Behavioral variant frontotemporal dementia in a 23-year-old man.

A 23-year-old man presented with behavioral disinhibition, stereotypies, motor apathy, flattened affect, and inappropriate laughter. CT demonstrated generalized cerebral atrophy. He was admitted with a diagnosis of unspecified psychosis and discharged on antipsychotic medication. He was readmitted 3 months later, was diagnosed with schizophrenia, and antipsychotic medication was continued. Owing to symptom progression and aggressive behavior, he was readmitted 2 months later. CT again demonstrated moderate central and cortical cerebral atrophy. MRI showed severe, stable atrophy with frontotemporal predominance, and he was diagnosed with probable behavioral variant frontotemporal dementia (bvFTD).  Over the next year he rapidly deteriorated, with loss of cognitive abilities. Genetic testing revealed several variants, none of which are clearly disease-causing.