Although some of the physical, cognitive, and psychological deficits associated with traumatic brain injury (TBI) resolve during the recovery period, other symptoms can cause long-term complications. One such complication is autonomic dysfunction, which occurs when the nerves of the autonomic nervous system – responsible for regulating basic functions like heart rate, breathing, and body temperature – are damaged after injury. Individuals with TBI may experience mild to serious autonomic dysfunction years after initial injury, contributing to an increase in long-term TBI-related mortality rates.
A group of researchers investigated the relationship between long-term autonomic dysfunction and TBI severity. They evaluated autonomic functions (including blood pressure, respiration, and heart rate) in participants who had experienced mild, moderate, or severe TBI six months to six years prior to the study. They found that those with moderate to severe TBI were significantly more likely to have long-term, heart-related autonomic dysfunction than those who had experienced mild TBI.
Individuals who sustain moderate to severe TBI may be at higher risk of autonomic dysfunction and mortality in the months or years following injury. To reduce the long-term mortality rate associated with TBI, targeted intervention protocols may be necessary to ensure that individuals with more severe TBI receive appropriate treatment – during and after the initial recovery period – for any damage to the autonomic nervous system.
Hilz MJ, Wang R, Markus J, et al. Severity of traumatic brain injury correlates with long-term cardiovascular autonomic dysfunction. Journal of Neurology. (September 2017).