The Cerebellar Neuropsychiatric Rating Scale in the Spinocerebellar Ataxias

There is currently no established screening instrument that detects neuropsychiatric features in individuals with cerebellar ataxia. We hypothesized that the Cerebellar Neuropsychiatric Rating Scale (CNRS) would capture the neuropsychiatry of patients enrolled in the natural history study of the Clinical Research Consortium for the Study of Cerebellar Ataxia, and provide novel insights not revealed by other measures. We studied CNRS data in 362 patients with spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 10, and 27B, and cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS). We grouped patients by mild, moderate, and severe disease severity according to Friedreich Ataxia Rating Scale (FARS) functional stage. We analyzed scores on the CNRS and its five constituent domains for the entire cohort and by severity subgroup. We fit a mixed effects model to examine the effect of severity. We analyzed correlations with other clinical measures: Cerebellar Cognitive Affective / Schmahmann Syndrome Scale (CCAS-S), Patient-Reported Outcome Measure of Ataxia (PROM-Ataxia), Patient Health Questionnaire-9 (PHQ-9), Euro-Qol 5-Dimension (EQ-5D), and Fatigue Severity Scale (FSS). The CNRS detected neuropsychiatric symptoms, with highest scores on Attentional and Emotional Control domains. The mixed effects model revealed that ataxia severity influences scores, with mean scores increasing with ataxia severity. The CNRS correlated with the PROM-Ataxia Mental domain, particularly between Emotional Control and section 1 (psychiatric) items. Emotional Control also correlated with PHQ-9 and EQ-5D. Correlations with the CCAS-S Affect and FSS were weak. The CNRS provides novel neuropsychiatric insights into spinocerebellar ataxia that are missed by other measures.