"Poor sleep is linked to impeded recovery from traumatic brain injury."

Kalmbach, David A., Deirdre A. Conroy, Hayley Falk, Vani Rao, Durga Roy, Matthew E. Peters, Timothy E. Van Meter, and Frederick K. Korley.

Sleep 41, no. 10 (2018): zsy147.

Conclusion:

Functionally impaired patients diagnosed predominantly with mild TBI exhibit high rates of insomnia and short sleep, which may impede TBI recovery. Monitoring sleep after head injury may identify patients with poor prognoses and allow for early intervention to improve functional outcomes.