Surgeons have for the first time restored cognitive function after brain injury
Deep stimulation of key brain circuits in the thalamus may help patients with long-term cognitive deficits after brain injury. Previous attempts at such recovery have been significantly less complete, effective, and safe.
Traumatic brain injury (TBI) often causes persistent physical, cognitive, emotional, and behavioral impairments that prevent the recipients from returning to their previous quality of life. As yet, there are no effective treatments available to alleviate the disabling effects of impairments in attention, executive function, working memory, or information processing speed caused by trauma.
In past studies, scientists have linked cognitive impairment to a loss of activity in key areas of the brain in the thalamus. The thalamus is located in the very center of the brain and is considered the brain center that controls sensation. It is responsible for transmitting sensory and motor information from the senses (except the sense of smell) to the appropriate areas.
Researchers recently conducted a small clinical trial to evaluate whether deep brain stimulation is feasible, safe, and can restore cognitive function in people with chronic disability after a traumatic brain injury. The results are published in the journal Nature Medicine.
Deep brain stimulation is a neurosurgical technique of guided exposure to specific targets in the brain using low-force electrical pulses to correct their function. It is already used to improve symptoms in Parkinson's disease, Tourette's syndrome, epilepsy and other pathologies.
The scientists selected four men and two women between the ages of 22 and 60. Each had suffered a moderate to severe traumatic brain injury that resulted in persistent neuropsychological impairment. Three to 18 years had elapsed since the injury. One participant was later suspended for not following protocol.
During the surgery, specialists surgically implanted electrodes in specific areas of the thalamus. To do this, they used new neuroimaging techniques that helped predict neural circuits with impaired activation.
No side effects were detected after the operation. But the effectiveness was determined immediately: the speed of information processing increased by 15-52% compared to the baseline level measured by a cognitive test for attention, mental flexibility, spatial and visual perception.
According to the authors, deep brain stimulation can indeed improve brain functioning in people with chronic cognitive disability. However, larger clinical trials are needed to put this method into practice.