowers the seizure threshold
cipro
Anti-GQ1b antibodies
Miller-Fisher syndrome is a variant of Guillain-Barre syndrome
Ataxia, areflexia and ophthalmoplegia are characteristic
Contradinidcations to triptans
ischaemic vascular disease
Causes of oculogyric crisis
antipsychotics
metoclopramide
postencephalitic Parkinson’s disease
The first-line treatment for spasticity in MS is
either gabapentin or baclofen.
Amiloride mecganism
selectively blocks the epithelial sodium transport channels in DCT
Creutzfeldt-Jakob disease is characterised by
rapid onset dementia and myoclonus
The MRI finding for Wernicke’s encephalopathy
The MRI finding of enhancement of the mamillary bodies due to petechial haemorrhages is specific for Wernicke’s encephalopathy,
What is the mechanism of post-LP headaches?
Leaking of cerebrospinal fluid from the dura
It is thought that ongoing leak of cerebrospinal fluid (CSF) through the puncture site causes ongoing CSF loss, leading to low pressure.
A post-LP headache is typically frontal or occipital and occurs within three days.
where is the medial longitudinal fasciculus located?
in the paramedian area of the midbrain and pons
Migraine acute vs prophylaxis mx
acute: triptan + NSAID or triptan + paracetamol
prophylaxis: topiramate or propranolol
vestibular neuronitis vs viral labyrinthitis.
vertigo that often develops following a viral infection.
no hearing loss = vestibular neuronitis
hearing loss/ tinnitis = viral labyrinthitis.
extorsion (outward rotation) and elevation of the affected eye.
4th nerve palsy
superior oblique muscle
ptosis (drooping eyelid), a dilated pupil, and an eye that is deviated downwards and outwards
3rd nerve palsy
unopposed action of lateral rectus and superior oblique muscles. Third cranial nerve palsy affects multiple extraocular muscles (medial rectus, inferior rectus, superior rectus, and inferior oblique), as well as levator palpebrae superioris which raises the upper eyelid.
which palsy would result in an inability to abduct the affected eye properly.
6th nerve palsy
lateral rectus muscle, which abducts the eye
horizontal diplopia that worsens when looking to the right side.
6th nerve palsy
lateral rectus muscle, which abducts the eye
what drug can cause functional B12 deficiency?
What confirms this?
nitrous oxide
check for a HIGH methylmalonic acid (MMA) level.
Parkinsons + ataxic vs shuffling gait
ataxic - multiple system atrophy (type Parkinsons vs type Cerebellum)
shuffling - parkinsons
distinguishing parkinsons and multiple system atrophy
look at the gait
both including parkinsons features, autonomic instability and cerebellar signs
which columns are affected in subacute combined degeneration of the spinal cord?
the dorsal columns and lateral corticospinal tracts and spinocerebellar tract are affected
which type of head injury presents with lucid interval before decline?
extradural (epidural) haematoma
which anti epileptic causes peripheral neuropathy?
phenytoin
why when patients start carbamazepine they may see a return of seizures after 3-4 weeks of treatment
Carbamazepine is known to exhibit autoinduction, increasing its metabolising
so dose needs to be increased
myasthenia gravis.
Which receptor is involved in the pathophysiology?
Skeletal muscle contraction is dependent on acetylcholine which activates NICOTINIC acetylcholine receptors
NOT Muscarinic annoyingly
what should be given given prior to or with the first dose of antibiotic in bacterial meningitis
Intravenous dexamethasone to reduce the risk of neurological sequelae by reducing cerebrospinal inflammation.
If pneumococcal meningitis is suspected or confirmed from clinical features, cerebrospinal fluid parameters or culture results, then dexamethasone should be continued for 4 days.
avoid dexamethasone in septic shock, meningococcal septicaemia, or if immunocompromised, or in meningitis following surgery’
It should be stopped if another causative organism is strongly suspected or confirmed.
Mx
Medication overuse headache
simple analgesia + triptans: stop abruptly
opioid analgesia: withdraw gradually
Dipyridamole MOA
Dipyridamole is a non-specific phosphodiesterase inhibitor and decreases cellular uptake of adenosine
which migraine drug can precipitate extra pyramidal side effects
metoclopramide (dopamine antagonist) to young patients as acute dystonic reactions may develop
RAPD finding and causes
A relative afferent pupillary defect is when the affected and normal eye appears to dilate when light is shone on the affected eye
causes:
retina: detachment
optic nerve: optic neuritis e.g. multiple sclerosis
Drug-induced parkinsonism vs Parkinson’s disease
in drug induced parkinsonism:
rigidity and rest tremor are uncommon
motor symptoms are generally rapid onset and bilateral
recurrent sense of dejà vu associated with episodes of lip-smacking and postictal dysphasia suggest a seizure in which part of the brain?
a temporal lobe seizure.
cluster headache triggers
management
triggers - alcohol
acute
1. 100% oxygen (80% response rate within 15 minutes)
2. subcutaneous triptan (75% response rate within 15 minutes)
prophylaxis
1. verapamil
2. tapering dose of prednisolone
