2010 BC Guide in Determining Fitness to Drive

Chapter 24: Neurological disordersBACKGROUND24.1 About neurological disordersNeurological disorders can affect the brain, spinal cord, nerves and muscles. They can affect anindividual’s ability to think, see, communicate, move, and sense and coordinate movements.While any number of conditions fall within the category of neurological disorders, this chapterfocuses on three common disorders: multiple sclerosis, Parkinson’s disease, and cerebral palsy.Multiple sclerosisMultiple sclerosis (MS) is believed to be an autoimmune disorder in which the immune systemattacks specific structures of the central nervous system (brain and spinal cord), resulting ininflammation, demyelination, and axonal damage. Myelin is an essential insulation sheath of thenerve processes (axons). If it is damaged, signal transmission is slowed. Demyelination canultimately result in permanent axonal damage in the form of scars and is called gliosis.MS has an unpredictable and chronic course, leading to numerous physical and cognitiveimpairments. The cause is unknown. There are four clinical types of MS: Relapsing – Remitting (RRMS) Secondary Progressive (SPMS) Primary Progressive (PPMS), and Progressive Relapsing (PRMS).Relapsing – Remitting (RRMS)It is estimated that 55% of individuals with MS have RRMS. It is characterized by unpredictableattacks (relapses) followed by periods of months to years with no new clinical signs of diseaseactivity (remissions). Impairments suffered during relapses may either resolve or becomepermanent. Approximately 10% of those with RRMS have “benign MS”, where impairmentsusually completely resolve between relapses and no disability is present after 10 years of diseaseonset. The longer a person has MS, the greater the probability that the relapses will notcompletely resolve and they will experience increasing disability.RRMS accounts for over 90% of initial diagnoses of MS, but in many cases a different typeemerges as the disease progresses. Approximately 50% of individuals with RRMS willeventually progress to Secondary Progressive MS within 10 years of disease onset.Secondary Progressive (SPMS)It is estimated that 30% of individuals with MS have SPMS. It is characterized by an initialpresentation as RRMS, transitioning to a gradual progression of disability with or withoutsuperimposed relapses and minor remissions. Relapses may include new neurologic symptoms316