Insomnia, fatigue, and excessive daytime sleepiness are common problems after a traumatic brain injury. However, it can be difficult to determine if sleep problems are a primary disorder or a symptom of something else. For instance, daytime fatigue could be a symptom of insomnia, or a primary problem caused by biological changes from the injury.
A recent study looked at the relationship between insomnia and fatigue in the two years after a brain injury. They found that insomnia without concurrent fatigue was rare at 2%. However, fatigue that occurred without insomnia was more common at 23%. This means that post-traumatic fatigue was often not the result of insomnia, but was instead a primary problem related to the injury.
In addition, most people (93%) who suffered from insomnia after the injury had not suffered from insomnia before the injury. Anxiety and depression was strongly associated with both insomnia and fatigue. Both insomnia and fatigue were related to higher disability and lowered quality of life.
Cantor JB, Bushnik T, Cicerone K, et al. Insomnia, fatigue, and sleepiness in the first 2 years after traumatic brain injury. An NIDRR TBI model system module study. Journal of Head Trauma Rehabilitation. (December 2012).