Non-motor symptoms in Huntington's disease: a comparative study with Parkinson's disease

The presence of non-motor symptoms in Huntington's disease (HD) has not been systematically assessed so far. Our objective was to know their prevalence and to compare it with a cohort of patients with Parkinson's disease (PD).

Participants were consecutively recruited from our outpatient clinic. They were assessed through the motor part of the Unified Huntington's Disease Rating Scale, the motor part of the Unified Parkinson's Disease Rating Scale, the total functional capacity scale and the PD non-motor symptoms questionnaire.

We enrolled 123 participants: 53 HD, 45 PD and 25 healthy controls (HC). Non-motor symptoms were significantly more prevalent in HD patients than in HC. The most frequent non-motor symptoms in HD, involving more than 50% of patients, were attentional deficits, apathy, dysphagia, memory complaints, depression falls, insomnia and urinary urgency. The total score of non-motor symptoms correlated with disease duration, total functional capacity and disease stage. HD scored significantly higher than PD in 11 items (dysphagia, constipation, bowel incontinence, faecal tenesmus, weight loss, memory, apathy, attention, falls, nightmares, delusions) and in four domains (cognitive, hallucinations and delusions, digestive and cardiovascular). PD did not score significantly higher than HD in any domain.

HD patients have a high prevalence of non-motor symptoms, which is even higher than in PD, and correlates with disease progression.