Neuro Flashcards
what is MS
autoimmune disease causing CNS demyleination
CD4 mediated oligodendrocyte destruction + humoral response to myelin binding protein
mainly affects female 20-40yr
associated with HLA-DRB1 gene (+ absence of HLA-A)
what is radio + histological hallmark feature of MS
demyelination plaques in CNS - radiological
eventual axonal loss - pathological
what are the classifications of MS
primary progressive
relapsing-remitting -> secondary progressive
mostly relapsing remitting
progressive-relapsing
what is diagnostic criteria for MS
McDonalds criteria to diagnose
2+ relapses disseminated in time (by a month) and space (2+ hyper intense T2-weighted lesions on MRI)
if 1 ep of demyelination + clinical signs = clinically isolated syndrome
not diagnosed as MS as not disseminated in time+space
what are 2 phases of MS
early active phase neuroinflammation (disease activity):
macrophage myelin destruction, T cell infiltration, axonal damage, reactive astrocytes
new T2 lesions on MRI +/- clinical relapse (may be asymptomatic)
late chronic phase neurodegeneration:
myelin debris, axonal loss, activated microglia
more clinical markers (MRI, atrophy) but independent of relapse activity (occurs but symptoms don’t worsen)
what is pathophysiology of MS + effects on white/grey matter
only affects oligodendrocytes in CNS
causes multifocal neuroinflammation plaques within:
white matter - more apparent
grey matter (subcortical/cortical) - fewer T/B cells, causes cognitive impairment (late disease)
what immune cells cause MS
auto-CNS-reactive T cells (mostly CD8>CD4)
infiltrates CNS via endothelial adhesion molecules
APC reactive T cell so they release MMP that breakdown BBB
causes oligodendrocyte demyelination, axonopathy, gliosis
what occurs in first attack
MS usually presents with optic neuritis (first attack)
inflammatory processes occur long before
causes optic neuritis - loss of central vision, painful eye movements
MS is disseminated in time and space - so affects different nerves, causing different symptoms
how does early + late MS disease differ
early - re-myelination can resolve symptoms
late - re-myelination is incomplete, so symptoms don’t resolve
how does MS present
optic neuritis (first attack) - loss of central vision (central scotoma), painful eye movements, impaired colour vision
CN6 lesion - double vision, conjugate lateral gaze disorder
lesion in medial longitudinal fasciculus - internuclear opthalmoplegia
Horner syndrome, limb paralysis, incontinence
what are MS RF
20-40yr female, scandanavian
symptoms improve in pregnancy + postpartum
low VitD, UVB exposure, past EBV infection
obese, diabetes, smoker
genes: present HLA-DRB1, absent HLA-A
sarcoidosis, SLE
how is MS investigated
CSF shows oligoclonal bands, indicating ongoing inflammation
gold standard - MRI (shows hyper intense T2-weighted lesions disseminated in time + space)
lesions = inflammation, demyelination, axon damage, oedema
location: periventricular, juxtacortical, infratentorial, medullar
how does MS look micro + macroscopically
micro - initial perivascular/myelin swelling with BBB breakdown
early active phase (neuroinflammation) - T cell infiltration, macrophage myelin destruction, reactive astrocytes
late chronic phase (neurodegenration) - myelin debris, axonal loss, activated microglia
macro - global atrophy, hydrocephalus ex vacuo, thinned corpus callosum, periventricular/juxtacortical demyelination
how is acute MS attack managed
glucocorticoids = IV methylprednisolone 1g OD for 3/7
if not responding to steroids, give plasma exchange
how is relapsing-remitting MS chronically managed
DMART + symptom relief
DMART - reduce disease activity to induce long term remission (3months to reach full effectiveness)
symptom relief - physiotherapy, baclofen (for muscle spasm), anticholinergic (for incontinence), sildenafil (for erectile dysfunction)
what DMART are given for MS
injectable: B-interferon, glatiramer
oral: dimethyl fumarate, teriflunamide, fingolimod
biologic: natalizumab, alemtuzumab
what are neurological + cardiological causes of collapse
neuro - sieuzures, non-epileptic attack disorders
cardio - syncope
how do seizure + syncope differ
seizure = post-ictal confusion, syncope = no confusion
seizure:
sudden onset, with limb jerk/tongue bite/incontinence
usually last <5min
pt is confused after (post-ictal confusion) and may have Todd paresis (residual focal neurological deficit)
syncope:
there is no confusion after fall
vasovagal (neurocardiogenic) - sweating, light-headed, narrowing of vision, lower themself to floor
arrhythmogenic syncope (stokes adams attack) - abrupt onset, no warning
what is status epileptics
seizure lasting 30min+, or multiple seizures over 30min with incomplete resolution
assume status epileptics at 5min
what are 4 stages of status epileptics management
premonitory 0-10min
early status 0-30min
established status 0-60min
refractory 30-90min
how is status epileptics immediately managed
premonitory 0-10min
rectal diazepam 10-20mg
repeat (or buccal midazolam 10mg) once 15min later if status continues
if seizures continue (in hospital), IV lorazepam and if needed repeat once 15min after
what is monitored during status epileptics
O2 sats + glucose (as they are common and rapidly reversible causes of seizures)
if history of alcohol abuse, give parbinex before glucose - to prevent wernicke encephalopathy
how are epileptic syndromes categorised
focal + generalised
focal - usually temporal lobe:
simple
complex - consciousness impaired, loose consciousness after an aura/seizure onset
secondary generalised - initially focal, then become bilateral seizure (usually tonic clonic - convulsive seizure)
generalised:
absence - common in children, lasting <10sec
tonic-clonic - pt looses consciousness with post-ictal confusion, limbs stiffen (tonic) then jerks (clonic)
myoclonic - sudden jerking of limb/trunk/face
atonic seizure - pt falls due to sudden loss of muscle tone, pt retains consciousness
what are features of specific focal seizures
temporal lobe - most common:
hallucinations - auditory/olfactatory/gustatory, automatism (lip smacking)
frontal lobe:
motor features = dysphasia, Todd paresis (residual focal neurological deficit),
Jacksonian (only on 1 side, progressing from 1 muscle group to nearby ones quickly)
parietal lobe: sensory symptoms (tingling/numbness)
occipital lobe: visual symptoms (spots/lines in field)
