Balance, attention, and dual-task performance during walking after brain injury: associations with falls history.

OBJECTIVE: To examine the relationship between balance, attention, and dual-task performance in individuals with acquired brain injury.

DESIGN: Cross-sectional study.

SETTING: Rehabilitation center and supported living program.

PARTICIPANTS: Twenty-four individuals aged 18 to 58 years (mean = 39 years) with acquired brain injury who were able to ambulate 40 ft with (29%) or without an assistive device. Fifty-eight percent were independent community ambulators. Fifty-four percent had fallen in the past 6 months; and 42% reported feeling unsteady with standing or walking.

INTERVENTIONS: Participants completed a battery of balance, attention, and dual-task assessments.

MAIN OUTCOME MEASURES: Balance: Berg Balance Scale (BBS), Four Square Step Test (FSST), High Level Mobility Assessment Test (HiMAT); Attention: Symbol Digit Modalities Test (SDMT), Moss Attention Rating Scale (MARS), modified for a single test session; and a walking dual-task assessment, the Walking and Remembering Test.

RESULTS: Mean scores: BBS, 48 of 56; FSST, 19.6 seconds; HiMAT, 20 of 54; SDMT, 30 correct; and MARS, 80. Dual-task costs were observed with variable patterns across subjects: 48% demonstrated primarily motor slowing, 9% had reduced cognitive accuracy without motor slowing, and 35% demonstrated decrements in both tasks. Subjects with a falls history had more impaired balance (HiMAT, BBS, and FSST, all P <.026) but were not significantly different in dual-task performance or attention measures.

CONCLUSIONS: The test battery matched the range of motor and cognitive abilities of the sample. Balance was more strongly related to falls history than measures of attention or dual-task performance. Injury chronicity may have allowed some subjects to develop strategies to optimize dual-task performance. Alternatively, motor slowing in dual-task conditions may be an adaptive strategy, allowing performance of multiple tasks with reduced safety risk. Further investigation in this area is warranted to clarify the utility of dual-task methods in identifying falls risk after brain injury.