Background: Prior studies have relied on conventional observer-based severity ratings such as the Unified Huntington’s Disease Rating Scale (UHDRS) to identify early motor markers of decline in Huntington’s disease (HD). Objective: The present study examined the predictive utility of graphomotor measures handwriting and drawing movements. Methods: Seventeen gene-positive premanifest HD subjects underwent comprehensive clinical, cognitive, motor, and graphomotor assessments at baseline and at follow-up intervals ranging from 9–36 months. Baseline graphomotor assessments were subjected to linear multiple regression procedures to identify factors associated with change on the comprehensive UHDRS index. Results: Subjects were followed for an average of 21.2 months. Three multivariate regression models based on graphomotor variables derived from a complex loop task, a maximum speed circle drawing task and a combined task returned adjusted R2 coefficients of 0.76, 0.71, and 0.80 respectively accounting for a significant portion of the variability in cUHDRS change score. The best-fit model based on the combined tasks indicated that greater decline on the cUHDRS was associated with increased pen movement dysfluency and stroke-stroke variability at baseline. Conclusion: Performance on multiple measures of graphomotor dysfluency assessed during the premanifest or prodromal stage in at-risk HD individuals was associated with decline on a multidimensional index on HD morbidity preceding an HD diagnosis.

Background Individuals with Huntington's disease (HD) experience motoric, cognitive, and psychiatric dysfunction. These difficulties can cause maladaptive behaviors that can be very distressing to family and caregivers. Capturing these behaviors in clinical and research settings is crucial. Objectives To develop and evaluate the psychometric properties of an instrument that is brief, yet comprehensive, in assessing a broad range of behaviors in HD. Methods A pool of 30 items encompassing common behaviors in HD was generated. Items were scored on a 4‐point Likert scale ranging from completely disagree to completely agree, with higher scores indicating greater dysfunction. The self‐report measure was piloted on a small sample of individuals with HD. Reliability (test–retest, internal consistency) and validity (convergent, discriminant, criterion) were evaluated. Results The HD–Behavioral Questionnaire (HD‐BQ) demonstrated evidence for reliability with a test–retest correlation coefficient of r = 0.81 and an internal consistency of 0.96. Validity was established with evidence for good convergent, divergent, and criterion validity. A receiver operating characteristic curve showed that the HD‐BQ outperformed a similar commonly used measure in diagnostic capability of behaviors in HD. Conclusions The HD‐BQ, a patient self‐report measure, was created to more fully explore behavioral issues that people with HD experience in response to limitations of commonly used instruments in the field. Psychometric evidence supports that the HD‐BQ is a valid and reliable instrument for the brief, yet comprehensive, assessment of problematic behaviors in HD.

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