In People with Subacute Mild Traumatic Brain Injury, earlier Physical Therapy Improved Symptoms at a Faster Rate than Later Physical Therapy: Randomized Controlled Trial.

Importance: There is unclear evidence on when to initiate physical therapy after mild traumatic brain injury (mTBI) in non-athlete, adult population.

Objective: The objective of this study was to investigate physical therapy timing after mTBI through changes in patient-reported and clinically-assessed tools and objective and mechanism measurements of sensorimotor balance control.

Design: This study was an investigator-blinded randomized control trial (NCT03479541).

Setting: The study took place at an academic research center.

Participants: Two hundred and three participants were randomized to earlier physical therapy (n = 82) or to later physical therapy (n = 121).

Intervention: After enrollment, the earlier physical therapy group started rehabilitation within 1 week and the later group started rehabilitation after a 6-week wait period. All participants received similar rehabilitation; 6-week program administered and progressed by licensed physical therapists.

Main outcomes and measures: The primary outcome was the Dizziness Handicap Inventory (DHI). Secondary outcomes included common patient-reported/clinical assessments of mTBI and objective/mechanism measurements of balance, including novel measures of central sensorimotor integration. Differences between and within the groups on outcomes were examined with linear mixed-effect models, t tests, and effect sizes.

Results: While both groups significantly improved and reached similar levels on patient-reported outcomes (DHI and secondary outcomes), the earlier physical therapy group had significantly larger and faster rates of improvement compared to later physical therapy. There were differential effects of physical therapy timing on the objective/mechanism-measured outcomes. Specifically, there were significant improvements in sensorimotor time delay for the earlier physical therapy group and no change in the later group. Further, the later group worsened in the motor activation components for balance control while there was no change in the early group.

Conclusion and relevance: Earlier physical therapy after mTBI can improve symptoms at a faster rate relative to later physical therapy. Earlier physical therapy also showed improvements in sensorimotor aspects of balance control, not seen in the later group. There may be an important window to address central sensorimotor deficits after mTBI.