Huntington’s Disease Care Education and Research Center: Clinical Care Resources
It is generally believed that treatments are available to manage irritability in Huntington’s disease (HD). However, lack of an evidence base prevents the establishment of treatment guidelines for this symptom. The research literature fails to address behavioral intervention strategies, drug selection, drug dosing, management of inadequate response to a single drug, or preferred drugs when additional behavioral symptoms comorbid to irritability are present. In an effort to inform clinical decision-making we surveyed an international group of experts to address these points. The experts consistently endorsed an antipsychotic drug (APD) as first choice for treatment of urgent and aggressive irritability behaviors. However, there was variation in practice patterns for treating less severe symptoms. Serotonin reuptake inhibitors (SSRIs) were first choice drug treatments by most respondents across all geographic regions. However, APDs were also endorsed as first choice for mild or moderate irritability, more frequently in Europe than in North America and Australia. Antiepileptic mood stabilizers (AEDs) were used by fewer respondents as first choice drug. Perceived efficacy for control of mild or moderate irritability was judged somewhat higher for APDs than SSRIs or AEDs. Benzodiazepines were not used as monotherapy, but frequently as an adjunctive drug in the setting of comorbid anxiety. Though many cited lack of experience with mirtazapine, others familiar with its use in HD chose it as an alternative monotherapy, or as adjunctive therapy if insomnia was a comorbid factor. This report presents survey results, reviews available irritability studies, and lastly proposes an algorithm for the treatment of irritability in HD derived from expert preferences obtained through this survey
It is generally believed that treatments are available to manage chorea in Huntington’s disease (HD). However, lack of evidence prevents the establishment of treatment guidelines. The HD chorea research literature fails to address the indications for drug treatment, drug selection, drug dosing and side effect profiles, management of inadequate response to a single drug, and preferred drug when behavioral symptoms comorbid to chorea are present. Because there is lack of an evidence base to inform clinical decision-making, we surveyed an international group of experts to address these points. Survey results showed that patient stigma, physical injury, gait instability, work interference, and disturbed sleep were indications for a drug treatment trial. However, the experts did not agree on first choice of chorea drug, with the majority of experts in Europe favoring an antipsychotic drug (APD), and a near equal split in first choice between an APD and tetrabenazine (TBZ) among experts from North America and Australia. All experts chose an APD when comorbid psychotic or aggressive behaviors were present, or when active depression prevented the use of TBZ. However, there was agreement from all geographic regions that both APDs and TBZ were acceptable as monotherapy in other situations. Perceived efficacy and side effect profiles were similar for APDs and TBZ, except for depression as a significant side effect of TBZ. Experts used a combination of an APD and TBZ when treatment required both drugs for control of chorea and a concurrent comorbid symptom, or when severe chorea was inadequately controlled by either drug alone. The benzodiazepines (BZDs) were judged ineffective as monotherapy but useful as adjunctive therapy, particularly when chorea was exacerbated by anxiety. There was broad disagreement about the use of amantadine for chorea. Experts who had used amantadine described its benefit as small and transient. In addition to survey results, this report reviews available chorea studies, and lastly presents an algorithm for the treatment of chorea in HD which is based on expert preferences obtained through this international survey.
It is generally believed that treatments are available to manage obsessive-compulsive behaviors (OCB’s) in Huntington’s disease (HD). However, lack of an evidence base prevents guideline development. The research literature fails to address the indications for behavioral interventions, drug selection, drug dosing, management of inadequate response to a single drug, and preferred drugs when additional behavioral symptoms comorbid to OCBs are present. In an effort to inform clinical decision-making, we surveyed an international group of experts to address these points. Survey results showed that experts utilized behavioral therapy only for patients with mild cognitive impairment. There was expert agreement that a selective serotonin reuptake inhibitor (SSRI) was the first choice drug, although clomipramine (CMI) was cited as a monotherapy choice by the smaller number of experts familiar with its use. Perceived efficacy for control of OCBs was similar for both SSRIs and CMI. Though less favored choices overall, antipsychotics (APDs) and antiepileptic mood stabilizers (AEDs) were most often used as augmentation strategies. In addition to survey results, this report reviews available studies, and lastly presents an algorithm for the treatment of OCBs in HD based on practice-based preferences obtained from this survey.