Neuro Flashcards
how does lamotrigine work?
decreases sodium currents and glutamate transmission
how does carbamazepine work?
prevents repeated firing through sodium channels
how does sodium valproate work?
potentiates GABA activity
what is hypomimia?
lack of facial expression
sign of parkinsons
what can be given to help tremour? what is a side effect?
anticholinergic eg procyclidine
anti cholinergic burden = confusion
how to distinguish parkinsons from pressure hydrocephalus? (produces a magnetic gait)
parkinsons doesnt have incontinence
how to determine parkinsonian tremour from essential tremour?
PD = pill rolling essential = worse on intention, better with alcohol and more family history
what is the Cushing reflex?
in ischaemic stroke
increasing BP, decreasing heart rate, erratic breathing
BP increases in response to hypoperfusion in brain
carotid sinus baroreceptors detect increased BP – slow heart rate
irregular breathing because brainstem is compressed by raised ICP
what does agonal breathing suggest?
herniation of the brainstem
what medications cause medication over use headache?
10 days/month: ergotamine
triptans
opioids
15 days/month: nsaid
paracetamol
aspirin
what virus causes chickenpox/shingles?
varicella zoster – chickenpox
lies dormant –
reactivates – shingles – now called herpes zoster
what can happen if you develop chickenpox for the first time in adulthood?
pneumonitis (can be fatal)
foetal varicella syndrome, if you catch it in pregnancy – causes maldevelopment of foetus
what is a chickenpox rash classically like?
macule-papule-vesicle-pustule-crust
centrifugal distribution
where does the chickenpox virus usually lay dormant?
dorsal route ganglion
trigeminal nerve
olfactory nerve
presentation of shingles?
macular -- vesicular rash in dermatomal distribution, one side of midline, thoracic pain/itching/tingling/neuropathy malaise, myalgia headache fever
investigations for shingles?
& a specific stain?
serology
viral PCR
tzank - confirms presence of herpesvirus but doesnt differentiate which
management of shingles?
aciclovir or valaciclovir
iv immunoglobulin
what is ramsey-hunt syndrome?
complication of shingles paralysis of facial nerve rash on ear/mouth tinitus hearing loss
are brain tumours generally malignant or benign?
55% are malignant
are brain tumours usually primary or secondary?
secondary / metastatic more common
what grading system do brain tumours follow, how does it work?
WHO classicification
1 - slow growing benign
2 - cytological atypia eg large hyperchromic nuclei
3 - anaplasia, mitotic
4 - microvascular proliferation or necrosis
what is the most common type of brain tumour?
glioma
what is an empendymoma?
from lining of ventricle/central canal
a glioma
what is oligodendroglioma? how can it be identified? what does it cause?
40s and 50s frontal cortex = behavioural changes grade 2 or 3 calcification deletion of 1p1qq glioma
what is glioblastoma mutliformae?
glioma
from astrocytes
very malignant, grade 4
de novo or develop from grade 2 astrocytoma
what is a diffuse astrocytoma?
grade 2
type of glioma
can develop into glioblastoma multiformae which is much more malignant
what is an anaplastic astrocytoma?
grade 3 (anaplastic) type of glioma
what is a pilocytic tumour?
glioma
grade 1
in children
good prognosis
what is mengingioma?
generally benign
cause symptoms because take up space = nerve lesions & raised ICP
what is a hemangioblastoma?
brain tumour from blood vessels
develops in cerebellum in middle age
usually low grade
what is acoustic neuroma?
aka schwanoma - cn 8
what is medulloblastoma?
brain cancer
small blue cell
cerebellum in children
grade 4
focal neurological manifestation of a frontal cortex problem?
hemiparesis
personality change
focal neurological manifestation of a temporal lobe problem?
dysphasia
amnesia
focal neurological manifestation of a occipital lobe problem?
contralateral visual defect
focal neurological manifestation of a parietal lobe problem?
hemisensory loss
in brain tumour what is the headache like?
worse on coughing/bending/lying/in morning
constant
disturbs sleep
some symptoms of raised ICP?
headache vomitting seizures papilloedema 3rd and 6th CN palsies visual field defects
investigations for ?brain tumour?
MRI (then maybe fMRI)
CT contrast
stereotactic biopsy for histology
– MGMT methylation predicts response to treatment
–IDH-1 mutation indicates glioma replication
what chemotherapy is commonly used for brain tumour?
PCV - procarbazine, lomustine, vincristine
temozolamide
what is usually 1st line for glioma?
radiotherapy
which tumours are most likely to metastasise to the brain?
lung breast prostate colorectal renal malignant melanoma
in lateral tentorial herniation what is compressed?
posterior cerebral and superior cerebellar arteries
cerebellum and midbrain
CN 3
how is peripheral neuropathy defined?
axonal or demyelinating damage to several nerves
5 aetiology of peripheral neuropathy?
Diabetes Alcohol Vit b12 deficiency Infective eg guillian barre, lyme Drugs - isoniazid, amiodarone
gluten sensitivity
CKD
amyloid, sarcoid
paraneoplastic
schwann cells vs oligodendrocytes?
both produce myelin
schwann - peripheral
oligodendrocytes - cns
5 mechanisms of damage in peripheral neuropathy?
demyelination / schwann cell damage
axonal degradation - eg charcot marie tooth
compression
wallerian - trauma - axon separated from cell body
infarction - eg diabetes, arteritis
infiltration - leprosy, cancer
what are the 4 types of sensory fibre?
A alpha
A beta
A delta
C
what are A alpha fibres?
sensory neurones large myelinated proprioception if there is damage to them you fall over when you close your eyes
what are A beta fibres?
large, myelinated
fine touch, vibration
what are A delta fibres?
small
myelinated
pain & cold
damage = loss of sensation or severe neuropathic pain
what are C fibres?
sensory unmyelinated slow pain very small so vulnerable to damage damage = loss of pain or neuropathic pain
what motor neurones are affected in peripheral neuropathy, & when?
what symptoms?
lower motor neurones, motor neurone involvement is a late sign
muscle cramp
weakness
atrophy - distal muscles - foot arches, pes cavus
fasciculations
what pattern of neurones are affected in symmetrical sensorimotor neuropathy?
longest first - so starts in toes and ascends
sensory then motor
sensory - pain, tingling, numbness
what pattern of neurones are involved in asymetrical sensory peripheral neuropathy?
what causes this?
patchy
dorsal route ganglion
paraneoplastic
sjorens
gluten
what is mononeuritis multiplex?
peripheral neuropathy aka asymmetrical sensorimotor
loss of motor & sensory in two separate areas
what is assymetrical sensorimotor peripheral neuropathy most associated with?
systemic vasculitis
what will you see on clinical examination of someone with peripheral neuropathy?
decreased reflexes
sensory deficits
weakness
wasting
investigation of peripheral neuropathy?
nerve conduction studies
- if demyelination, conduction will be slow
- if the axon is damaged, impulse will be smaller
treatment for cramps in neuropathy?
quinine
treatment for pain in peripheral neuropathy?
amitryptiline
gabapentin
how is Huntingtons inherited?
autosomal dominant
anticipation so if parents are borderline but dont have symptoms, their child could still have it
what kind of mutation is seen in Huntingtons?
trinucleotide repeat (CAG) on chr 4, huntingtin / HTT gene
what does the mutation in Huntingtons code for & what is the effect of the mutation?
CAG codes for glutamine
too many CAG repeats = build up of glutamine
= misfolding/aggregation
= loss of GABA producing cells, loss of inhibitionn
how is movement affected in Huntingtons?
it can be initiated but then is hard to stop or change
clinical presentation of Huntingtons?
cognitive / mood changes chorea - involuntary abnormal movements eye movement disorders dysarthria dysphagia dementia infections
management of Huntingtons disease?
antipsychotic eg olanzapine
tetrabenazine - DA depleting
benzodiazepine
3 places that can be stenosed in spinal cord stenosis & the names for them?
central spinal canal = central stenosis
nerve root canals = lateral stenosis
intervertebral foramina = foramina stenosis
3 causes of spinal stenosis?
congenital age related degeneration herniated disk thickening of ligaments eg ligamentum flavum fractures tumour spondylolisthesis (slipped disk)
presentation of spinal cord stenosis?
gradual intermittent neurogenic claudication leg weakness worse when standing saddle anaesthesia lower back/buttock/leg pain
investigations for spinal stenosis?
MRI
CT angiogram and ABPI to exclude peripheral artery disease
how does B12 deficiency affect the spinal cord and what is the effect of this lesion?
B12 deficiency = posterior spinal cord syndrome
affects dorsal columns = bilateral loss of proprioception and fine touch
what does syringomyelia cause?
syringomyelia = development of fluid filled cyst in spinal cord
cape like distriibution - loss of sensation over arms
what is an afferent fibre?
afferent = sensory
annie is sensitive
what is an efferent fibre?
efferent = motor
has an effect on the muscle
what is in a cognitive impairment screen?
orientation attention language visuospatial motor
what are red flags for spinal cord compression? - 3
loss of bowel/bladder function
UMN in lower limbs
LMN in upper limbs
what is brown sequard syndrome?
hemisection of the spinal cord
in exams is typically A&E knife injury + loss of sensation
presentation of brown sequard syndrome?
ipsilateral hemiplegia (loss of proprioception, vibration sensation and potentially spastic pareparesis)
contralateral pain and temperature loss below lesion
complete loss of sensation at site of penetration
first line investigation for brown-sequard (or any penetrating trauma?)
plain radiograph
can do MRI/neuro exam later
treatment for brown sequard?
spine immobilisation
steroids
physio
what is charcot marie tooth?
inherited peripheral neuropathy
the 4 types of charcot marie tooth syndrome?
1 - unstable myelin - children, weakness and loss of sensation starting from feet and going up
2 - axonal - like type 1 but later onset
3 - marked segmental demyelination - floppy baby
4 - demyelination - males more common
how is duchenne muscular dystrophy inherited?
x linked - males
what is the problem in duchenne muscular dystrophy?
lack of dystrophin (which should strengthen muscle)
presentation of duchenne muscular dystrophy?
cannot run, hop or jump fatigue recurrent falls under 3 milestones delayed speech is slurred
investigation for duchenne muscular dystrophy?
raised serum creatinine kinase
muscle biopsy
complications of duchenne muscular dystrophy?
learning difficulties resp failure cardiomyopathy osteoporosis infections
what is clozepine?
an antipsychotic, dopamine antagonist
important because can cause Parkinsonism
where is the clot if there is hemianopia?
posterior circulation
risk factors for intracerebral haemorrhage?
hypertension
age / smoking // alcohol / diabetes
anticoagulation/ thrombolysis
microanneurysms
what is hydrocephalus caused by?
CSF obstruction
raised ICP
when can you test CSF for xanthrochromia?
after 12hrs
only if ICP is fine
what is wernickes encephalopathy?
ataxia
opthalmoplegia
confusion
vitamin B1 deficiency - thiamine
chronic alcoholics
flapping tremour
management - B vitamin infusion
most common origin of secondary brain tumour?
non small cell lung cancer
what is korsakoffs?
ecephalopathy can develop from wernickes
what kind of acteylcholine receptors are affected in myasthenia gravis?
nicotinic
if there is automatisms where is the seizure?
temporal lobe
if there is motor features eg jacksonian march where is the seizure?
frontal lobe
locked in syndrome is caused by damage to which vessels?
pontine
signs of raised ICP?
papilloedema vomitting seizures extensor posturing pupil dilation (cn3 palsy) cn6 palsy headache decreased consciousness
what is delirium tremens?
alcohol withdrawal
what is Romberg’s test?
for peripheral neuropathy
ask patient to close their eyes
and stand on one leg
if either proprioception or vestibular function is compromised they will fall over –> pos rhombergs test
pos rhombergs indicates peripheral neuropathy eg vit b12 deficiency, ehlers danlos, or vestibular dysfunction
if they sway but dont fall over this indicates cerebellar pathology
progressive weakness that gets better with exertion is
lambert eaton myasthenic syndrome
related to small cell lung cancer
apart from the neuropathy, how does vit B12 deficiency present?
anaemia yellow tinge angular cheilitis depression etc fatigue glossitis
what kind of motor neurones are found in the anterior horn cells?
lower
what is gowers sign?
in duchenne muscular dystrophy
use arms to get up from sitting
gambling is linked with what parkinsons drugs?
dopamine agonists eg ropinarole
what cranial nerves are involved in the reflex that makes you blink when something touches the cornea?
sensing - trigeminal nerve. if this is damaged the opposite eye wont blink either
motor - facial nerve. if this is damaged one eye will not blink, when you touch it or the other one. but the other eye will respond in both situations
nystagmus is a problem with which cranial nerve?
vestibulocochlear
of the 6 eye movement muscles, which 2 are not innervated by CN3?
LR6 SO4 (lardy arse sofa)
lateral rectus - 6 (abducens)
superior oblique - 4
who gets Felty’s syndrome?
50-70s white with long standing rheumatoid arthritis
what are the 3 components of charcots neurological triad and who does it affect?
MS
dysarthria (scanning/stuccato speech)
intention tremour
nystagmus
