Abnormal brain scans in multiple sclerosis.

A 25 year old man, with a family history of multiple sclerosis in two preceding generations, developed transient sensory changes and incoordination, initially on the left side, and then several months later on the right side in association with an elevated CSF gamma globulin. This was followed by an acute optic neuritis. During the latter episode he developed a positive brain scan which was unaccompanied by any clinical findings explained by a lesion in that area. Cerebral arteriography was normal and the brain scan returned to normal four weeks later, possibly as a result of blood brain barrier restoration. Abnormal brain scans appear to occur only during acute exacerbations of demyelinating disease, and multiple sclerosis should be part of the differential diagnosis of a positive brain scan in a person in the appropriate age range.