Searching brain and peripheral biomarkers is a requisite to cure Huntington's disease (HD). To search for markers indicating the rate of brain neurodegenerative changes in the various disease stages, we quantified changes in brain atrophy in subjects with HD. We analyzed the cross-sectional and longitudinal rate of brain atrophy, quantitatively measured by fully-automated multiparametric magnetic resonance imaging, as fractional gray matter (GM, determining brain cortex volume), white matter (WM, measuring the volume of axonal fibers), and corresponding cerebral spinal fluid (CSF, a measure of global brain atrophy), in 94 gene-positive subjects with presymptomatic to advanced HD, and age-matched healthy controls. Each of the three brain compartments we studied (WM, GM, and CSF) had a diverse role and their time courses differed in the development of HD. GM volume decreased early in life. Its decrease was associated with decreased serum brain-derived-neurotrophic-factor and started even many years before onset symptoms, then decreased slowly in a nonlinear manner during the various symptomatic HD stages. WM volume loss also began in the presymptomatic stage of HD a few years before manifest symptoms appear, rapidly decreasing near to the zone-of-onset. Finally, the CSF volume increase began many years before age at onset. Its volume measured in presymptomatic subjects contributed to improve the CAG-based model of age at onset prediction. The progressive CSF increase depended on CAG mutation size and continued linearly until the last stages of HD, perhaps representing the best marker of progression rate and severity in HD (R(2)= 0.25, P < 0.0001).

The linear correlation between decreased metabolic FDG uptake and worsening clinical scores in the placebo-treated patients suggests that FDG-PET may be a valuable procedure to assess brain markers of HD.

Health-related quality-of-life instruments are critical for assessing disease burdens. Generic tools allow comparison between diseases but do not discriminate between disease severities. Specific tools also tend to be more sensitive. No specific tool is available to assess quality of life in patients with Huntington's disease (HD). In the context of the European study on HD burden, a specific tool was created: the Huntington Quality of Life Instrument (H-QoL-I). The aim of this study was to optimize the content and validate the H-QoL-I. After a semistructured interview with patients, caregivers and HD specialists, we conducted a patient focus group. A self-reported questionnaire was then developed in French and Italian. A total of 252 patients were recruited to answer the questionnaire. Face, internal and external validities were examined using a variety of methods. The shortened H-QoL-I that resulted from the successive analyses comprises 11 items, which are divided into three dimensions: motor functioning (four items), psychology (four items) and socializing (three items). These three domains were identified as being essential to cover the full domain of the quality of life for patients affected by HD. The H-QoL-I showed an acceptable reliability (Cronbach's α>0.84). Factor analyses demonstrated satisfactory construct validity. Moreover, the item internal consistency and item discriminant validity criteria were fulfilled. No differential item functioning was detected. External validity supported the scale's robustness. These data support the validity of the H-QoL-I in patients with HD.

Findings indicate the HDQoL-C is multi-lingual, multi-cultural and easily applicable in other languages.

No abstract