A gradual severe deterioration in cognitive and motor function occurred during the next 12 months. She had periods of severe confusion, agitation, depression, and visual hallucinations of animals and unfamiliar people in her home. In desperation, she was taken to several other physicians and was treated unsuccessfully with selegiline hydrochloride, a combination product of carbidopa and levodopa, vitamin E, thioridazine, alprazolam, fluoxetine hydrochloride, thiothixene, benztropine mesylate, trazodone hydrochloride, lorazepam, and electroconvulsive therapy. The trial of electroconvulsive therapy was aborted after 1 treatment because of severe delirium. Administration of thioridazine (50 mg/d) and thiothixene (5 mg/d) each produced a disabling increase in her parkinsonism. Selegiline hydrochloride (5 mg) administered twice daily and a combination product of carbidopa and levodopa (25 and 100 mg, respectively) administered 3 times daily produced no appreciable improvement in her bradykinesia or rigidity, and use of both drugs increased her confusion and hallucinations. Twenty months after her initial hospitalization, she was dependent in all activities of daily living, and her Mini-Mental State Examination score was 0. Language comprehension and expression were limited to simple sentences. She had a persistent left homonymous hemianopsia to static objects and to gross hand and arm movement, and this visual field deficit was superimposed on severe simultanagnosia in all visual fields. She exhibited marked facial masking and generalized severe rigidity, paratonia, and bradykinesia but no tremor. Her posture and gait were markedly parkinsonian, and she had occasional myoclonic jerks of the torso and extremities. A single-photon emission computed tomographic scan with technetium Tc 99m hexamethylpropyleneamine oxime revealed a large area of right parietal-occipital and inferior temporal hypoperfusion. An electroencephalogram revealed diffuse medium amplitude polymorphic theta and delta slowing and no alpha rhythm. Cerebrospinal fluid examination was normal. Apo-E genotyping was not performed. She died while sleeping 21 months after her initial symptoms, by which time she was bedridden and mute.