Sensorimotor and Physiological Indicators of Impairment in Mild Traumatic Brain Injury: A Meta-Analysis

To systematically review the literature with meta-analysis to determine whether persistence of sensorimotor or physiological impairment exists between 4 weeks to 6 months post mild traumatic brain injury (mTBI), and assign level of evidence to findings.

The databases PubMed, pscyINFO, SPORTdiscus, Medline, CINAHL and Embase were searched from inception to November 2016 using a priori inclusion criteria. Critical appraisal was performed, and an evidence matrix established level of evidence. Meta-analysis of pooled results identified standardized mean difference (SMD) and 95% confidence intervals (95% CI) between mTBI and healthy controls for a variety of physiological and sensorimotor indicators.

Eighteen eligible articles, with a mean quality score of 15.67 (SD = 2.33) were included in the final review. Meta-analysis of center of motion variable; maximal mediolateral center of motion/center of pressure separation distance SMD [95% CI] approached significance at (-0.42 [-0.84, -0.00], I² = 0%) for dual task, level walking indicating a potential reduction in maximal mediolateral excursion during gait in the mTBI group compared to healthy controls. Significantly reduced variability in the standard deviation of heart beat intervals was observed in the mTBI group (-0.51 [-0.74, -0.28], I² = 0%). Overall, significant group differences in 36 sensorimotor and physiological variables (eg, balance, gait velocity and motion analysis outcomes, various oculomotor tasks, as well as heart rate variability frequency domains) were identified.

Findings demonstrate that persistence of sensorimotor and physiological changes beyond expected recovery times following subacute mTBI in an adult population is possible. These findings have implications for post-injury assessment and management.