Clauss R and Nel W (2006) Drug induced arousal from the permanent vegetative state. NeuroRehabilitation 21: 23–28

Zolpidem is an omega-1-specific indirect γ-aminobutyric acid (GABA) agonist used to treat insomnia; this drug has also previously been reported to improve the condition of patients with brain disorders ranging from the permanent vegetative state (PVS) to stroke-induced aphasia. A recent study of patients categorized to the PVS who were given long-term treatment with the drug has now also reported very encouraging results.

The researchers investigated the effects of a 10 mg daily dose of zolpidem in three patients. Two of the patients were aged 31 years and had been in PVS for 3 years following motor vehicle accidents; the third patient was 29 years old and had been in the condition for 5 years after almost drowning. Patients were scored on the Glasgow Coma Scale and the Rancho Los Amigos Cognitive Scale before and 1 h after drug treatment; in each patient, dramatic improvements on both scales were recorded after treatment.

At the time of the study report, the patients had been receiving zolpidem daily for between 3 and 6 years. All patients experienced daily arousal from their PVS following treatment, with dramatic improvements in their ability to interact meaningfully with others. The patients experienced maximum arousal 1 h after treatment, and the drug's effects subsided approximately 4 h later. No long-term adverse effects were observed.

The authors propose that zolpidem's mode of action could involve reactivation of dormant neurons in injured brain tissue. They suggest that the drug might have a wide application in patients with brain injury, and add that further testing is planned to assess the effects in larger groups of patients with brain damage.