Vestibulo-ocular reflex dynamics with head-impulses discriminates spinocerebellar ataxias types 1, 2 and 3 and Friedreich ataxia.

摘要: OBJECTIVE Although the diagnosis of inherited ataxias is ultimately genetic, this usually means an extensive and expensive process. This justifies search for distinct clinical signs that may potentially help orient molecular diagnosis. METHODS We explored vestibulo-ocular reflex (VOR) with video Head Impulse Test in patients diagnosed spinocerebellar ataxia (SCA) type 3 (n = 15), 1 (n = 4) 2 (n = 4), Friedreich's (FA) (n = 9) healthy controls (n = 40). estimated latency, regression (VORr) instantaneous VOR gain at 40, 60 80 ms (VOR40, VOR60 VOR80), determined peak-velocity occurrence rate catch-up saccades triggered head-impulses. RESULTS latency was higher FA (p < 0.001) SCA3 (p = 0.02) as compared to controls, discriminating from other ataxic overall diagnostic accuracy 88%. VORr, VOR40 were significantly lower (p < 0.01). VOR80 only than (p < 0.01), these 78%. Covert but low peak velocity (11.1 ± 28.5% 77.50 15.30°/s) whereas overt present all groups. VORr showed a negative correlation disease severity evaluated SARA (Spearman r = -0.46, p = 0.01). CONCLUSIONS vHIT provides phenotypic information differentiates autosomal can serve strategy genetic A between raises possibility using neurophysiologic biomarker severity.