Multiple SclerosisMultiple Sclerosis

Charity, Scott, NataliaCharity, Scott, Natalia

Unless otherwise noted all information was obtained via National MS Society and National MS Society WA Chapter

Multiple Sclerosis MysteryMultiple Sclerosis Mystery

► MS is thought to be an autoimmune disease MS is thought to be an autoimmune disease ► Affects CNS Affects CNS ► Triggers are unknown, but research is Triggers are unknown, but research is

focusing in on viruses, environmental, and focusing in on viruses, environmental, and genetic factorsgenetic factors

► Antibody titers to many viruses are elevated Antibody titers to many viruses are elevated in MS patients. in MS patients. Varicella zoster, vaccinia, rubella, Epstein-Barr, Varicella zoster, vaccinia, rubella, Epstein-Barr,

HHV-6HHV-6 HHV-6 antibodies have been detected near brain HHV-6 antibodies have been detected near brain

lesions characteristic of MSlesions characteristic of MS

FACTORS & INFLUENCESFACTORS & INFLUENCES

► Age of diagnosis usually 20 to 50Age of diagnosis usually 20 to 50 Patients have been as young as 2 and as old as 75Patients have been as young as 2 and as old as 75

► EnvironmentEnvironment NW has a higher incidenceNW has a higher incidence Predominant in cooler climates and areas further from the Predominant in cooler climates and areas further from the

equatorequator► Vitamin D may play a roleVitamin D may play a role

► Genetic Factors Genetic Factors 2-3 times more likely in females than males2-3 times more likely in females than males Variable among races and ethnicitiesVariable among races and ethnicities

► Highest in northern European Caucasians Highest in northern European Caucasians ► Lowest in AsiansLowest in Asians

No particular gene has been identified – likely multiple No particular gene has been identified – likely multiple genes are involvedgenes are involved

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

►Key playersKey players AxonsAxons MyelinMyelin OligodendrocytesOligodendrocytes Blood vessels that supply oxygen and Blood vessels that supply oxygen and

nutrientsnutrients Cytokines Cytokines T-cellsT-cells Antigen-presenting cells (APCs) Antigen-presenting cells (APCs)

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

► During immune response cells identify antigens and During immune response cells identify antigens and interpret components of myelin as foreigninterpret components of myelin as foreign

► APC cells present myelin antigen to T-cellsAPC cells present myelin antigen to T-cells T-cells pass through blood brain barrier (BBB)T-cells pass through blood brain barrier (BBB)

► Normal BBB prevents passage of potential harmful Normal BBB prevents passage of potential harmful substances through blood vessel walls within brainsubstances through blood vessel walls within brain

► MS patients’ BBB ‘springs a leak’ MS patients’ BBB ‘springs a leak’ Allows activated T-cell to cross BBB and mount attack on Allows activated T-cell to cross BBB and mount attack on

myelinmyelin► This leads to several events that lead to demyelinationThis leads to several events that lead to demyelination

SwellingSwelling Activation of macrophagesActivation of macrophages More activation of cytokines More activation of cytokines

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

► DemyelinationDemyelination Information transmission via axon is interrupted Information transmission via axon is interrupted

► Interferes with conduction of nerve impulses from Interferes with conduction of nerve impulses from sensory organs to CNS and from CNS to musclessensory organs to CNS and from CNS to muscles

► May result in permanent loss of neuron transmissionMay result in permanent loss of neuron transmission

► Remyelination – repair processRemyelination – repair process Myelinating oligodendrocytes are able to rebuild Myelinating oligodendrocytes are able to rebuild

thinner, less effective myelin sheathsthinner, less effective myelin sheaths May be reason symptoms decrease of May be reason symptoms decrease of

temporarily disappear during early part of temporarily disappear during early part of diseasedisease

There is still irreversible loss and nerve damageThere is still irreversible loss and nerve damage

Courtesy of Multiple Sclerosis Research Australia

SYMPTOMSSYMPTOMS

► Symptoms are unpredictable and varySymptoms are unpredictable and vary► Fatigue – 90% Fatigue – 90% ► Depression – 70%Depression – 70%

Suicide 7.5 times higherSuicide 7.5 times higher► Motor involvement – muscle weakness, numbness Motor involvement – muscle weakness, numbness ► Visual symptoms – blurring, twitching of eyesVisual symptoms – blurring, twitching of eyes► Cerebellar involvement – intention tremor, seizureCerebellar involvement – intention tremor, seizure► Genitourinary symptoms – constipation, urine Genitourinary symptoms – constipation, urine

frequencyfrequency► Cognitive defects – short-term memory dysfunction Cognitive defects – short-term memory dysfunction

TREATMENTSTREATMENTS

►No cure for MSNo cure for MS►Treatment focused on relief of Treatment focused on relief of

symptoms and slowing progressionsymptoms and slowing progression►Patient response to disease and Patient response to disease and

treatment will differtreatment will differ►Corticosteroids – most commonCorticosteroids – most common

Methylprednisolone IV and prednisone Methylprednisolone IV and prednisone Decrease intensity of body’s defense Decrease intensity of body’s defense

reactionreaction Prevent damage to BBBPrevent damage to BBB

TREATMENTSTREATMENTS

► InterferonsInterferons Beta 1-a: Avonex and RebifBeta 1-a: Avonex and Rebif

►Anti-inflammatory propertiesAnti-inflammatory properties

Beta 1-b: BetaseronBeta 1-b: Betaseron►Diminish activity of specific WBCs causing Diminish activity of specific WBCs causing

diseasedisease

Glatiramer acetateGlatiramer acetate►Believed to modify immune process that Believed to modify immune process that

causes MScauses MS

TREATMENTSTREATMENTS

►Psychotherapy Psychotherapy ►PT/OT/STPT/OT/ST►STICK TO TREATMENT PLAN!STICK TO TREATMENT PLAN!

PROGNOSISPROGNOSIS

►Life expectancy ~35 years after onsetLife expectancy ~35 years after onset►Relatively normal lifeRelatively normal life►After ~25 years, 2/3 remain mobileAfter ~25 years, 2/3 remain mobile

Eventually leads to physical limitations for Eventually leads to physical limitations for ~70% of patients~70% of patients

KEY FEATURES OF MSKEY FEATURES OF MS

►Thought to be an autoimmune disease Thought to be an autoimmune disease affecting CNSaffecting CNS

► Involves myelin damage that Involves myelin damage that interrupts nerve conductioninterrupts nerve conduction

►No cure – treatment focused on No cure – treatment focused on comfort and slowing progressioncomfort and slowing progression

►Response to disease and treatment Response to disease and treatment will vary among patients will vary among patients

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