Volume 24 Issue 1, Pages 15-24 (January 15, 2009)
Published Online: November 17, 2008
Authors: David Shprecher, DO, Roger Kurlan, MD
Read Abstract | Listen to Podcast Review
A tic is a stereotyped repetitive involuntary movement or sound, frequently preceded by premonitory sensations or urges. Most tic disorders are genetic or idiopathic in nature, possibly due to a developmental failure of inhibitory function within frontal-subcortical circuits modulating volitional movements. Currently available oral medications can reduce the severity of tics, but rarely eliminate them. Botulinum toxin injections can be effective if there are a few particularly disabling motor tics. Deep brain stimulation has been reported to be an effective treatment for the most severe cases, but remains unproven. A comprehensive evaluation accounting for secondary causes, psychosocial factors, and comorbid neuropsychiatric conditions is essential to successful treatment of tic disorders.
© 2008 Movement Disorder Society
Podcast review by Dr. Joseph Jankovic, MD, Professor of Neurology, and Director of the Parkinson Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, Texas
In their review article, Drs. Shprecher and Kurlan correctly point out that before instituting any symptomatic therapy, potentially "curable" causes of tics should be excluded. Although these are rare, we have, for example, encountered patients with adult-onset tics caused or triggered by the use of dopamine receptor blocking drugs (neuroleptics), cocaine and other drugs.
Another question that must be addressed at the beginning is whether the tics are troublesome enough to require symptomatic therapy. I agree with the authors that behavioral approaches, such as habit reversal therapy (HRT), are rarely effective, partly because they require full cooperation of the children and their parents as well as quite demanding compliance with the training. Although not very useful or practical, some parents, however, are so reluctant to initiate pharmacological therapy that HRT may be considered, particularly if the tics are relatively mild, localized, or self-injurious.
While a majority of patients with tics probably do not require any form of therapy, except for some counseling about the role of psychosocial stressors, those who are referred to our Tourette clinic are usually so troubled by their motor of phonic tics that some form of pharmacological or even surgical intervention is warranted. Although the authors suggest starting with guanfacine or clonidine as the initial drugs for the treatment of tics, I do not find these alpha agonists particularly useful for the treatment of tics, but tend to use them, particularly guanfacine, for impulse control disorder, a common comorbidity in patients with Tourette syndrome (TS).
Most patients with troublesome tics require treatment with antidopaminergic drugs. Although haloperidol and pimozide are the only two drugs FDA-approved for TS I rarely used them and, instead prefer, fluphenazine or tetrabenazine. While the risk of tardive dyskinesia from fluphenazine should not be underestimated and must be pointed out to the patients, in my experience of treating well over thousand patients with the drug over the past 30 years, I have never encountered it as an adverse effect. Tetrabenazine, a monoamine depleter recently approved by the FDA for the treatment of chorea associated with Huntington's disease, has never been reported to cause tardive dyskinesia. In a longitudinal study of 77 patients with TS treated with tetrabenazine for an average of 2 years, the drug was associated with moderate to marked improvement in TS-related symptoms and functional improvement in 83.1% of patients. About a third of the patients experienced drowsiness, but all side effects resolved with reduction in dosage.
The so-called atypical neuroleptics, in our experience, are poorly tolerated and rarely result in meaningful symptomatic improvement. We have recently shown in a double-blind, controlled trial that topiramate has a significant anti-tic effect and the adverse effect profile was similar to that of placebo.
I find botulinum toxin injections particularly effective for the treatment of focal clonic tics, such as frequent blinking, or dystonic tics, such as the "whiplash" cervical tics which, if left untreated, can cause secondary cervical spine complications including compressive myelopathy. The occurrence of severe, potentially life-threatening tics, warrants the consideration of deep brain stimulation. In our center, we have targeted the globus pallidus and achieved remarkable improvement in patients with the so-called "malignant" TS. With better understanding of the genetics and pathophysiology of this complex neurobehavioral disorder it is possible that pathogenesis-targeted therapies will be developed in the future.
About Dr. Joseph Jankovic, MD
Dr. Jankovic is Professor of Neurology, and Director, Parkinson Disease Center and Movement Disorders Clinic, and holds the Distinguished Chair in Movement Disorders, Department of Neurology, Baylor College of Medicine, Houston, Texas. Past president of The Movement Disorder Society and a recipient of the 2007 American Academy of Neurology Movement Disorders Research Award and the 2008 Guthrie Family Humanitarian Award, Dr. Jankovic has been elected an Honorary Member of the American Neurological Association, the French Neurological Society and other prestigious organizations. Listed in ISIHighlyCited.com, Dr. Jankovic has authored over 750 articles and chapters, and has edited or co-edited 35 books, including several standard textbooks such as "Neurology in Clinical Practice," "Parkinson's Disease and Movement Disorders," and "Principles and Practice of Movement Disorders." Dr. Jankovic has trained numerous fellows, many of whom have become internationally recognized leaders in the field of Movement Disorders. His seminal research in botulinum toxin and tetrabenazine paved the way for the approval of these drugs by the Food and Drug Administration. (www.jankovic.org)