The rate of chronic fatigue after traumatic brain injury is more than four times higher than the general population. Chronic fatigue is a complex disorder, and research has shown that is related to sleep problems, cognitive impairment, attention deficits, depression, anxiety, and chronic pain-problems that are also common after traumatic brain injury. Hormonal insufficiencies that can occur after traumatic brain injury can also contribute to chronic fatigue.
A recent study examining both hormonal and non-hormonal causes of chronic fatigue after traumatic brain injury found that vitamin D deficiency was a surprisingly strong risk factor. Poor sleep was also a strong, but obvious, cause of fatigue. Anxiety was associated with chronic fatigue, although less so than sleep problems. Hormone deficiencies were shown to be unrelated to chronic fatigue.
The link between vitamin D deficiency and chronic fatigue is an intriguing one. Traumatic brain injury can lead to an isolated and inactive lifestyle that results in lowered sun exposure and subsequent vitamin D deficiency. Vitamin D deficiency can cause muscle pain and weakness, two symptoms that are also common in chronic fatigue. Fortunately, vitamin D replacement is a simple and inexpensive therapy that may help to reverse chronic fatigue after traumatic brain injury.
Schnieders J, Willensen D, & de Boer H. Factors contributing to chronic fatigue after traumatic brain injury. Journal of Head Trauma Rehabilitation. (February 2012).