The authors measured the rate of whole-brain atrophy over 6 months in 13 patients with early Huntington disease (HD) and seven matched controls. Patients with early HD had significantly increased rates of whole-brain atrophy vs controls (mean [SD] HD, 1.10 [0.88]%/year; controls, 0.26 [0.54]%/year). The measurement of cerebral change over short time periods (e.g., 6 months) may be relevant for trials designed to assess effects on neurodegeneration or atrophy.