Helen Albert, Senior medwireNews Reporter (Dec. 18, 2012)-A month of daily transcranial magnetic stimulation targeting the supplemental motor area (SMA) results in lasting improvements in symptoms of Tourette syndrome, show study findings.
“Repetitive transcranial magnetic stimulation (rTMS)… involves repetitive generation of a brief, powerful magnetic field by a small coil positioned over the scalp that induces an electric current in the brain,” explain Nong Xiao (Chongqing Medical University, Yuzhong district, China) and colleagues.
The technique is designed as a noninvasive treatment for a range of neurological and psychiatric disorders including migraine, stroke, and Parkinson’s disease.
In this study, the researchers tested the capacity of low-frequency 1 Hz rTMS applied at 20 daily sessions (Monday-Friday) over 4 weeks for treatment of the motor and speech neurological tics displayed by patients with Tourette syndrome, on the basis that low-frequency rTMS (≤1 Hz) inhibits and high-frequency rTMS (>5 Hz) promotes cortical excitability.
In total, 25 children under 16 years took part in the study. After 4 weeks of treatment, the team observed no improvements in tic symptoms in six children, but significant improvements in these symptoms that lasted until 3 months in 19 children, and until 6 months in 17 children (68%).
On average, significant reductions were seen in the scores obtained on various tests by the children at 4 weeks compared with baseline. These included the Yale Global Tic Severity Scale; Clinical Global Impression Scale; Swanson, Nolan and Pelham Rating Scale, version IV for attention-defict hyperactivity disorder (SNAP-IV); Children’s Depression Inventory; Spence Children’s Anxiety Scale; and a novel Attention Test.
Overall scores for all these tests were lower at 6 months than at baseline, but only the SNAP-IV and Attention test scores were significantly lower at 6 months than at 4 weeks.
“Low-frequency (1 Hz) rTMS to the SMA significantly improved Tourette syndrome symptoms, suggesting that it is effective on tics, hyperactivity, attention deficit, depression and anxiety in children with Tourette syndrome,” write Xiao and co-workers in the Journal of Clinical Neuroscience.
“These collective results suggest the need for further studies using rTMS as a research and clinical therapeutic tool in psychiatric and neurological diseases, with particular attention to patients with Tourette syndrome.”