Neuroscience: Deep brain stimulation in a minimally conscious state

The responses of a single patient in a minimally conscious state have improved with deep brain stimulation.During this intervention, the patient’s arousal level and motor control increased to the point that he was able to chew and swallow food.
‘Minimally conscious state’ refers to a level of consciousness characterized by intermittent evidence of awareness of oneself or the environment, and is distinct from persistent vegetative state or coma. At present there are no reliable means for improving recovery from this extended loss of consciousness, which can occur following traumatic brain injury, although recent evidence suggests some brain activity may be preserved in minimally conscious patients. In the current study, Nicholas Schiff and colleagues implanted electrodes into the brain of a 38-year-old male, six years after he suffered a severe brain injury that resulted in a minimally conscious state. The electrodes were used to stimulate an area known as the thalamus, on both sides of the brain, which has been suggested to have a role in arousal. The authors report that during periods of stimulation, the frequency of communicative behaviours, functional limb control and oral feeding increased.
The authors caution that the extent to which their results might apply to other patients is unknown, and that expectations raised by their findings should be tempered — the specific injury suffered and its effects on responsiveness will not be shared by all patients in a minimally conscious state. The present findings should, however, motivate further research into the mechanisms of recovery, as their replication could have important implications for clinical practice.
CONTACT

Nicholas Schiff (Weill Cornell Medical College, New York, NY, USA)

Joseph Fins (Weill Cornell Medical College, New York, NY, USA)

Ali Rezai (Cleveland Clinic Foundation, OH, USA)

Joseph Giacino (JFK Johnson Rehabilitation Institute / New Jersey Neuroscience Institute, Edison, NJ, USA)