A Prospective, Multicenter Study to Assess the Safety and Efficacy of Translingual Neurostimulation Plus Physical Therapy for the Treatment of a Chronic Balance Deficit Due to Mild-to-Moderate Traumatic Brain Injury

Abstract

Objectives: Translingual neurostimulation (TLNS) studies indicate improved outcomes in neurodegenerative disease or spinal cord injury patients. This study was designed to assess the safety and efficacy of TLNS plus targeted physical therapy (PT) in people with a chronic balance deficit after mild-to-moderate traumatic brain injury (mmTBI).

Materials and methods: This international, multicenter, randomized study enrolled 122 participants with a chronic balance deficit who had undergone PT following an mmTBI and had plateaued in recovery. Randomized participants received PT plus either high-frequency pulse (HFP; n = 59) or low-frequency pulse (LFP; n = 63) TLNS. The primary efficacy and safety endpoints were the proportion of sensory organization test (SOT) responders (SOT composite score improvement of ≥15 points) and fall frequency after five weeks of treatment, respectively.

Results: The proportion of SOT responders was significant in the HFP + PT (71.2%) and LFP + PT (63.5%) groups compared with baseline (p < 0.0005). For the pooled population, the SOT responder rate was 67.2% (p < 0.00005), and there were clinically and statistically significant improvements in SOT composite scores after two and five weeks (p < 0.0005). Both groups had reductions in falls and headache disability index scores. Mean dynamic gait index scores in both groups also significantly increased from baseline at weeks 2 and 5.

Conclusions: Significant improvements in balance and gait, in addition to headaches, sleep quality, and fall frequency, were observed with TLNS plus targeted PT; in participants who had a chronic balance deficit following an mmTBI and had plateaued on prior conventional physiotherapy.

Keywords: Balance; clinical trial; gait; randomized; traumatic brain injury.

Figure 1

CONSORT flow diagram. HFP, high‐frequency pulse; LFP, low‐frequency pulse; PT, physical therapy.

Figure 2

SOT responders at five weeks. SOT responder rate in the HFP + PT, LFP + PT, and pooled groups at five weeks. Responders were defined as participants who had an improvement of ≥15 points in SOT score from baseline. *p < 0.0005 vs baseline. HFP, high‐frequency pulse; LFP, low‐frequency pulse; PT, physical therapy; SOT, sensory organization test.

Figure 3

Mean increase in SOT composite score from baseline in the pooled population (HFP + PT and LFP + PT). Mean changes (+SD) from baseline to weeks 2 and 5 in SOT composite score for the pooled group. *p < 0.0005 vs baseline. HFP, high‐frequency pulse; LFP, low‐frequency pulse; SD, standard deviation; SOT, sensory organization test.

Figure 4

Mean increase in DGI score from baseline. The mean DGI score at weeks 2 and 5 was calculated for both the HFP + PT and LFP + PT treatment arms. *p < 0.0001 vs baseline. DGI, dynamic gait index; HFP, high‐frequency pulse; LFP, low‐frequency pulse; PT, physical therapy.

Figure 5

Change in SOT composite score from baseline over the duration of prior PT. The pooled population of HFP + PT and LFP + PT groups were analyzed through linear regression analysis (orange line) and locally weighted scatter plot smoothing (LOESS; blue line). The corresponding shaded areas represent confidence bands for the linear regression and LOESS lines; fit of the solid line within the associated confidence band suggests there is no likely relationship between the observed change in SOT composite score from baseline and the duration of prior PT. LOESS, locally weighted scatterplot smoothing; PT, physical therapy; SOT, sensory organization test.

Figure 6

Reduction in falls and in HDI scores from baseline. Reduction in total number of falls (a) and changes in mean HDI (+ SD) scores (b) from baseline and at five weeks were calculated for each treatment arm. HDI, headache disability index; HFP, high‐frequency pulse; LFP, low‐frequency pulse; PT, physical therapy; SD, standard deviation.