Effects of interactive metronome therapy on cognitive functioning after blast-related brain injury: a randomized controlled pilot trial.

Objective: We report preliminary findings on the efficacy of interactive metronome (IM) therapy for the remediation of cognitive difficulties in soldiers with persisting cognitive complaints following blast-related mild-to-moderate traumatic brain injury (TBI).

Method: Forty-six of a planned sample of 50 active duty soldiers with persistent cognitive complaints following a documented history of blast-related TBI of mild-to-moderate severity were randomly assigned to receive either standard rehabilitation care (SRC) or SRC plus a 15-session standardized course of IM therapy. Primary outcome measures were Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Index Scores. Secondary outcome measures included selected subtests from the Delis-Kaplan Executive Functioning System (Trail Making Test and Color-Word Interference) and the Wechsler Adult Intelligence Scale-Fourth Edition (Symbol Search, Digit-Symbol Coding, Digit Span, and Letter-Number Sequencing) as well as the Integrated Visual and Auditory Continuous Performance Test.

Results: Significant group differences (SRC vs. IM) were observed for RBANS Attention (p = .044), Immediate Memory (p = .019), and Delayed Memory (p = .031) indices in unadjusted analyses, with the IM group showing significantly greater improvement at Time 2 than the SRC group, with effect sizes in the medium-to-large range in the adjusted analyses for each outcome (Cohen's d = 0.511, 0.768, and 0.527, respectively). Though not all were statistically significant, effects in 21 of 26 cognitive outcome measures were consistently in favor of the IM treatment group (binomial probability = .00098).

Conclusion: The addition of IM therapy to SRC appears to have a positive effect on neuropsychological outcomes for soldiers who have sustained mild-to-moderate TBI and have persistent cognitive complaints after the period for expected recovery has passed.