High-level mobility in chronic traumatic brain injury and its relationship with clinical variables and magnetic resonance imaging findings in the acute phase

Abstract

Objectives: To compare high-level mobility in individuals with chronic moderate-to-severe traumatic brain injury (TBI) with matched healthy controls, and to investigate whether clinical variables and magnetic resonance imaging (MRI) findings in the acute phase can predict high-level motor performance in the chronic phase.

Design: A longitudinal follow-up study.

Setting: A level 1 trauma center.

Participants: Individuals (N=136) with chronic TBI (n=65) and healthy matched peers (n=71).

Interventions: Not applicable.

Main outcome measures: High-Level Mobility Assessment Tool (HiMAT) and the revised version of the HiMAT performed at a mean of 2.8 years (range, 1.5-5.4y) after injury.

Results: Participants with chronic TBI had a mean HiMAT score of 42.7 (95% confidence interval [CI], 40.2-45.2) compared with 47.7 (95% CI, 46.1-49.2) in the control group (P<.01). Group differences were also evident using the revised HiMAT (P<.01). Acute-phase clinical variables and MRI findings explained 58.8% of the variance in the HiMAT score (P<.001) and 59.9% in the revised HiMAT score (P<.001). Lower HiMAT scores were associated with female sex (P=.031), higher age at injury (P<.001), motor vehicle collisions (P=.030), and posttraumatic amnesia >7 days (P=.048). There was a tendency toward an association between lower scores and diffuse axonal injury in the brainstem (P=.075).

Conclusions: High-level mobility was reduced in participants with chronic, either moderate or severe TBI compared with matched peers. Clinical variables in the acute phase were significantly associated with high-level mobility performance in participants with TBI, but the role of early MRI findings needs to be further investigated. The findings of this study suggest that the clinical variables in the acute phase may be useful in predicting high-level mobility outcome in the chronic phase.

Keywords: Diffuse axonal injury; Magnetic resonance imaging; Motor skills; Rehabilitation.