Pearls & Oy-sters: Family history of Huntington disease disguised a case of dentatorubral-pallidoluysian atrophy.

Case report A 42-year-old woman of Caucasian ancestry presented with an episode of acute paranoid psychosis, an 8-month history of slowly progressive generalized choreoathetosis, gait and speech disturbance, as well as cognitive impairment. Her choreoathetosis remarkably improved due to olanzapine, and subsequently, cerebellar signs became obvious upon neurologic examination (video, http://links.lww.com/WNL/A45). CranialMRI revealedmoderate atrophy of the vermal part of the cerebellum but not of the caudate nucleus. EEG showed runs of frontal intermittent high-amplitude delta activity. The patient reported a positive family history for Huntington disease (HD) (figure). Genetic testing was negative twice for HD and spinocerebellar ataxias (SCAs) including SCA17, but revealed 59 ± 2 CAG repeats (<48) in the ATN1 gene confirming the first German case of adult-onset dentatorubral-pallidoluysian atrophy (DRPLA).