Evaluating Sensory Acuity as a Marker of Balance Dysfunction After a Traumatic Brain Injury: A Psychophysical Approach

Abstract

There is limited research on sensory acuity i.e., ability to perceive external perturbations via body-sway during standing in individuals with a traumatic brain injury (TBI). It is unclear whether sensory acuity diminishes after a TBI and if it is a contributing factor to balance dysfunction. The objective of this investigation is to first objectively quantify the sensory acuity in terms of perturbation perception threshold (PPT) and determine if it is related to functional outcomes of static and dynamic balance. Ten individuals with chronic TBI and 11 age-matched healthy controls (HC) performed PPT assessments at 0.33, 0.5, and 1 Hz horizontal perturbations to the base of support in the anteriorposterior direction, and a battery of functional assessments of static and dynamic balance and mobility [Berg balance scale (BBS), timed-up and go (TUG) and 5-m (5MWT) and 10-m walk test (10MWT)]. A psychophysical approach based on Single Interval Adjustment Matrix Protocol (SIAM), i.e., a yes-no task, was used to quantify the multi-sensory thresholds of perceived external perturbations to calculate PPT. A mixeddesign analysis of variance (ANOVA) and post-hoc analyses were performed using independent and paired t-tests to evaluate within and between-group differences. Pearson correlation was computed to determine the relationship between the PPT and functional measures. The PPT values were significantly higher for the TBI group (0.33 Hz: 2.97 ± 1.0, 0.5 Hz: 2.39 ± 0.7, 1 Hz: 1.22 ± 0.4) compared to the HC group (0.33 Hz: 1.03 ± 0.6, 0.5 Hz: 0.89 ± 0.4, 1 Hz: 0.42 ± 0.2) for all three perturbation frequencies (p < 0.006 post Bonferroni correction). For the TBI group, the PPT for 1 Hz perturbations showed significant correlation with the functional measures of balance

Graph-theoretical Analysis of EEG Functional Connectivity during Balance Perturbation in Traumatic Brain Injury: A Pilot Study

“…BBS has been shown to more strongly correlate with functional measures of balance such as timed up-and-go (TUG) than laboratory measures of body sway during quiet standing or in response to perturbation [60], which is consistent with our findings from our group in the same population [61]. The authors suggested that BBS includes several tasks that may capture several and different functional measures of balance impairment, compared to the more controlled environment of laboratory measures.…”

Graph‐theoretical analysis of EEG functional connectivity during balance perturbation in traumatic brain injury: A pilot study

“…Despite a moderate relationship between COP and BBS ( r = −.52, p = .03) in our sample, the two measures may reflect different aspects of balance control. Berg et al found that BBS was more strongly correlated with functional measures of balance such as timed up‐and‐go than laboratory measures of body sway during quiet standing or in response to perturbation (Berg et al, 1992, b), which is consistent with our findings from our group in the same population (Pilkar et al, 2020). The authors suggested that BBS includes various tasks that may capture several and different functional measures of balance impairment, compared to the more controlled environment of laboratory measures (Berg et al, 1992, b).…”

Oculomotor Deficits and Symptom Severity Are Associated With Poorer Dynamic Mobility in Chronic Mild Traumatic Brain Injury

“…The number of people with post-concussion syndrome is unclear, with prior studies reporting numbers ranging from 15 to 82% (3,9,15,17). Oculomotor (18), vestibular (19,20), and visualvestibular processing deficits (21)(22)(23) have been reported in the chronic stage of mTBI. These deficits may arise from injury to the peripheral vestibular structures (11,24,25) or due to traumatic central axonal injury (26)(27)(28)(29)(30).…”