Regaining consciousness for prolonged comatose patients with right median nerve stimulation

During the past half year, we have utilized right median nerve stimulation (produced by Empi. Co. USA) to awaken consciousness of patients on 6 cases, 2 with brain trauma, one with aneurysm rupture, one with hemorrhagic stroke and two with hypoxic encephalopathy. The comatose duration ranged from 6 to 17 weeks. All patients underwent SPECT scan for cerebral perfusion evaluation and neurotransmitter quantification before and after the stimulation. The stimulation time lasted from 8 to 10 hours on daytime. The stimulation persisted for 3 months in all patients. Four patients recovered from the consciousness within 35 days. There was no obvious clinical improvement in two patients. Brain perfusion increased in all cases through the SPECT study after stimulation. The elevation of neurotransmitter in CSF was found in 5 out of the 6 cases. Median nerve stimulation elevates the cerebral blood flow and may influence the patient's consciousness. Young patients (<40 years old) had better results than old patients. The stimulation could be initiated if the patient's acute stage was over. In our series, although increase in cerebral blood flow was found in all cases, some patients did not regain consciousness.