EHR525 Week 13 Multiple Sclerosis- Part A (DG) (1 Slide) PDF

WARNING This material has been reproduced and communicated to you by or on behalf of Charles Sturt University in accordance with section 113P of the Copyright Act 1968 (Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of th...

WARNING This material has been reproduced and communicated to you by or on behalf of Charles Sturt University in accordance with section 113P of the Copyright Act 1968 (Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice School of Allied Health, Exercise and Sports Sciences 1 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 1 EHR525 EXERCISE FOR NEUROLOGICAL & MENTAL HEALTH CONDITIONS Multiple Sclerosis- Part A Presenter: Darren Gray School of Allied Health, Exercise and Sports Sciences 2 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 2 What We Will Cover: ■ Multiple Sclerosis and it’s primary features. ■ Prevalence statistics for MS in Australia. ■ Pathophysiology of MS and its effect on neural function. ■ Common sites for neural lesions and common signs and symptoms associated with MS. ■ General risk factors for developing MS. School of Allied Health, Exercise and Sports Sciences 3 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 3 Introduction ■ Multiple Sclerosis (MS): Is a chronic, inflammatory disease of the CNS characterised by disseminated demyelination of nerve fibres in the brain and spinal cord. ■ Most common cause of neurological impairment in young adults in Australia and worldwide. ■ Impact of MS can be enormous because the disease course is unpredictable and the symptoms can change. ■ No known cure and progresses to disability in the majority of cases but treatments are available to slow progression. School of Allied Health, Exercise and Sports Sciences 4 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 4 Multiple Sclerosis Statistics ■ More than 23,000 people are diagnosed with MS in Australia. ■ A further 1,000 people are diagnosed every year. ■ Age of onset ranges from 20-50 years in 85% of cases. ■ Average age of diagnosis is between 25-35 years old. ■ 75% of people diagnosed are women. Palmer A. (2011). Economic Impact of MS in 2010 Australian MS Longitudinal Study. School of Allied Health, Exercise and Sports Sciences 5 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 5 Economic Impact of Multiple Sclerosis ■ Total cost of MS in Australia is $1.04 billion per year. ■ $500 million due to lost productivity. ■ 50-80% of people with MS cease work full time within 10 years of diagnosis. Supporting MS patients is highly costly in Australia ■ Replacement cost of informal care provided to Australians with MS is $125 million. ■ Australians with MS pay $78m per year out of their own pockets. Palmer A. (2011). Economic Impact of MS in 2010 Australian MS Longitudinal Study. School of Allied Health, Exercise and Sports Sciences 6 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 6 Pathophysiology Of Multiple Sclerosis ■ Considered an inflammatory autoimmune disease of the CNS. ■ Characterised by random nerve axon demyelination. ■ Axons are spared from disease process but nerve may be damaged due to inflammation. ■ Results in multiple areas of scarring (sclerosis) and formation of plaques that eventually slows or blocks nerve conduction. ■ Can potentially occur anywhere within the white matter of CNS. School of Allied Health, Exercise and Sports Sciences 7 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 7 Classification of MS ■ Relapsing – Remitting MS Most Common Flare ups relapse then repair. ■ Secondary Progressive MS Often unmanaged condition transition ■ Primary Progressive MS Less Common Steady progress without relapse or remissions School of Allied Health, Exercise and Sports Sciences 8 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 8 Nerve Cell Structure And Function School of Allied Health, Exercise and Sports Sciences 9 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 9 Oligodendrocytes ■ Oligodendrocytes: Myelinating cells of the CNS. ■ Composed of 80% lipid and 20% protein. ■ Each cell may support up to 40 neurons. ■ Myelin supports saltatory conduction and efficient neural communication. School of Allied Health, Exercise and Sports Sciences Oligodendrocytes are the cells damaged in MS 10 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 10 Electrical Characteristics Of Demyelinated Nerve Fibres ■ Increased leakage of current and reduced capacitance: □ Impaired depolarisation. □ Longer to reach threshold. □ Conduction block. ■ Hyperexcitability: □ Spontaneous discharge and mechanical stimulation. □ Ephapthic impulse transmission. ■ Increased temperature sensitivity: □ Current flows too fast to excite adjacent node. School of Allied Health, Exercise and Sports Sciences 11 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 11 Saltatory Nerve Conduction ■ Myelin prevents the local current from leaking across the membrane allowing it to flow farther along the axon. ■ Voltage-gated Na+ channels are present only at the nodes of Ranvier. ■ Generation of active, voltage-gated currents only occur at unmyelinated regions. ■ Result is a greatly enhanced velocity of action potential conduction. School of Allied Health, Exercise and Sports Sciences 12 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 12 Pathophysiology Of Multiple Sclerosis ■ Although the exact cause of MS is still unknown. ■ Believed that an autoimmune response that is influenced by a combination of environmental, infectious, and genetic factors. ■ Process likely initiated by autoreactive T cells: □ Cross blood–brain barrier and begin myelin damage. □ Antibodies and white blood cells attack proteins in the myelin sheath. School of Allied Health, Exercise and Sports Sciences Note the general pathophys of MS 13 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 13 New Sodium Channels And Myelin Repair ■ New sodium channels may develop in demyelinated node but conduction is unreliable. ■ Remyelination can occur following acute demyelination: □ Remyelination is always thinner that original myelin sheath. □ Nodal length is reduced. □ Impaired conduction velocity. ■ In older lesions macrophages and astrocytes proliferate and remove debris and lay down a scar of fibrous tissue (sclerosis) on the axon. Myelin repair can occur after damage, but □ No potential for recovery. School of Allied Health, Exercise and Sports Sciences nerve conduction still impaired and symptoms are still present 14 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 14 Signs/Symptoms Of Multiple Sclerosis ■ A number of signs and symptoms may be associated with MS. ■ May occur at any time during the course of the disease. ■ May affect any CNS function: □ □ □ □ □ Motor system. Sensory system. Vision. Cognition. Emotion. All symptoms can be exacerbated by heat School of Allied Health, Exercise and Sports Sciences 15 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 15 Location Of Lesions ■ Populated sites of Myelin Most frequent lesion sites: □ Spinal cord: Approximately 55-75% of clients with MS have spinal cord lesions at some point during the disease. □ Optic nerve: Approximately 20% of clients with MS present with optic neuritis as a first demyelinating event, and 40% may experience this during their disease. □ MLF – Ocular control □ Other sites: Brainstem and Cerebellum (Corticobulbar and Pontine) ■ The location of lesions directly correlates with signs and symptoms. □ There is a poor correlation between lesion size and area and function/disability. School of Allied Health, Exercise and Sports Sciences 16 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 16 MRI Of Spinal Cord School of Allied Health, Exercise and Sports Sciences 17 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 17 MRI Of Optic Nerve Note the plaques identified by the red arrows What symptoms may occur in this patient? School of Allied Health, Exercise and Sports Sciences 18 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 18 MRI Of Cerebellum Note the location of the plaques identified by the red arrows What symptoms may occur in this patient? School of Allied Health, Exercise and Sports Sciences 19 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 19 MRI Of Cerebral Hemispheres Note the plaques identified by the red arrows What symptoms may occur in this patient? School of Allied Health, Exercise and Sports Sciences 20 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 20 Clinical Outcome instrument Of MS The FSS and EDSS constitute one of the oldest and probably the most widely utilized assessment instruments in MS (Kurtzke, 1983). Based on a standard neurological examination, the 7 functional systems (plus "other") are rated. These ratings are then used in conjunction with observations and information concerning gait and use of assistive devices to rate the EDSS. Each of the FSS is an ordinal clinical rating scale ranging from 0 to 5 or 6. The EDSS is an ordinal clinical rating scale ranging from 0 (normal neurologic examination) to 10 (death due to MS) in halfpoint increments. The FSS and EDSS have been used in virtually every major clinical trial that has been conducted in MS during the last four decades and in numerous other clinical studies School of Allied Health, Exercise and Sports Sciences 21 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 21 Kurtzke FSS and EDSS Note the Scales School of Allied Health, Exercise and Sports Sciences 22 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 22 Risk Factors For Multiple Sclerosis ■ Age :15-60 years. ■ Gender : Females>. ■ Genetics : Family history. ■ Infections : (Epstein-Barr virus and infectious mononucleosis). ■ Vitamin D low levels ■ Ethnicity : Northern European descent. ■ Geography : Climate, environmental exposure(temperate zones; sun exposure? Or Vit D?). School of Allied Health, Exercise and Sports Sciences 23 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 23 Vitamin D and MS ■ Low levels of Vit D are associated with the Risk of MS. ■ Immunomodulatory effects as MS is an autoimmune disease. ■ May assist with the system control with Relapses and inflammation. Some evidence for a role of vit D in MS ■ The effect is theoretical and more research is needed. School of Allied Health, Exercise and Sports Sciences 24 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 24 Risk Factors For Multiple Sclerosis Climate is a Risk factor for MS People with ancestors from cold climates (far northern/ southern hemispheres) at higher risk School of Allied Health, Exercise and Sports Sciences 25 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 25 Summary ■ MS is a chronic, progressive demyelinating disease of the CNS. ■ MS has significant economic costs for individuals and the health care system. ■ Location of MS lesions is random cannot be accurately predicted. ■ MS is associated with a myriad of sign/symptoms that may influence sensory-motor, cognitive, and/or emotional functioning. ■ General risk factors for developing MS include age, sex, family history, exposure to infection, race, and climate. School of Allied Health, Exercise and Sports Sciences 26 SCHOOL OF EXERCISE SCIENCE, SPORT & HEALTH 26