Improving Perception of Perturbations and Balance Using a Novel Dynamic Computerized Biofeedback Based Intervention after Traumatic Brain Injury.

ABSTRACT

Traumatic Brain Injury (TBI) impairs the integration and organization of the visual, auditory, and somatosensory inputs that permit body position awareness in relation to self and environment resulting in balance dysfunction (BD). The sensitivity levels to which the environmental perturbations are perceived are also critical for attaining the position awareness and the equilibrium. Undetectable perturbations, however small they may be, can result in fatal falls, especially after TBI. In this investigation, we used a novel dynamic computerized biofeedback based (CBB) intervention aimed at improving the perception of external perturbations, and static and dynamic balance in individuals with TBI. The effect of the CBB intervention on balance was accessed using a clinical measure - Berg Balance Scale (BBS), a novel psychophysical measure - perception of perturbation threshold (PPT), and biomechanical measures derived from center of pressure (COP) data during controlled sinusoidal varied-amplitudes anterior-posterior perturbations of 0.33 Hz, 0.5 Hz, and 1 Hz to the base of support. At baseline, the TBI-Control (TBI-C) group (n=5) and the TBI-Intervention (TBI-I) group (n=2) showed impaired balance compared to the healthy control (HC) group (n=5). This was shown by lower BBS and elevated values of PPT and COP measures (RMS COP, COP velocity, Phase Plane Indices (PPI)). Post CBB intervention, TBI-I group showed increased BBS and reduction in PPTs, COP measures (velocity and PPI), suggesting improvements in postural stability and balance. This investigation explores a potential link between the perception of perturbations and balance and demonstrates the applicability of the CBB intervention for improving interpretation and organization of multisensory information in a task-specific environment to improve balance post-TBI.