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

Broadbent, Hannah; Eynde, Fréderique Van den; Guillaume, Sébastien; Hanif, Emma L; Ståhl, Daniel; David, Anthony S.; Campbell, Iain C.; Schmidt, Ulrike

doi:10.3109/15622975.2010.541281

Cited by 55 publications

(39 citation statements)

References 38 publications

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“…When subanalyses results are interpreted, the lack of statistical powering and the potential for type 1 and type 2 errors (in the eCH and cCH cohorts, respectively) should be considered. The difference in AE descriptions provided by subjects treated with the nVNS (eg, drooping/pulling of the lip/face) and sham (eg, burning, soreness, stinging) devices may help to explain results of the blinding analyses, which are similar to those observed in previous sham‐controlled trials 23, 24. The burning sensation and other pain‐related AEs reported by the sham‐treated group in ACT1 may have led to a placebo effect based on impressions that the subjects were receiving active treatment.…”

Section: Discussionmentioning

confidence: 60%

Non–Invasive Vagus Nerve Stimulation for the ACute Treatment of Cluster Headache: Findings From the Randomized, Double‐Blind, Sham‐Controlled ACT1 Study

et al. 2016

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ObjectiveTo evaluate non‐invasive vagus nerve stimulation (nVNS) as an acute cluster headache (CH) treatment.BackgroundMany patients with CH experience excruciating attacks at a frequency that is not sufficiently addressed by current symptomatic treatments.MethodsOne hundred fifty subjects were enrolled and randomized (1:1) to receive nVNS or sham treatment for ≤1 month during a double‐blind phase; completers could enter a 3‐month nVNS open‐label phase. The primary end point was response rate, defined as the proportion of subjects who achieved pain relief (pain intensity of 0 or 1) at 15 minutes after treatment initiation for the first CH attack without rescue medication use through 60 minutes. Secondary end points included the sustained response rate (15‐60 minutes). Subanalyses of episodic cluster headache (eCH) and chronic cluster headache (cCH) cohorts were prespecified.ResultsThe intent‐to‐treat population comprised 133 subjects: 60 nVNS‐treated (eCH, n = 38; cCH, n = 22) and 73 sham‐treated (eCH, n = 47; cCH, n = 26). A response was achieved in 26.7% of nVNS‐treated subjects and 15.1% of sham‐treated subjects (P = .1). Response rates were significantly higher with nVNS than with sham for the eCH cohort (nVNS, 34.2%; sham, 10.6%; P = .008) but not the cCH cohort (nVNS, 13.6%; sham, 23.1%; P = .48). Sustained response rates were significantly higher with nVNS for the eCH cohort (P = .008) and total population (P = .04). Adverse device effects (ADEs) were reported by 35/150 (nVNS, 11; sham, 24) subjects in the double‐blind phase and 18/128 subjects in the open‐label phase. No serious ADEs occurred.ConclusionsIn one of the largest randomized sham‐controlled studies for acute CH treatment, the response rate was not significantly different (vs sham) for the total population; nVNS provided significant, clinically meaningful, rapid, and sustained benefits for eCH but not for cCH, which affected results in the total population. This safe and well‐tolerated treatment represents a novel and promising option for eCH. ClinicalTrials.gov identifier: NCT01792817.

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Section: Discussionmentioning

confidence: 60%

Non–Invasive Vagus Nerve Stimulation for the ACute Treatment of Cluster Headache: Findings From the Randomized, Double‐Blind, Sham‐Controlled ACT1 Study

et al. 2016

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“…Reviews of the therapeutic uses of rTMS have emphasised the crucial importance of a placebo condition even in small, proof-of-principle studies 13. There exists considerable debate as to what constitutes an appropriate placebo condition in TMS studies, with many of the proposed methods (eg, a sham coil that makes a similar sound to the real coil but emits no magnetic pulse; a real coil held at a 45° angle from the skull) offering inadequate blinding such that the participant is able to guess which trial arm he or she was in, if asked 29. This situation is made more problematic still in many of the current studies, as, in contrast to typical rTMS protocols, many studies used suprathreshold stimulation intensities which cause a muscle twitch with each pulse.…”

Section: Discussionmentioning

confidence: 99%

A systematic review of transcranial magnetic stimulation in the treatment of functional (conversion) neurological symptoms

Pollak

Nicholson

Edwards

et al. 2013

Journal of Neurology, Neurosurgery & Psychiatry

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Functional (conversion) neurological symptoms (FNS) are commonly encountered in neurological and psychiatric clinical settings and represent a considerable burden on healthcare systems. There is a conspicuous paucity of evidence-based treatments for FNS. Transcranial magnetic stimulation (TMS) offers a safe, non-invasive method of probing changes in cortical excitability and/or connectivity. It has already had some success in demonstrating abnormalities of cortical excitability in patients with FNS, particularly when the functional symptom in question relates to movement. We reviewed the literature for studies in which TMS has been used in the treatment of FNS. All patients in the identified studies had motor symptoms (either weakness or movement disorder). There was considerable heterogeneity in terms of study quality, population sampled, study design, TMS parameters and outcome measures. No studies were placebo controlled. Despite the majority of studies claiming success for the technique, there is insufficient good quality evidence to establish TMS as an effective treatment modality for FNS. We outline the methodological considerations that should be taken into account in future studies of the efficacy of TMS in treating FNS and discuss mechanisms by which TMS, if efficacious, may exert a therapeutic effect, including: (a) via genuine neuromodulation, (b) via non-specific placebo effects and (c) by demonstrating, through its immediate effects on the motor system (eg, movement in a 'paretic' limb), that symptom improvement is possible, thus directly changing higher level beliefs that may be responsible for the maintenance of the disorder.

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“…In the comparison between active and sham conditions, a potential bias due to insuffi cient blinding has to be considered. Correct estimation of treatment condition was signifi cantly above chance level, indicating the urgent need for more sophisticated sham conditions (Rossi et al 2007;Mennemeier et al 2009) and for controlling blinding success in rTMS trials (Broadbent et al 2011).…”

Section: Patient Fl Ow and Rtms Side Effectsmentioning

confidence: 99%

Efficacy of different protocols of transcranial magnetic stimulation for the treatment of tinnitus: Pooled analysis of two randomized controlled studies

Langguth

Landgrebe

Frank

et al. 2012

The World Journal of Biological Psychiatry

106

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

Abstract: Few RCTs in rTMS report on blinding success. As current sham methods may inadequately mimic real rTMS, this could result in only partial success of blinding and bias estimations of treatment effects.

Cited by 55 publications

References 38 publications

Non–Invasive Vagus Nerve Stimulation for the ACute Treatment of Cluster Headache: Findings From the Randomized, Double‐Blind, Sham‐Controlled ACT1 Study

Non–Invasive Vagus Nerve Stimulation for the ACute Treatment of Cluster Headache: Findings From the Randomized, Double‐Blind, Sham‐Controlled ACT1 Study

A systematic review of transcranial magnetic stimulation in the treatment of functional (conversion) neurological symptoms

Efficacy of different protocols of transcranial magnetic stimulation for the treatment of tinnitus: Pooled analysis of two randomized controlled studies

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