Brain implants effective in restoring cognitive abilities after traumatic brain injury

Brain injuries are devasting and often affect quality of life. More than 5 million Americans live with the lasting effects of moderate to severe traumatic brain injury-difficulty focusing, remembering and making decisions. Though many recover enough to live independently, their impairments prevent them from returning to school or work and from resuming their social lives.

The clinical trial is the first to target this region of the brain in patients with moderate to severe traumatic brain injury, and it offers hope for many who have plateaued in their recovery

In 2001, Gina Arata was in her final semester of college, planning to apply to law school, when she suffered a traumatic brain injury in a car accident. The injury so compromised her ability to focus she struggled in a job sorting mail.

Her parents learned about research being conducted at Stanford Medicine and reached out; Arata was accepted as a participant. In 2018, physicians surgically implanted a device deep inside her brain, then carefully calibrated the device’s electrical activity to stimulate the networks the injury had subdued. The results of the clinical trial wi published Dec. 4 in Nature Medicine.

The new technique, developed by Stanford Medicine researchers and collaborators from other institutions, is the first to show promise against the long-lasting impairments from moderate to severe traumatic brain injuries.

But the fact that these patients had emerged from comas and recovered a fair amount of cognitive function suggested that the brain systems that support attention and arousal-the ability to stay awake, pay attention to a conversation, focus on a task-were relatively preserved.

These systems connect the thalamus, a relay station deep inside the brain, to points throughout the cortex, the brain’s outer layer, which control higher cognitive functions.

In the trial, the researchers recruited five participants who had lasting cognitive impairments more than two years after moderate to severe traumatic brain injury. They were aged 22 to 60, with injuries sustained three to 18 years earlier.

The therapy was so effective the researchers had trouble completing the last part of their study. They had planned a blinded withdrawal phase, in which half the participants would be randomly selected to have their devices turned off. Two of the patients declined, unwilling to take that chance. Of the three who participated in the withdrawal phase, one was randomized to have their device turned off. After three weeks without stimulation, that participant performed 34% slower on the trail-making test.

Reference: Schiff, N.D., Giacino, J.T., Butson, C.R. et al. Thalamic deep brain stimulation in traumatic brain injury: a phase 1, randomized feasibility study. Nat Med (2023). https://doi.org/10.1038/s41591-023-02638-4.