Rapidly progressive frontal-type dementia associated with Lyme disease.

The authors report a case of fatal neuropsychiatric Lyme disease (LD) that was expressed clinically by progressive frontal lobe dementia and pathologically by severe subcortical degeneration. Antibiotic treatment resulted in transient improvement, but the patient relapsed after the antibiotics were discontinued. LD must be considered even in cases with purely psychiatric presentation, and prolonged antibiotic therapy may be necessary.