Dystonia in Huntington's disease: Prevalence and clinical characteristics

Abstract

BACKGROUND The prevalence and clinical characteristics of dystonia in Huntington's disease (HD) have not been formally assessed. OBJECTIVES To study (1) the prevalence of dystonia in HD in a clinic population, (2) the clinical features of dystonia, and (3) clinical correlates of dystonia (for example, age, disease duration). METHODS Patients with HD attending the HD Center at the New York State Psychiatric Center were administered the Unified HD Rating Scale and underwent a standardized 5.5‐minute videotaped examination. Two neurologists reviewed the videotaped examination and rated the severity and constancy of dystonia, calculating a total dystonia score for each patient. RESULTS Prevalence of dystonia of any severity was 95.2%. Twenty‐four of 42 (57.1%) had dystonia in at least one body region that was moderate and present more than half of the time, and seven of 42 (16.7%) had dystonia that was severe and constant. The most prevalent types of dystonia were internal shoulder rotation (64.3%), sustained fist clenching (47.1%), excessive knee flexion (42.9%), and foot inversion (42.9%). In 37 of 42 (88.1%) patients, there were more than two types of dystonia, and in the average patient, three to four types of dystonia. The mean severity was between 1 (mild) and 2 (moderate), and the mean constancy was between 2 (present less than half of the time) and 3 (present more than half of the time). Multivariate linear regression revealed that disease duration (p = 0.0005) and taking an antidopaminergic agent (p = 0.03) were positively associated with the total dystonia score. CONCLUSIONS The majority of patients in this HD clinic exhibited some dystonia. The dystonia was present in several body regions and manifested by a variety of movements and postures not typical of idiopathic torsion dystonia. The dystonia was not bothersome to most patients, and its severity was a function of disease duration and use of an antidopaminergic agent.

The functional neuroanatomy of dystonia

“…Dysfunction of nigrostriatal pathways also is thought to be responsible for both acute dystonic reactions and tardive dystonia associated with antagonists of dopamine receptors. Dystonia similarly co-exists with chorea, for example in Huntington’s disease where there is prominent degeneration of the striatum (Louis et al, 1999). …”

Risk-taking and pathological gambling behavior in Huntington’s disease

“…Dysphagia (swallowing difficulties) is observed in most patients with an onset at mid-disease stages, and gradually worsens until patients can no longer eat unassisted and often require a feeding tube in late-stage HD (Heemskerk and Roos, 2011). Other, non-choreic motor symptoms that usually become apparent at mid-stage disease include complex gait disorder, postural instability, and dystonia (involuntary muscle contractions that cause slow repetitive movements and abnormal postures), which is often accompanied by frequent falls (Koller and Trimble, 1985; Tian et al, 1992; Louis et al, 1999; Grimbergen et al, 2008). Rigidity and bradykinesia (slowness of movement and reflexes) are sometimes observed, but are mostly restricted to cases of juvenile-onset HD (Bittenbender and Quadfasel, 1962; Hansotia et al, 1968).…”

Convergent mechanisms in etiologically-diverse dystonias

“…It is therefore presumed that this phenomenon contributes to the expression of dystonic symptoms as well. Dystonia can also present in Huntington's disease (HD) [112,113], which is characterized by degeneration of the striatum. Interestingly, in young-onset HD, dystonia may be predominant over choreic movements, which are typical in adult-onset HD [114].…”