• Title/Summary/Keyword: Cortical stimulation

Search Result 112, Processing Time 0.025 seconds

Acupuncture Stimulation for Motor Cortex Activities: Evidence from 3T Functional MRI Study

  • Choe, Bo-Young;Jeun, Sin-Soo;Kang, Sei-Kown;Park, Gi-Soon;Chung, Sung-Taek;Yoo, Seung-Schik;Chu, Myung-Ja;Lee, Hyoung-Koo;Suh, Tae-Suk
    • Proceedings of the Korean Society of Medical Physics Conference
    • /
    • 2002.09a
    • /
    • pp.352-355
    • /
    • 2002
  • The purpose of this study was to investigate whether or not acupuncture of GB34 produces a significant response of the modulation of somatomotor areas by functional magnetic resonance imaging (fMRI) study. The acupoint, GB34, located in the back of the knee, is known to be effective in recovering motor function after stroke. Using 3T MRI scanner, functional MR imaging of the whole brain was performed in 12 normal healthy subjects during two stimulation paradigms; acupuncture manipulation on GB 34 and sham points. This study investigates the activation of the mortor cortex elicited by a soft and an intensified stimulation of GB 34. Three different paradigms were carried out to detect any possible modulation of the Blood Oxygenation Level Dependent (BOLD) response in the somatomortor area to motor stimulation through acupuncture. Group analysis from seven individuals showed that bilateral sensorimotor areas (BA 3,4,6 and 7) showed stimulation related BOLD signal contrast of approximately 6% whereas very few areas were activated when sham stimulation is given. The present study shows that acupuncture fMRI study can be safely conducted in 3T MRI environment, and acupuncture stimulation in GB34 modulates the cortical activities of the somatomotor area in human. The present findings may shed light on the CNS mechanism of motor function by acupuncture and form a basis for future investigations of motor modulation circuits in the stroke patients.

  • PDF

Targeting motor and cognitive networks with multichannel transcranial direct current stimulation along with peripheral stimulation in a subacute stroke survivor: single case study

  • Midha, Divya;Arumugam, Narkeesh
    • Physical Therapy Rehabilitation Science
    • /
    • v.9 no.4
    • /
    • pp.318-323
    • /
    • 2020
  • Objective: Reacquisition of motor functions following stroke depends on interhemispheric neural connections. The intervention highlighted in the present case is an insight for augmenting motor recovery by stimulating the lesioned area and adjacent areas governing the motor behaviour of an individual. The purpose of this study was to determine the changes in the motor and cognitive outcomes through multi target stimulation of cortical areas by application of multichannel transcranial direct current stimulation (M-tDCS) in a stroke survivor. Design: A case report. Methods: The patient was a participant of a trial registered with the clinical trial registry of India (CTRI/2020/01/022998). The patient was intervened with M-tDCS over the left primary motor cortex i.e. C3 point and left dorsolateral prefrontal cortex i.e. F3 point with 0.5-2 mA intensity for the period of 20 minutes. SaeboFlex-assisted task-oriented training, functional electrical stimulation over the lower extremity (LE) to elicit dorsiflexion at the ankle and eversion of the foot, and conventional physiotherapy rehabilitation including a tailored exercise program were performed. Outcome assessment was done using the Fugl-Meyer assessment scale (FMA) for the upper and lower extremity (UE and LE), Montreal Cognitive Assessment (MOCA), Wisconsin Gait Scale (WGS) and the Stroke Specific Quality of Life (SSQOL) measures. Assessment was taken at Day 0, 15 and 30 post intervention. Results: Improvement was observed in all the outcome measures i.e FMA (UE and LE), MOCA, SSQOL and WGS across the span of 4 weeks. Conclusions: M-tDCS induced improvement in motor functions of the UE and LE, gait parameters and cognitive functions of the patient.

Posterior Tibial Nerve Somatosensory Evoked Potentials Recorded on Subdural Electrodes around Paracentral Lobule (부중심소엽 주변 경막하 전극들에서 기록된 후경골신경 체성감각유발전위)

  • Seo, Dae Won
    • Annals of Clinical Neurophysiology
    • /
    • v.1 no.2
    • /
    • pp.112-117
    • /
    • 1999
  • Background : Posterior tibial nerve somatosensory evoked potentials (PTSEP) have cortical potentials on primary sensory area of foot around 40 msec. The direct cortical recordings of the cortical potentials shows high voltage positive wave on medial hemisphere, especially on paracentral lobule (PCL). However, it is so difficult to record the potential directly on PCL that the cortical potential of PTSEP is not well understood. We investigated the cortical potential of PTSEP on subdural electrodes. Methods : We recorded cortical potentials to posterior tibial nerve stimulation on subdural electrodes which were on medial hemisphere near PCL in 15 intractable neocortical epilepsy patients. The numbers of subdural electrodes were 8 in 10 subjects ($1{\times}8array$) and 16 in 5 subjects ($2{\times}8arrays$). Seven subjects had three-dimensional imaging fusion (3D-fusion) of MRI and the electrodes using Analyze program. We investigated the amplitude, latency, polarity, and phase of the waves regarding location. Results : The waves had maximal amplitude on PCL in 4 subjects, precuneus in 1, cingulate gyrus nearest to PCL in 2 among 7 subjects with 3D-fusion. Also the electrodes were located on posterior area of PCL (2 out of 2 subjects with more than two electrodes put on PCL in 3D-fusion) and superior area of it (5 out of 5 subjects with $2{\times}8arrays $). All the high (more than 20 uV) amplitude around 40msec had positive polarity in 7 subjects. The phase reversals were detected between the electrodes with the highest amplitude and the just posterior (2 subjects) or anterior (6 subjects) located electrodes. The just posterior located electrodes had sharper phase reversal than the anterior one. Conclusion : PTSEP might have maximal amplitude of cortical potentials on the more superior and posterior area of PCL. The highest amplitude potential has positivity. The wave with maximal amplitude could have phase reversal of cortical potentials with surrounding electrodes, especially shaper with posterior part than with anterior one.

  • PDF

Neurophysiological Evaluation of the Motor System Using Transcranial Magnetic Stimulation (뇌자기자극을 이용한 운동신경계의 신경생리학적 평가)

  • Shin, Hae-Won;Sohn, Young-H.
    • Annals of Clinical Neurophysiology
    • /
    • v.13 no.1
    • /
    • pp.1-12
    • /
    • 2011
  • Transcranial magnetic stimulation (TMS) is a non-invasive tool used to study aspects of human brain physiology, including motor function and the pathophysiology of various brain disorders. A brief electric current passed through a magnetic coil produces a high-intensity magnetic field, which can excite or inhibit the cerebral cortex. Although various brain regions can be evaluated by TMS, most studies have focused on the motor cortex where motor evoked potentials (MEPs) are produced. Single-pulse and paired-pulse TMS can be used to measure the excitability of the motor cortex via various parameters, while repetitive TMS induces cortical plasticity via long-term potentiation or long-term depression-like mechanisms. Therefore, TMS is useful in the evaluation of physiological mechanisms of various neurological diseases, including movement disorders and epilepsy. In addition, it has diagnostic utility in spinal cord diseases, amyotrophic lateral sclerosis and demyelinating diseases. The therapeutic effects of repetitive TMS on stroke, Parkinson disease and focal hand dystonia are limited since the duration and clinical benefits seem to be temporary. New TMS techniques, which may improve clinical utility, are being developed to enhance clinical utilities in various neurological diseases.

Laser Speckle Contrast Imaging for Measuring Cerebral Blood Flow Changes Caused by Electrical Sensory Stimulation

  • Cho, Ahra;Yeon, Chanmi;Kim, Donghyeon;Chung, Euiheon
    • Journal of the Optical Society of Korea
    • /
    • v.20 no.1
    • /
    • pp.88-93
    • /
    • 2016
  • Recently laser speckle contrast (LSC) imaging has become a widely used optical method for in vivo assessment of blood flow in the animal brain. LSC imaging is useful for monitoring brain hemodynamics with relatively high spatio-temporal resolution. A speckle contrast imaging system has been implemented with electrical sensory stimulation apparatus. LSC imaging is combined with optical intrinsic signal imaging in order to measure changes in cerebral blood flow as well as neural activity in response to electrical sensory stimulation applied to the hindlimb region of the mouse brain. We found that blood flow and oxygen consumption are correlated and both sides of hindlimb activation regions are symmetrically located. This apparatus could be used to monitor spatial or temporal responses of cerebral blood flow in animal disease models such as ischemic stroke or cortical spreading depression.

Repetitive Transcranial Magnetic Stimulation Combined with Task Oriented Training to Improve Upper Extremity Function After Stroke

  • Kim, Myoung-Kwon
    • Journal of Magnetics
    • /
    • v.19 no.2
    • /
    • pp.170-173
    • /
    • 2014
  • The purpose of the present study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with task oriented training, on cortical excitability and upper extremity function recovery in stroke patients. This study was conducted with 31 subjects who were diagnosed as a hemiparesis by stroke. Participants in the experimental (16 members) and control groups (15 members) received rTMS and sham rTMS, respectively, during a 10 minutes session, five days per week for four weeks, followed by task oriented training during a 30 minutes session, five days per week for four weeks. Motor cortex excitability was performed by motor evoked potential and upper limb function was evaluated by motor function test. Both groups showed a significant increment in motor function test and amplitude, latency in motor evoked potential compared to pre-intervention (p < 0.05). A significant difference in post-training gains for the motor function test, amplitude in motor evoked potential was observed between the experimental group and the control group (p < 0.05). The findings of the current study demonstrated that incorporating rTMS in task oriented training may be beneficial in improving the effects of stroke on upper extremity function recovery.

Emotional Preference Modulates Autonomic and Cortical Responses to Tactile Stimulation (촉각자극에 의한 자율신경계 및 뇌파 반응과 감성)

  • Estate Sokhadze;Lee, Kyung-Hwa;Imgap Yi;Park, Sehun;Sohn, Jin-Hun
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
    • /
    • 1998.11a
    • /
    • pp.225-229
    • /
    • 1998
  • The purpose of the current study was comparative analysis of autonomic and electrocortical responses to passive and active touch of the tektites with different subjective emotional preference. Perspective goal of the project is development of a template for classification of tactile stimuli according to subjective comfort and associated physiological manifestations. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and B10PAC 100 systems with AcqKnowledge III software. Frontal, parietal and occipital EEG (relative power spectrum /percents/ of EEG bands - delta, theta, slow and fast alpha, low and fast beta), and autonomic variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, rise time and number of SCRs) were analyzed for rest baseline and stimulation conditions. Analysis of the overall pattern of reaction indicated that autonomic response to tactile stimulation was manifested in a form of moderate HR acceleration, RSP increase, RSA decrease (lowered vagal tone), decreased n and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand) were featured by short-term alpha-blocking, slightly reduced theta and significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome. Nevertheless, development of sufficiently sensitive .and reliable template for classification of emotional responses to tactile stimulation based on physiological response pattern may require more extensive empirical database.

  • PDF

Repetitive transcranial magnetic stimulation in central post-stroke pain: current status and future perspective

  • Riva Satya Radiansyah;Deby Wahyuning Hadi
    • The Korean Journal of Pain
    • /
    • v.36 no.4
    • /
    • pp.408-424
    • /
    • 2023
  • Central post-stroke pain (CPSP) is an incapacitating disorder that impacts a substantial proportion of stroke survivors and can diminish their quality of life. Conventional therapies for CPSP, including tricyclic antidepressants, anticonvulsants, and opioids, are frequently ineffective, necessitating the investigation of alternative therapeutic strategies. Repetitive transcranial magnetic stimulation (rTMS) is now recognized as a promising noninvasive pain management method for CPSP. rTMS modulates neural activity through the administration of magnetic pulses to specific cortical regions. Trials analyzing the effects of rTMS on CPSP have generated various outcomes, but the evidence suggests possible analgesic benefits. In CPSP and other neuropathic pain conditions, high-frequency rTMS targeting the primary motor cortex (M1) with figure-eight coils has demonstrated significant pain alleviation. Due to its associaton with analgesic benefits, M1 is the most frequently targeted area. The duration and frequency of rTMS sessions, as well as the stimulation intensity, have been studied in an effort to optimize treatment outcomes. The short-term pain relief effects of rTMS have been observed, but the long-term effects (> 3 months) require further investigation. Aspects such as stimulation frequency, location, and treatment period can influence the efficacy of rTMS and ought to be considered while planning the procedure. Standardized guidelines for using rTMS in CPSP would optimize therapy protocols and improve patient outcomes. This review article provides an up-to-date overview of the incidence, clinical characteristics, outcome of rTMS in CPSP patients, and future perspective in the field.

Brain Activation Evoked by Sensory Stimulation in Patients with Spinal Cord Injury : Functional Magnetic Resonance Imaging Correlations with Clinical Features

  • Lee, Jun Ki;Oh, Chang Hyun;Kim, Ji Yong;Park, Hyung-Chun;Yoon, Seung Hwan
    • Journal of Korean Neurosurgical Society
    • /
    • v.58 no.3
    • /
    • pp.242-247
    • /
    • 2015
  • Objective : The purpose of this study is to determine whether the changes of contralateral sensorimotor cortical activation on functional magnetic resonance imaging (fMRI) can predict the neurological outcome among spinal cord injury (SCI) patients when the great toes are stimulated without notice. Methods : This study enrolled a total of 49 patients with SCI and investigated each patient's preoperative fMRI, postoperative fMRI, American Spinal Injury Association (ASIA) score, and neuropathic pain occurrence. Patients were classified into 3 groups according to the change of blood oxygenation level dependent (BOLD) response on perioperative fMRI during proprioceptive stimulation with repetitive passive toe movements : 1) patients with a response of contralateral sensorimotor cortical activation in fMRI were categorized; 2) patients with a response in other regions; and 3) patients with no response. Correlation between the result of fMRI and each parameter was analyzed. Results : In fMRI data, ASIA score was likely to show greater improvement in patients in group A compared to those belonging to group B or C (p<0.001). No statistical significance was observed between the result of fMRI and neuropathic pain (p=0.709). However, increase in neuropathic pain in response to the signal change of the ipsilateral frontal lobe on fMRI was statistically significant (p=0.030). Conclusion : When there was change of BOLD response at the contralateral sensorimotor cortex on perioperative fMRI after surgery, relief of neurological symptoms was highly likely for traumatic SCI patients. In addition, development of neuropathic pain was likely to occur when there was change of BOLD response at ipsilateral frontal lobe.

Acupuncture Analgesia : A Sensory Stimulus Induced Analgesia Observed by functional Magnetic Resonance Imaging (침의 진통효과: 체성감각신경자극으로 유도된 진통작용에 대한 기능성자기공명영상장치를 이용한 연구)

  • Cho, Zang-hee;Hwang, Seon-chool;Son, Young-don;Kang, Chang-ki;Wong, Edward K.;Bai, Sun-joon;Lee, Un-jung;Sung, Kang-kyung;Park, Tae-seok;Kim, Young-bo;Min, Hoon-ki;Oleson, Terry
    • Journal of Acupuncture Research
    • /
    • v.21 no.2
    • /
    • pp.57-71
    • /
    • 2004
  • Objective : Physiological evidence regarding acupuncture's effect in human patients is not yet well established, despite considerable evidence for its therapeutic efficacy. Besides target or disease specificity of acupuncture, acupuncture analgesia (AA) appears to be another large subclass that poses many questions, such as whether there is point specificity with respect to which acupoint is most effective for a particular condition. Methods : We observed brain activation with functional magnetic resonance imaging (fMRI) using a set of stimuli that consist of pain, pain following Meridian acupuncture, and pain following Sham acupuncture. Results : Among the new observations, the most interesting fact is that data sets of both Meridian acupuncture and Sham acupuncture show decreased activation of the same brain areas related to the pain processing signals. Present functional MRI study demonstrate two important biological observations that could elucidate AA mechanism in human participants: the effects of acupuncture occur through mediation of the higher brain areas. Sham acupuncture stimulation appears to be almost as effective as traditional Meridian acupoint stimulation, suggesting that acupuncture is not entirely point specific. Decreased activation in the limbic paleo cortical areas appears to be the probable neurological manifestation of AA and strongly implies that acupuncture stimulation inhibits the transmission of ascending pain signals to the higher cortical areas by the previously known descending pain inhibitory circuit. Conclusion : We, therefore, a hypothesized that this pain inhibitory circuit is initiated and mediated via the broad sense Hypothalamus Pituitary Adrenal (BS HPA) axis in conjunction to the "sensory stimulation."

  • PDF