Repetitive transcranial magnetic stimulation for tic disorders

rTMS for tics: Mixed evidence

We reviewed the results of 11 studies that described the use of rTMS for TS and other tic disorders (Table 1^{1,24-26,28,29} and Table 2^{3,8,23,27,30,31}). They included:

• 2 double-blind, randomized controlled trials^28,29
• 2 single-blind trials^24-26
• 1 double-blind trial with an open-label extension¹
• 4 open-label studies^3,8,23,30
• 1 case series²⁷ and 1 case report.³¹

Study characteristics. In the 11 studies we reviewed, the duration of rTMS treatment varied from 2 days to 4 weeks. The pulses used were 900, 1,200, 1,800, and 2,400 per day, and the frequencies were 1 Hz, 4 Hz, 15 Hz and 30 Hz. Seven studies did not use placebo- or sham-controlled arms.^{1,3,8,23,27,30,31}Although several different scales were used to measure outcomes, many of the studies employed the Yale Global Tic Severity Scale (YGTSS), and effectiveness of rTMS was defined as a significant reduction in the YGTSS score.

Efficacy. Two double-blind trials^28,29 found no significant improvement in tic severity in patients treated with rTMS (P = .066 and P = .43, respectively). In addition, the 2 single-blind studies showed no beneficial effects of rTMS for patients with tics (P > .05).^24-26 However, 3 of the 4 open-label studies found a significant improvement in tics.^3,23,30 In one of the double-blind trials, researchers added an open-label extension phase.¹ They found no significant results in the double-blind phase of the study (P = .27), but in the open-label phase, patients experienced a significant improvement in tic severity (P = .04).¹ Lastly, the case series and case report found an improvement in tic severity and improvement in TS symptoms, respectively, with rTMS treatment.

rTMS might also improve symptoms of OCD that may co-occur with TS.^8,23,28 Two studies found significant improvement in tic severity in a subgroup of patients suffering from comorbid OCD.^8,28

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