Neuro Flashcards
at what age does epilepsy usually develop?
before 20 or over 65
what are focal seizures?
in an isolated part of the brain (usually temporal lobe)
affect speech/motor/hearing/memory
do partial seizures impair consciousness?
some do - partial complex - do not know you are having eg psychomotor (automatisms)
some don’t -partial simple - myoclonic, jacksonian
what are secondary generalised seizures?
begin in one part of the brain and spread to both sides
what is a generalised seizure?
affecting both hemispheres of the brain
what is an atonic seizure?
‘drop attack’, muscles go floppy
what is a tonic-clonic seizure?
generalised
loss of consciousness
muscles stiff (tonic)
violent muscle contractions (clonic)
some features of an epileptic seizure?
prodromal phase - irritability/confusion aura post ictal confusion, drowsiness, headache lasting 5-30 mins seizure lasts for 30-120 secs stereotypy cyanosis can occur from sleep lateral tongue bite positive ictal symptoms eg head turning
some features of non epileptic seizures?
situational
longer duration
very fast or very slow post ictal recovery
eyes closed
pelvic thrusting
ictal crying
no cyanosis, tongue biting, incontinence or injury
investigations for ?epilepsy?
EEG
MRI
ECG
serology
2 drugs for focal epilepsy?
carbamazepine
lamotrigine
2 drugs for generalised seizures?
sodium valproate
lamotrigine
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
side effect of sodium valproate?
teratogenic
liver damage
hair loss
side effect of carbamazepine?
agranulocytosis
aplastic anaemia
side effect of lamotrigine?
stevens johnson syndrome
how is status epilepticus defined?
seizure for more than 5 mins
or 3 seizures in 1 hour
treatment of status epilepticus?
ABCDE
secure airway
oxygen (high flow)
check cardiac, resp function, glucose
IV lorazepam
repeat after 10 mins if not successful
IV phenytoin or phenobarbitol
what is the pathophysiology of parkinsons?
death of dopaminergic cells in the substantia nigra
what is a lewy body?
collection of alpha synuclein
in lewy body dementia and also sometimes parkinsons
classic 3 features of parkinsons?
bradykinesia
tremour - pill rolling
rigidity - cogwheel
what is the gait/posture like in parkinsons?
stooped posture
shuffling ‘festinant’ gait with decreased arm swing
what is hypomimia?
lack of facial expression
sign of parkinsons
autonomic symptoms of parkinsons?
urinary frequency (not incontinence)
dribbling
postural hypotension
constipation
how is parkinsons diagnosed?
usually clinical
DATSCAN to visualise DA-ergic activity in striatum
what is first line for parkinsons, how does it work?
levodopa (DA precurser) with carbidopa (peripheral decarboxylase inhibitor)
some side effects of levodopa w/ carbidopa?
dystonia chorea dyskinesia nausea psychosis
what are ripinirole & bromocriptine? a side effect?
DA agonist
used in parkinsons
pulmonary fibrosis
what is selegiline, how is it used?
MOA-B inhibitor - stops breakdown of DA and NA
used for depression & parkinsons
what is entecapone?
COMT inhibitor
similar to carbidopa
carbidopa + entecapone may extend ‘on’ time of levodopa
what can be given to help tremour? what is a side effect?
anticholinergic eg procyclidine
anti cholinergic burden = confusion
what happens when drugs for parkinsons stop working?
on dyskinesias = hyperkinetic movement
off dyskinesias = painful dystonic posturing
unpredictable freezing
is parkinsons symmetrical?
no
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
define stroke?
acute sudden onset neurological deficit
due to cerebrovascular pathology
symptoms persisting for more than 24hrs or death
what are the main vessels in the anterior cerebral circulation? - 6
posterior communicating middle cerebral - anterior choroidal internal carotid anterior cerebral anterior communicating
what main arteries branch off basilar?
posterior cerebral superior cerebellar pontine anterior inferior cerebellar -- vertebral arteries - posterior inferior cerebellar & spinal are branches
what are brocas & wernickes area?
wernicke = understanding words brocas = forming words/speaking
where is wernickes area? what is it supplied by?
parietal/temporal lobe
opposite side to dominant hand
supplied by middle cerebral artery
where is brocas area, what is it supplied by?
frontal lobe
opposite side to dominant hand
supplied by middle cerebral artery
what parts of the brain does the anterior cerebral artery supply?
front & top - so frontal cortex and some of the motor cortex (esp upper limbs)
what does the middle cerebral artery supply?
sides of brain inc brocas, wernickes, motor (esp lower limbs) and sensory
what is the most common artery to have a stroke in?
middle cerebral
what does the posterior circulation supply, what are the symptoms of a stroke there?
cerebellum and brainstem
dysarthria, dysphasia, diplopia, dizziness, ataxia, quadrantanopia, reduced GCS
what is a lacunar infarct & how does it present?
of the deep ppenetrating arteries
produces an isolated deficit, eg one hand weakness
no visual field defect or cortical malfunction
how do you differentiate stroke from bells palsy?
stroke = lower face weakness but forehead spared
bells palsy = forehead affected
are the motor symptoms ipsilateral or contralateral to the infarct?
contralateral
what is the bamford classification?
for ischaemic stroke, total anterior = 3/3 and partial anterior = 2/3
hemiplegia
homonymous hemianopia
higher cortical dysfunction eg speech
what is the first investigation in suspected stroke?
non contrast CT head to exclude haemorrhagic
if you are going to do a thrombectomy how will you find the clot?
CT angiogram
what is gold standard for ischaemic stroke investigation?
diffusion weighted MRI head
what is endarterectomy? what inv for it?
to remove atherosclerotic plaques
doppler
what screening programme for stroke in the community?
FAST
what is first line for stroke if presented within 4.5 hrs of onset?
alteplase (tissue plasminogen activator)
+ aspirin
contraindications for thrombolysis? 5
hypertension bleeding elsewhere surgery in the last 3 months brain malignancy over 4.5 hrs since onset
when should you do a thrombectomy in ischaemic stroke?
within 6hrs or if you can prove the tissue is viable
there is a risk of reperfusion injury so only do if it will be worthwhile
should you lower BP in stroke?
no, this increases the risk of hypoperfusion
secondary prevention after stroke?
aspirin for 14 days
clopidogrel
atorvastatin
bp control
risk factors for ischaemic stroke/TIA?
age hypertension diabetes hypercholesterolaemia smoking AF thrombophilia sickle cell
what is a crescendo TIA?
2 or more TIA within a week
high risk of stroke
what is the definition of TIA?
symptoms of a stroke with complete resolution within 24hrs
what is the pathophysiology of TIA?
ischaemia without infarction (the tissue does not die)
what score assesses risk of another TIA or stroke?
ABCD2 Age (over 60 = 1) BP (over 140 or 90 = 1) Clinical features (speech impaired = 1, unilateral weakness =2) Duration (10 mins+ = 1, 1hr + = 2) Diabetes
if more than 4 admit
surgical treatment for TIA?
endarterectomy if 70% or more stenosis
stent eg carotid stent
long term treatment for TIA?
aspirin + clopidogrel for 2 weeks - then just clopidogrel
statins
BP control
what is the usual epidemiology of extradural haemorrhage?
young patient with traumatic head injury esp skull fracture
what are the 3 layers of meninges?
outer: dura mater - tough fibrous - periosteal and meningeal
middle: arachnoid mater: loose connective tissue
inner: pia mater - thin, tightly adhered to brain
PADS
in an extradural haemorrhage where is the blood?
between the skull and the dura mater - usually tightly stuck!
where are the dural venous sinuses?
between the two layers of dura, the periosteal and meningeal layers
what artery is most commonly implicated in an extradural haemorrhage?
meningeal artery rupture
at the pteron (frontal bone joins parietal bone)
typical history of extradural haemorrhage?
blow to side of head
lucid period for a few hours (these vessels bleed slowly)
– loss of consciuosness
what does an extradural haemorrhage look like on CT?
hyperdense bright white
lemon shaped
doesnt cross suture lines
skull x ray may also show fracture
management of extradural haemorrhage?
ICU / intubate
mannitol - to decrease ICP
craniotomy
where is the blood in a subdural haemorrhage?
between the dura and arachnoid
typical history in subdural haemorrhage?
what vessels are typically affected?
acute - car crash with accelleration-deceleration
chronic - elderly or alcoholic with trivial fall weeks ago
tear of bridging veins - in elderly/alcoholic this is more likely as brain is shrunken
veins so bleeding can be slow – chronic
what do you see on CT in a subdural haemorrhage?
crescent/banana shaped bleeding - all way to midline at each side
acute (white) or chronic (grey) blood
midline shift
presentation of subdural haemorrhage?
acute = reduced worsening GCS chronic = progressive confusion focal neurological symptoms raised ICP (vomitting/reduced ICP/blurred vision)
treatment for subdural haemorrhage?
burr hole
craniotomy
mannitol
where is the bleeding in a subarachnoid haemorrhage?
between the arachnoid and pia mater
where the CSF should be
what vessels are most often implicated in subarachnoid haemorrhage?
usually caused by ruptured berry anneurysm
in circle of willis, esp junctions, in anterior comm/ int carotid/ MCA
typical history/epidemiology for subarachnoid haemorrhage?
sudden onset thunderclap headache
while playing sport
female 45-60/connective tissue disorders
symptoms of subarachnoid haemorrhage?
sudden onset worse ever headache, occipital (at back)
meningism - photophobia, neck stiffness
vision/speech changes
confusion
what do you see on CT in subarachnoid haemorrhage?
star shaped
hyperattenuation in subarachnoid space
apart from CT head, what other investigations might be helpful in subarachnoid haemorrhage?
lumbar puncture for xanthochromia - yellow colour indicates bilirubin from blood in csf space
angiography to find the source
treatment for subarachnoid haemorrhage?
endovascular coiling/clipping to stop bleeding
nimodipine (calcium channel blocker) to prevent vasospasm secondary to bleeding
lumbar drain for CSF, if hydrocephalus develops
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
some triggers for migraine in susceptible people?
chocolate/wine/cheese/caffeine oral contraceptive menstruation bright lights strong smells lack of sleep
how long does a migraine last?
4-72 hours
what is the pain like in migraine?
unilateral
throbbing/pulsating
moderate-severe
apart from pain, some presentations of migraine?
prodromal fatigue/mood changes nausea photophobia phonophobia aura cannot carry out daily activities, want to lie in a dark room
what is a hemiplegic migraine?
unilateral weakness, ataxia, altered consciousness
some common features of migraine aura?
flashing lights
zig zag lines in vision
ringing in ears
what is a silent migraine?
aura but no headache
acute management of migraine? 3
NSAIDS/paracetamol
triptans eg sumatriptan
antiemetic eg metoclopramide
what are triptans for & how do they work?
for acute treatment of migraine 5ht agonist causes vasoconstriction inhibits peripheral pain receptors reduces CNS activity
prophylaxis of migraine?
propanolol
topiramate
amitriptyline
riboflavin
some triggers for tension headache?
stress posture lack of sleep eye strain depression alcohol skipping meals dehydration
what is the pain like in tension headache?
bilateral
mild-moderate
pressing/tight sensation
photophobia or phonophobia but not both and no nausea
10 headache red flags?
new onset over 50 immunosupressed neck stiffness history of cancer history of trauma jaw claudication visual disturbance changes with posture started by coughing/laughing etc = increased ICP fever seizure papilloedema vomitting change in personality
epidemiology of cluster headache?
male
20-50
smoker
what is the pathophysiology of cluster headache?
hyperactivity of trigeminal-autonomic reflex arc
vasodilation and trigeminal stimulation
histamine & mast cells
autonomic nervous system activated
presentation of cluster headache?
severe 'boring' 'hot poker' pain over one eye myosis, ptosis, red/swollen eye nasal discharge and tears sweating on one side of face photophobia agitation/restlessness
how long does a cluster headache last?
15 min - 3hrs
episodic vs chronic cluster headache?
episodic = pain free for 1 month + chronic = no pain free months
management of cluster headache?
neuro referral
acute - sumatriptan, high flow oxygen
prophylaxis - verapamil, prednisolone, lithium
what medications cause medication over use headache?
10 days/month: ergotamine
triptans
opioids
15 days/month: nsaid
paracetamol
aspirin
what is the pain like in trigeminal neuralgia?
in one or more distributions of the trigeminal nerve no radiation severe stabbing pain unilateral secs-mins triggered by stimuli
management of trigeminal neuralgia?
carbamazepine
surgery to decompress or damage the nerve
Some factors that contribute to the epidemiology of MND?
smoking
pesticides
SOD1 & C90RF genes
what are upper motor neurones?
go from cortex to anterior horn of spinal cord
what are lower motor neurones?
go from the spinal cord to the muscle
does MND affect upper or lower motor neurones?
can be either or both
if it is affecting only upper motor neurones it is called primary lateral sclerosis
if it affecting only lower motor neurones it is called primary muscular atrophy
if it is affecting upper and lower it is called amyotrophic lateral sclerosis (this is most common)
what is the most common onset of MND?
limb
features of upper MND affecting the limbs?
pyramidal weakness
– extensors in arms and flexors in legs
spasticity
brisk reflexes
features of lower MND affecting the limbs?
weakness
wasting
fasciculations
some features of bulbar MND?
dysarthria - speech is slurred or quiet
excessive saliva
choking
jaw spasm
what type of respiratory failure is seen in MND?
type 2 (because it is a problem with the muscles so you are unable to both breathe oxygen in AND co2 out)
when is the breathlessness worst in MND?
at night or when lying flat
some general symptoms of MND?
foot drop tripping/falling difficulty using hands fatigue, sleep disturbance anorexia frontotemporal dementia emotional lability
is MND symmetrical?
no
3 signs that suggest it is not MND?
Symmetry
incontinence
sensory disturbance (MND is specifically of the MOTOR neurones)
relapsing-remitting pattern (MND is gradually worsening)
investigations for MND affecting upper neurones?
MRI brain and spine - need to exclude other things
investigations for lower motor neurone pathology? (eg in MND)
nerve conduction studies - test how well the nerve conducts the signal
EMG (electromyography) - tests how well the muscle responds to impulses
what is riluzole?
antioxidant, may improve symptoms in MND or extend life by a few months
motor neurones that are spared in MND?
oculomotor nerve onufs nucleus (controls bladder/continence)
most common cause of meningitis in neonates?
group B strep
most common cause of meningitis in adults?
s pneumoniae
n meningitidis is a common cause of meningitis, especially in which populations?
adults/students
h influenzae is a cause of meningitis, most commonly affecting ____
children
listeria monocytogenes is a cause of meningitis, most commonly in which populations?
immunocomp elderly neonates cancer diabetic pregnant
some viral causes of meningitis?
HSV
VZV
define meningitis?
inflammation of the meninges, which cover the brain and spinal cord
why is a rash associated with meningitis?
n meningitidis is a common cause of meningitis
meningococcal sepsis = disseminated intravascular coagulation, the ‘rash’ is the red spots produced by the tiny clots
classic triad of meningism?
photophobia
neck stiffness
headache
apart from meningism, some features of meningitis?
vomitting fever impaired consciousness seizures kernigs sign brudzinskis sign non blanching purpuric rash, if meningoccoccal
what is kernigs sign?
meningitis
patient lying on back
flex hip and straighten knee
= back pain
what is brudzinskis sign?
patient lying on back
flex neck – knees and hips with flex too
what is the CSF like in bacterial meningitis?
cloudy
neutrophils/granulocytes
high protein
low glucose
what is the CSF like in viral meningitis?
lymphocytes
high protein
normal glucose
what is the CSF like in fungal meningitis?
lymphocytes
high protein
low glucose
do you need to send a CSF if you have meningism + rash?
no, you can do a blood test for n meningitidis instead
if a CSF contains gram pos cocci what is it most likely to be?
strep pneumoniae
if a CSF contains gram pos bacilli what is it likely to be?
h influenzae
listeria
what empirical antibiotics should you give for ?meningitis while you are waiting for results?
cefotaxine / ceftriaxone
+ amoxicillin if you suspect listeria
what should you give to contacts of someone known to be infected with n meningitidis?
ciprofloxacin
what drug reduces the risk of developing complications after meningitis?
dexamethasone
potential complications of meningitis?
hearing loss epilepsy cognitive impairment memory loss focal neurological deficits
some differentials for MND?
MS
spinomuscular atrophy
muscular dystrophy
myasthenia
what is the most common cause of encephalitis?
HSV
what is encephalitis?
inflammation of the brain parenchyma
features of encephalitis?
fever headache fatigue confusion change in behaviour/psychosis focal neurological defect eg aphasia/hemiparesis/cerebellar seizures
investigations for encephalitis?
MRI head to see inflammation - frontal/temporal
CSF
throat swab for virus serology blood culture FBC, CRP, UE EEG - non specific
what can the EEG show in encephalitis?
periodic lateralised discharges at 2Hz (not specific)
empirical management for encephalitis?
aciclovir
gancyclovir
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
what is the epidemiology of MS?
under 50
more females
more further from the equator
may be related to EBV exposure in teenage
is MS in the CNS or PNS?
CNS
what is the pathophysiology of MS?
autoimmune
lymphocytes cross the BBB – destroy oligodendrocytes
demyelination & loss of axons
remyelination – remission for a period (but symptoms may reappear eg when axons stretched by a hot shower)
some presenting features of MS?
optic neuritis nystagmus focal weakness - face/arms/legs spasticity vertigo paresthesia cerebellar ataxia sensory loss
what is optic neuritis & why can it happen in MS?
painful unilateral visual loss
demyelination of optic nerve
relative afferent pupillary defect: consensual but not direct constriction
what is internuclear opthalmoplegia in MS?
dysfunction of the fibre than connects CN 3, 4 and 6 for co ordinated eye movement
where is the problem in a conjugate lateral gaze disorder?
CN6 - affected eye cannot abduct
what are two ‘pre-MS’ syndromes?
radiologically isolated: changes apparent on MRI, but no symptoms
clinically isolated: 1 episode of symptoms but you need at least 2 to call it MS
3 patterns of disease course in MS?
relapsing-remitting
– partial or full recovery between, minimal disability
secondary progressive
- relapsing-remitting which becomes progressive,
- or, gradually worsening with relapses superimposed
primary progressive
– gradually worsens from onset
what is Lhermitte’s sign?
sensations shooting down spine when bending neck
associated with MS
investigations for MS?
MRI w/ contrast - shows immune activity in CNS
lumbar puncture : oligoclonal bands in CSF
indicates immune activity in CSF
what signs might you find on a bedside examination of a patient with MS?
brisk reflexes eyes don't move together pyramidal weakness unco-ordinated babinskis sign lhermittes sign
what is 1st and 2nd line acute treatment for MS relapses?
1st – oral methylprednisolone
2nd – IV steroids
treatment for MS symptoms?
amitryptiline baclofen anti cholinergics (to treat incontinence)
drugs that prevent MS relapses?
natalizumab - stops lymphocytes crossing BBB alemtuzumab: anti CD20 betaferon/IFN1beta daclizumab stem cell transplant
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
what is myasthenia gravis?
autoantibodies to the Ach receptor, causing muscle weakness
what condition is myasthenia gravis associated with?
thymoma and thymic hyperplasia
what normally happens at the neuromuscular junction to trigger muscle contraction?
depolarisation of lower motor neurone = calcium channels open
calcium influx into LMN
calcium = exocytosis of Ach from vesicles
Ach crosses synapse and binds to postsynaptic receptors
ach binding opens the intrinsic channel, potassium out sodium in
voltage gated sodium channels open = depol along t tubule
depol = opening of calcium stores in sarcoplasmic reticulum
calcium = contraction
as well as anti-AchR antibodies, what other antibodies might (less commonly) be found in myasthenia gravis?
anti-musk (muscle specific kinase)
some ocular manifestations of myasthenia gravis?
ptosis
upward gaze
complex opthalmoplegia
double vision (because of difficulty with eye movement)
some general features of myasthenia gravis?
fatiguability muscle weakness dysarthria dysphagia shortness of breathing fatigue when chewing head drop
are antibodies always present in myasthenia gravis?
no, in fact anti-AchR antibodies only present in 80% pts and only 50% of ocular
what are 2 investigations for myasthenia gravis?
what will you see?
single fibre EMG
decremental potentiation - response decreases as stimulus is repeated
- this will tell you there is fatiguability
tensilon test
tensilon = ach esterase inhibitor
this will tell you if the symptoms are caused by myasthenia or not (definitive/confirm)
what is the treatment for myasthenia gravis?
1st line - pyridostigmine (Ach esterase inhibitor)
2nd line - azathiopurine
other immunosuppressants eg prednisolone, methotrexate
rituximab good for MuSK Ab +ve
what is myasthenic crisis?
complication of myasthenia gravis respiratory difficulty SOB, reduced breath sounds, reduced chest expansion normal saturation, normal ABG decreased FVC
how to treat myasthenic crisis?
IV immunoglobulin
steroids
plasma exchange
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
what infections does guillian barre follow?
GI eg campylobacter jejuni
EBV
CMV
what is the pathophysiology of guillian-barre?
autoimmune
molecular mimicry
antibodies to nerves eg myelin sheath or axon
= peripheral neuropathy
is guillian barre symmetrical?
yes
presentation of guillian barre?
following an infection ataxia ascending flaccid motor weakness, starts at feet hyporeflexia facial weakness reduced sensation neuropathic pain respiratory involvement
timeframe of guillian barre?
develops within 4 weeks of infection
peaks 2-4 weeks after that
takes months to years to recover
how is guillian barre diagnosed?
clinical diagnosis
Brighton criteria
CSF - high protein, normal glucose and white cells
nerve conduction studies - low signal
treatment for guillian barre?
heparin/apixaban
plasma exchange
IV immunoglobulins
3 causes of spinal cord compression?
cancer (metastatic myeloma, bone tumour, glioma) disc herniation infection eg epidural abscess haematoma spinal stenosis
what part of the spine is most commonly compressed by tumours?
thoracic
3 classifications of spinal cord compression caused by tumour?
intramedullary - in the vertebral canal
leptomeningeal - where the meninges should be
extradural - compressing the dura from the outside
what is the pain like in spinal cord compression?
what makes it worse?
radicular (spreading down spinal root to legs) or local
worse when lying/coughing
presentation of spinal cord compression?
back pain
progressive motor weakness - umn and lmn
sensory loss
bladder/bowel dysfunction, retention
describe the motor impairment in a spinal cord lesion?
LMN signs at the level of the lesion – wasting, weakness, hyporeflexia
UMN signs BELOW the level of the lesion – hyperreflexia, contralateral spasticity, extensor plantar reflex
describe the sensory impairment in spinal cord compression?
ascending numbness
parasthesia
1-5 caudal levels below the lesion
less common than motor symptoms
what is the gold standard investigation for spinal cord lesion?
MRI
some differentials for spinal cord compression?
MS
MND
guillian barre
spinal cord compression
treatment of spinal cord compression?
IV dexamethasone
surgical decompression - eg remove tumour, discectomy etc
epidural steroid injections
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
what is cauda equina syndrome?
compression of the bundle of nerves at the bottom of the spinal column, ‘the cauda equina’
what is the most common cause of cauda equina syndrome?
herniated lumbar disk
what is the piece of dura in the middle of the cauda equina called?
conus medullaris
what happens to the nerves in the cauda equina?
they still exit the spinal cord at their respective vertebral level
for the cauda equina nerves this is L3-L5, S1-S5, C0
what do the nerves of the cauda equina supply?
sensation to bladder rectum & perineum
parasympathetic to bladder & rectum
motor to anal & rectal sphincters
motor to lower limbs
clinical presentation of cauda equina?
saddle anaesthesia
urinary retention and/or urinary incontinence
faecal incontinence
bilateral sciatica
bilateral severe motor weakness in legs #
erectile dysfunction
loss of anal tone on PR exam
how can you distinguish cauda equina from spinal cord compression?
cauda equina only affects lower motor neurones
spinal cord compression affects both UMN and LMN so you will also see some hyperreflexia
depending on the cause spinal cord compression could be gradual onset (eg in spinal stenosis), cauda equina is always a sudden onset
what investigations for cauda equina?
urgent MRI spine
bladder USS to check for urinary retention
check reflexes and anal tone
treatment for cauda equina?
emergency lumbar decompression surgery
what nerve is compressed in carpal tunnel syndrome?
what is the function of this nerve?
palmar digital cutaneous branch of the median nerve
- sensory function to first 3.5 fingertips (not the palm though, this is a different branch that doesnt go through the carpal tunnel)
- thumb motor function (thenar muscles) – abductor pollicis brevis, opponens pollicis, flexor pollicis brevis (not the adductor!)
the carpal tunnel is formed by what?
flexor retinaculum, aka transverse carpal ligament
clinical presentation of carpal tunnel syndrome?
gradual onset, intermittent, worst at night, wakes you up
sensory changes to first 3.5 fingers - numbness, paraethsia, burning, pain
reduced thumb grip strength/difficulty with fine movements
what relieves carpal tunnel syndrome?
shaking the hand
what is phalins test?
for carpal tunnel
fully flex the wrist and hold it - pos if it causes symptoms
what is tinnels test?
for carpal tunnel
tap the carpal tunnel- pos if it produces symptoms
what is the kameth and stoddart questionnaire?
shows the likelihood of carpal tunnel
what is gold standard investigation for ? carpal tunnel syndrome?
nerve conduction studies
risk factors for carpal tunnel?
diabetes hypothyroid obesity repetitive strain acromegaly perimenopause RA
management of carpal tunnel syndrome?
rest
wrist splints
steroid injection
cut the flexor retinaculum
what do the dorsal spinal columns transmit?
proprioception
fine touch
which spinal cord pathway has gracilis and cuneate nuclei and what are these for?
dorsal spinal column
gracilis = medial = legs
cuneate = lateral = arms
what does the spinothalamic tract transmit?
pain
temperature
where do the dorsal spinal columns decussate?
medulla
where do the spinothalamic tracts decussate?
spinal cord
what does the corticospinal tract transmit?
motor
where does the corticospinal tract decussate?
85% decussates in the medulla, this is the lateral tract
15% decussates in the spinal cord, this is the medial tract
remember that corticospinal tract is motor so impulses travel down from brain to spine
thus the lateral tract is contralateral to the brain but ipsilateral to the muscles it innervates
damage to the anterior spinal artery causes what effect?
damages the lateral spinothalamic tract
– lose pain and temperature sensation
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
does spinal cord lesion affect upper or lower motor neurones?
usually both
how is continence affected in spinal cord lesions?
UMN pathology
increased sphincter tone
retention and constipation
is there is a spinal cord lesion above the level of T6 what happens?
autonomic dysreflexia
hypertension
bradycardia
sweating and flushing
if all limbs are affected where is the spinal cord lesion?
cervical
if only the legs are affected where is the spinal cord lesion?
thoracic
if the diaphragm is affected where is the spinal cord lesion?
above C3
investigation for ?spinal cord lesion?
MRI whole spine
what kind of nerves are carried in spinal nerves? (ie sympathetic, motor etc)
all kinds - autonomic, sensory and motor
what is an afferent fibre?
afferent = sensory
annie is sensitive
what is an efferent fibre?
efferent = motor
has an effect on the muscle
what nerve is damages in elbow trauma and what functions does this nerve provide?
ulnar nerve
(C7-T1 via brachial plexus)
for wrist flexion, crossing fingers, sensory to little and 4th fingers
lesion = claw hand
wrist drop indicates damage to which nerve?
what else is the nerve for?
radial nerve
for spreading hands and opening fist
sensation to dorsal thumb
a heavy rucksack or broken rib commonly causes damage to the ___
brachial plexus
what happens when the phrenic nerve is damaged?
loss of innervation to diaphragm
= orthopnoea and diaphragm is raised on CXR
lung cancer, thymoma and TB commonly damage which nerve?
phrenic
foot drop indicates damage to which nerve?
common peroneal (branch of sciatic), aka common fibular nerve
pelvis fracture commonly damages which nerve?
sciatic
L4 - S3
common peroneal nerve is from which spinal levels and could be damaged by what?
L4-S1
trauma to fibular head
which nerve innervates plantar flexion and sensation on the sole of the foot?
tibial
damage to what nerve causes burning thigh pain?
lateral cutaneous L2-L3
what condition is highly associated with Alzheimers?
Down’s, everyone with Down’s will get Alzheimer’s
what is the most common type of dementia?
Alzheimer’s
pathological features of Alzhiemer’s? (histology etc)
beta amyloid plaques
tau containing tangles
synaptic degradation
atrophy of the centre of the brain
presentation of Alzheimers?
MEMORY - short term and make new language attention/concentration personality change eg aggression disorientation time and place
investigations for Alzheimers?
MRI
MMSE
to rule out other causes:
U&E
thyroid tests
B12
what is pyridostigmine?
Ach esterase inhibitor
used for myasthenia gravis and alzheimers
who is frontotemporal dementia more common in?
under 65s
what is the pathophysiology of frontotemporal dementia?
frontal and temporal atrophy
no plaques, but tau positive & TD43 negative inclusions
what is the presentation of frontotemporal dementia?
behavioural problems
progressive aphasia - difficulty forming language
semantic dementia - loss of vocabulary
how is frontotemporal dementia inherited?
dominant
drugs for frontotemporal dementia?
SSRI
what is the pattern of onset in vascular dementia?
stepwise
stable symptoms with a sudden increase which you do not recover from
presentation of vascular dementia?
visual disturbance UMN signs attention deficit depression incontinence emotional disturbance if the original infarct was subcortical, may get dysarthria, parkinsons memory loss
investigations for vascular dementia?
MRI to look for previous infarcts
cognitive impairment screen
have they had strokes before?
what is in a cognitive impairment screen?
orientation attention language visuospatial motor
what is an eosinophyllic intracytoplasmic neuronal inclusion body?
lewy bodies
how is lewy body dementia diagnosed?
dementia \+ 2 of: fluctuating concentration visual hallucinations spontaneous Parkinsonism SPECT/PET scan shows low DA transmission
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
what is CN1?
olfactory nerve
for smelling!
how can the olfactory nerve be damaged?
trauma to cribriform plate
a left parietal lesion of the optic radiation causes what kind of vision deficit?
Quadrantanopia
of inferior right quadrant
PITS - parietal lesion = inf loss, temporal lesion = superior loss)
optic nerve vs optic tract?
optic nerve is from the eye to the optic chiasm
optic tract is from the chiasm to the lateral geniculate body
if one pupil is not constricting to direct or consensual light stimulation to the other eye, where is the problem?
CN3 - the pupil is not constricting
if the right pupil constricts in response to light shone in the left eye, but when you shine the light on the right neither constrict - where is the problem?
CN2 - the optic nerve
as the pupil is not detecting the light
what does CN3 innervate?
CN3 is the occulomotor nerve
superior and inferior and medial rectus
inferior oblique
pupillary sphincter
lps to lift eyelid
signs of a lesion to CN3?
ptosis
pupil does not accomodate to light
absent pupillary light reflex
outward deviation - as there is function of the lateral rectus to look out (CN6) but not inf oblique (CN3) to counteract it
what does CN4 innervate?
how does damage to it present?
CN4 = trochlear nerve
innervates superior oblique - looks in and down
damage = diplopia when walking downstairs
what does the superior oblique muscle do and what is it innervated by?
looks in and down (even tho is superior oblique)
trochlear nerve CN4
what does the superior rectus muscle do and what is it innervated by?
looks up
occulomotor nerve CN3
what does the inferior oblique muscle do and what innervates it?
looks up and in
cn3 occulomotor nerve
what are the 3 branches of the trigeminal nerve?
v1 - opthalmic - forehead sensation
v2 - maxillary - cheeks sensation
v3 - mandibular - chewing + sensation on anterior 2/3 tongue
how can the trigeminal nerve be damaged?
trigeminal neuralgia
herpes zoster
nasopharyngeal carcinoma
acoustic neuroma
medial deviation of eyes at rest indicates a problem with which nerve?
abducens CN6
abducens innervates lateral rectus
abducens damaged = unopposed medial rectus
what is CN7?
facial nerve - facial expression
what are the parasympathetic functions of the facial nerve?
lacrimation
salivation
causes of facial nerve dysfunction?
bells palsy
temporal bone fracture
herpes zoster
what is CN8?
Vestibulocochlear - hearing and balance
aminoglycosides cause damage to which nerve?
vestibulocochlear CN 8
what is CN9?
glossopharyngeal
sensory to pharynx, taste on post 1/3 tongue
parasympathetic - parotid gland
which cranial nerves innervate the tongue?
facial - taste on ant 2/3
glossopharyngeal - taste on post 1/3
trigeminal - sensation
hypoglossal - motor
how can you test the glossopharngeal nerve?
gag reflex
what is CNX?
vagus nerve
sensory and motor to pharynx and larynx
speech, cough
parasymp to GI tract and viscera
which cranial nerve innervates the accessory muscles?
CN 11, accessory
how can you test the accessory nerve?
ask pt to shrug their shoulders or turn head
how can you test CN12?
CN 12 is hypoglossal
ask pt to stick tongue out, it will deviate to weak side
some general causes of cranial nerve damage?
polio guillian barre MS tumour vasculitis stroke lupus syphilis TB/fungal meningitis
in ischaemic stroke how does the hemiplegia change over time?
initially flaccid, then becomes spastic as UMN lesion
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
when there has been a latent period after subdural haemorrhage why does it suddenly get worse?
clot starts to autolyse = draws water in
when is sumatriptan contraindicated?
heart disease
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
presentation of progressive bulbar palsy?
dysarthria dysphagia nasal regurg of fluids choking lmn lesions of tongue 'trouble initiating swallow'
acute vision loss suggests suggests stroke in
posterior circulation
what is the most common cause of meningitis in pregnancy?
listeria
what is 1st line for ?meningitis?
blood cultures
lumbar puncture = gold standard
use when CT shows is fine
what is the prophylactic antibiotic for contacts of listeria?
ciprofloxacin
3 contraindications for lumbar puncture?
raised ICP
focal neurology
haemodynamically unstable eg bradycardia, hypotension
decreased GCS
how is sumatriptan given in acute cluster headache?
subcutaneous
what are risk factors for Alzheimer’s?
Down’s syndrome
depression
reduced physical activity
lonliness
3 causes of guillian barre?
camp
CMV
EBV
mycoplasma
how is guillian barre diagnosed?
CSF shows raised proteins with no immune cells
what ABCD2 score is high risk?
6
as well as paralysis of facial muscles, what might you see in bells palsy?
loss of taste hearing loss (as cn7 innervates the stapedius muscle)
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
3 symptoms of frontotemporal dementia?
change in speech disinhibition social withdrawal impulsivity loss of personal awareness primitive hyperreflexia stereotypy
what treatment is first line for MS?
methylprednisolone
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
if you suspect MS is it best to do an MRI or lumbar puncture?
MRI is best
it is less invasive
CSF to look for oligochromal bands is reserved for atypical cases
which dementia is associated with hallucinations & recurrent falls / syncope?
lewy body
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
