***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Carefully design ed controlled studies are essential in further evaluating the therapeutic efficacy of transcranial magnetic stimulation ( TMS ) in psychiatric disorders . A major method ological concern is the design of the " sham " control for TMS . An ideal sham would produce negligible cortical stimulation in conjunction with a scalp sensation akin to real treatment . Strategies employed so far include alterations in the position of the stimulating coil , but there has been little systematic study of their validity . In this study , we investigated the effects of different coil positions on cortical activation and scalp sensation . METHODS In nine normal subjects , single TMS pulses were administered at a range of intensities with a " figure eight " coil held in various positions over the left primary motor cortex . Responses were measured as motor-evoked potentials in the right first dorsal interosseus muscle . Scalp sensation to TMS  with the coil in various positions over the prefrontal area was also assessed . RESULTS None of the coil positions studied met the criteria for an ideal sham . Arrangements associated with a higher likelihood of scalp sensation were also more likely to stimulate the cortex . CONCLUSIONS The choice of a sham for TMS involves a trade-off between effective blinding and truly inactive " stimulation . " Further research is needed to develop the best sham condition for a range of applications Although electrical stimulation of the pre central gyrus ( MCS ) is emerging as a promising technique for pain control , its mechanisms of action remain obscure , and its application largely empirical . Using positron emission tomography ( PET ) we studied regional changes in cerebral flood flow ( rCBF ) in 10 patients undergoing motor cortex stimulation for pain control , seven of whom also underwent somatosensory evoked potentials and nociceptive spinal reflex recordings .  The most significant MCS-related increase in rCBF concerned the ventral-lateral thalamus , probably reflecting cortico-thalamic connections from motor areas . CBF increases were also observed in medial thalamus , anterior cingulate/orbitofrontal cortex , anterior insula and upper brainstem ; conversely , no significant CBF changes appeared in motor areas beneath the stimulating electrode . Somatosensory evoked potentials from SI remained stable during MCS , and no rCBF changes were observed in somatosensory cortex during the procedure . Our results suggest that descending axons , rather than apical dendrites , are primarily activated by MCS , and highlight the thalamus as the key structure mediating functional MCS effects . A model of MCS action is proposed , whereby activation of thalamic nuclei directly connected with motor and premotor cortices would entail a cascade of synaptic events in pain-related structures receiving afferents from these nuclei , including the medial thalamus , anterior cingulate and upper brainstem . MCS could influence the affective-emotional component of chronic pain by way of cingulate/orbitofrontal activation , and lead to descending inhibition of pain impulses by activation of the brainstem , also suggested by attenuation of spinal flexion reflexes . In contrast , the hypothesis of somatosensory cortex activation by MCS could not be confirmed by our results OBJECTIVE There is growing interest in neuropsychiatry for repetitive transcranial magnetic stimulation ( rTMS ) as a neuromodulatory treatment . However , there are limitations in interpreting rTMS effects as a real consequence of physiological brain changes or as placebo-mediated unspecific effects , which may be particularly strong in psychiatric patients . This is due to the fact that existing sham rTMS procedures are less than optimal . A new placebo tool is introduced here , called real electro-magnetic placebo ( REMP ) device , which can simulate the scalp sensation induced by the real TMS , while leaving both the visual impact and acoustic sensation of real TMS unaltered . METHODS Physical , neurophysiological and behavioural variables of monophasic and biphasic single-pulse TMS and biphasic 1Hz and 20Hz rTMS procedures ( at different intensities ) were tested in subjects who were expert or naïve of TMS . Results of the real TMS were compared with those induced by the REMP device and with two other currently used sham procedures , namely the commercially available Magstim sham coil and tilting the real coil by 90 degrees . RESULTS The REMP device , besides producing scalp sensations similar to the real TMS , attenuated the TMS-induced electric field ( as measured by a dipole probe ) to a biologically inactive level . Behaviourally , neither expert nor naïve TMS subjects identified the " coil at 90 degrees " or the " Magstim sham coil " as a real TMS intervention , whilst naïve subjects were significantly more likely to identify the REMP-attenuated TMS as real . CONCLUSIONS The " goodness of sham " of the REMP device is demonstrated by physical , neurophysiological , and behavioural results . SIGNIFICANCE Such placebo TMS is superior to the available sham procedures when applied on subjects naïve to TMS , as in case of patients undergoing a clinical rTMS trial Background Many double-blind clinical trials of transcranial direct current stimulation ( tDCS ) use stimulus intensities of 2 mA despite the fact that blinding has not been formally vali date d under these conditions . The aim of this study was to test the assumption that sham 2 mA tDCS achieves effective blinding . Methods A r and omised double blind crossover trial . 100 tDCS-naïve healthy volunteers were incorrectly advised that they there were taking part in a trial of tDCS  on word memory . Participants attended for two separate sessions . In each session , they completed a word memory task , then received active or sham tDCS ( order r and omised ) at 2 mA stimulation intensity for 20 minutes and then repeated the word memory task . They then judged whether they believed they had received active stimulation and rated their confidence in that judgement . The blinded assessor noted when red marks were observed at the electrode sites post-stimulation . Results tDCS at 2 mA was not effectively blinded . That is , participants correctly judged the stimulation condition greater than would be expected to by chance at both the first session ( kappa level of agreement ( κ ) 0.28 , 95 % confidence interval ( CI ) 0.09 to 0.47 p = 0.005 ) and the second session ( κ = 0.77 , 95%CI 0.64 to 0.90 ) , p = < 0.001 ) indicating inadequate participant blinding . Redness at the reference electrode site was noticeable following active stimulation more than sham stimulation ( session one , κ = 0.512 , 95%CI 0.363 to 0.66 , p<0.001 ; session two , κ = 0.677 , 95%CI 0.534 to 0.82 ) indicating inadequate assessor blinding . Conclusions Our results suggest that blinding in studies using tDCS at intensities of 2 mA is inadequate . Positive results from such studies should be interpreted with caution OBJECTIVE Brain polarization in the form of transcranial direct current stimulation ( tDCS ) , which influences motor function and learning processes , has been proposed as an adjuvant strategy to enhance training effects in Neurorehabilitation . Proper testing in Neurorehabilitation requires double-blind sham-controlled study design s. Here , we evaluated the effects of tDCS and sham stimulation ( SHAM ) on healthy subjects and stroke patients ' self-report measures of attention , fatigue , duration of elicited sensations and discomfort . METHODS tDCS or SHAM was in all cases applied over the motor cortex . Attention , fatigue , and discomfort were self rated by study participants using visual analog scales . Duration of perceived sensations and the ability to distinguish tDCS from Sham sessions were determined . Investigators question ing the patients were blind to the intervention type . RESULTS tDCS and SHAM elicited comparably minimal discomfort and duration of sensations in the absence of differences in attention or fatigue , and could not be distinguished from SHAM by study participants nor investigators . CONCLUSIONS Successful blinding of subjects and investigators and ease of application simultaneously with training protocol s supports the feasibility of using tDCS in double-blind , sham-controlled r and omized trials in clinical Neurorehabilitation . SIGNIFICANCE tDCS could evolve into a useful tool , in addition to TMS , to modulate cortical activity in Neurorehabilitation 
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We did not find evidence that rTMS  improved disability .
We found no evidence relating to the effectiveness of CES on disability .
We found evidence of small study bias in the tDCS analyses .
We did not find evidence that tDCS improved disability .
We did not find evidence that low-frequency rTMS , rTMS applied to the dorsolateral prefrontal cortex and CES are effective for reducing pain intensity in chronic pain .