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.