Does Sleep Bruxism Contribute to Headache-Related Disability After Mild Traumatic Brain Injury? A Case-Control Study

To explore whether traumatic brain injury (TBI) patients have a higher prevalence of sleep bruxism (SB) and a higher level of orofacial muscle activity than healthy controls and whether orofacial muscle activity in the context of mild TBI (mTBI) increases the risk for headache disability.

Sleep laboratory recordings of 24 mTBI patients (15 males, 9 females; mean age ± standard deviation [SD]: 38 ± 11 years) and 20 healthy controls (8 males, 12 females; 31 ± 9 years) were analyzed. The primary variables included degree of headache disability, rhythmic masticatory muscle activity (RMMA) index (as a biomarker of SB), and masseter and mentalis muscle activity during quiet sleep periods.

A significantly higher prevalence of moderate to severe headache disability was observed in mTBI patients than in controls (50% vs 5%; P = .001). Although 50% and 25% of mTBI patients had a respective RMMA index of ≥ 2 episodes/hour and ≥ 4 episodes/hour, they did not present more evidence of SB than controls. No between-group differences were found in the amplitude of RMMA or muscle tone. Logistic regression analyses suggested that while mTBI is a strong predictor of moderate to severe headache disability, RMMA frequency is a modest but significant mediator of moderate to severe headache disability in both groups (odds ratios = 21 and 2, respectively).

Clinicians caring for mTBI patients with poorly controlled headaches should screen for SB, as it may contribute to their condition.