MARCEL SIMIS

(Fonte: Lattes)
Índice h a partir de 2011
14
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Medicina Física e de Reabilitação, Hospital das Clínicas, Faculdade de Medicina
LIM/40 - Laboratório de Imunohematologia e Hematologia Forense, Hospital das Clínicas, Faculdade de Medicina

Resultados de Busca

Agora exibindo 1 - 10 de 49
  • article 1 Citação(ões) na Scopus
    Effect of transcutaneous abdominal electrical stimulation in people with constipation due to spinal cord injuries: a pilot study
    (2022) SANTOS, Livia Tech dos; MATOS, Gabrielle Silveira Rocha; NOGUEIRA, Paula Cristina; SIMIS, Marcel
    Objective: To evaluate the effect of abdominal electrical stimulation (EE) on bowel movement frequency and feces consistency and expelled amount in people with constipation due to spinal cord injuries (SCI). Method: This is an experimental, crossover, randomized pilot study with two treatment groups: conventional intestinal rehabilitation and conventional rehabilitation associated with EE via 8- and 20-Hz Functional Electrical Stimulation (FES) of the abdominal muscles. Both groups were followed for two weeks with daily 30-minute EE sessions. Participants were hospitalized in a rehabilitation institute in the municipality of S??o Paulo. Data were analyzed using descriptive and inferential statistics. Results: This study included 10 people with SCI, of which most were male (70%), with a mean age of 39 years (SD = 16.37). EE, associated with conventional treatment, was more effective in increasing defecation frequency (p = 0.029) and amount of feces expelled (p = 0.031). Conclusion: Abdominal EE, associated with conventional treatment, helped to increase defecation frequency and amount of feces expelled in people with constipation due to SCI. This pilot study will serve as the basis for a future clinical trial with greater sampling and statistical evidence.
  • article 36 Citação(ões) na Scopus
    Motor cortex-induced plasticity by noninvasive brain stimulation: a comparison between transcranial direct current stimulation and transcranial magnetic stimulation
    (2013) SIMIS, Marcel; ADEYEMO, Bamidele O.; MEDEIROS, Liciane F.; MIRAVAL, Forella; GAGLIARDI, Rubens J.; FREGNI, Felipe
    The aim of this study was to test and compare the effects of a within-subject design of repetitive transcranial magnetic stimulation (rTMS) [coupled with sham transcranial direct current stimulation (tDCS)] and tDCS (coupled with sham rTMS) on the motor cortex excitability and also compare the results against sham tDCS/sham rTMS. We conducted a double-blinded, randomized, sham-controlled, cross-over trial. Eleven right-handed, healthy individuals (five women, mean age: 39.8 years, SD 13.4) received the three interventions (cross-over design) in a randomized order: (a) high-frequency (HF) rTMS (+sham tDCS), (b) anodal tDCS (+sham rTMS), and (c) sham stimulation (sham rTMS+sham tDCS). Cortical excitability measurements [motor threshold, motor evoked potential (MEP), intracortical facilitation and inhibition, and transcallosal inhibition] and motor behavioral assessments were used as outcome measures. Between-group analysis of variance showed that MEP amplitude after HF rTMS was significantly higher than MEP amplitude after anodal tDCS (P=0.001). Post-hoc analysis showed a significant increase in MEP amplitude after HF rTMS (25.3%, P=0.036) and a significant decrease in MEP amplitude after anodal tDCS (-32.7%, P=0.001). There was a similar increase in motor function as indexed by Jebsen-Taylor Hand Function Test in the two active groups compared with sham stimulation. In conclusion, here, we showed that although both techniques induced similar motor gains, they induce opposing results in cortical excitability. HF rTMS is associated with an increase in corticospinal excitability, whereas 20 min of tDCS induces the opposite effect. We discuss potential implications of these results to future clinical experiments using rTMS or tDCS for motor function enhancement. (C) 2013 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
  • article 21 Citação(ões) na Scopus
    Effects of Combined and Alone Transcranial Motor Cortex Stimulation and Mirror Therapy in Phantom Limb Pain: A Randomized Factorial Trial
    (2021) GUNDUZ, Muhammed Enes; PACHECO-BARRIOS, Kevin; PINTO, Camila Bonin; DUARTE, Dante; VELEZ, Faddi Ghassan Saleh; GIANLORENCO, Anna Carolyna Lepesteur; TEIXEIRA, Paulo Eduardo Portes; GIANNONI-LUZA, Stefano; CRANDELL, David; BATTISTELLA, Linamara Rizzo; SIMIS, Marcel; FREGNI, Felipe
    Phantom limb pain (PLP) is a frequent complication in amputees, which is often refractory to treatments. We aim to assess in a factorial trial the effects of transcranial direct current stimulation (tDCS) and mirror therapy (MT) in patients with traumatic lower limb amputation; and whether the motor cortex plasticity changes drive these results. In this large randomized, blinded, 2-site, sham-controlled, 2 x 2 factorial trial, 112 participants with traumatic lower limb amputation were randomized into treatment groups. The interventions were active or covered MT for 4 weeks (20 sessions, 15 minutes each) combined with 2 weeks of either active or sham tDCS (10 sessions, 20 minutes each) applied to the contralateral primary motor cortex. The primary outcome was PLP changes on the visual analogue scale at the end of interventions (4 weeks). Motor cortex excitability and cortical mapping were assessed by transcranial magnetic stimulation (TMS). We found no interaction between tDCS and MT groups (F = 1.90, P = .13). In the adjusted models, there was a main effect of active tDCS compared to sham tDCS (beta coefficient = -0.99, P = .04) on phantom pain. The overall effect size was 1.19 (95% confidence interval: 0.90, 1.47). No changes in depression and anxiety were found. TDCS intervention was associated with increased intracortical inhibition (coefficient = 0.96, P = .02) and facilitation (coefficient = 2.03, P = .03) as well as a posterolateral shift of the center of gravity in the affected hemisphere. MT induced no motor cortex plasticity changes assessed by TMS. These findings indicate that transcranial motor cortex stimulation might be an affordable and beneficial PLP treatment modality.
  • article 8 Citação(ões) na Scopus
    Transcranial direct current stimulation combined with robotic training in incomplete spinal cord injury: a randomized, sham-controlled clinical trial
    (2021) SIMIS, Marcel; FREGNI, Felipe; BATTISTELLA, Linamara R.
    Study design A randomized, sham-controlled clinical trial. Objective To test the effects of tDCS, combined with robotic training, on gait disability in SCI. Our hypothesis was that participants who received active tDCS would experience greater walking gains, as indexed by the WISCI-II, than those who received sham tDCS. Setting University of Sao Paulo, Brazil. Methods This randomized, double-blind study comprised 43 participants with incomplete SCI who underwent 30 sessions of active (n = 21) or sham (n = 22) tDCS (20 min, 2 mA) before every Lokomat session of 30 min (3 times a week over 12 weeks or 5 times a week over 6 weeks). The main outcome was the improvement in WISCI-II. Participants were assessed at baseline, after 15 and 30 sessions of Lokomat, and after three months of treatment. Results There was a significant difference in the percentage of participants that improved in WISCI-II at the 30-session, compared with baseline: 33.3% in the sham group and 70.0% in the active group (p = 0.046; OR: 3.7; 95% CI: 1.0-13.5). At the follow-up, the improvement compared with baseline in the sham group was 35.0% vs. 68.4% for the active group (p = 0.046; OR: 3.7; 95% CI: 1.0-13.5). There was no significant difference at the 15-session. Conclusion Thirty sessions of active tDCS is associated with a significant improvement in walking, compared to sham. Moreover, 15 sessions had no significant effect. The improvement in WISCI-II can be related to different aspects of motor learning, including motor recovery and compensation.
  • article 3 Citação(ões) na Scopus
    The Combined Use of Transcranial Direct Current Stimulation and Robotic Therapy for the Upper Limb
    (2018) PAI, Marcus Yu Bin; TERRANOVA, Thais Tavares; SIMIS, Marcel; FREGNI, Felipe; BATTISTELLA, Linamara Rizzo
    Neurologic disorders such as stroke and cerebral palsy are leading causes of long-term disability and can lead to severe incapacity and restriction of daily activities due to lower and upper limb impairments. Intensive physical and occupational therapy are still considered main treatments, but new adjunct therapies to standard rehabilitation that may optimize functional outcomes are being studied. Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that polarizes underlying brain regions through the application of weak direct currents through electrodes on the scalp, modulating cortical excitability. Increased interest in this technique can be attributed to its low cost, ease of use, and effects on human neural plasticity. Recent research has been performed to determine the clinical potential of tDCS in diverse conditions such as depression, Parkinson's disease, and motor rehabilitation after stroke. tDCS helps enhance brain plasticity and seems to be a promising technique in rehabilitation programs. A number of robotic devices have been developed to assist in the rehabilitation of upper limb function after stroke. The rehabilitation of motor deficits is often a long process requiring multidisciplinary approaches for a patient to achieve maximum independence. These devices do not intend to replace manual rehabilitation therapy; instead, they were designed as an additional tool to rehabilitation programs, allowing immediate perception of results and tracking of improvements, thus helping patients to stay motivated. Both tDSC and robot-assisted therapy are promising add-ons to stroke rehabilitation and target the modulation of brain plasticity, with several reports describing their use to be associated with conventional therapy and the improvement of therapeutic outcomes. However, more recently, some small clinical trials have been developed that describe the associated use of tDCS and robot-assisted therapy in stroke rehabilitation. In this article, we describe the combined methods used in our institute for improving motor performance after stroke.
  • article 12 Citação(ões) na Scopus
    Increased motor cortex inhibition as a marker of compensation to chronic pain in knee osteoarthritis
    (2021) SIMIS, Marcel; IMAMURA, Marta; MELO, Paulo S. de; MARDUY, Anna; PACHECO-BARRIOS, Kevin; TEIXEIRA, Paulo E. P.; BATTISTELLA, Linamara; FREGNI, Felipe
    This study aims to investigate the associative and multivariate relationship between different sociodemographic and clinical variables with cortical excitability as indexed by transcranial magnetic stimulation (TMS) markers in subjects with chronic pain caused by knee osteoarthritis (OA). This was a cross-sectional study. Sociodemographic and clinical data were extracted from 107 knee OA subjects. To identify associated factors, we performed independent univariate and multivariate regression models per TMS markers: motor threshold (MT), motor evoked potential (MEP), short intracortical inhibition (SICI), intracortical facilitation (ICF), and cortical silent period (CSP). In our multivariate models, the two markers of intracortical inhibition, SICI and CSP, had a similar signature. SICI was associated with age (beta: 0.01), WOMAC pain (beta: 0.023), OA severity (as indexed by Kellgren-Lawrence Classification) (beta: - 0.07), and anxiety (beta: - 0.015). Similarly, CSP was associated with age (beta: - 0.929), OA severity (beta: 6.755), and cognition (as indexed by the Montreal Cognitive Assessment) (beta: - 2.106). ICF and MT showed distinct signatures from SICI and CSP. ICF was associated with pain measured through the Visual Analogue Scale (beta: - 0.094) and WOMAC (beta: 0.062), and anxiety (beta: - 0.039). Likewise, MT was associated with WOMAC (beta: 1.029) and VAS (beta: - 2.003) pain scales, anxiety (beta: - 0.813), and age (beta: - 0.306). These associations showed the fundamental role of intracortical inhibition as a marker of adaptation to chronic pain. Subjects with higher intracortical inhibition (likely subjects with more compensation) are younger, have greater cartilage degeneration (as seen by radiographic severity), and have less pain in WOMAC scale. While it does seem that ICF and MT may indicate a more acute marker of adaptation, such as that higher ICF and MT in the motor cortex is associated with lesser pain and anxiety.
  • article 9 Citação(ões) na Scopus
    Median nerve stimulation induced motor learning in healthy adults: A study of timing of stimulation and type of learning
    (2018) CARVALHO, Sandra; FRENCH, Melanie; THIBAUT, Aurore; LIMA, Wilrama; SIMIS, Marcel; LEITE, Jorge; FREGNI, Felipe
    Median nerve stimulation (MNS) has been shown to change brain metaplasticity over the somatosensory networks, based on a bottom-up mechanism and may improve motor learning. This exploratory study aimed to test the effects of MNS on implicit and explicit motor learning as measured by the serial reaction time task (SRTT) using a double-blind, sham-controlled, randomized trial, in which participants were allocated to one of three groups: (a) online active MNS during acquisition, (b) offline active MNS during early consolidation and (c) sham MNS. SRTT was performed at baseline, during the training phase (acquisition period), and 30min after training. We assessed the effects of MNS on explicit and implicit motor learning at the end of the training/acquisition period and at retest. The group receiving online MNS (during acquisition) showed a significantly higher learning index for the explicit sequences compared to the offline group (MNS during early consolidation) and the sham group. The offline group also showed a higher learning index as compared to sham. Additionally, participants receiving online MNS recalled the explicit sentence significantly more than the offline MNS and sham groups. MNS effects on motor learning have a specific effect on type of learning (explicit vs. implicit) and are dependent on timing of stimulation (during acquisition vs. early consolidation). More research is needed to understand and optimize the effects of peripheral electrical stimulation on motor learning. Taken together, our results show that MNS, especially when applied during the acquisition phase, is a promising tool to modulate motor leaning.
  • article 6 Citação(ões) na Scopus
    Electroencephalography as a Biomarker for Functional Recovery in Spinal Cord Injury Patients
    (2021) SIMIS, Marcel; CAMSARI, Deniz Doruk; IMAMURA, Marta; FILIPPO, Thais Raquel Martins; SOUZA, Daniel Rubio De; BATTISTELLA, Linamara Rizzo; FREGNI, Felipe
    Background Functional changes after spinal cord injury (SCI) are related to changes in cortical plasticity. These changes can be measured with electroencephalography (EEG) and has potential to be used as a clinical biomarker. Method In this longitudinal study participants underwent a total of 30 sessions of robotic-assisted gait training (RAGT) over a course of 6 weeks. The duration of each session was 30 min. Resting state EEG was recorded before and after 30-session rehabilitation therapy. To measure gait, we used the Walking Index for Spinal Cord Injury Scale, 10-Meter- Walking Test, Timed-Up-and-Go, and 6-Min-Walking Test. Balance was measured using Berg Balance Scale. Results Fifteen participants with incomplete SCI who had AIS C or D injuries based on American Spinal Cord Injury Association Impairment Scale classification were included in this study. Mean age was 35.7 years (range 17-51) and the mean time since injury was 17.08 (range 4-37) months. All participants showed clinical improvement with the rehabilitation program. EEG data revealed that high beta EEG activity in the central area had a negative correlation with gait (p = 0.049; beta coefficient: -0.351; and adj-R-2: 0.23) and balance (p = 0.043; beta coefficient: -0.158; and adj-R-2:0.24) measured at baseline, in a way that greater high beta EEG power was related to worse clinical function at baseline. Moreover, improvement in gait and balance had negative correlations with the change in alpha/theta ratio in the parietal area (Gait: p = 0.049; beta coefficient: -0.351; adj-R-2: 0.23; Balance: p = 0.043; beta coefficient: -0.158; and adj-R-2: 0.24). Conclusion In SCI, functional impairment and subsequent improvement following rehabilitation therapy with RAGT correlated with the change in cortical activity measured by EEG. Our results suggest that EEG alpha/theta ratio may be a potential surrogate marker of functional improvement during rehabilitation. Future studies are necessary to improve and validate these findings as a neurophysiological biomarker for SCI rehabilitation.
  • article 2 Citação(ões) na Scopus
    Functional Changes in Cortical Activity of Patients Submitted to Knee Osteoarthritis Treatment An Exploratory Pilot Study
    (2022) IUAMOTO, Leandro Ryuchi; IMAMURA, Marta; SAMESHIMA, Koichi; MEYER, Alberto; SIMIS, Marcel; BATTISTELLA, Linamara Rizzo; FREGNI, Felipe
    Introduction There is evidence that brain plasticity is the central mechanism involved in the functional recovery process of patients with knee osteoarthritis. Studies involving the analysis of central nervous system mechanisms of pain control and recovery could provide more data on future therapeutic approaches. Objective The aim of the study was to explore possible functional changes in cortical activity of patients submitted to knee osteoarthritis standardized pain treatment using electroencephalography. Methodology Ten patients with clinical and radiological diagnosis of painful knee unilateral or bilateral osteoarthritis were recruited to participate in clinical (Pain's Visual Analog Scale), radiological (Kellgren-Lawrence Scale), and neurophysiological (electroencephalography) assessments to evaluate cortical activity during cortical pain modulation activity. The clinical and neurophysiological analyses were performed before and after standardized pain treatment. Results Eight patients participated in this study. A significant improvement in pain perception and relative increase in interhemispheric connectivity after therapies was observed. In electroencephalography analysis, tests with real movement showed a relative increase in density directed at Graph's analysis. Conclusions Relative increase density directed measures at connectivity analysis in electroencephalography after pain treatment can be possible parameters to be explored in future research with a larger number of patients.
  • article 16 Citação(ões) na Scopus
    EEG theta and beta bands as brain oscillations for different knee osteoarthritis phenotypes according to disease severity
    (2022) SIMIS, Marcel; IMAMURA, Marta; PACHECO-BARRIOS, Kevin; MARDUY, Anna; MELO, Paulo S. de; MENDES, Augusto J.; TEIXEIRA, Paulo E. P.; BATTISTELLA, Linamara; FREGNI, Felipe
    This study aims to investigate the multivariate relationship between different sociodemographic, clinical, and neurophysiological variables with resting-state, high-definition, EEG spectral power in subjects with chronic knee osteoarthritis (OA) pain. This was a cross-sectional study. Sociodemographic and clinical data were collected from 66 knee OA subjects. To identify associated factors, we performed independent univariate and multivariate regression models by frequency bands (delta, theta, alpha, beta, low-beta, and high-beta) and by pre-defined regions (frontal, central, and parietal). From adjusted multivariate models, we found that: (1) increased frontocentral high-beta power and reduced central theta activity are positively correlated with pain intensity (beta = 0.012, 95% CI 0.004-0.020; and beta = - 0.008; 95% CI 0.014 to - 0.003; respectively); (2) delta and alpha oscillations have a direct relationship with higher cortical inhibition; (3) diffuse increased power at low frequencies (delta and theta) are associated with poor cognition, aging, and depressive symptoms; and (4) higher alpha and beta power over sensorimotor areas seem to be a maladaptive compensatory mechanism to poor motor function and severe joint degeneration. Subjects with higher pain intensity and higher OA severity (likely subjects with maladaptive compensatory mechanisms to severe OA) have higher frontocentral beta power and lower theta activity. On the other hand, subjects with less OA severity and less pain have higher theta oscillations power. These associations showed the potential role of brain oscillations as a marker of pain intensity and clinical phenotypes in chronic knee OA patients. Besides, they suggest a potential compensatory mechanism of these two brain oscillators according to OA severity.