Gait, balance, and falls in Huntington disease.

Huntington disease (HD) is an autosomal-dominant, progressive, neurodegenerative disorder, characterized by involuntary movements and other motor impairments, cognitive/behavioral symptoms, and psychiatric disorders. Gait and balance impairments and falls greatly impact on the quality of life among people with HD, and being fall-prone is one of the strongest predictors of nursing-home placement. Gait impairment in HD is characterized by bradykinesia, reduced velocity, and increased variability in spatiotemporal features. Detrimental changes in symmetry, step length, stride time, balance measures, gait adaptability (external cues, dual tasking), and hypo/hyperkinesia have also been observed. Balance impairment is characterized by impairments of anticipatory balance without a change in base of support, anticipatory balance with a change in base of support, and reactive balance. In addition to gait and balance impairment, people with HD have a range of intrinsic and extrinsic factors that increase fall risk, including reduced cognitive reserve for dual tasking. Currently there is some evidence to suggest exercise interventions can address some HD-specific gait and balance deficits. However, no intervention studies to date have specifically targeted falls. Large, well-designed, randomized controlled trials are needed to guide future fall prevention interventions in people with HD.