Journal Article

Behavioural improvements with thalamic stimulation after severe traumatic brain injury

Schiff, N. D., Kalmar, K., O’Connor, J., Fins, J. J., Plum, F., Victor, J. D., Gerber, M., Fritz, B., Eisenberg, B., Rezai, A. R., McCagg, C., Farris, S., Machado, A., Baker, K., Kobylarz, E. J., Giacino, J. T.

2007

Overview

Brain activity revived At present there is no reliable way of enhancing recovery from extended loss of consciousness in patients with traumatic brain injury. But recent evidence suggesting that a level of cerebral activity is preserved in some minimally conscious patients has raised interest in the topic. In a single subject study, Schiff et al . show that bilateral deep brain stimulation in the thalamus in a minimally conscious state following brain injury can increase behavioural responsiveness and function. The observations, made six years after the injury, challenge current thinking on the management of patients with severe brain injury. There are currently no reliable means for enhancing recovery from extended loss of consciousness following traumatic brain injury. But this paper demonstrates that bilateral deep brain stimulation in the thalamus of a single subject, in a minimally conscious state after brain injury that occured six years earlier, can increase behavioural responsiveness and function. Widespread loss of cerebral connectivity is assumed to underlie the failure of brain mechanisms that support communication and goal-directed behaviour following severe traumatic brain injury. Disorders of consciousness that persist for longer than 12 months after severe traumatic brain injury are generally considered to be immutable; no treatment has been shown to accelerate recovery or improve functional outcome in such cases 1 , 2 . Recent studies have shown unexpected preservation of large-scale cerebral networks in patients in the minimally conscious state (MCS) 3 , 4 , a condition that is characterized by intermittent evidence of awareness of self or the environment 5 . These findings indicate that there might be residual functional capacity in some patients that could be supported by therapeutic interventions. We hypothesize that further recovery in some patients in the MCS is limited by chronic underactivation of potentially recruitable large-scale networks. Here, in a 6-month double-blind alternating crossover study, we show that bilateral deep brain electrical stimulation (DBS) of the central thalamus modulates behavioural responsiveness in a patient who remained in MCS for 6 yr following traumatic brain injury before the intervention. The frequency of specific cognitively mediated behaviours (primary outcome measures) and functional limb control and oral feeding (secondary outcome measures) increased during periods in which DBS was on as compared with periods in which it was off. Logistic regression modelling shows a statistical linkage between the observed functional improvements and recent stimulation history. We interpret the DBS effects as compensating for a loss of arousal regulation that is normally controlled by the frontal lobe in the intact brain. These findings provide evidence that DBS can promote significant late functional recovery from severe traumatic brain injury. Our observations, years after the injury occurred, challenge the existing practice of early treatment discontinuation for patients with only inconsistent interactive behaviours and motivate further research to develop therapeutic interventions.

• Publisher: Nature Publishing Group UK,Nature Publishing,Nature Publishing Group
• Subject: Adult / Adult and adolescent clinical studies / Arousal - physiology / Awareness - physiology / Biological and medical sciences / Brain damage / Brain Injuries - physiopathology / Brain Injuries - rehabilitation / Brain Injuries - therapy / Consciousness / Deep Brain Stimulation / Electric Stimulation / Electrodes / Humanities and Social Sciences / Humans / Injuries of the nervous system and the skull. Diseases due to physical agents / letter / Logistic Models / Male / Medical sciences / multidisciplinary / Neurosciences / Organic mental disorders. Neuropsychology / Psychology. Psychoanalysis. Psychiatry / Psychopathology. Psychiatry / Science / Science (multidisciplinary) / Speech - physiology / Thalamus - physiology / Thalamus - physiopathology / Time Factors / Transplants & implants / Traumas. Diseases due to physical agents / Treatment Outcome