Demyelinating Diseases Flashcards
major proteins of cns myelin
plp
mpb
what is dysmyelination
production of abnormal and unstable myelin sheath (hypomyelination)
what is demyelination
destruction of normal myelin
primary: oligodendroglia and schwann cells with myelin sheath, axons preserved
secondary: axon loses myelin sheath, axons damaged
what is multiple sclerosis
episodes of focal disorders of the optic nerves, spinal cord, and brain
diagnosis requires: history of remission and relapse and evidence of examination of more than one discrete lesion of the cns
most common symptoms
pyramidal weakness or numbness, visual loss, sensory
clinically isolated syndrome
optic neuritis, transverse myelitis, cerebellar ataxia, brainstem syndromes
clinically isolated syndrome = syndrome + other features of ms
characteristics of optic neuritis
sudden loss of monocular partial or complete vision
pain with movement of affected eye
loss of color vision, particularly the color red
uhtoff’s phenomenon: worsening neurologic symptoms with increased body temp
mri of optic neuritis
hyperintense optic nerve = active inflammation
funduscopy: edema or swelling of the optic head
natural history of optic neuritis
worsens over several days to 2 weeks and then improves
visual acuity complete in 5 weeks
50% of patients develop other signs of ms
presentation of transverse myelitis
acute/subacute sx/sy of neurologic dysfunction in motor, sensory, or autonomic nerves and spinal cord symmetrical or asymmetrical paraparesis or paraplegia ascending paresthesia loss of deep sensibility of feet sensory level on trunk sphincter dysfunction bilateral babinski prior infectious illness
csf and mri findings in transverse myelitis
csf: modest number of lymphocytes and increased total protein
mri: focal demyelination of spinal cord + hyperintense areas
incidence of ms
21-40 ys f > m white populations western areas lack of vitamin d
etiology of ms
viral infection is trigger
ebv and hhv6
chlamydia and borrelia burgdorferi
three types of ms
acute and tumefactive ms
diffuse cerebral sclerosis of schilder
concentric sclerosis of balo
presentation of acute and tumefactive ms (marburg’s)
rapidly progressive and highly malignant
cerebral, brainstem, and spinal manifestations
stupor, coma, decerebrate with prominent cn and corticospinal abnormalities
what is diffuse cerebral sclerosis of schilder
large, sharply outline asymmetrical foci demyelination in cerebral hemispheres
causes steady or unremitting or punctuated by a series of episodes
diagnostic findings for acute and tumefactive ms
table 5
diagnostic findings for schilder ms
table 6 – mbp
what is concentric sclerosis of balo
similar to schilder ms
have alternating bands of destruction and preservation of myelin in a series of concentric rings
most helpful ancillary exam in ms diagnosis
mri to se ms plaques
mri findings for ms in brain and spinal cord
brain: ms plaques are hyperintense
dawson’s fingers - multifocal, well demarcated, oval, or linear radially oriented lesions that denote ms
spinal cord: motor weakness
csf findings for ms
oligoclonal bands for confirmation of ms (but not specific and sensitive)
mononuclear pleocytosis
compute igg index
evoked potentials in ms
visual evoked responses may show prolonged latency
brainstem auditory responses can show which part of auditory response is affected
somatosensory response is delayed
common locations of cerebral plaque
lateral ventricle
optic nerve
spinal cord
cerebellum
____ signifies the demyelination process
hypopigmentation
what is an ms attack
neurological disturbance
at least 24 hour duration in absence of fever or infection
more acceptable if it’s multiple episodes over 24 h
mcdonald criteria for ms
table 7
what is progressive relapsing ms
initial manifestations improve partially or completely but recur or form new ones in different parts of the nervous system
steady decline or disease progression
primary progressive ms
> 40 yo, disease steadily progresses
no relapses or remissions
relapsing/remitting ms
unpredictable attacks followed by period of remission
may or may not leave permanent deficits
secondary progressive ms
rrms that develops into progressive type after a certain time
suddenly begins to decline and loses period of remission and relapses
treatment for acute demyelinating optic neuritis
currently no treatment
short course iv methylprednisolone + 2 weeks oral prednisone to improve recovery (but visual function decline is same)
treatment for acute exacerbations of ms
3-5d pulsated high dose methylprednisolone
followed by oral prednisone over 11-14 d
improvement: maintain steroids
no improvement: plasma exchange
available immuno-modulators
beta-interferon 1a/1b glatirament acetate (mimis myelin basic protein) monoclonal antibodies immunosuppressants plasma exchange
what is neuromyelitis optica
simultaneous or successive and severe involvement of optic nerves and contiguous segments of spinal cord
no cerebral demyelination
clinical presentation of devic’s disease
subacute to acute onset of blindness in 1 or both eyes, followed within days or weeks by severe transverse or ascending myelitis
necrotizing and cavitary spinal cord lesions
lab findings in devic’s disease
(+) antibody towards aquaporin 4 water channel protein
(-) oligoclonal bands in the csf
distinguishing factor of adem to acute ms
multifocal meningeal infiltration
manifestations of adem
more common in children
previous viral infection or vaccination or tetanus antitoxin
encephalitis: acute fever, headache, confusion, somnolence, convulsion, stiff neck
cerebritis: acute ataxia
acute transverse myelitis: paraparesis or quadriparesis, areflexia, sensory, bowel and bladder problems
most fulminant form of demyelinating disease
acute necrotizing hemorrhagic encephalomyelitis
manifestations of anhe
previous respiratory infection (mycoplasma pneumoniae)
headache, fever, stiff neck, confusion
cerebral and brainstem signs: focal seizures, hemiplegia, quadriplegia, pseudobulbar paralysis, progressively deepening coma
diagnosis of anhe
peripheral leukocytosis
increased icp
ct/mri showing edema and hemorrhage
what is graft vs host disease
brain inflammation after bone marrow transplant
s/sx appear months or years later: subacute hemiparesis, seizures, behavioral changes, atazia
