Substantia Nigra as Brainstem Signature in Pediatric‐Onset Huntington's Disease: The RAREST ‐ JHD Study

This is the authors' abstract. We don't add key points for this paper.

BACKGROUND: Pediatric-onset Huntington's disease (POHD) is usually associated with signs and symptoms of parkinsonism and dystonia predominating on chorea, which is typical of adult-onset HD (AOHD). Brain changes responsible of such an atypical POHD phenotype remain poorly understood. OBJECTIVES: To detect Midbrain and Substantia Nigra (SN) volumetric changes and their potential association with clinical parameters. METHODS: Cross-sectional study by 3 T high-field Magnetic Resonance Imaging and Unified Huntington Disease Rating Scales assays in POHD cohort with ≥60 CAG repeats and AOHD cohort with ≤59CAG repeats in HTT gene. RESULTS: POHD had volumes of SN lower than adult-onset HD (AOHD) (P = 0.003), in addition to lower striatum volume (P < 0.05). The lower SN volume of the whole HD population correlated significantly with clinical measures of UHDRS motor (P = 0.009), functional capacity (P = 0.001) and independence (P = 0.021) scores. CONCLUSIONS: Our findings suggest SN volume decrease as potential POHD brain signature contributing to the atypical HD parkinsonism.