Gait Performance in People with Symptomatic, Chronic Mild Traumatic Brain Injury

Abstract

There is a dearth of knowledge about how symptom severity affects gait in the chronic (>3 months) mild traumatic brain injury (mTBI) population despite up to 53% of people reporting persisting symptoms following mTBI. The purpose of this investigation was to determine if gait is affected in a symptomatic, chronic mTBI group and to assess the relationship between gait performance and symptom severity on the Neurobehavioral Symptom Inventory (NSI). Gait was assessed under single-and dual-task conditions using five inertial sensors in 57 control subjects and 65 people with chronic mTBI (1.1 year from mTBI).The single-and dual-task gait domains of Pace, Rhythm, Variability, and Turning were calculated from individual gait characteristics. Dual-task cost (DTC) was calculated for each domain. The mTBI group walked (domain z-score mean difference: single-task = 0.70; dual-task = 0.71) and turned (z-score mean difference: single-task = 0.69; dual-task = 0.70) slower (p<0.001) under both gait conditions, with less rhythm under dual-task gait (z-score difference = 0.21, p=0.001). DTC was not different between groups.Higher NSI somatic sub-score was related to higher single-and dual-task gait variability as well as slower dual-task pace and turning (p<0.01). People with chronic mTBI and persistent symptoms exhibited altered gait, particularly under dual-task, and worse gait performance related to greater symptom severity. Future gait research in chronic mTBI should assess the possible underlying physiological mechanisms for persistent symptoms and gait deficits.

Free-living Turning Rather Than Gait Differentiates People with Chronic Mild Traumatic Brain Injury from Controls

“…Thirdly, the differences in this mTBI cohort's chronicity are likely to limit the direct comparison with other studies. Our study's cohort was chronic with a median post-injury time greater than 1-year, which compared to other studies examining people post-mTBI is a long time since injury [23,51].…”

“…Lack of signi cant differences and low effect sizes in gait characteristics between chromic mTBI and health controls may be related to the considerable chronicity (median 1.2 years post injury) of this mTBI cohort. Meaning this cohort of chronic mTBI may have developed compensation strategies over-time to replicate 'normal' gait patterns during walking in their daily life, whereas turning may require more cognitive or sensory processing, which may be a complex task that is di cult to compensate for and therefore turning reveals subtle mobility de cits [23,33,53]. As such, we would expect if we tested these participants in the laboratory under complex conditions (e.g.…”

“…However variation in the exact length of time participants wore wearables (minimum three days) could introduce differences and therefore not re ect true habitual freeliving mobility as used in other studies [50,59]. Using multiple IMUs may provide more detailed spatial and temporal data for turning, balance and gait as used in previous studies [23], but this carries different limitations; such as longer data download, processing complexity and increased wearer burden, limiting the practical or clinical application. This trade-off should be considered in future studies as a potential improvement to the assessment protocol.…”

“…Chronic mTBI patients completed the NSI symptom questionnaire, which is widely used in assessment of mTBI symptoms [23,44]. The NSI and subscales [45] have acceptable reliability in characterising presence and tracking severity of symptoms in TBI [45,46].…”

“…Laboratory-based gait studies have primarily found pace-related gait de cits (stride length and gait speed) in chronic mTBI compared to healthy controls [23], suggesting gait may be a useful diagnostic marker. Additionally, Fino et al 2018 [2] highlighted that more challenging mobility tasks elicit more gait impairments in mTBI (acute and chronic) compared to healthy controls [2,24].…”