Efficacy of zolpidem in promoting awakening from persistent vegetative state in patients with brain injury

Abstract

Objective To investigate the effect of zolpidem in promoting awakening from persistent vegetative state in patients with brain injury and analyze the relation between the timing of drug administration and the awakening of the patients. Methods Brain 99mTc-ethyl cysteinate dimer (99mTc-ECD) single-photon emission computed tomography (SPECT) was performed in 7 patients in persistent vegetative state following brain injury 30 min before and 30 min and 7 days after treatment with 10 mg zolpidem administered through a nasogastric tube. Visual analysis of cerebral perfusion changes in the injured brain regions after the treatment was performed. A cerebral state monitor was used to observe the changes in the cerebral state index, electromyogram index, and burst suppression ratio, and the patients' linguistic function, motor function of the limbs, muscular tension and sleeping were also monitored. Results After the treatment, the cerebral state index and electromyogram index were significantly increased (P<0.05) and the burst suppression ratio significantly lowered (P<0.05);cerebral perfusion in the injured brain regions was significantly improved in all the patients as compared with that before treatment. Awakening was achieved in 3 patients, who were capable of simple communication30 min after zolpidem administration, and of simple calculations and lower limb flexion and extension 2 days later. The symptom of limb tremor was significantly relieved in one of the awakened patients. Muscle spasm was significantly relieved and sleep cycle improved in the other 4 patients. Conclusion Zolpidem is effective to restore the brain function in some patients in persistent vegetative state following brain injuries. Zolpidem-induced brain function recovery is not related to the time length after the administration, and the effect is instant instead of being gradual. Key words: Zolpidem; Craniocerebral trauma; Coma