Sham or real—Post hoc estimation of stimulation condition in a randomized transcranial magnetic stimulation trial

Abstract

Selecting a suitable sham condition within the frame of repetitive transcranial magnetic stimulation (rTMS) treatment trials is a central issue. On the one hand, the ideal sham condition should not have a real stimulation effect; on the other hand, it should not be recognized as sham by patients, particularly when considering that real stimulation conditions come along with rTMS specific side effects. Within the course of a multi-centre trial assessing the antidepressant effects of rTMS, patients were randomized to sham or real stimulation, in both cases using a standard stimulation coil. In one centre, patients (n = 33) were asked about their impression whether they received the sham or the real treatment, and if they would recommend the treatment to others. 29 patients returned the questionnaires and were included into the analysis. From 15 subjects with real stimulation, 11 suggested to have obtained real, and 4 to have obtained sham. From 14 sham stimulated subjects, 9 suggested to have obtained the real condition and 5 to have been sham stimulated. This difference was not significant (p = 0.60, chi square test). In addition, the major part of patients in both stimulation conditions would recommend rTMS to others. In both conditions, real and sham, the majority of subjects believed to have obtained the real condition. This implies suitability of the sham condition used since subjects appeared not to be able to identify the condition. The results imply the feasibility of a valid sham condition with a "real" coil. stimulated. This difference was not significant (p=0.60, chi square test). In addition, the major part of patients in both stimulation conditions would recommend rTMS to others. In both conditions, real and sham, the majority of subjects believed to have obtained the real condition. This implies suitability of the sham condition used since subjects appeared not to be able to identify the condition. The results imply the feasibility of a valid sham condition with a "real" coil.

Can Intermittent Theta Burst Stimulation as Add-On to Psychotherapy Improve Nicotine Abstinence? Results from a Pilot Study

“…However, posttreatment interrogation of assumed group assignment indicated actual blindness. Consistently, Herwig et al [43] showed that TMS novices could not distinguish rTMS treatment from sham rTMS. Fourth, dropouts were increasing over time and differed between the groups at 12 months, which should be interpreted cautiously; labeling dropouts as relapsing participants may not reflect reality and bias the results (however, see footnote 2).…”

Blinding success of rTMS applied to the dorsolateral prefrontal cortex in randomised sham-controlled trials: A systematic review

“…Nine of the 13 studies reported raw data on blinding success (Fitzgerald et al 2003(Fitzgerald et al , 2006Nahas et al 2003;Loo et al 2007;Jorge et al 2008;Mogg et al 2008;Kang et al 2009;Herwig et al 2010; Van den Eynde et al 2010). These data were analyzed to determine whether there was a difference between World J Biol Psychiatry Downloaded from informahealthcare.com by University of Sydney on 01/02/15…”

“…The studies were separated into two groups, depending on the given number of choices in the assessment of blinding: studies where participants were given two choices ( " real " or " sham " ) (Fitzgerald et al 2003(Fitzgerald et al , 2006Nahas et al 2003;Jorge et al 2008;Mogg et al 2008;Herwig et al 2010;Van den Eynde et al 2010) and those with three choices ( " real " , " sham " or " unsure " ) Kang et al 2009). the suggestion that guidelines on reporting of blinding procedures and success are needed (Hrobjartsson et al 2009).…”

Effects of Repetitive Transcranial Magnetic Stimulation on Dystonia: An Overview

“…In line with that, Herwig et al (2010) investigating the antidepressant effects of rTMS, asked for patients to give their impression whether they received the sham or the real treatment and if they would recommend the treatment to others. From 15 patients with real stimulation, 11 suggested that they obtained true stimulation and 4 to have obtained sham.…”

“…In fact, there is now a growing interest in the research of new treatment for neurological and psychiatric disorders, however, the main focus of the possible therapeutic effects of rTMS is still in the domain of depression (Hoppner et al, 2010, Schonfeldt-Lecuona et al, 2010. Within this context, this review paper aims to provide information on the current research and main findings related to the potential therapeutic effects of rTMS on dystonia.…”