Transient tic disorder following carbon monoxide poisoning.

We report a 12-year-old male patient who developed transient motor and vocal tics twelve days after carbon monoxide (CO) poisoning. Cranial magnetic resonance image (MRI) of the patient showed bilateral symmetric hyperintensity in the caudate nucleus and putamen. Tic disorder was successfully treated with haloperidol. Thirty-three months after CO poisoning, the patient was asymptomatic and MRI revealed atrophy in caudate nucleus and putamen. The mechanism of tic disorder in CO intoxication is discussed.