Callosal hyperintensities and gait speed gain from two types of mobility interventions in older adults.

OBJECTIVE: To assess whether the volume of callosal hyperintensities in the genu and splenium of older adults with mobility impairment is differentially associated with the degree of gain in gait speed after 2 types of gait interventions.

DESIGN: Single-blind randomized controlled trial of 2 types of gait exercises in older adults.

SETTING: Research center in an academic institution.

PARTICIPANTS: Ambulatory adults (N=44) aged ≥65 years with a slow and variable gait.

INTERVENTION: Twelve-week physical therapist-guided trial of a conventional walking, endurance, balance, and strength (WEBS) intervention (n=20) versus a timing and coordination of gait (TC) intervention (n=22).

MAIN OUTCOME MEASURE: Gain in gait speed after the intervention and its relation to callosal hyperintensities in the genu and splenium of the corpus callosum.

RESULTS: Gait speed improved in both the WEBS group (mean change, 0.16m/s) and the TC group (mean change, 0.21m/s; both P<.05). The volume of white matter hypertintensities (WMHs) in the genu was differentially associated with gait speed gain (group × genual WMH interaction, P=.05). Greater genual WMH volume was related to a smaller gait speed gain in the WEBS group (P=.01) but not in the TC (P=.10) group. Splenial WMH volume was not differentially associated with gait speed gain (interaction, P=.90).

CONCLUSIONS: Callosal hyperintensities differentially influence gait speed gain by the type of gait rehabilitation. Mobility impaired older adults with genual hyperintensities may benefit from a rehabilitation program focused on motor skill learning rather than on strength and endurance training.