Traumatic brain injury (TBI) is a looming epidemic, growing most rapidly in the elderly population. Some of the most devastating sequelae of TBI are related to depressed levels of consciousness (e.g., coma, minimally conscious state) or deficits in executive function. To date, pharmacological and rehabilitative therapies to treat these sequelae are limited. Deep brain stimulation (DBS) has been used to treat a number of pathologies, including Parkinson disease, essential tremor, and epilepsy. Animal and clinical research shows that targets addressing depressed levels of consciousness include components of the ascending reticular activating system and areas of the thalamus. Targets for improving executive function are more varied and include areas that modulate attention and memory, such as the frontal and prefrontal cortex, fornix, nucleus accumbens, internal capsule, thalamus, and some brainstem nuclei. The authors review the literature addressing the use of DBS to treat higher-order cognitive dysfunction and disorders of consciousness in TBI patients, while also offering suggestions on directions for future research.
Keywords: CNS = central nervous system; DBS = deep brain stimulation; DR = dorsal raphe; EEG = electroencephalography; MCS = minimally conscious state; MR = median raphe; MSN = medial septal nucleus; TBI = traumatic brain injury; TMS = transcranial magnetic stimulation; VS = vegetative state; cognition; coma; consciousness; deep brain stimulation; minimally conscious state; thalamus; vegetative state.