TBI can negatively affect medical decision-making capacity

A traumatic brain injury can negatively affect a patient's medical decision-making ability at a time when patients or their families must make myriad complex decisions, say researchers from the University of Alabama at Birmingham.

"Immediately following injury and during the rehabilitation and recovery period, patients and their families must make ongoing and often complex medical decisions, including treatment of brain trauma and orthopedic injuries, choice of rehabilitation programming and treatment of neuropsychiatric problems," said Daniel C. Marson, J.D., Ph.D., professor of Neurology, director of the UAB Division of Neuropsychology and senior author of a study published in the April 11, 2012, issue of Neurology, the medical journal of the American Academy of Neurology.

The severity of the injury directly corresponds to the amount of impairment, according to findings. Patients with mild TBI showed little impairment one month after injury, while those with more severe injury were significantly impaired.

The UAB investigators say there has been little research on the effects of TBI on an individual's ability to make complicated decisions. The findings have importance for both medical professionals and family members as they help patients make important medical decisions in the aftermath of a head injury.

Marson and his team studied 86 patients with TBI, divided into three classifications of severity — mild, complicated mild and moderate/severe — and 40 healthy controls. Patients were evaluated using a standardized measure of medical decision-making capacity developed by Marson that assesses five consent standards: expressing choice, reasonable choice, appreciation, reasoning and understanding.

"One month after injury, medical decision-making capacity was mostly intact for those classified with mild TBI, but significantly impaired for those classified with complicated mild TBI and those with moderate/severe TBI," said Kristen Triebel, Psy.D., assistant professor of neuropsychology and first author of the study. "Until we know more about the time required for return to normal decision-making capabilities, physicians need to carefully assess decisional capacity in their TBI patients, particularly those with complicated, moderate or severe TBI."

The group with moderate-to-severe TBI performed significantly worse than controls on the three of the five complex consent standards: appreciation, reasoning and understanding. Those with complicated mild TBI scored below controls on the understanding standard but not on appreciation or reasoning. Mild TBI patients performed the same as controls on all five consent standards.

"This suggests that one month following injury, consent capacity has returned to normal for people with mild TBI, but the structural brain changes characteristic of complicated mild cases may contribute to more significant impairments in decisional capacity that have not resolved 30 days after injury," said Marson.

"This study strongly suggests that impaired medical decision-making capacity is prevalent in acute TBI and is related to injury severity," said Marson. "Longitudinal studies are needed to better assess the time required for recovery of decisional capacity across varying levels of injury severity."