Traumatic Brain Injury Can Cause Long-term Sleep Problems and Excessive Daytime Sleepiness

head injury
A new study suggests serious traumatic brain injury can cause long-term sleep problems. Mike Blake/REUTERS

Most physicians know a person who suffers traumatic brain injury (TBI) is likely to have long-term neurological effects for years afterward. Thanks to increased research and awareness, people in the field are more attuned to spot problems related to concussion and serious head injuries, such as memory and cognitive problems. However, some still go unnoticed.

A study published April 27 in Neurology finds that people who suffer TBI may experience sleep problems a year and a half after the injury. Additionally, these patients often aren't aware that it's a problem.

The study involved 31 patients who had experienced a serious head injury 18 months before; some of the injuries were mild, while others were more severe. The researchers also included a control group of 42 people who didn't have a history of TBI.

Each participant was asked to keep track of sleeping habits and how well-rested he or she felt during the day. Each patient spent a night in a sleep lab, where brain activity, muscle and eye movements and heart function were monitored in real time, and where the patients were assessed for daytime sleepiness. Researchers also asked the patients about other medical conditions unrelated to TBI that could affect sleep.

They found that 67 percent of the study participants with TBI had problems with daytime sleepiness, compared with 19 percent of the control group. However, the TBI patients didn't report feeling any sleepier during the day than the healthy patients, suggesting that they were unaware that their injuries may have resulted in chronic sleep problems. Patients with TBI also slept for a longer duration than those without injuries. The study proposes that TBI may cause physical damage to the part of the brain that is partially responsible for regulating sleep patterns.

Previous studies suggest that nearly half of patients with severe TBI will experience daytime sleepiness and changes in their sleep-wake cycle. Disturbances to a normal sleep-wake cycle—even in healthy people—affects cognition, memory and executive function. Perhaps unsurprisingly, the research also shows there is a strong correlation between severe TBI and pleisomnia (excessive sleep need) six months after injury. Studies suggest that this is a physiological response and that the brain requires extra sleep to heal from the injury.

An accompanying editorial suggests the recent study's findings may be an indication that physicians shouldn't rely on a patient's own reports to assess the person's recovery status, even though that is currently the standard in diagnostic evaluation of patients with TBI. One possible solution, they say, is to make sleep lab evaluation part of the standard protocol for any patient with severe TBI. Experts drawing up guidelines in the future will have to weigh the value of sleep lab work against the high costs involved and the potential distress sleep labs can cause patients.