Neuro Flashcards
Which medications may worsen myasthenia gravis
Beta blockers
Several antibiotics
Lithium and anti malarials
anticholiergics- oxybutynin
What disease may present with worsening neuro symptoms after exercise
multiple sclerosis (uhtoff’s phenomenon)
Describe optic neuritis
inflammation of the optic nerve - leads to pain and changes in vision such as reduced visual acuity
First line treatment of focal seizures
lamotrigine or levetiracetam
first line treatment of absence seizures
ethosuximide
Where would a lesion causing disinhibition be expected to be located in the brain?
the prefrontal cortex
If presenting within 4.5 hours and having confirmed occlusion on imaging, what should be the treatment?
thrombolysis and thrombectomy
When can antiepileptic medication be stopped?
after being seizure free for >2 years.
Drugs are stopped over 2-3 months
Treatment of muscle spasticity in ms
baclofen or gabapentin
How do retinal artery strokes present q
amaurosis fugax- transient darkening of vision
Most common organism associated with Guillain - Barre syndrome
Campylobacter jejuni
How long do cluster headaches typically last
15 minutes to 2 hours
What are acoustic neuromas?
Slow growing tumours of the Schwann cells that surround the auditory nerve (vestibulocochlear nerve)
Also called vestibular schwannomas
Where are acoustic neuromas located?
At the cerebellopontine angle
At what age do acoustic neuromas typically present?
40-60
If someone has bilateral acoustic neuromas what is suggested?
Neurofibromatosis type II
Presentation of acoustic neuromas
Unilateral hearing loss
Intermittent dizziness and vertigo
Sensation of fullness in the ear
Facial numbness- due to tumour compressing the facial nerve
Unilateral tinnitus
Swallowing difficulty
Cerebellar symptoms if compression of brain stem
Two complications of acoustic neuromas
Facial nerve palsy
Obstructive hydrocephalus
How are acoustic neuromas diagnosed
Audio gram
MRI
CT head
Treatment of acoustic neuromas
1st line- focussed radiation or surgery
What is neurofibromatosis
A genetic condition causing nerve cell tumours (neuromas) to develop throughout the nervous system
Genetics of neurofibromatosis type I
Mutation in a gene on chromosome 17 which codes for a protein called neurofibromin (a tumour suppressor protein)
What is the inheritance of neurofibromatosis type I
Autosomal dominant
Genetics of neurofibromatosis type II
A mutation in a gene on chromosome 22 which encodes for the tumour suppressor protein Merlin
What is anterior cord syndrome?
incomplete spinal injury that affects the anterior 2/3 of the spinal cord
Causes of anterior cord syndrome
- Occlusion of the anterior spinal artery and ischaemia to the are that the ASA supplies
- direct injury or trauma
- spinal canal mass
- radiation myelopathy
Causes of occlusion to to the anterior spinal artery
iatrogenic - cross clamping of the aorta during thoracic or abdominal aortic aneurysm repair
severe hypotension
atherothrombotic disease
vasculitis
cocaine
What spinal cord tracts are damaged in anterior cord syndrome?
corticospinal tract
spinothalamic tract
descending autonomic tract
presentation of anterior cord syndrome
bilateral motor deficit below the level of the lesion
bilateral loss of pain and temperature
autonomic dysfunction- urinary incontinence, abnormal blood pressure
preserved posterior columns - position, vibration and light touch
How is anterior cord syndrome diagnosed?
MRI- shows pencil like intensities
Treatment of anterior cord syndreom
IV methylprednisolone shown to improve outcome if used in first 23 hours
Thrombolysis if embolic cause
immunosuppression if vasulitis
Surgery - laminectomy for spinal decompression
Prognosis of anterior cord syndrome ?
poor
Complications of anterior cord syndrome
respiratory failure
autonomic dysreflexia
spasticity
urinary incontinence
complications of immobility- DVT, pressure ulcers.
What is bells palsy
sudden onset unilateral facial nerve paralysis
Who is at increased risk of bells palsy
pregnant women
Aetiology of bells palsy
unknown- though to be linked with viral illnesses in particular herpes simplex virus type 1
Is the forehead involved in the paralysis of bells palsy?
yes the forehead is paralysed
This is because it is a lower motor neurone lesion- upper motor innervation is bilateral so if upper lesion it will be spared
presentation of bells palsy
unilateral facial paralysis including the forehead
postauricular pain (ear pain)
altered taste
dry eyes
hyperacusis
Why may there be a change of taste in bells palsy
the facial nerve supplies the anterior two thirds of the tongue- the chorda tympani branch
How does bells palsy present on examination
asymmetrical smile
loss of the nasolabial folds
drooping eyebrow
drooping corner of the mouth
what is bell’s sign
upward movement of the eye maintained on attempt to close the eye
Treatment of bells palsy
if presenting within 72 hours of onset prednisolone may be given (50mg for 10 days)
lubricating eye drops
eye tape for at night
Why might you get hyperacusis in bells palsy?
a branch of the facial nerve branches off in the facial canal to supply the stapedius muscle of the inner ear
why is eye care important in bells palsy
to prevent exposure keratopathy
What are brain abscesses?
localised focal necrosis of brain tissue with inflammation- usually due to bacterial infection
RF of brain abscesses
right to left shunt cardiac defects, bronchiectasis, immnosupression
causes of brain abscesses
direct implantation- head trauma leading to fracture and contamination
iatrogenic procedures
local extension of infection from adjacent areas - ear infection, dental abscess, paranasal sinusitis
haematogenous spread - organ infection
why do right to left shunt cardiac defects increase the likelihood of brain abscesses
means that the blood bypasses the filtration in the lungs so pathogens are more likely to spread
How do brain abscesses present
fever
progressively worsening focal neurology
headache
increased ICP - can lead to early morning headache, nausea and vomiting, papilloedema
mental status changes
seizures
How are brain abscesses diagnosed?
MRI or CT scan- initially will not be able to distinguish with space occupying lesions and infarcts but after 4-5 days a capsule will form
LP if no signs of raised ICP
how are brain abscesses treated?
antibiotic therapy: IV 3rd generation cephalosporin and metronidazole
Surgery: craniotomy and debridement of the abscess
dexamethasone for raised ICP
What are the most common cancers that metastasise to the brain
lung, breast, colorectal and prostate
what is the most common primary brain tumour in adults
glioblastomas
How do glioblastomas present on imaging?
solid tumours with central necrosis and a rim
prognosis of glioblastomas
1 year
What is the second most common brain tumour in adutls
meningioma
pathophysiology of meningiomas
most commonly benign
arise from the arachnoid cap cells of the meninges
Cause symptoms due to compression rather than invasion
Explain the relation ship between the location of cerebellar lesions and the signs produced
unilateral cerebellar lesion will cause ipsilateral signs
causes of cerebellar disease
Genetic inherited disorders- Freidreich’s ataxia
Neoplasms- cerebellar haemangioma
Stroke
alcohol- thiamine deficiency
MS
hypothyroidism
drugs- phenytoin, lead poisoning
Signs of cerebellar disease
dysdiadochokinesia
ataxia- limb and truncal
nystagmus
intention tremor
slurred speech
hypotonia
DANISH
Describe a benign essential tremor
a fine tremor affecting all voluntary muscles
most notable usually in the hands but can also affect other areas- head, jaw, vocal
Describe the features of a benign essential tremor that make it differ from parkinsons
- fine tremor (6-12Hz)
- usually absent at rest and worse with intentional movements
- worse when tired, stressed or after caffeine
- can be suppressed with drugs such as alcohol and benzodiazepines
Diagnosis of benign essential tremor- what tests might you do to rule out other causes
CT or MRI
serum ceruloplasmin and 25 hour urinary copper- wilsons
thyroid function tests
1st line treatment of benign essential tremro
propranolol or primidone
2nd line treatment of benign essential tremor
gabapentin, alprazolam or topiramate
what procedures may be done to treat benign essential tremor if medications are unsuccessful
deep brain stimulation
focused US thalamotomy
gamma knife thalamotomy
Where is an extradural haemorrhage located?
between the dura mater and the inner surface of the skull
what is the most common cause of extradural haematoma
skull fracture due to skull trauma in the temporoparietal region (over the pterion) leading to rupture of the middle meningeal artery
What % of extra dural haematomas are caused by rupture of the middle meningeal artery?
75%
Presentation of a extradural haematoma
previous head trauma
lucid period - lasting minutes to hours- followed by progressively decreasing consciousness
headache
nausea and vomiting
confusion
neurological signs - cranial, motor or sensory nerve deficits
What is cushings triad
a physiological response to raised ICP which aims to improve perfusion
presentation of cushings triad
hypertension
bradycardia
irregular breathing pattern
diagnosis of an extradural haematoma
CT scan- shows a biconvex lemon shaped lesion that cannot extend past the suture lines
may have midline shift and brain herniation
cause sof extradural haematomas other than middle meningeal artery trauma
AV malformations
bleeding disorders
treatment of extradural haematomas
correct anticoagulation (reversal agents)
reduce ICP = mannitol
IF small bleed then conservative
if acute- burr hole craniotomy
definitive treatment for extradural haematome
BURR HOLE CRANIOTOMY
COMPLICATIONS OF EXTRADURAL HAEMATOMAS
INFECTION- WOUND OR SURGERY
CEREBRAL ISCHAEMIA
SEIZURES
COGNITIVE IMPAIRMENT
HEMIPARESIS
HYDROCEPHALUS
BRAINSTEM INJURY
what is giant cell arteritis
a chronic vasculitis characterised by granulomatous inflammation in the walls of the medium and large arteries- most commonly the branches of the carotid artery (temporal, ophthalmic and occipital)
What condition is giant cell arteritis associated with
polymyalgia rheumatica
age of patients affected by giant cell arteritis
mainly those over 50 (peak in 70s)
Presentation of giant cell arteritis
rapid onset of:
unilateral headache,
scalp tenderness,
jaw claudication,
blurred vision,
systemic illness (fever, anorexia)
a tender palpable temporal artery
What visual disturbances may occur in giant cell arteritis
vision loss, diplopia, amaurosis fugax
what is the pathophysiology of visual disturbances in giant cell arteritis
anterior ischaemia optic neuropathy resulting from occlusion of the posterior ciliary artery (causes ischaemia of the optic nerve head)
what is seen on fundoscopy in giant cell arteritis
a swollen pale disc and blurred margins
Investigations for giant cell arteritis
Raised inflammatory markers - ESR >50
Temporal artery biopsy - shows multinucleated giant cells, may not be present if skip lesions
Duplex Ultrasonography - hypoechoic halo sign and stenosis of the temporal artery
Diagnostic criteria of giant cell arteritis
Three of the following:
- aged >/= 50
- new headache
- temporal artery abnormality
- elevated ESR (>50)
- abnormal temporal artery biopsy
How is giant cell arteritis treated ?
high dose corticosteroids:
- if no visual disturbances then high dose prednisolone
- if visual disturbances IV methylprednisolone prior to starting oral pred
Bone protection due to steroids- bisphosphonates
What is guillain-barre syndrome
an acute inflammatory demyelinating polyneuropathy that affects the peripheral nervous system- an acute symmetrical ascending weakness and potentially sensory symptoms
pathophysiology of guillain barre
- immune mediated demyelination of the peripheral nerves
- usually triggered by an infection (campylobacter jejuni)
- The antibodies to the infectious organism also attack the nerves due to molecular mimicry
Presentation of guillain barre syndrome
progressive symmetrical weakness of all limbs- ascending (legs before arms)
reflexes are usually reduced or absent
Sensory symptoms tend to be mild - may have some paraesthesia
May have cranial nerve involvement - diplopia, bilateral facial nerve palsy
May have autonomic involvement- urinary retention, diarrhoea
How soon after an infection does guillain barre usually present?
3 weeks after a gastroenteritis like illness- usually campylobacter
How is guillain barre diagnosed?
lumbar puncture- rise in protein by normal white cell count
Nerve conduction studies- decreased motor nerve conduction velocity due to demyelination, prolonged distal motor latency, increased F wave latency
How is guillain barre treated?
IV immunoglobulins - first line
plasmapheresis
DVT prophylaxis - TEDS and LMWH
What needs to be monitored in patients with guillain barre
FVC- can cause respiratory failure
What is Miller-Fisher syndrome
A variant of Guillain-Barre syndrome
Associated with ophthalmoplegia, areflexia and ataxia
Usually associated with anti-GQ1b antibodies
What is Horner’s syndrome?
A condition that affects one half of the face causing ptosis, miosis and facial anhidrosis
Occurs due to a disruption of the sympathetic nerve supply
Causes of Horner’s syndrome
can be central lesions, pre-ganglionic lesions and post- ganglionic lesions
Central lesions: strokes (lateral medullary syndrome), MS, pituitary or basal ganglia tumours, basal meningitis, syringomyelia, spinal cord tumours
Pre-ganglionic lesions: apical lung tumours (pancoast), lymphadenopathy, trauma, thyroidectomy
post-ganglionic lesions: carotid artery dissection, carotid aneurysm, cavernous sinus thrombosis, cluster headache
If a central lesions has caused horners syndrome, how will it present?
anhidrosis will occur on the face, arm and trunk
if a pre-ganglionic lesion has causes horners syndrome, how will it present?
anhidrosis will only affect the face
if a post ganglionic lesion has causes horner’s syndrome, how will it present?
no anhidrosis
How can you remember the different causes of horners
Central- The 4 S’s (stroke, multiple Sclerosis, Syringomyelia, Spinal cord tumours)
Pre-ganglionic- the 4 T’s (pancoast Tumour, Thyroidectomy, Trauma, Top of cervical rip)
Post-ganglionic- the 4 C’s (carotid artery aneurysm, carotid artery dissection, cavernous sinus thrombosis, cluster headache)
What additional feature will congenital horner’s syndrome have?
heterochromia
How is horners syndrome diagnosed?
usually a clinical diagnosis however can be confirmed with cocaine or apraclonidine drops
How can cocaine drops confirm the diagnosis of horners syndrome?
cocaine blocks the reuptake of noradrenaline at the nerve synapse. In a normal eye will lead to pupillary dilation however in horners where there is impaired sympathetic innervation it will have no affect
How can apraclonidine drops confirm the diagnosis of horners syndrome?
apraclonidine is an alpha-adrenergic agonist- it usually causes pupillary constriction however in horners it causes dilation as there is alpha 1 supersensitivity
What drops can be used to localise the lesion in horners syndrome
hydroxyamphetamine- in 1st and 2nd order lesions it will lead to dilation, in 3rd it will have no effect
Does horners syndrome present on the contralateral or ipsilateral side of the face to the lesion?
ipsilateral
What is lateral medullary syndrome?
a type of stroke caused by infarction of the posterior inferior cerebellar artery
how does lateral medullary syndrome present?
cerebellar features: ataxia and nystagmus
Brainstem features:
- ipsilateral dysphagia, facial numbness, Horners
- contralateral limb sensory loss
what is encephalitis?
inflammation of the brain parenchyma caused by an infection- mainly viral
What are the most common causes of viral encephalitis
HSV 1 or 2, varicella zoster virus, arbovirus, enteroviruses
most common cause of encephalitis in adults
HSV type 1
what part of the brain is most commonly effected in encephalitis
the temporal and inferior frontal lobes
How does encephalitis present
fever
headache
seizures
vomiting
focal features- aphasia
peripheral unrelated features- cold sores
How is encephalitis diagnosed?
LP- lymphocytosis, elevated proteins,
PCR of CSF = test for HSV, VZV etc
Neuroimaging- MRI shows hyperintense lesions
EEG
How is encephalitis treated?
IV aciclovir in all cases
complications of encephalitis
memory loss, muscle weakness, personality change, vision loss, hydrocephalus
inheritance of huntingtons
autosomal dominant
genetics of huntingtons
trinucleotide repeat of the CAG triplet in the huntingtin gene on chromosome 4
>40 repeats leads to HD, reduced penetrance may be seen in those with 36 to 39 repeats
what is anticipation
a phenomenon where the disease presents earlier in successive generations due to increases repeats
pathophysiology of huntingtons
degeneration of the cholinergic and GABAergic neurones in the striatum of the basal ganglia
how does huntingtons present?
- chorea
- personality change- irritability, apathy, depression
- intellectual impairment
- dystonia
- incoordination
at what age does huntingtons typically present ?
35
How can huntingtons disease be treated?
no cure
- symptomatic treatment of chorea- tetrabenazine, antipsychotics
- antidepressants
- consider dopamine agonist for bradykinesia and rigidity
what is menieres disease?
a disorder of the inner ear of unknown cause characterised by excessive pressure and progressive dilation of the endolymphatic system
how does menieres disease present?
a triad of hearing loss, tinnitus and vertigo
Aural fullness
May have drop attacks and nystagmus
symptoms are typically unilateral initially and the progress to bilateral
How is menieres disease diagnosed?
clinical evaluation
May use audiometry- bone and air conduction
MRI to rule out other causes
How is menieres disease treated?
diuretics may help reduce endolymph fluid
Low salt diets- reduce endolymph
Prophylactic betahistine
in acute attacks- prochlorperazine
How are attacks prevented in menieres
lifestyle changes and betahistine
how are acute attacks treated in menieres
prochlorperazine
describe episodes of vertigo associated with menieres
sudden onset unprovoked attacks lasting 20 mins to several hours
May be associated with nausea and vomiting.
describe how hearing loss presents in menieres disease
initially fluctuates and occurs with vertigo attacks
Gradually becomes more permanent
Sensorineural hearing loss
affects lower frequencies first
What is motor neurone disease?
A neurodegenerative condition of unknown cause which can affect the lower and upper motor neurones
What is the most common type of motor neurone disease?
amylotrophic lateral sclerosis (up to 80% of cases)
Describe ALS
loss of motor neurones in the motor neurones of the motor cortex and the anterior horn of the spinal cord
Typically has lower motor neurone signs in the arms and UMN signs in the legs
Types of MND
amylotrophic lateral sclerosis
primary lateral sclerosis
progressive muscular atrophy
progressive bulbar palsy
Desribe primary lateral sclerosis
loss of Betz cells in the motor cortex- will only have upper motor neurone signs
Describe progressive muscular atrophy
loss of the anterior horn cells- lower motor neurone signs only
Affects distal muscles before proximal
Describe progressive bulbar pasly
affects cranial nerves IX to XII - leads to palsy of the tongue, muscles of chewing and facial muscles
which MND has the worse prognosis
progressive bulbar palsy
How does MND present
- asymmetrical limb weakness
- mix of lower and upper motor neurone signs
- foot drop
- loss of dexterity
- slurred speech
- muscle wasting- small hand muscles
- No sensory signs
what symptoms will not be present in motor neurone disease>
no sensory disturbance
no ocular muscle disturbance
No sphincter dysfunction
no cerebellar sigms
how is MND diagnosed?
clinical
May use nerve conduction studies- normal motor conduction
EMG- reduced action potentials and increased amplitude
MRI to rule out cervical cord compression and myelopathy
Which drug can be used to prolong life in MND
riluzole- prolongs life by about 3 months
Respiratory support- non invasive ventilation at night
symptomatic baclofen for spasticity
Nutrition support- may need PEG tube
What is the median survival of MND from symptom onset
3-5 years
what is normal pressure hydrocephalus?
a condition characterised by the symptoms of hydrocephalus without significantly elevated CSF pressure
triad of normal pressure hydrocephalus
- urinary incontinence
- dementia
- gait abnormality
theory of the pathophysiology of normal pressure hydrocephalus
thought to be due to reduced CSF absorption at the arachnoid villi or reduced blood perfusion to the basal ganglia
Aetiology of normal pressure hydrocephalus
can be idiopathic or secondary to conditions such as SAH, meningitis, head trauma
how is normal pressure hydrocephalus diagnosed?
imaging- will show ventriculomegaly in the absence of, or out of proportion to sulcal enlargement
LP- shows normal pressure
how is normal pressure hydrocephalus treated ?
ventriculoperitoneal shunting
carbonic anhydrase inhibitors - acetazolamide
serial lumbar punctures
management of a TIA if within 24 hours of onset
300mg of aspirin immediately
urgent assessment within 24 hours by a stroke specialist
management of a TIA if more than 7 days after symptoms
should be seen by a stroke specialist within 7 dyas
treatment options for spasticity in MS
baclofen and gabapentin are first line
what key causes of status epilepticus should be ruled out first
hypoxia and hypoglycaemia
what is autonomic dysreflexia
a clinical syndrome in patients who has a spinal cord injury at or above T6 spinal level
Most commonly triggered by faecal impaction or urinary retention
Presents as an unbalanced sympathetic response with unbalanced parasympathetic response
how does autonomic dysreflexia present?
extreme hypertension
flushing and sweating above the lesion
agitation
What is paroxysmal hemicrania?
severe attacks of severe unilateral headache in the orbital, supraorbital or temporal region
These are often associated with autonomic features and usually last less than 30 minutes and can occur multiple times a day
Treatment of paroxysmal hemicrania
indomethacin
When should patients with bells palsy be referred to ENT
if no improvement after 3 weeks refer urgently to ENT
why can a subdural haematoma cause a third nerve pasly?
increased ICP can lead to herniation which can compress the third cranial nerve
how does a third nerve palsy present?
down and out eye position (abducted and depressed)
ptosis
dilated pupil- cannot constrict in response to light
first line radiological investigation for suspected stroke
non contrast CT
first line treatment for focal seizures
lamotrigine or levetiracetam
What is wernicke’s aphasia
receptive aphasia- impaired comprehension, fluent speech, inability to repeat back phrases
think W- what?
What is broca’s aphasia
expressive aphasia- speech is non-fluent however will be able to comprehend
where in the brain is Wernicke’s area
superior temporal gyrus
where in the brain is brocas area
inferior frontal gyrys
what migraine phophylactic is associated with cleft lip and palate
topiramate
if a parietal lesion where will visual defects be?
inferior
If a temporal lesion where will visual defects be?
superior
If there is evidence of infarction on imaging can a TIA be diagnosed?
no - TIA can only be diagnosed if there is no evidence of acute infarction on imagn
How are acute relapses of MS treated?
high dose steroids (methylprednisolone)
first line treatment of absence seizures
ethosuximide
What is Weber’s syndrome
a form of midline stroke characterised by ipsilateral cranial nerve III palsy and contralateral hemiparesis
what screening tool is used to assess stroke symptoms in an acute setting
ROSIER
how does juvenile myoclonic epilespy present?
seizures in the morning/ following sleep deprivation
what blood test can be used to determine if a seizure has been a true seizure or a pseudoseizure
prolactin
what radiculopathy causes loss of sensation on the dorsal aspect of the thumb and index finger
c6
Causes of cauda equina
lumbar disc herniation- most common cause
lumbar stenosis
trauma
abscesses
malignancy
spondylolisthesis
congential cause (spinal bifida)
epidural haematoma
presentation of cauda equine
lower back pain
radicular pain
leg weakness
difficulty walking
saddle anaesthesia
bowel or bladder dysfunction
erectile dysfunction
diagnosis of cauda equina
urgent whole spine MRI
CT myelography if cant have MRI
treatment of cauda equine
emergency surgery for cord decompression
complications of cauda equina
premanent paralysis
sensory loss
bladder and bowel dysfunction
sexual dysfunction
RF for SAH
hypertension
polycystic kidney disease
smoking
excessive alcohol intake
aged 45-70
cocaine use
connective tissue disorders- Marfans, Ehlers danlos
pathophysiology of SAH
rupture of a berry aneurysm - 85% occur in the circle of willis
Rarer causes- AV malformations, vasculitis, arterial dissection, venous thrombosis
complication of SAH
vasospasm causing ischaemic injury
presentation of SAH
thunderclap headache- occipital, worse headache ever
may have preceding sentinel headache
neck stiffness
photophobia
nausea and vomiting
new symptom of altered brain function - reduced consciousness, seizure
coma
examination findings of SAH
isolated pupil dilation with loss of light reflex
ophthalmoscopy may show intraocular haemorrhage
oculomotor nerve impairment
Investigations for a SAH
urgent CT - hyperattentuated- hyperdense bright blood distributes in the basal cisterns, sulci and potentially the ventricular system
LP- xanthochromia, used if >12 hours since onset if CT was normal after 6 (CT less reliable after 6 hours)
CT angiography - to show the cause of SAH
Treatment of SAH
initial- nimodipine to reduce vasospasm
definitive- endovascular coiling r neurosurgical clipping
complications of SAH
hydrocephalus, electrolyte disturbance, seizures, hyponatraemia
what is brudzinski’s sign
flexing of the neck causes hip and knee flexion
what is kernig’s sign
extending leg from 90 degrees elicits pain
how does optic neuritis present
graying or blurring of vision in one eye
may have pain on moving eye and loss of colour discrimination (particularly red)
acute management of myasthenia gravis
pyridostigmine
management of myasthenic crisis
plasma exchange, IV Ig
where are most adult brain tumours located
supratentorial
where are most paediatric brain tumours located
infratentorial
What condition is associated with myasthenia gravis
thymomas
pathophysiology of myasthenia gravis
antibodies against the nicotinic Ach receptors on the post-synaptic membrane which block the binding of Ach preventing the end plate potential becoming large enough to trigger muscle contracti
How does myasthenia gravis present
muscle fatiguability
ocular symptoms- diplopia, ptosis (may be worse with prolonged upwards gaze)
fatiguable chewing
expressionless face (myasthenic sneer)
how is myasthenia gravis diagnosed?
tensilon test - infusion of acetylcholinesterase inhibitor will briefly improve symptoms (edrophonium)
measure AChR and MuSK antibodies
EMG
What antibodies are associated with myasthenia gravis
AChR and MuSK
Long term treatment of myasthenia gravis
corticosteroids (prednisolone)
Immunosuppressives (azathioprine)
thymectomy
What is a side effect of phenytoin
megaloplastic anaemia due t altered folate metabolism
Others: peripheral neuropathy, gingival hyperplasia
How does subacute degeneration of the spinal cord present?
hyperreflexia
loss of proprioception
loss of vibration sense
what is the first line treatment of stroke and TIA in those who have gastric ulcers and are high risk of bleeding
clopidogrel
first line treatment of trigeminal neuralgia
carbamazepine
what type of MRI should be used for MS
MRI brain with contrast
if clopidogrel is not tolerated what treatment can be given from secondary prevention following a stroke
aspirin 75mg
1st like medications for alzheimer’s
donezepil
medications that can be used for alzheimer’s disease?
donezepil
rivastigmine
Memantine
if someone with dementia suffers hallucinations what medication is good ?
rivastigmine
What is trigeminal neuralgia
severe episodic facial pain in the distribution of one of the branches of the 5th trigeminal cranial nerve
epidemiology of trigeminal neuralgia
increased in women, increases with age (rare those younger than 40)
pathophysiology of trigeminal neuralgia
90% thought to be caused by vascular compression of the trigeminal nerve
Causes demyelination and abnormal electrical activity in response to stimuli
How does trigeminal neuralgia present?
paroxysmal attacks of pain that may be triggered by precipitating factors such as touching the face, cold wind, vibration and cleaning teeth
What is the pain like in trigeminal neuralgia
electric shock like severe pain, usually unilateral, short-lived, recurrent and episodic.
Treatment of trigeminal neuralgia
1st line- carbamazepine
2nd line- gabapentin, lamotrigine
pathophysiology of wernicke’s encephalopathy
thiamine deficiency leadsing to decreased activity of thiamine dependent enzymes
Causes neuronal death in parts of the brain including- medial dorsal thalamic nucleus, mamillary bodies, periaqueductal grey matter, floor of the first ventricle and cerebellar vermis
How does wernicke’s encephalopathy present?
triad of confusion, ataxia and ophthalmoplegia / nystagmus
triad of korsakoff’s
retrograde amnesia, anterograde amnesia, confabulation
How is wernicke’s encephalitis treated
thiamine
magnesium sulphate
pabrinex
if a patient on levodopa presents with postural instability what is the most likely cause?
the parkinsons disease not the medication
what is ramsey hunt syndrome?
shingles affecting the facial nerve
how does ramsey hunt syndrome present?
ear pain, vesicles in the external auditory canal, vertigo, tinnitus
triggers for migraines
chocolate
hangovers
oral contraceptive pill
cheese
orgasms
lie ins
alcohol
tumult
exercsie
How does a migraine present
unilateral throbbing headache lasting 4-72 hours,
moderate to severe
associated with nausea and vomiting
photophobia and phonophobia
may have an associated aura- zig zag lines, pins and needles
what features may occur in the prodrome of a migraine?
yawning
fatigue
mood changes
craving
what classifies chronic migraines
occur on at least 15 days a month
What is the criteria for migraines
- at least 5 attacks.
- headache lasting 4-72 hours
- headache has at least 2 of the following qualitites:
- unilateral
- pulsating
- moderate to severe
- aggravated by physical activity - there is at least one of the following:
- nausea +/- vomiting
- photophobia +/- phonophobia - headache cannot be attributed to another disorder
what aura symptoms of migraine are atypical and require further investigation
motor weakness
double vision
visual symptoms in one eye
poor balance
decreased level of consciousness
1st line acute treatment of a migraine
combination therapy of oral triptan and either paracetamol or NSAID
may add anti-emetic if not effective (e.g metoclopramide)
prophylactic drugs for migraines
propranolol
topiramate
amitriptyline
which migraine prophylactic should not be used in pregnant women
topiramate- teratogenic and can reduce effectiveness of prophylaxis
what treatment can be given to women with menstrual cycle related migraines
frovatriptan or zolmitriptan when needed
how does an atonic seizure present
sudden weakness in all muscles of the body with retained awareness
what sign of multiple sclerosis is characterised by tingling in hands when flexing neck
Lhermitte’s phenomenon
which type of seizure may be associated with plucking of clothes?
temporal lobe
what is the initial management of a suspected TIA in someone on anticoagulants
immediate referral to emergency department for imaging
what is the management of a brain abscess
IV cephalosporin + metronidazole
how does a brain abscess present?
headache
fever
focal neurology
conditions of raised ICP- nausea, papilloedema, seizures
how does a brain abscess present on CT scan
ring enhancing lesion
most common complication following meningitis
sensorineural hearing loss
when would you offer thrombectomy alongside thrombolysis
when there is confirmed occlusion of the proximal anterior circulation
what motor pattern will be seen in an anterior cerebral artery stroke
leg weakness but not face or speech impairment
what should be done on all stroke patients to reduce aspiration pneumonia
swallow assessment to evaluate swallow function before any oral intake
how do chronic subdural haematomas present on CT
hypodense (dark)
how does third nerve palsy present?
ptosis, dilated pupil and down and out appearance of the eye
how does an ulnar nerve palsy present?
wasting of the hypothenar muscles, loss of thumb adduction, wasting of the first web space and ulnar claw hand
what are the components of a GCS score
motor response
verbal response
eye opening
6 types of motor response scores for GCS
6- obeys commands
5- localises to pain
4- withdraws from pain
3- abnormal flexion to pain
2- extending to pain
1- none
5 types of verbal response scores for GCS
5- orientated
4- confused
3- words
2- sounds
1- none
4 types of eye opening response
4- spontaneous
3- to speech
2- to pain
1- none
If a ‘seizure’ is associated with a period of feeling light headed and sweaty before what is the likely cause
Vasovagal syncope
what is myasthenic gravis
a chronic autoimmune condition caused by insufficiency acetyl choline receptors in the neuromuscular junction
pathophysiology of myasthenia gravis
antibodies to the acetyl choline receptor on the post synaptic membrane (prevents Ach binding and causing muscle contraction)
a type II hypersensitivity reaction
associated diseases to MG
thymomas in 15%
autoimmune diseases- thyroid disease, rheumatoid, SLE, pernicious anaemia
how does MG present?
muscle fatiguability - muscle weakness that improves on rest and is worse towards the end of the day
- proximal muscles first
- arms more than legs
Weakness of the extraocular muscles - diplopia, ptosis (may be worse on prolonged upward gaze)
dysphagia
Facial weakness- myasthenic sneer
respiratory muscle weakness
how is MG diagnosed?
antibody testing= acetylcholinesterase receptor antibody (85-90%) and anti-muscle specific- tyrosine kinase antibody (MuSK)
Gold- single fibre EMG
May also CT for thymoma
what test can be done for MG
tensilon test- give patient IV edrophonium and there should be temporary improvement in symptoms (as it is an acetylcholinesterase inhibitor)
what is the first line treatment of MG
pyridostigmine- long acting acetylcholinesterase inhibitor
overview of MG treatment
- pyridostigmine
- can add immunosuppressant (prednisolone, azathioprine)
- thymoma
what is myasthenic crisis
a life threatening worsening of myasthenia causing respiratory failure
treatment of myasthenic crisis
plasmapheresis
IV immunoglobulins
what can trigger myasthenic crisis
warm weather, infection, surgery, stress, pregnancy, illness
medications- penacillamine, quinidine, procainamide, beta blockers, lithium, phenytoin, antibiotics (gentamycin, tetracyclines, macrolides)
what additional tests should be done in young patients (under 55) who present with stroke with no obvious cause
thombophilia and autoimmune screening
How can you distinguish between foot drop caused by common peroneal nerve pasly and that caused by L5 radiculopathy
in common peroneal nerve pasly there will be weakness in eversion of the feet whereas in L5 there will be weakness in inversion
How is meningitis treated in those with penicillin allergy
IV chloramphenicol- cannot use IV ceftriaxone as there is cross-reactivity between penicillins and cephalosporins
treatment of ramsey hunt
oral aciclovir
How might a typical migraine aura be described?
transient hemianopic disturbance or a spreading scintillating scotoma (jagged crescent)
RF for ischaemic stroke
age
htn
smoking,
hyperlipidaemia
dm
AF
RF for haemorrhagic stroke
HTN ,
anticoagulants
age
AV malformations
What vessels are effected in weber syndrome
the branches of the posterior cerebral artery that supply the midbrain
How does Weber’s syndrome present?
ipsilateral cranial nerve III palsy
contralateral weakness in the upper and lower limbs
What vessels are effected in Wallenberg syndrome (lateral medullarly syndrome)
posterior inferior cerebellar artery
How does lateral medullary syndrome (Wallenberg’s) present?
ipsilateral loss of pain and temperature in the face
contralateral loss of pain and temperature in the limbs and torso
ataxia
nystagmus
What artery is effected in lateral pontine syndrome
anterior inferior cerebellar artery
how does lateral pontine syndrome present?
similar to wallenbergs but with ipsilateral facial paralysis and deafness
How does a stroke affecting the retinal/ ophthalmic artery present?
amaurosis fugax
How does a stroke affecting the basilar artery present?
locked in syndrome
How does a lacunar stroke present?
either:
- unilateral weakness (+/- sensory loss) of face, arm or leg, or all three
- purely sensory loss
- ataxic hemiparesis
How does a stroke affecting the anterior cerebral artery present?
contralateral hemiparesis and sensory loss (legs more than arms)
how does a stroke affecting the middle cerebral artery present?
contralateral hemiparesis and sensory loss (arms more than legs)
contralateral homonymous hemianopia
haphasia
how does a stroke affecting the posterior cerebral artery present ?
contralateral homonymous hemianopia with macular sparing
visual agnosia
What three presentations are considered in the oxford stroke classification
unilateral hemiparesis and/or hemisensory loss of the face, arm , leg
homonymous hemianopia
higher cognitive dysfunction (e.g. dyphasia)
what may be shown on CT of ischaemic stroke
low density white and grey matter,
hyperdence artery
what may be shown on CT of haemorrhagic stroke?
hyperdence material with surrounding low dense oedema
what should blood pressure be bought down to before thrombolysis
185/110
what are some contraindications to thombolysis
previous intracranial haemorrhage
seizure on stroke onset
intracranial neoplasm
suspected SAH
stroke or injury in preceding 3 months
LP in previous 7 days
GI haemorrhage in preceding 3 weeks,
oesophageal varices
uncontrolled HTN
what is the inheritance of neurofibromatosis ?
autosomal dominant
what is the mutation associated with neurofibromatosis type 1?
a mutation on chromosome 17- encodes for the tumour suppressor protein neurofibrin
what is the mutation associated with neurofibromatosis type 2?
a mutation on chromosome 22- encodes for merlin, a tumour suppressor protein which is important in schwann cells
how does neurofibromatosis type 1 present?
Cafe-au-lait spots
Axillarly and inguinal freckling
Peripheral neurofibromas
Iris haematomas (Lisch nodules)
Scoliosis
phaeochromocytosis
how does neurofibromatosis type 2 present?
bilateral vestibular schwannomas
mutliple intracranial schwannomas, meningiomas and ependymomas
how may neurofibromas are indicative of neurofibromatosis ?
two or more or one plexiform neurofibroma
what are two key complications of neurofibromatosis
GI stromal tumours
malignant peripheral nerve sheath tumours
What is a brain abscess?
a localised area of necrosis in the brain tissue with associated inflammation
Causes of brain abscesses?
direct implantation- from trauma or iatrogenic
local spread of infection from adjacent structures (e.g. sinusitis, otitis media)
haematogenous spread from other organ infections
RF for brain abcesses
right to left shut (allows blood to bypass the lungs where infection could be filtered out)
bronchiectasis
immunsupression
how does a brain abscess present?
fever
headache
progressive focal neurology
May have nausea, early morning headache, seizures, papilloedema
How is a brain abscess diagnosed?
CT or MRI- shows bright ring of capsule around necrotic core
How are brain abscesses treated?
surgery- craniotomy and abscess debridement
antibiotics- IV cephalosporins and metronidazole
dexamethasone
What areas of the brain are affected in wernicke’s
mamillary bodies, ventricle walls, periaqueductal grey matter, floor of the 4th ventricle
triad of wernicke’s encephalopathy
cognitive decline
gait ataxie
oculomotor dysfunction- nystagmus, ophthalmoplegia
what ophthalmoplegia can occur in wernicke’s encephalopathy?
lateral rectus palsy
conjugate gaze palsy
what investigations may be done for wernicke’s
thiamine levels
CT/MRI to rule out other causes
decreases red cell transketolase
triad of korsakoff’s
retrograde amnesia
anterograde amnesia
confabulation
What is spinal stenosis?
a condition where the central canal of the spine is narrowed which causes compression of the nerves and pain
Most common cause of spinal stenosis
age related degenerative change
what is the pathophysiology of how age- related degeneration causes spinal stenosis
- biochemical changes in the intervertebral disc (cell death, loss of proteoglycan and water content) lead to progressive disc bulging and collapse
- hypertrophy and osteophyte formation on the facet joints
- thickening of the ligamentum flavum
These three features (bulging disc, facet hypertrophy and ligamentum flavum thickening) lead to narrowing of the spinal canal and compression of nerves
How does spinal stenosis present ?
similar to PAD- claudication like pain of the proximal thigh and buttock
- differs from PAD as it is relieved when walking up hill and worse on stretching of the canal (e.g. walking downstairs)
- may also have neurological symptoms- burning and tingling
How is spinal stenosis diagnosed?
MRI
How is spinal stenosis treated?
1st line- analgesia, physio, weight loss
definitive- laminectomy
what are myopathies?
diseases of the skeletal muscle (not caused by nerve disorders) that cause the muscle to become weak and wasted
what are the three broad types of myopathies
hereditary
inflammatory
endocrine
What are some examples of hereditary myopathies
duchenne muscular dystrophy
becker muscular dystrophy
mitochondrial myopathies
metabolic myopathies
Give some examples of inflammatory myopathies
polymyositis and dermatomyositis
what drugs can cause temporary myopathies?
statins, steroids
How does polymyositis present?
proximal muscle weakness
Reynauds
Resp muscle weakness
dysphagia
dysphonia
interstitial lung disease
what skin signs may be present in dermatomyositis ?
helitrope rash- macular periorbital rash
shawl sign- macular rash over back and shoulders
Gottron’s papules- roughened red papules over the extensor surfaces of the fingers)
Holter’s sign- erythema of the buttocks, hips and lateral thighs
photosensitive rashes
what investigations may be done to diagnose polymyositis and dermatomyositis
raised creatinine kinase
raised muscle enzymes (LDH)
Anti-jo-1 and anti-mi-2
EMG
muscle biopsy
how are dermatomyositis and polymyositis treated?
in the acute stage- high dose corticosteroids then wean down
DMARDs longterm
What is the most common cause of subarachnoid haemorrhage
Traumatic head injury
What is a subarachnoid haemorrhage that happens in the absence of trauma called?
A spontaneous subarachnoid haemorrhage
What are some causes of spontaneous subarachnoid haemorrhages?
Rupture of a berry aneurysm (85%)
AV malformations
Pituitary apoplexy
Mycotoxins aneurysms
What are some conditions associated with berry aneurysms ?
Hypertension
Adult polycystic kidney disease
Ehlers danlos syndrome
Coarctation of the aorta
Where do most Berry aneurysms occur?
In the anterior circulation
What are some risk factors for subarachnoid haemorrhages?
Hypertension
Smoking
Age 45-70
Women
Black ethnic origin
Family history
Cocaine use
Connective tissue disorders
Sickle cell anaemia
Neurofibromatosis
Polycystic kidney disease
How does a subarachnoid haemorrhage present?
Sudden acute headache- thunderclap, worst headache ever had, usually occipital
May have a sentinel headache weeks prior
Neck stiffness
Photophobia
Nausea and vomiting
Focal neurological deficit
Decreased consciousness
Seizures
Cranial nerve palsy’s (loss of light reflex)
Coma
How is a subarachnoid diagnosed
CT scan no contrast- should be performed within 6 hours as can become less reliable
Lumbar puncture may be done if after 6 hours and CT negative - shows xanthochromia
What investigation may be done to work out the location of pathology after a subarachnoid haemorrhage
CT angiography
Management of a subarachnoid haemorrhage
Oral nifedipine (reduces vasospasm)
Definitive- endovascular coiling and surgical clipping
What are some complications of subarachnoid haemorrhages (5)
Re-bleeding
Hydrocephalus
Vasospasm (delayed cerebral ischaemia)
Hyponatraemia
Seizures
Why can hyponatraemia occur after a subarachnoid haemorrhage?
Syndrome of inappropriate anti-diuretics hormone may occur
Where does an extradural haemorrhage occur ?
Between the dura mater and the skull
How does an extradural haematoma present?
Often post trauma
Patient may have an initial loss of consciousness followed by a period of lucidness
Consciousness will then deteriorate
Other symptoms:
- headache
- nausea and vomiting
- confusion
- cranial nerve defects (down and out, fixed pupil)
- motor or sensory signs
- Cushing’s triad (bradycardia, hypertension, irregular breathing)
How is an extradural haematoma diagnosed?
CT scan - shows a biconvex (lentiform/ lemon) shaped lesion
- lesion will be limited by the suture lines
- lesion will be hyperdense
- may cause midline shift and brain stem herniation
Treatment of an extradural haematoma
Initial management may include ABCDE, mannitol to reduce ICP, anticonvulsants
Definitive surgery can include burr hole craniotomy, trauma craniotomy and hemicraniectomy
What is the most common causes of a subdural haematoma?
Tearing of a bridging vein in acceleration deceleration injuries
Infant shaking baby syndrome
What are the three types of subdural haematomas and how are they classified
Acute- symptoms develop within 48 hours of injury
Subacute - symptoms develop days to weeks post injury
Chronic - symptoms develop weeks to months, patients may not recall as specific injury
Who is at high risk of subdural haematomas and why?
Elderly - cerebral atrophy puts tension of the bridging veins, also more susceptible to injury
Alcoholics- thrombocytopenia, prolonged bleeding times and head trauma
Baby’s- shaken baby syndrome
How do subdural haematomas present?
- altered mental status- often fluctuations in conscious occur
- focal neurological deficit
- headaches- may be one sided and worsen over time.
- seizures
- signs of raised ICP- pappilloedema, nausea and vomiting, Cushing’s triad
- gait abnormalities - ataxia
- hemiparesis or hemiplegia
- third cranial nerve palsy
Chronic SDH can present with progressive decline over a period of weeks/months
How are subdural haematomas diagnosed and what is seen
CT scan- shows a crescent shaped haematoma that is not limited by suture lines.
Acute with present as hyperdense
Chronic will present as hypodense
Treatment of subdural haematomas
Mannitol for ICP
Treatment depends on size but may include burr hole craniotomy, clot evacuation
What is trigemminal neuralgia
A pain syndrome classified by severe unilateral facial pain in one or more of the branches of the trigemminal nerve
What causes trigemminal neuralgia
Most are idiopathic
May be due to vascular compression of the nerve
May be secondary to tumours (acoustic neuromas) pressing on the nerve
Explain the theory of how vascular compression can cause trigemminal neuralgia
Paroxysmal attacks of pain- described as electric shock like pain
May be triggered by precipitating factors- brushing teeth, shaving, smoking, light touch
Where are some trigger areas associated with trigemminal neuralgia
Nasolabial folds or chin
First line treatment of trigemminal neuralgia
Carbamazepine
Second line management of trigemminal neuralgia
Gabapentin
Lamotrigine
What are some red flag features that may suggest trigemminal neuralgia has a serious underlying cause
Onset before 40 years old
Sensory changes
Deafness or ear problems
History of skin or oral lesions that could have spread
Pain in only the ophthalmic division
Optic neuritis
Family history of MS
what features of a seizure suggest it is a non -epileptic attack (9)
pelvic thrusting
crying after the seizure
seizures dont occur when alone
gradual onset
duration of over 2 minutes
fluctuating course
eyes closed
violent thrashing movements
side to side head movements
what features might suggest that a seizure is epileptic and non due to non-epileptic attack disorder (4)
tongue biting
automatisms
incontinence
raised serum prolactin
How does internuclear ophthalmoplegia present?
when looking to the side there will be impaired adduction of one eye and nystagmus in the abducting eye.
where would a lesion causing internuclear ophthalmoplegia be?
in the medial longitudinal fasciculus- will be on the side that fails to adduct
what is the key diagnostic investigation for idiopathic intracranial hypertension
lumbar puncture
what drug treatment may benefit idiopathic intracranial hypertension?
carbonic anhydrase inhibitors such as acetazolamide
how does idiopathic intracranial hypertension present?
non-pulsatile bilateral headaches- worse in morning, worse on bending forward
visual disturbances (e.g. transient darkening) due to optic nerve ischaemia
bilateral papilloedema
6th nerve palsy - horizontal diplopia
who is the typical patient who experiences idiopathic intracranial hypertension?
young obese women
how does lateral medullary syndrome present?
cerebellar symptoms - falling over (to the side of the lesion), vertigo, multidirectional nystagmus, diplopia
autonomic dysfunction- ipsilateral horners, hiccups
sensory symptoms- loss of pain and temperature on ipsilateral face, loss of pain and temp on contralateral body
ipsilateral bulbar weakness- hoarse voice
what arteries are involved in lacunar strokes?
perforating arteries around the internal capsule, thalamus and basal ganglia
what does Romberg’s test look for?
to determine if ataxia is sensory or cerebellar
if sensory it will be positive as the patient will loose balance when they shut their eyes
how does parietal lobe damage present?
visual inattention in the contralateral visual field, constructional apraxia, dressing apraxia
define dementia
a clinical syndrome characterised by a significant deterioration in mental function leading to an impairment of normal function
What genetics are associated with dementia and what is their inheritance?
5% of cases are associated with a genetic mutation in one of the following:
- amyloid precursor protein (chromosome 21)
- presenilin 1 (chromosome 14)
- presenilin 2 (chromosome 1)
these are autosomal dominant.
What gene has been found to be a risk factor of alzheimer’s (not a causative gene)
apoprotein E (APOE gene)
What are the macroscopic changes to the brain seen in alzheimer’s
widespread cerebral atrophy particularly of the cortex and hippocampus
what are the microscopic changes causing alzheimer’s
- beta amyloid plaques that form outside neurones
- neurofibrilliary tangles - that form inside neurones, caused by hyperphosphorylation of the tau protein
Give some examples of screening tests that may be used in dementia diagnosis?
10 point cognitive screener
6 item cognitive impairment test
mini mental state examination
addenbrookes cognitive examination III
What additional tests should be done in the diagnosis of dementia?
bloods
neuroimaging
What non-pharmalogical recommendations does NICE recommend for alzheimer’s
- offering a range of activities to promote wellbeing
- offering group stimulation therapy to patients with mild to moderate dementa
- offering group reminiscence therapy and cognitive rehabilitation
what is the first line drug treatment for alzheimer’s
acetylcholinesterase inhibitors such as donezepil, rivastigmine or galantamine
what is the second line treatement of dementia
memantine (a N-methyl-D-aspartic acid receptor antagonist)
How does alzheimer’s disease present?
memory loss- initially short time memory and an inability to learn new information
agitation
disorientation
language problems
sleep wake cycle disturbances
what is a rare inherited form of vascular dementia
CADASIL
what criteria does NICE recommend to diagnose vascular dementia?
NIMDS-AIREN criteria- made up of having cognitive decline, cerebrovascular disease (Defined by neuro signs or imaging) and a relationship between the two
RF for vascular dementia
history of stroke or TIA
AF
hypertension
diabetes
hyperlipidaemia
smoking
obesity
coronary heart disease
what subtypes of vascular dementia are there?
stroke-related VD- multi-infarct or single infarct dementia
subcortical VD- caused by small vessel disease
mixed VD - mix of vascular and alzheimer’s
should acetylcholinesterase inhibitors and memantine be used in vascular dementia ?
only if there is cormorbid alzheimers, parkinsons dementia or lewy body dementia
Pathophysiology of Lewy Body dementia
alpha-synuclein cystoplasmic inclusions (Lewy bodies) in the substantia nigra, paralimbic and neocortical areas
How does Lewy body dementia present
progressive cognitive decline- more likely to fluctuate than other dementia
early impairment of attention and executive functioning
parkinsonisms
visual hallucinations
what type of drug should be avoided in lewy body dementia and why
neuroleptics (antipsychotics) - can cause irreversible parkinsonisms
how can lewy body dementia be treated?
acetylcholinesterase inhibitors (rivastigmine) and memantine
how is lewy body dementia diagnosed?
usually clincial, may do a SPECT scan
what are the key features of frontotemporal lobe dementia
- onset is before 65
- insidious onset
- relatively preserved memory and visuospatial skills
- personality change and social conduct problems
What is the characteristic appearance of pick’s disease in the brain ?
frontal gyral atrophy with a knife blade appearance
microscopic changes seen in picks disease (4)
pick bodies (spherical aggregations of silver staining tau proteins)
gliosis
neurofibrillary tangles
senile plaques
what allele is related to narcolepsy
HLA-DR2
what genetic mutation is common in narcolepsy type 1
DQB1 0602
pathophysiology of narcolepsy
loss of hypocretin secretin neurone in the lateral hypothalamus
how is narcolepsy diagnosis
multiple sleep latency EEG
polysomnography
How is narcolpesy treated
nighttime sodium oxalate
daytime stimulants
how does optic neuritis present?
unilateral decrease in visual acuity
poor colour discrimination- red desaturation
pain that is worse with eye movement
relative afferent pupillary defect
central scotoma
how would optic neuritis be investigated?
MRI of the brain and orbit with gadolinium staining
how is optic neuritis treated
high dose steroids
what are some conditions that can cause optic neuritis?
multiple sclerosis
diabetes
syphilis
what is a relative afferent pupillary defect and where in the brain is pathology that causes it?
it is where shining light in the affected eye will cause dilation of both the affected and normal eye.
Caused by a lesion anterior to the optic chiasm (e.g. in the optic nerve or the retina)
How does third nerve palsy present? (3)
Eye is down and out
pupil is dilated
ptosis
causes of third nerve palsy
Weber’s syndrome
raised ICP causing brain herniation
diabetes
vasculitis
posterior communicating artery aneurysm
cavernous sinus thrombosis
How does fourth nerve palsy present?
eye will be upwards and outwards
there will be vertical diplopia when looking down
patient may develop a head tilt
what key sign is seen in vestibular neuromas?
absent corneal reflex (due to damage to the trigemminal nerve)
How can you differentiate viral labyrinthitis and vestibular neuronitis?
labyrinthitis will have hearing loss whereas in neuronitis there will be no hearing loss
what patholophysiological process is a risk factor in haemorrhagic stroke and is associated with dementia?
cerebral amyloid angiopathy
What is Creutzfeldt- Jacob disease?
a rapidly progressive and universally fatal neurodegenerative condition caused by prion proteins.
Leads to rapidly progressive dementia, psychiatric disturbance and myoclonus
what can cause trochlear nerve palsy?
ocular trauma and diabetes mellitus
what patients with MS are liscenced to use interferon beta?
those with relapsing and remitting MS who are able to walk unaided
If parkinsonism is associated with spontaneous activity of the effected limb, what is the likely cause?
cortico-basal degeneration
How does progressive supranuclear palsy present?
parkinsonism with supranuclear gaze palsy.
what drug prevents cluster headaches?
verapamil
How would damage to the brachial plexus present?
small hand muscle paralysis, dermatomal sensory disturbance and ptosis
Also called Klumpke’s palsy
What are two types of brachial plesus injuries
Erb’s palsy and Klumpke’s pasly
What are the nerve roots of the brachial plexus
C5 to T1
what drug can be given to reverse dabigatran in a haemorrhagic stroke?
idarucizumab
what is used to acutely manage MS
IV methylprednisolone
What drugs might be used in the long term treatment of MS to prevent relapses
biologics:
- natalizumab
- ocrelizumab
- fingolimod
- beta interferon
what are the parkinsons plus syndromes?
progressive supranuclear palsy
corticobasal degeneration
Dementia with Lewy bodies
Multiple system atrophy
How does multiple system atrophy present?
parkinsonisms
autonomic dysfunction - erectile dysfunction, postural hypotension, atonic bladder
cerebellar signs
How does progressive supranuclear palsy present?
parkinsonism- mainly bradykinesia
impairment of the vertical gaze (mainly on looking down)- patient may describe difficulty going down the stairs)
postural instability and falls - may have a broad based gait
cognitive decline- mainly frontal lobe dysfunction
What is lambert eaton syndrome
It is an autoimmune condition associated with small cell lung cancer where antibodies target the pre-synaptic voltage gated calcium channels
How does lambert eaton syndrome present?
repeated muscle contraction improves muscle strength (in comparison with MG where it decreases strength)
limb girdle wakness
hyporeflexia
autonomic symptoms - dry mouth, impotence
how is lambert eaton diagnosed and what will it show
EMG- incremental response to repetitive electrical activation
What patients cannot take triptans for cluster headaches
those with coronary artery disease as it can cause vasospasm
what two symptoms make up Creutzfeldt - Jakob disease
rapid onset dementia and myoclonus
What subtypes of diabetic peripheral neuropathy are there?
distal symmetrical sensory neuropathy
small fibre predominant neuropathy
diabetic amyotrophy
mononeuritis multiplex
autonomic neuropathy
what is the most common form of diabetic neuropathy
distal symmetrical sensory neuropathy
What is damaged in distal symmetrical sensory neuropathy and how does it present?
Loss of the small sensory fibres.
Sensory loss is in the glove and stocking distribution- mainly loss of touch vibration and proprioception
What is damaged in small fibre predominant neuropathy and how does it present?
loss of the small sensory fibres.
Manifests as deficits in pain and temperature in the glove and stocking distribution, alongside episodes of burning pain
What is damaged in diabetic amyotrophy and how does it present?
inflammation of the lumbosacral plexus or the cervical plexus
characterised by severe pain around the thighs and hips, along with proximal weakness
How does autonomic neuropathy present?
postural hypotension
gastroparesis
constipation
urinary retention
arrhythmias
erectile dysfunction
Differentials for diabetic neuropathy?
vitamin B12 deficiency
alcohol induced peripheral neuropathy
chronic inflammatory demyelinating polyneuropathy
How is diabetic peripheral neuropathy treated?
- manage blood glucose levels
- symptomatic management including gabapentin or pregabalin
what is charcot arthopathy
a chronic progressive condition characterised by destructive changes in the bones and joint of patients with neuropathy, most commonly from diabetes
how does charcot arthopathy present?
the 6 D’s
Destruction
Deformity
Degeneration
Dense bones
Debris
Dislocation
How is charcot arthropathy diagnosed?
x rays
what PPI should be prescribed in people taking clopidogrel and why?
lansoprazole
- omeprazole reduces the antiplatelet function of clopidogrel
What is charcot marie tooth syndrome?
a hereditary motor and sensory neuropathy
what two types of charcot marie tooth are there?
type 1 - demyelinating form, most common
type 2- axonal
what is the most common mutation associated with charcot marie tooth?
an autosomal dominant mutation in the peripheral myelin protein 22 gene.
How is the pattern of nerve involvement in charcot marie tooth described?
length dependent- the longest nerves are affected first
Means patients often present with symptoms affecting the feet, and later the hands
How charcot marie tooth present?
often begins in puberty
- enlargement and thickening of the nerves
- symmetrical distal muscular atrophy, appears as champagne bottle legs and claw hands
- pes cavus
How is charcot marie tooth diagnosed?
genetics
EMG- CMT 1 will have slow conduction whereas CMT 2 will have normal
what drugs can cause idiopathic intracranial hypertension?
oral contraceptive
steroids
tetracycline
vitamin A
lithium
what are two types of hydrocephalus ?
obstructive and communicating hydrocephalus
explain obstructive hydrocephalus
occurs when there is narrowing of the flow of CSF in one or more of the passages connecting the ventricles.
This may include the foramen of monro, cerebral aqueduct or fourth ventricle
explain communicating hydrocephalus
occurs when CSF can exit the ventricular system but absorption into the blood stream is impaired.
This is common after SAH and infective meningitis where they might have been damage to the arachnoid granulations
what is the first line drug in the management of chronic relapsing and remitting multiple sclerosis ?
glatiramer acetate
How soon after alteplase should aspirin be given?
24 hours
What causes subacute degeneration of the spinal cord?
vitamin B12 deficiency- may be precipitated by recreational nitric oxide use or by replacing folate before B12 in deficiency
Pathophysiology of subacute degeneration of the spinal cord
damage to the:
- dorsal columns (vibration and proprioception)
- lateral corticospinal tract
- spinocerebellar tract
how does subacute combined degeneration of the spinal cord present?
impaired vibration and proprioception sense
Muscle weakness, hyperreflexia and spasticity
sensory ataxia (romberg positive)
How is vitamin B12 replaced?
IM hydroxocobalamin
How does Brown-Sequard present?
ipsilateral weakness
ipsilateral loss of proprioception and vibration
contralateral loss of pain and temperature 1-2 levels below.
Management of benign essential tremor if asthmatic
topiramate or primidone
