Zolpidem improves akinesia, dystonia and dyskinesia in advanced Parkinson's disease.

Zolpidem, an imidazopyridine hypnotic drug acting as a selective gamma-aminobutyric acid (GABA) type A agonist, has been reported to produce significant motor improvement in patients with Parkinson’s disease (PD). However, relevant reports are scarce. We report a patient with advanced PD who had had a unilateral pallidotomy, unilateral thalamotomy and bilateral deep brain stimulation (DBS) of the subthalamic nuclei, who demonstrated an immediate improvement in akinesia, dystonia and dyskinesia after 10 mg zolpidem. A 53-year-old man was diagnosed with PD at the age of 30 years. The initial presentation was with left hemiparkinsonism, characterized by rest tremor, bradykinesia and rigidity. He had undergone right pallidotomy in 1985 (without improvement), right thalamotomy in 1985, and bilateral deep brain stimulation (DBS) in 2001. In 2005, after adjustment of his medication and reprogramming of the DBS, he remained severely disabled (Hoehn and Yahr stage V). In addition, he also developed episodic and unpredictable dyskinesia and mild dystonia. Ten months later, he experienced an episode of severe dystonia which presented as sustained mouth-opening and head-turning to the right side. He could barely move. We administered 10 mg zolpidem at night for his insomnia. Approximately 15 min later, he was able to speak well and his dystonia resolved. He was also able to get up from the bed, and to walk with minimal aid, as well as open his mouth, chew and swallow. His dyskinesia also improved. However, improvement in motor function lasted for only 2 hours. The antidystonia and antidyskinesia effects lasted for about half a day, longer than the duration of improvement of motor function. Other hypnotics (lorazepam 2 mg) did not have such an effect. The motor score of the Unified Parkinson’s Disease Rating Scale (UPDRS-III) was performed before and after the administration of 10 mg zolpidem; a 27% improvement in the score was noted (Table 1A). There was no significant somnolence with this dose. A lower dosage of zolpidem (5 mg) was tested; although the improve-