***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: Transcranial direct current stimulation ( tDCS ) of the human motor cortex results in polarity-specific shifts of cortical excitability during and after stimulation . Anodal tDCS enhances and cathodal stimulation reduces excitability . Animal experiments have demonstrated that the effect of anodal tDCS is caused by neuronal depolarisation , while cathodal tDCS hyperpolarises cortical neurones . However , not much is known about the ion channels and receptors involved in these effects . Thus , the impact of the sodium channel blocker carbamazepine , the calcium channel blocker flunarizine and the NMDA receptor antagonist dextromethorphane on tDCS-elicited motor cortical excitability changes of healthy human subjects were tested . tDCS- protocol s inducing excitability alterations ( 1 ) only during tDCS and ( 2 ) eliciting long-lasting after-effects were applied after drug administration . Carbamazepine selectively eliminated the excitability enhancement induced by anodal stimulation during and after tDCS . Flunarizine result ed in similar changes . Antagonising NMDA receptors did not alter current-generated excitability changes during a short stimulation , which elicits no after-effects , but prevented the induction of long-lasting after-effects independent of their direction . These results suggest that , like in other animals , cortical excitability shifts induced during tDCS in humans also depend on membrane polarisation , thus modulating the conductance of sodium and calcium channels . Moreover , they suggest that the after-effects may be NMDA receptor dependent . Since NMDA receptors are involved in neuroplastic changes , the results suggest a possible application of tDCS in the modulation or induction of these processes in a clinical setting . The selective elimination of tDCS-driven excitability enhancements by carbamazepine proposes a role for this drug in focussing the effects of cathodal tDCS , which may have important future clinical applications 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 OBJECTIVE Several studies have shown that repetitive transcranial magnetic stimulation ( rTMS ) over the dorsolateral prefrontal cortex ( DLPFC ) is effective in the treatment of depression in patients with Parkinson disease ( PD ) . However , since research into the effect of this type of rTMS regime on motor function is limited , we studied the effect of rTMS over the DLPFC on the motor functions in PD patients . METHODS Thirteen patients were r and omly assigned into 2 groups , one receiving real-rTMS ( 90 % of resting motor threshold , 10 Hz , 450 pulses-day for 10 consecutive days ) over the DLPFC contralateral to the more affected side , and the other group receiving sham-rTMS . Assessment included a clinical motor evaluation using part III of the Unified Parkinson 's Disease Rating Scale ( UPDRS ) , and several motor tasks . The UPDRS was applied before and after 10 days of rTMS . Finger tapping , reach movement , grip movement and gait were measured in each session before and after the rTMS over the 10 day period . RESULTS Statistical analysis ( ANOVA for repeated measures ; group * day * side * rTMS ) only showed a significant effect for finger tapping , reach movement and gait for the factor day . No significant change was reported for the UPDRS in any group . CONCLUSIONS Application of rTMS over the DLPFC as a 10 day course had no significant effect on motor functions and clinical motor status , and the improvement in performance of motor tasks can be attributed to the effects of practice . SIGNIFICANCE rTMS over the DLPFC did not lead to any motor improvement in PD patients OBJECTIVE To investigate the dopamine-dependent effect of combining transcranial direct current stimulation ( tDCS ) with visually cued gait training on cortical excitability and functional mobility in individuals with Parkinson 's disease . DESIGN A pilot , r and omized , double-blind , controlled trial . METHODS Twenty-two patients with Parkinson 's disease were r and omly assigned to 2 groups : ( i ) active anodal tDCS over the supplementary motor area ( experimental group ) , or ( ii ) sham tDCS ( control group ) . After tDCS , both groups participated in a visually cued gait training .  Functional mobility was evaluated with the Timed Up and Go test ( TUG ) . Cortical excitability was assessed by active motor threshold and motor-evoked potential amplitudes elicited by transcranial magnetic stimulation in patients in on and off medication states . RESULTS In the TUG test both groups achieved improvements either in on or off medication condition compared with baseline . However , for both medication conditions , these gains were maintained only in the experimental group during 1-month follow-up , compared with baseline . In the experimental group , enhancement of cortical excitability was observed at post-intervention and 1-month follow-up ( both only for the " on " phase ) compared with baseline . CONCLUSION These findings suggest that tDCS , independent of dopaminergic medication state , might prolong the positive effect induced by cued gait training on functional mobility PURPOSE The aim of this study was to investigate the site-specific effects of repetitive transcranial magnetic stimulation ( rTMS ) on freezing of gait ( FOG ) in patients with parkinsonism . METHODS Twenty patients with parkinsonism and FOG were included . A single session of 10 Hz rTMS was applied over three different cortical regions of the dominant hemisphere : the primary motor cortex of the lower leg ( M1-LL ) , the supplementary motor area ( SMA ) , and the dorsolateral prefrontal cortex ( DLPFC ) . We also performed sham stimulation as a control . The Timed Up and Go ( TUG ) test , Turn Steps and Turn Time in 180 ° turning , Unified Parkinson 's Disease Rating Scale ( UPDRS ) part III , FOG Question naire ( FOG-Q ) , and motor evoked potential ( MEP ) studies were performed before and after each intervention . RESULTS There were significant improvements in TUG test times after rTMS over the M1-LL and the DLPFC . Improvement was significantly greater after the M1-LL stimulation than sham condition . The M1-LL and DLPFC stimulation also result ed in significant improvements in both the number of Turn Steps and Turn Time . UPDRS-III scores were significantly decreased after the M1-LL and DLPFC stimulation . CONCLUSIONS Use of 10 Hz rTMS on the M1-LL and DLPFC is therapeutically effective for FOG in patients with parkinsonism Objective : To investigate the safety and efficacy of intermittent theta-burst stimulation ( iTBS ) in the treatment of motor symptoms in Parkinson disease ( PD ) .  Background : Progression of PD is characterized by the emergence of motor deficits , which eventually respond less to dopaminergic therapy and pose a therapeutic challenge . Repetitive transcranial magnetic stimulation ( rTMS ) has shown promising results in improving gait , a major cause of disability , and may provide a therapeutic alternative . iTBS is a novel type of rTMS that may be more efficacious than conventional rTMS . Methods : In this r and omized , double-blind , sham-controlled study , we investigated safety and efficacy of iTBS of the motor and dorsolateral prefrontal cortices in 8 sessions over 2 weeks ( evidence Class I ) . Assessment of safety and clinical efficacy over a 1-month period included timed tests of gait and bradykinesia , Unified Parkinson 's Disease Rating Scale ( UPDRS ) , and additional clinical , neuropsychological , and neurophysiologic measures . Results : We investigated 26 patients with mild to moderate PD : 13 received iTBS and 13 sham stimulation . We found beneficial effects of iTBS on mood , but no improvement of gait , bradykinesia , UPDRS , and other measures . EEG/EMG monitoring recorded no pathologic increase of cortical excitability or epileptic activity . Few reported discomfort or pain and one experienced tinnitus during real stimulation . Conclusion : iTBS of the motor and prefrontal cortices appears safe and improves mood , but failed to improve motor performance and functional status in PD . Classification of evidence : This study provides Class I evidence that iTBS was not effective for gait , upper extremity bradykinesia , or other motor symptoms in PD Background Depression is one of the most common psychiatric illnesses worldwide , but is nevertheless preventable . Since the children of parents who have depression are at greatest risk of developing depression themselves , prevention programmes for this population are a major public health priority . Here we report the study protocol of a r and omised controlled trial of a group-based psychological intervention for families with i ) at least one parent who suffers ( or has suffered ) from depression and ii ) at least one child who has no current or previous psychiatric diagnosis . Methods / Design Eligible families will be r and omly allocated to receive either a German adaptation of the 12-session cognitive-behavioural Raising Healthy Children intervention ( Gesund und glücklich aufwachsen ; N = 50 ) , or no intervention ( usual care ; N = 50 ) . The primary outcome ( child diagnosis of an episode of depression ) will be assessed at 15-month follow-up . The secondary outcomes ( child psychopathological symptoms ) will be assessed immediately following completion of the intervention ( 6-months ) , as well as at 9- and 15-month follow-up . We hypothesise that children in the intervention condition , compared with those who do not receive the intervention , will show fewer symptoms of psychopathology , and be less likely to meet diagnostic criteria for a depressive episode , at follow-up . Discussion Despite their elevated risk of developing depression , there is little formal support available for the children of parents with depression . This study provides an important step in the development of more effective depression prevention measures , which are needed if the personal , social and economic burden of depression is to be reduced . Trial registration Clinical Trials NCT02115880 . Registered April 7 2014 Weak transcranial direct current stimulation ( tDCS ) induces persisting excitability changes in the human motor cortex . These plastic excitability changes are selectively controlled by the polarity , duration and current strength of stimulation . To reveal the underlying mechanisms of direct current (DC)-induced neuroplasticity , we combined tDCS of the motor cortex with the application of Na(+)-channel-blocking carbamazepine ( CBZ ) and the N-methyl-D-aspartate (NMDA)-receptor antagonist dextromethorphan ( DMO ) . Monitored by transcranial magnetic stimulation ( TMS ) , motor cortical excitability changes of up to 40 % were achieved in the drug-free condition . Increase of cortical excitability could be selected by anodal stimulation , and decrease by cathodal stimulation . Both types of excitability change lasted several minutes after cessation of current stimulation . DMO suppressed the post-stimulation effects of both anodal and cathodal DC stimulation , strongly suggesting the involvement of NMDA receptors in both types of DC-induced neuroplasticity . In contrast , CBZ selectively eliminated anodal effects . Since CBZ stabilizes the membrane potential voltage-dependently , the results reveal that after-effects of anodal tDCS require a depolarization of membrane potentials . Similar to the induction of established types of short- or long-term neuroplasticity , a combination of glutamatergic and membrane mechanisms is necessary to induce the after-effects of tDCS . On the basis of these results , we suggest that polarity-driven alterations of resting membrane potentials represent the crucial mechanisms of the DC-induced after-effects , leading to both an alteration of spontaneous discharge rates and to a change in NMDA-receptor activation Objective . To investigate the safety and efficacy of 50-Hz repetitive transcranial magnetic stimulation ( rTMS ) in the treatment of motor symptoms in  Parkinson disease ( PD ) . Background . Progression of PD is characterized by the emergence of motor deficits that gradually respond less to dopaminergic therapy . rTMS has shown promising results in improving gait , a major cause of disability , and may provide a therapeutic alternative . Prior controlled studies suggest that an increase in stimulation frequency might enhance therapeutic efficacy . Methods . In this r and omized , double blind , sham-controlled study , the authors investigated the safety and efficacy of 50-Hz rTMS of the motor cortices in 8 sessions over 2 weeks . Assessment of 
    Output:
    
Neither rTMS nor TES improved cognition .
No effects for stimulation parameters on motor or cognitive function were observed .