Multiple Sclerosis Flashcards
what is MS?
- progressive autoimmune disease characterized by inflammation, selective demyelination, and gliosis
- demyelinating lesions (plaques) impair neural transmission, causing nerve fibres to fatigue rapidly
- characterized by replase, remission, progression
- unpredictable course
describe the pathophysiology of MS
- abnormal immuno-mediated response attacks myelin, oligodendrocytes, and the axons themselves throughout the CNS
- activation of immune cells that cross BBB, enter CNS, and initate damaging inflammatory cascade of events
- acute inflammatory attack, gradually subsides (REMISSION)
- remyelination often incomplete
- with time, anti-inflammatory response/remyelination cannot keep up
- demyelination areas undergo gliosis
- white matter > gray matter
epidemiology of MS
- Most common cause of disability in young and middle-aged adults
- >900,000 cases in US
- 362 per 100,000
- average age of onset between 15-50 years
describe the etiology of MS
an autoimmune disorder without a clear origin
thought to be viral/infectious
several different triggers
Predisposing factors for MS
- Women > Men (3:1)
- Population genetics
- Caucasian of Nordic origin
- Higher income countries
- Temperature zones (genes and geography)
- western europe and north america
- inconsistent latitude effect
- low vitamin D exposure during childhood and teenage years
- exposure to Epstein-Barr virus
how is MS diagnosed?
- Clinical presentation
- MRI
- dissemination in space
- dissemination in time
- Additional lab tests
- visual evoked potentials
- lumbar puncture
- elevated IgG index, pressure of oligoclonal bands, or both
what is dissemination in space?
refers to plaque build up in different areas of the CNS, most common in MS:
- periventricular
- juxtacortical
- infratentorial
- spinal cord
T/F: early detection of MS doesn’t change much
FALSE
significant decline in number of attacks, lesion sites, and disability in pts that participate in early drug treatment protocols
what is a CIS?
- clinically isolated syndrome
- first clinical episode of a disease that shows characteristics of inflammatory demyelination that could be MS but has yet to fulfill criteria of dissemination in time
- can be monofocal or multifocal
common sites for CIS
- optic nerve
- brainstem
- spinal cord
initial treatment for CIS
- high-dose glucocorticoids for acute symptoms
risk factors for conversion of CIS to MS
- polysymptomatic presentation
- >/= T2 MRI lesions
- Oligoclonal bands present in CSF, not in serum
relationship between CIS and MRI findings
- CIS + MRI findings indicative of early event = confirmed MS diagnosis
- CIS + MRI findings = 60-80% chance of MS developing
- CIS without MRI findings = 20% chance of MS developing
S/S of optic neuritis resulting from CIS
- unilateral reduced visual acuity
- Orbital pain particularly with eye movement
- reduced color vision
- afferent pupillary defect
- retrobulbar or mild disc swelling
S/S of brainstem CIS
- bilateral internuclear opthalmoplegia
- ataxia and gaze evoked nystagmus
- 6th nerve palsy
- multi-focal symptoms
- facial sensory loss
- vertigo
- ataxia
- dysarthria
S/S of spinal cord CIS
- incomplete transverse myelitis
- (+) Lhermitte’s sign
- sphincter symptoms
- asymmetric limb weakness
- symptom progression between 4 hours and 21 days
MS Clinical Signs and Symptoms
- Motor function deficits
- Sensory function deficits
- Visual deficits
- Cognitive function
- Poor tolerance for temperature increases
- Fatigue
- Pain
- sleep disorders
- speech and swallow impairments
- dizziness
- bowel and bladder dysfunction
- sexual dysfunction
motor function deficits MS
- weakness
- spasticity
- coordination (cerebellar)
sensory function deficits MS
- complete loss of sensation rare
- numbness
- paresthesia
- proprioceptive/kinesthetic deficits
cognitive function deficts MS
- Hallmark → slowed information processing speed
- Attention deficits (divided, sustained)
types of pain present in MS
- trigeminal neuralgia
- paroxysmal limb pain
- headache
- chronic neuropathic pain
MS and heat insensitivity
- 80% of pts with MS are sensitive to increases in core body temp
- Uhthoff symptom
- increase in presence of neurological symptoms in response to heating condition
- pseudo-exacerbation
describe the neuroblockade hypothesis
hypothesis for heat insensitivity in MS pts
- demyelinated neurons ability to conduct APs decrease as temp increases
- Internal vs External sources
- internal = vigorous exercise, high fevers
- external = environmental temp, bathing or swimming in hot water
MS and Fatigue
- Up to 80% experience some type of acute or chronic fatigue
- 75% of which report fatigue as severe
- 50-60% report fatigue as most troublesome symptom
- # 1 cause of unemployment
- tends to worsen as day progresses
- exacerbated by heat, exercise
- primary, secondary fatigue
- central, peripheral, psychological factors
- can often lead to fear of fatigue → decreased physical activity → disuse → worsening disability