Effects of Transcranial Direct Current Stimulation, Transcranial Pulsed Current Stimulation, and Their Combination on Brain Oscillations in Patients with Chronic Visceral Pain: A Pilot Crossover Randomized Controlled Study

Abstract

ObjectiveChronic visceral pain (CVP) syndromes are persistently painful disorders with a remarkable lack of effective treatment options. This study aimed at evaluating the effects of different neuromodulation techniques in patients with CVP on cortical activity, through electreocephalography (EEG) and on pain perception, through clinical tests.DesignA pilot crossover randomized controlled study.SettingsOut-patient.SubjectsAdults with CVP (>3 months).MethodsParticipants received four interventions in a randomized order: (1) transcranial pulsed current stimulation (tPCS) and active transcranial direct current stimulation (tDCS) combined, (2) tPCS alone, (3) tDCS alone, and (4) sham condition. Resting state quantitative electroencephalography (qEEG) and pain assessments were performed before and after each intervention. Results were compared with a cohort of 47 healthy controls.ResultsWe enrolled six patients with CVP for a total of 21 visits completed. Compared with healthy participants, patients with CVP showed altered cortical activity characterized by increased power in theta, alpha and beta bands, and a significant reduction in the alpha/beta ratio. Regarding tES, the combination of tDCS with tPCS had no effect on power in any of the bandwidths, nor brain regions. Comparing tPCS with tDCS alone, we found that tPCS induced higher increase in power within the theta and alpha bandwidths.ConclusionThis study confirms that patients with CVP present abnormal EEG-indexed cortical activity compared with healthy controls. Moreover, we showed that combining two types of neurostimulation techniques had no effect, whereas the two interventions, when applied individually, have different neural signatures.

Transcranial electrical and magnetic stimulation (tES and TMS) for addiction medicine: A consensus paper on the present state of the science and the road ahead

“…Reproducibility of the results is paramount and there must be a clear description of the protocol used for the interventions (Brunoni et al, 2012). Montages with anode and cathode positions (including number of respective electrodes) (Nasseri et al, 2015), how this montage was determined (measurements, neuro-navigation), size and shape of electrodes (rectangular, circular or EEG type), current intensity, duration, number of sessions and interval between sessions (Thibaut et al, 2017) are extremely important parameters that need to be made explicit (Pinto et al, 2018). For tACS, a particularly vexing problem for the field has been the confusion between peak-to-peak and true (baseline-topeak) amplitude.…”

Network Mapping of Connectivity Alterations in Disorder of Consciousness: Towards Targeted Neuromodulation

“…Such heterogeneity may be explained by single site stimulation and therefore an inability to produce a meaningful whole brain effect. Following this rationale, in a recent study [43], the fronto-parietal network was stimulated using tDCS. However, results showed that only 30% of MCS patients positively responded to stimulation.…”

“…However, results showed that only 30% of MCS patients positively responded to stimulation. Crucially, in this study the stimulation targets were not chosen based on functional connectivity maps [43].…”

“…This approach is applicable to all tES modalities (e.g. tACS, tDCS, tRNS) and had already been implemented successfully in healthy subjects [38][39][40] and patients [41][42][43].…”

The effect of combined transcranial pulsed current stimulation and transcutaneous electrical nerve stimulation on lower limb spasticity in children with spastic cerebral palsy classified on Gross Motor Function Classification System (GMFCS) levels III–V: a randomized and controlled clinical study

“…However, these samples did not include severe SCP children of GMFCS levels III-V. To our knowledge, there is only one NIBS study involving children with spastic quadriplegia [15] in which high frequency (5 Hz) repetitive transcranial magnetic stimulation (rTMS) was used to treat upper limb spasticity; however, measured outcomes using Ashworth scale tests failed to reach significance. Moreover, there are no studies that have investigated the effects of NIBS on lower limb spasticity in children with SCP in GMFCS levels III-V. Transcranial pulsed current stimulation (tPCS) is a novel type of NIBS that has recently gained increasing attention in experimental settings [16][17][18][19][20][21][22][23][24][25][26], delivering pulsed currents at a predetermined frequency to the cortex, as opposed to the direct current provided by tDCS. While there are yet no studies done involving tPCS and children with SCP, the safety of tPCS had been investigated in the treatment of Parkinson's disease, with no adverse events recorded, and post-treatment results showed significant improvement in gait and balance [27].…”