MS Flashcards
definition of MS
Inflammatory demyelinating disease of the CNS
different classifications of MS
relapsing remitting
clinically isolated syndrome
primary progressive MS
marburg variant
relapsing remitting MS
- Commonest
- Clinical attacks of demyelination
- Complete recovery in between attacks
clinically isolated syndrome MS
- Single clinical attack of demyelination
- Doesn’t qualify as MS
- 10-50% progress to MS
primary progressive MS
- Steadily accumulation of disability
- No relapsing-remitting
marburg variant of MS
- Severe fulminant variant of MS
- Leading to advanced disability of death in a period of weeks
- Distinct from acute disseminated encephalomyelitis (ADEM)
acute disseminated encephalomyelitis
Uncommon acute monophasic CNS demyelinating condition – thought to be a post-viral autoimmune phenomenon
Intubation may be needed
Treated high dose steroids
Neuromyelitis optica (Devic’s syndrome)
Rare demyelinating condition which is typified by optic neuritis and extensive transverse myelitis.
Associated with anti-aquaporin-4 antibodies
aetiology of MS
Unknown
Autoimmune bases with postulated env trigger in genetically susceptible
Immune mediated damage to CNS myelin = impaired conduction
Grey matter atrophy
RF for MS
- EBV exposure
- Prenatal vit D levels
- Strong concordance in monozygotic versus dizygotic twins(25% vs 3%)
- Geographical variation – (temporate>tropical) with individuals carrying risk of pre-pubertal (<13yr) country of origin
epidemiology of MS
Prev in UK 1 in 1000
Rare in far east
Female more
20-40yrs
increasing incidence with latitude in some parts of the world (NB: adult migrants take their risk with them; children acquire the risk of where they settle) - leading to hypothesis of roles of vitamin D and infection
systems MS can effect
usually monsymptomatic, symptoms may worsen with heat eg hot bath/exercise
optic
sensory
motor - corticospinal tract
psychological
autonomic
uhthoff’s phenomenon
bladder
optic effects of MS
optic neuritis:
- Unilateral deterioration in visual acuity and colour perception
- Pain on eye movement
- reduced rapid central vision
diplopia
hemianopia
visual phenomena eg on exercise
bilateral internuclear ophthalmoplegia
pupil defects
argyll robertson pupil - The pupil is constricted and unreactive to light, but reacts to accommodation. The iris may be patchily atrophied, irregular, and depigmented
motor Sx of MS
- Limb weakness
- Spasms
- Stiffness
- Heaviness
- myelitis
sensory sx of MS
- Pins and needles
- Numbness
- Burning
psychological sx of MS
- Depression
- Psychosis
- accidents
- amnesia
- reduced executive functioning
autonomic sx of MS
- Urinary urgency
- Hesitancy
- Incontinence
- Impotence
uhthoff’s phenomenon
- Transient increase or recurrence of symptoms due to conduction block precipitated by a rise in body temp
signs of optic nueritis - MS
- Impaired acuity (most common)
- Loss of colour vision
- On fundoscopy in active disease – swollen optic nerve head, in chronic disease may be optic atrophy
signs of MS
optic neuritis
visual field testing - Central scotoma (optic nerve not affected) or field defects (optic radiations affected)
relative afferent pupillary defect - swinging torch test = Both pupils contractwhen light is shone on the unaffected side, both pupils dilate when light is swung to the diseased (eye).
intranuclear opthalmoplegia - Lateral horizontal gaze = failure of adduction of the contralateral eye, Indicates lesion of contralateral medial longitudinal fasciculus
sensory - Parasthesia (vibration and joint position sense loss more common than pain and temp), dysaesthesia, trigeminal neuralgia
motor - UMN signs – spastic weakness, brisk reflexes
cerebellar:
- Limb ataxia (intention tremor, past-pointing and dysmetria on finger nose and heel-shin test)
- Dysdiadochokinesis
- Ataxic wide-based gait
- Scanning speech
- falls
lhermitte’s phenomenon - Electric shock like sensation in arms and leds, precipitated by neck flexion
Ix for MS
Diagnosis based on 2 or more CNS lesions with corresponding symptoms, separated in time and space (McDonald criteria)
- LP
- Microscopy to exclude other infective or inflamm causes
- CSF electrophoresis shows unmatched oligoclonal bands that are not present in serum - suggest CNS inflammation
- MRI-brain, cervical and thoracic spine with gadolinium
- Plaque detection highlighted as high signal lesions
- Gadolinium enhancement indicates an active lesion.
- exclude other causes eg cord compression
- Evoked potentials
- Visual, Auditoy or somatosensory evoked potentials (VEP, BEP, SEP) may show delayed conduction velocity
- VEPs are delayed in 90% pts with MS
pathology of MS
inflammatory plaques of demyelination in the CNS disseminated in place and time, ie occuring at multiple sites with>30d between attacks
demyelination heals poorly = axonal loss
>80% pts develop progressive disability
dx of MS
clinical
made by a consultant neurologist using criteria, after alternative dx have been excluded
early dx reduces relapse rates and disability so refer as soon as MS is suspected
progression of MS
most pts have relapsing remitting with initial recovery between relapses
with time remission becomes incomplete - disability accumulates (secondary progression)
primary progressive MS - 10% pts, steadily progressive disability in the abscence of relapses
minority of patients experience no progressive disablement at all
pregnancy Does not alter the rate of progression: relapses may reduce during pregnancy and increase 3–6 months afterwards, but return to their previous rate thereafter
Gi sx of MS
swallowing disorders
constipation
sexual/GU sx of MS
erectile dysfunction
anorgasmia
urine retention
incontinence
criteria to dx MS
Devic’s syndrome
(=Neuromyelitis optica, NMO.)
MS variant with transverse myelitis, (loss of motor, sensory, autonomic, reflex, and sphincter function below the level of a lesion), optic atrophy, and anti-aquaporin 4 antibodies
Lhermitte’s sign
Neck flexion causes ‘electric shocks’ in trunk/limbs.
(Also +ve in cervical spondylosis, cord tumours and low B12.)
uhthoff’s phenomenon
worsening of sx with heat eg bath
charles bonnet syndrome
rare
reduced acuity/temporary blindness +- complex visual hallucinations of faces, as well as animals, plants and trees
pulfrich effect
unequal eye latencies - causing disorientation in traffic as straight trajectories seem curved and distances are misjudged on looking side ways
Mx of MS acute relapse
IV Methylprednisolone
consider plasma exchange
mx for relapsing remitting MS
Immunomodulation - interferon B
sensory sx - anticonvulsant/antidepressant
increased tone - baclofen, physio
tremor - propranolol
gait - fampridine
urinary frequency - oxybutinin
fatigue - amantadine
oscillopsia (visual fields appear to oscillate) - gabapentin
mx of secondary progressive MS
siponimod or methylprednisolone
mx for primary progressive MS
biologics - ocrelizumab
complications of MS
UTI
osteopenia, osteoporosis
depression
visual impairment
Erectile dysfunction
cognitive impairment
impaired mobility
px of MS
variable
poor px - frequent relapse, motor/cerebellar onset
higher MRI lesion burden equates to poorer px
good px - female, sensory/optic neuritis onset
monitoring for MS
review every 12 mo
check DM, vit B12, vit D, thyroid (hypo)
MRI 6mo after starting DMARDs
yearly MRI in stable (also looks for complications of rx)
spinal cord imaging of spinal cord phenotype
