Deep Brain Stimulation Holds Promise for Tourette Syndrome Sufferers

A new study from University Hospitals Case Medical Center in Cleveland is finding that Deep Brain Stimulation (DBS) is helpful for people with Tourette Syndrome, reducing frequency and severity of tics.

Tourette Syndrome, an inherited neurological disorder, is characterized by the presence of multiple physical tics and at least one vocal tic. The uncontrollable exclamation of obscene words or socially inappropriate and derogatory remarks is actually present in a relatively small minority of those with TS, contrary to popular belief. (1) Although the exact cause of Tourette’s is unknown, it is established that both genetic and environmental factors are involved(2).

The researchers at Neurological Institute at University Hospitals Case Medical Center followed five adults with TS over the course of 12 months in a double-blind study. The 3-month data are published in the November 2007 issue of the Journal of Neurosurgery.

The team concluded that the majority of patients experienced a significant reduction in symptoms and an improved quality of life. The study followed their landmark case in 2004 when the UHCMC neurological team used DBS to treat a 31-year-old man with Tourette Syndrome. Once his deep brain stimulators were turned on he had an immediate and nearly complete resolution of his symptoms.(3)

Pacemaker for the Brain

DBS, which is approved by the Food and Drug Administration for treatment of Parkinson’s disease, essential tremor and dystonia(4), involves the surgical implantation of electrodes in the brain and pulse generators in the upper chest just beneath the collarbones.

The implanted pulse generator (IPG) is connected to the electrode in the brain by a thin cable that is placed under the skin. The IPG is then programmed to deliver a high-frequency electrical stimulation to the targeted area of the brain.

In this latest study, electrodes were placed in the thalamus, a portion of the brain that is involved in controlling movement. Prior to surgery the neurologic team at UHCMC mapped out regions of the patients brains using MRI scans and 3-D computer images. Their goal was to locate the safest and most direct route to reach the thalamus.

Following surgery the researchers conducted double-blind video-based rating assessments of tic frequency and severity. They found that three of five patients had a marked reduction in their motor and vocal tics and all but one patient had a significant improvement in quality of life.

“Deep Brain Stimulation has been used to successfully treat certain movement disorders for years”, says David Riley, MD, Director of the UH Movement Disorders Center and Professor of Neurology at Case Western Reserve University. “We carefully studied its use in these five patients suffering from refractory Tourette Syndrome and found that it significantly reduced the tics in most of the patients and improved their quality of life.”

“The use of DBS for Tourette syndrome is still an emerging area of study but in this first of its kind clinical trial, our team found that DBS has good potential to be a viable treatment for people with this potentially debilitating syndrome,” says Christina Whitney, DNSc, RN, clinical nurse specialist in the movement disorders center. “The treatment was found to be safe and we plan to conduct a larger clinical trial to further determine its efficacy in helping patients who have failed traditional medical therapy for Tourette syndrome”.

Drawbacks of DBS

On the negative side, there is the potential with Deep Brain Stimulation surgery for neuropsychiatric side effects. Reports existing in medical literature express the possibility of apathy, hallucinations, compulsive gambling, hypersexuality, cognitive dysfunction, and depression as side effects(5). These may be temporary and related to errors in placement and calibration of the stimulator and thus potentially are reversible.

Other potential complications of surgery include bleeding within the brain and swelling of the brain tissue. Deep brain stimulation surgery is a relatively new procedure, having been approved by the FDA as a treatment for essential tremor in 1997, for Parkinson’s disease in 2002, and dystonia in 2003.

References

1. Schapiro NA. “Dude, you don’t have Tourette’s:” Tourette’s syndrome, beyond the tics. Pediatr Nurs. 2002 MayJun;28(3):2436, 24953. Full text

2. Walkup JT, Mink JW, Hollenback PJ, (eds). Advances in Neurology, Vol. 99, Tourette Syndrome. Lippincott, Williams & Wilkins, Philadelphia, PA, 2006, p. xv. ISBN 0-7817-9970-8

3. UHCMC Press Release April 1, 2004 Neurological Team at University Hospitals Case Medical Center Finds that New Treatment Holds Promise for Patients with Tourette Syndrome

4. Kringelbach M.L., Jenkinson N., Owen S.L.F. & Aziz T.Z. (2007) Translational principles of deep brain stimulation. Nature Reviews Neuroscience. 8:623-635. PMID 17637800.

5. Burn D, Troster A (2004). “Neuropsychiatric Complications of Medical and Surgical Therapies for Parkinson’s Disease.”. Journal of Geriatric Psychiatry and Neurology 17 (3): 172-180. PMID 15312281.

Image: yumikrum/Flickr