Medically unexplained symptoms and neuropsychological assessment.

Several illnesses expressed somatically that do not have clearly demonstrated pathophysiological origin and that are associated with neuropsychological complaints are reviewed. Among them are nonepileptic seizures, fibromyalgia, chronic fatigue syndrome, Persian Gulf War unexplained illnesses, toxic mold and sick building syndrome, and silicone breast implant disease. Some of these illnesses may be associated with objective cognitive abnormalities, but it is not likely that these abnormalities are caused by traditionally defined neurological disease.