A report that nerve stimulation was able to partially restore consciousness in a patient in a vegetative state has attracted a great deal of attention this week.
The paper, published in Current Biology from French researchers Martina Corazzol and colleagues, is certainly promising, but I didn't find it entirely convincing. Corazzol et al.'s patient was a 35-year old man who had been in a vegetative state for 15 years following a car accident. After receiving consent from his family members, surgeons implanted a device to electrically stimulate the patient's vagus nerve. Vagus nerve stimulation is a quite widely used technique for the treatment of epilepsy (and, experimentally, for depression), although its mechanism of action remains unclear. So what happened? After the stimulator was switched on, the intensity of the current was ramped up over a period of five weeks. The patient's level of consciousness, as rated by a clinician using ...
