Repetitive Transcranial Magnetic Stimulation Improved Symptoms of Obsessive-Compulsive Disorders but Not Executive Functions: Results from a Randomized Clinical Trial with Crossover Design and Sham Condition

Abstract

Objective: Whereas there is growing evidence that repetitive transcranial magnetic stimulation (rTMS) favorably impacts on symptoms of obsessive-compulsive disorders (OCD), less is known regarding the influence of rTMS on cognitive performance of patients with OCD. Here, we tested the hypothesis that rTMS has a positive impact both on symptom severity and executive functions in such patients. Methods: We assessed 10 patients diagnosed with OCD (mean age: 33.5 years) and treated with a standard medication; they were randomly assigned either to a treatment-first or to a sham-first condition. Symptom severity (experts' ratings) and executive functions (Wisconsin Card Sorting Test) were assessed by independent raters unaware of the patients' group assignments at baseline, after 2 and 4 weeks. After 2 weeks, treatment switched to sham condition, and sham condition switched to treatment condition. Results: Under treatment but not under sham conditions, symptom severity decreased. Performance on the executive function test increased continuously with every new assessment and was unrelated to rTMS treatment. Conclusion: Whereas the present study confirmed previous research suggesting that rTMS improved symptoms of OCD, rTMS did not improve executive functions to a greater degree than sham treatment. More research is needed to investigate the effect of rTMS on executive functions in patients with OCD.

Further Evidence of the Positive Influence of Repetitive Transcranial Magnetic Stimulation on Speech and Language in Patients with Aphasia after Stroke: Results from a Double-Blind Intervention with Sham Condition

“…Consequently, the present study is not fully comparable with study designs described elsewhere [9]. Sixth, as regards the sham condition, as in previous studies [13, 14, 29], we employed the technique of tilting the coil by 90°; in doing so, both the sound and the skin sensation were equivalent to genuine stimulation, but with no effect on the underlying cortex. However, Dollfus et al [30] suggested employing a sham coil, which may be a more reliable method for a placebo procedure.…”

“…Ideally, future studies should follow up their patients after 3–6 months. Fifth, although Thiel et al [9] proposed that the gold standard for stimulation should be at 90% of the resting motor threshold, we employed a 100% stimulation of the motor threshold, as employed in previous studies [13, 14, 29]. Consequently, the present study is not fully comparable with study designs described elsewhere [9].…”

A Pilot Study on Daily Intensive ECT over 8 Days Improved Positive and Negative Symptoms and General Psychopathology of Patients with Treatment-Resistant Schizophrenia up to 4 Weeks after Treatment

“…In this view, a sham condition would have allowed to balance the present results with results from a placebo condition. Sham conditions are successfully employed to investigate other neuromodulation interventions such as repetitive transcranial magnetic stimulation [35, 43, 44]. Second, relatedly, a further control condition could have been a standard ECT treatment with sessions every second day, as described in other studies [17-20].…”

TMS for OCD

“…After 2 weeks, patients switched conditions for an additional 2 weeks. In both groups, the patient's YBOCS improved after the active rTMS condition and not after the sham condition [23,24]. This was the second single blinded study this group did with the same crossover after 2 weeks [17,23].…”

“…In both groups, the patient's YBOCS improved after the active rTMS condition and not after the sham condition [23,24]. This was the second single blinded study this group did with the same crossover after 2 weeks [17,23]. Methodologically, they should do a double-blind non-crossover study, and at a significantly later date offer the sham patients active treatment.…”