Multifocal areas of CNS demyelination causing motor, sensory, visual, and cerebellar dysfunction are seen in multiple sclerosis (MS). Types include relapsing and remitting (90%), relapsing and progressive, and chronically progressive. Lhermitte sign is described as an electric shock sensation going down into the arms or legs from neck flexion. Physical examination shows decreased strength, increased tone, hyperreflexia, clonus, decrease in vibratory sense and joint proprioception, and reduced pain and temperature sense. Increases in body temperature may worsen symptoms. Optic neuritis is the presenting symptom in 30% of cases and may cause an afferent papillary defect (Marcus-Gunn pupil). Acute or subacute central vision loss occurs over days and is usually unilateral. Retrobulbar or extraocular pain usually precedes vision loss. Internuclear ophthalmoplegia causes abnormal adduction and horizontal nystagmus, often bilaterally and is strongly suggestive of MS. Cognitive and emotional problems are common. Rarely, acute transverse myelitis occurs.