A 27-year-old African-American woman had several episodes of neurologic deficits. The first event consisted of marked fatigue, decreased vision, and gait unsteadiness. The second event was characterized by decreased vision in both eyes. The third and fourth episodes were again characterized by impaired vision and disequilibrium.

This 27-year-old woman has had several episodes of neurologic dysfunction resulting in fatigue, blurred vision, and gait unsteadiness. Examination was notable for gaze-evoked nystagmus and an unsteady gait. Magnetic resonance imaging (MRI) showed increased T2 signal hyperintensities involving the left pons, and bilateral periventricular white matter. She was diagnosed with relapsing-remitting MS.

MS is a chronic demyelinating disease of the central nervous system (CNS) resulting in injury to the myelin sheaths, oligodendrocytes, and eventually axons. The clinical diagnosis of MS requires two temporally dissociated attacks of demyelination referable to two anatomically separate white matter pathways of the brain or spinal cord. The McDonald criteria for diagnosis of MS (Table 76.1) have resulted in earlier diagnosis of MS with a high degree of both specificity and sensitivity.