Treating chorea, or involuntary movements, is one aspect of Huntington disease (HD) management. A new guideline from the AAN, “Pharmacologic Treatment of Chorea in Huntington Disease,” recommends the best evidence–based treatments for controlling chorea in HD. The guideline was published electronically ahead of print on July 18, 2012, and will appear in the August 7, 2012, print edition of Neurology®.
Research shows that in addition to tetrabenazine (TBZ), the one drug with Food and Drug Administration approval for use in HD chorea, the drugs riluzole and amantadine can be helpful and nabilone may be helpful for treating chorea in people with HD. Each has its limitations in terms of cost and adverse effects, particularly elevated liver enzymes with riluzole; parkinsonism and depression/suicidality with TBZ; and drug dependency with nabilone. There is no high–quality research evidence for the most commonly used drugs in HD, neuroleptic agents.
However, because HD is a complex disease with a range of often severe symptoms, physicians should work with patients to determine on a case–by–case basis whether treating chorea symptoms is a priority for disease management. Important factors to consider include which HD symptoms need treatment the most, whether chorea is severe enough to require treatment, whether the potential benefits of the available treatments outweigh the potential risks, and whether one drug might be able to treat more than one symptom.
“We undertook this guideline project because we could not find many existing evidence–based guidelines on chorea treatment in HD,” said guideline lead author Melissa Armstrong, MD. “Our results surprised us. High–quality studies are unavailable for neuroleptics, the most commonly prescribed therapies for HD chorea, so no recommendations could be made for or against these agents. In contrast, we found studies of modest to moderate quality for a range of therapies not commonly utilized for this HD symptom.” She added, “A primary issue raised from our analysis is the need to identify the clinically important change score on scales used to measure HD chorea. An evidence–based understanding of this could help us better interpret study results – for example, whether the improvements seen in the studies were meaningful to patients – and inform treatment decisions.”
Moreover, the research on the benefit of chorea treatment is conflicting. “Some studies of therapies for HD chorea show that improvements in chorea decrease disability or improve quality of life whereas other studies show no association between chorea and functional decline,” Armstrong said. “In addition, patient preferences for chorea therapy are unstudied, highlighting the importance of individualized decisions.”
Source: American Academy of Neurology