Cortical Excitability In Patients Research Articles

Cortical excitability in patients with migraine with aura and depressive symptoms: a visual evoked potentials study

Background: Migraine is a brain disorder characterized by recurring headache attacks, and emotional comorbidities, such as anxiety and depression, may influence the repetition of these attacks. The lack of sensory habituation is a common neurophysiological abnormality in migraine, and research suggests that it is under the influence of serotonin and other monoamines that are also involved in mood disorders. This study aimed to investigate the influence of emotional symptoms on cortical information processing in patients with migraine with aura by correlating cortical activity with self-perceived emotional distress. Methods: Visual evoked potentials from monocular stimulation were recorded in 16 patients with migraine with aura (MA) and 22 healthy volunteers (HV). The visual stimulus consisted of a full-screen black-and-white checkerboard pattern with a reversal rate of 1.55 Hz. 600 consecutive traces were collected and divided into six sequential blocks of 100 sweeps. Before the recording session, both MA patients and HV completed the Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI). Pearson's correlation test was used to find correlations between electrophysiological and psychometric variables in HV and MA patients. Results: Compared to HV, MA patients showed a significant difference in the degree of habituation to repeated visual stimulation between the two groups, resulting in a habitation deficit. Psychometric test results showed that trait STAI and BDI values were significantly higher in MA patients. In the MA group, BDI correlated negatively with the amplitude of the first block and positively with the degree of habituation. Conclusions: These results highlight a link between the level of brain responsiveness and depressive symptoms in patients with MA. Further research is required to confirm whether the same correlations exist in patients with other headache disorders.

Influence of sports on cortical excitability in patients with spinal cord injury: a TMS study.

Patients with spinal cord injury (SCI) show abnormal cortical excitability that might be caused by deafferentation. We hypothesize a reduced short-interval intracortical inhibition preceding movement in patients with SCI compared with healthy participants. In addition, we expect that neuroplasticity induced by different types of sports can modulate intracortical inhibition during movement preparation in patients with SCI. We used a reaction test and paired-pulse transcranial magnetic stimulation to record cortical excitability, assessed by measuring amplitudes of motor-evoked potentials in preparation of movement. The participants were grouped as patients with SCI practicing wheelchair dancing (n = 7), other sports (n = 6), no sports (n = 9), and healthy controls (n = 24). There were neither significant differences between healthy participants and the patients nor between the different patient groups. A non-significant trend (p = .238), showed that patients engaged in sports have a stronger increase in cortical excitability compared with patients of the non-sportive group, while the patients in the other sports group expressed the highest increase in cortical excitability. The small sample sizes limit the statistical power of the study, but the trending effect warrants further investigation of different sports on the neuroplasticity in patients with SCI. It is not clear how neuroplastic changes impact the sensorimotor output of the affected extremities in a patient. This needs to be followed up in further studies with a greater sample size.

Yoga as an Add-on Therapy in Parkinson's Disease: A Single Group Open-label Trial.

We aimed to evaluate the effect of yoga on motor and non-motor symptoms and cortical excitability in patients with Parkinson's disease (PD). We prospectively evaluated 17 patients with PD at baseline, after one month of conventional care, and after one month of supervised yoga sessions. The motor and non-motor symptoms were evaluated using the Unified Parkinson's disease Rating Scale (motor part III), Hoehn and Yahr stage, Montreal Cognitive Assessment, Hamilton depression rating scale, Hamilton anxiety rating scale, non-motor symptoms questionnaire and World Health Organization quality of life questionnaire. Transcranial magnetic stimulation was used to record resting motor threshold, central motor conduction time, ipsilateral silent period (iSP), contralateral silent period (cSP), short interval intracortical inhibition (SICI), and intracortical facilitation. The mean age of the patients was 55.5 ± 10.8 years, with a mean duration of illness of 4.0 ± 2.5 years. The postural stability of the patients significantly improved following yoga (0.59 ± 0.5 to 0.18 ± 0.4, p = 0.039). There was a significant reduction in the cSP from baseline (138.07 ± 27.5 ms) to 4 weeks of yoga therapy (116.94 ± 18.2 ms, p = 0.004). In addition, a significant reduction in SICI was observed after four weeks of yoga therapy (0.22 ± 0.10) to (0.46 ± 0.23), p = 0.004). Yoga intervention can significantly improve postural stability in patients with PD. A significant reduction of cSP and SICI suggests a reduction in GABAergic neurotransmission following yoga therapy that may underlie the improvement observed in postural stability. CTRI/2019/02/017564.

Abnormal cortical excitability in patients with spinocerebellar ataxia type 12

BackgroundSpinocerebellar ataxia type 12 (SCA-12) is an uncommon autosomal dominant cerebellar ataxia characterized by action tremors in the upper limbs, dysarthria, head tremor, and gait ataxia. We aimed to evaluate the motor cortical excitability in patients with SCA-12 using transcranial magnetic stimulation (TMS). MethodsThe study was done in the department of Neurology at the National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore. Nine patients with SCA-12 (2 females) and 10 healthy controls (2 females) were included in the study. TMS was performed in all the subjects and various parameters such as resting motor threshold (RMT), central motor conduction time (CMCT) and contralateral silent period (cSP) were recorded. The left motor cortex was stimulated and the recording was done from right first dorsal interossei muscle. The severity of ataxia was assessed using the scale for assessment and rating in ataxia (SARA). ResultsThe mean age of the patients was 58.11 ± 7.56 years mean age at onset: 51.67 ± 4.18 years. The mean duration of illness was 9.44 ± 4.88 years. The mean SARA score was 13.83 ± 3.60. Patients with SCA-12 had significantly increased RMT (88.80 ± 12.78 %) compared to HC (44.90 ± 9.40 %, p < 0.05). A significantly prolonged CMCT was observed in patients (13.70 ± 2.52 msec) compared to HC (7.31 ± 1.21 msec, p < 0.05). In addition, cSP was significantly increased in SCA-12 patients (144.43 ± 25.79 msec) compared to HC (82.14 ± 28.90 msec, p < 0.05). ConclusionsPatients with SCA-12 demonstrate a reduced cortical excitability and increased cortical inhibition suggesting an increase in the GABAergic neurotransmission.

Clinical potential and neuroplastic effect of targeted virtual reality based intervention for distal upper limb in post-stroke rehabilitation: a pilot observational study

Purpose A library of Virtual Reality (VR) tasks has been developed for targeted post-stroke rehabilitation of distal upper extremities. The objective of this pilot study was to evaluate the clinical potential of the targeted VR-based therapeutic intervention in a small cohort of patients specifically with chronic stroke. Furthermore, our aim was to explore the possible neuronal reorganizations in corticospinal pathways in response to the distal upper limb targeted VR-intervention. Methodology Five patients with chronic stroke were enrolled in this study and were given VR-intervention of 20 sessions of 45 min each. Clinical Scales, cortical-excitability measures (using Transcranial Magnetic Stimulation): Resting Motor Threshold (RMT), and Motor Evoked Potential (MEP) amplitude, task-specific performance metrics i.e., Time taken to complete the task (TCT), smoothness of trajectory, relative % error were evaluated pre- and post-intervention to evaluate the intervention-induced improvements. Results Pre-to post-intervention improvements were observed in Fugl-Meyer Assessment (both total and wrist/hand component), Modified Barthel Index, Stroke Impact Scale, Motor Assessment Scale, active range of motion at wrist, and task-specific outcome metrics. Pre-to post-intervention ipsilesional RMT reduced (mean ∼9%) and MEP amplitude increased (mean ∼29µV), indicating increased cortical excitability at post-intervention. Conclusion VR-training exhibited improved motor outcomes and cortical-excitability in patients with stroke. Neurophysiological changes observed in terms of improved cortical-excitability might be a consequence of plastic reorganization induced by VR-intervention.

Individualized closed-loop TMS synchronized with exoskeleton for modulation of cortical-excitability in patients with stroke: a proof-of-concept study.

Repetitive TMS is used in stroke rehabilitation with predefined passive low and high-frequency stimulation. Brain State-Dependent Stimulation (BSDS)/Activity-Dependent Stimulation (ADS) using bio-signal has been observed to strengthen synaptic connections. Without the personalization of brain-stimulation protocols, we risk a one-size-fits-all approach. We attempted to close the ADS loop via intrinsic-proprioceptive (via exoskeleton-movement) and extrinsic-visual-feedback to the brain. We developed a patient-specific brain stimulation platform with a two-way feedback system, to synchronize single-pulse TMS with exoskeleton along with adaptive performance visual feedback, in real-time, for a focused neurorehabilitation strategy to voluntarily engage the patient in the brain stimulation process. The novel TMS Synchronized Exoskeleton Feedback (TSEF) platform, controlled by the patient's residual Electromyogram, simultaneously triggered exoskeleton movement and single-pulse TMS, once in 10 s, implying 0.1 Hz frequency. The TSEF platform was tested for a demonstration on three patients (n = 3) with different spasticity on the Modified Ashworth Scale (MAS = 1, 1+, 2) for one session each. Three patients completed their session in their own timing; patients with (more) spasticity tend to take (more) inter-trial intervals. A proof-of-concept study on two groups-TSEF-group and a physiotherapy control-group was performed for 45 min/day for 20-sessions. Dose-matched Physiotherapy was given to control-group. Post 20 sessions, an increase in ipsilesional cortical-excitability was observed; Motor Evoked Potential increased by ~48.5 μV at a decreased Resting Motor Threshold by ~15.6%, with improvement in clinical scales relevant to the Fugl-Mayer Wrist/Hand joint (involved in training) by 2.6 units, an effect not found in control-group. This strategy could voluntarily engage the patient. A brain stimulation platform with a real-time two-way feedback system was developed to voluntarily engage the patients during the brain stimulation process and a proof-of-concept study on three patients indicates clinical gains with increased cortical excitability, an effect not observed in the control-group; and the encouraging results nudge for further investigations on a larger cohort.

Cortical excitability in patients with REM sleep behavior disorder with abnormal TRODAT-1 SPECT scan: an insight into prodromal Parkinson's disease.

REM Sleep Behavior Disorder (RBD) has been highlighted to identify a patient with prodromal Parkinson's disease (PD). Although many studies focus on biomarkers to predict an RBD patient's evolution from prodromal PD to clinical PD, the neurophysiological perturbation of cortical excitability has not yet been well elucidated. Moreover, no study describes the difference between RBD with and without abnormal TRODAT-1 SPECT. By measuring the amplitude of motor evoked potentials (MEP), the cortical excitability changes after transcranial magnetic stimulation (TMS) were evaluated in 14 patients with RBD and eight healthy controls (HC). Seven of the 14 patients with RBD showed abnormal TRODAT-1 (TRA-RBD), and seven were normal (TRN-RBD). The tested parameters of cortical excitability include resting motor threshold (RMT), active motor threshold (AMT), short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), contralateral silence period (CSP), and input-output recruitment curve. The RMT and AMT showed no difference among the three studied groups. There was only SICI at inter-stimuli-interval 3 ms revealing group differences. The TRA-RBD demonstrated significant differences to HC in these aspects: decreased SICI, increased ICF, shortening of CSP, and augmented MEP amplitude at 100% RMT. Moreover, the TRA-RBD had a smaller MEP facilitation ratio at 50% and 100% of maximal voluntary contraction when compared to TRN-RBD. The TRN-RBD did not present any difference to HC. We showed that TRA-RBD shared similar cortical excitability changes with clinical PD. These findings would provide further insight into the concept that RBD is the highly prevalent entity in prodromal PD.

Smoking status ameliorates cholinergic impairments in cortical inhibition in patients with schizophrenia

RationaleModulation of cortical excitability, in particular inhibition, is impaired in patients with schizophrenia. Chronic nicotine consumption, which is prevalent in this group, has been shown to alter cortical excitability in healthy individuals and to increase inhibitory activity. Thus, beneficial effects of smoking on impaired cortical excitability in patients with schizophrenia have been proposed, though direct experimental evidence is still lacking. ObjectivesWe aimed to explore the effect of chronic smoking on cortical excitability by comparing smoking and non-smoking patients with schizophrenia. MethodTwenty-six smoking and 19 non-smoking patients diagnosed with schizophrenia were included. Transcranial magnetic stimulation (TMS) applied to the primary motor cortex served as experimental paradigm for measuring corticospinal and intracortical excitability as follows: Resting motor threshold (RMT) and the input/output curve (I/O curve) were obtained to assess corticospinal excitability. Intracortical excitability was explored using paired-pulse TMS techniques (intracortical facilitation (ICF), short-latency intracortical inhibition (SICI) and short-latency afferent inhibition (SAI)). ResultsA significantly stronger inhibition in the cholinergically driven SAI protocol was observed in smokers compared to non-smokers. All other measures did not show significant differences between groups. ConclusionOur results suggest an increased inhibition within cholinergic circuits due to chronic nicotine consumption in schizophrenia. This increase may compensate impaired cholinergic neurotransmission and could explain the high rate of smokers in schizophrenia.

Increased cortical excitability in patients with medication-overuse headache

Increased cortical excitability in patients with medication-overuse headache

Effect of electroacupuncture at back-shu points of five zang on fatigue status and cortical excitability in chronic fatigue syndrome

To observe the effect of electroacupuncture (EA) at back-shu points of five zang on fatigue status, quality of life and motor cortical excitability in patients with chronic fatigue syndrome (CFS), so as to explore the possible mechanism of EA for CFS. A total of 72 patients with CFS were randomized into an EA group (36 cases, 4 cases dropped off) and a sham EA group (36 cases, 3 cases dropped off). In the EA group, EA at Ganshu (BL 18), Xinshu (BL 15), Pishu (BL 20), Feishu (BL 13) and Shenshu (BL 23) was adopted, with continuous wave, 2 Hz in frequency. In the sham EA group, sham EA at non-acupoints (1.5-2.0 cm lateral to back-shu points of five zang) was applied, with shallow needling, and no current was connected. The treatment in the both groups was 20 min each time, once every other day, 2 weeks as one course, 3 courses were required. Before and after treatment, the scores of fatigue scale-14 (FS-14) and the MOS 36-item short form health survey (SF-36) were observed, and cortical excitability (the resting motor threshold [RMT], amplitude of motor-evoked potential [MEP-A] and latency of motor-evoked potential [MEP-L]) was detected in the two groups. After treatment, the physical fatigue score, mental fatigue score and total score of FS-14, as well as RMT of motor cortex in the EA group were decreased compared with those before treatment (P<0.01), the physical fatigue score and total score of FS-14 in the sham EA group were decreased compared with those before treatment (P<0.05); each item score and total score of FS-14 and RMT of motor cortex in the EA group were lower than those in the sham EA group (P<0.01, P<0.05). After treatment, each item score and total score of SF-36 and MEP-A of motor cortex in the EA group were increased compared with those before treatment (P<0.01), which were higher than those in the sham EA group (P<0.01, P<0.05). EA at back-shu points of five zang can effectively improve the fatigue status and quality of life in patients with CFS, its mechanism may be related to the up-regulating excitability of cerebral motor cortex.

Effect of repetitive transcranial magnetic stimulation on quality of life and cortical excitability in patients with cerebral infarction.

article: Effect of repetitive transcranial magnetic stimulation on quality of life and cortical excitability in patients with cerebral infarction - Panminerva Medica 2021 Oct 19 - Minerva Medica - Journals

Intermittent Theta Burst Stimulation to the Primary Motor Cortex Reduces Cortical Inhibition: A TMS-EEG Study.

Introduction: The aim of this study was to reveal the effects of intermittent theta burst stimulation (iTBS) in modulating cortical networks using transcranial magnetic stimulation and electroencephalography (TMS-EEG) recording. Methods: Eighteen young adults participated in our study and received iTBS to the primary motor cortex (M1), supplementary motor area, and the primary visual cortex in three separate sessions. A finger tapping task and ipsilateral single-pulse TMS-EEG recording for the M1 were administrated before and after iTBS in each session. The effects of iTBS in motor performance and TMS-evoked potentials (TEPs) were investigated. Results: The results showed that iTBS to the M1, but not supplementary motor area or the primary visual cortex, significantly reduced the N100 amplitude of M1 TEPs in bilateral hemispheres (p = 0.019), with a more prominent effect in the contralateral hemisphere than in the stimulated hemisphere. Moreover, only iTBS to the M1 decreased global mean field power (corrected ps < 0.05), interhemispheric signal propagation (t = 2.53, p = 0.030), and TMS-induced early α-band synchronization (p = 0.020). Conclusion: Our study confirmed the local and remote after-effects of iTBS in reducing cortical inhibition in the M1. TMS-induced oscillations after iTBS for changed cortical excitability in patients with various neurological and psychiatric conditions are worth further exploration.

WS2.2. Parameters of TMS

Transcranial magnetic stimulation (TMS) is a non-invasive painless technique to stimulate the human brain. This presentation will introduce basic physiological principles of how TMS excites human motor cortex. In addition, the following single-pulse and paired-pulse TMS measures of corticospinal and motor cortical excitability will be presented and discussed with respect to underpinning physiological mechanisms: motor threshold, motor evoked potential recruitment curve, cortical silent period, short-interval intracortical inhibition, intracortical facilitation, long- interval intracortical inhibition, short-interval intracortical facilitation, short-latency afferent inhibition. Pharmacological evidence will be summarized to explain the physiology of these measures. In addition, clinical utility will be exemplarily discussed by demonstrating abnormal TMS measures of corticospinal and motor cortical excitability in patients with epilepsy and Alzheimer's disease.

Evidence of neuroplasticity with robotic hand exoskeleton for post-stroke rehabilitation: a randomized controlled trial

BackgroundA novel electromechanical robotic-exoskeleton was designed in-house for the rehabilitation of wrist joint and Metacarpophalangeal (MCP) joint.ObjectiveThe objective was to compare the rehabilitation effectiveness (clinical-scales and neurophysiological-measures) of robotic-therapy training sessions with dose-matched conventional therapy in patients with stroke.MethodsA pilot prospective parallel randomized controlled study at clinical settings was designed for patients with stroke within 2 years of chronicity. Patients were randomly assigned to receive an intervention of 20 sessions of 45 min each, five days a week for four weeks, in Robotic-therapy Group (RG) (n = 12) and conventional upper-limb rehabilitation in Control-Group (CG) (n = 11). We intended to evaluate the effects of a novel exoskeleton based therapy on the functional rehabilitation outcomes of upper-limb and cortical-excitability in patients with stroke as compared to the conventional-rehabilitation. Clinical-scales– Modified Ashworth Scale, Active Range of Motion, Barthel-Index, Brunnstrom-stage and Fugl-Meyer (FM) scale and neurophysiological measures of cortical-excitability (using Transcranial Magnetic Stimulation) –Motor Evoked Potential and Resting Motor threshold, were acquired pre- and post-therapy.ResultsNo side effects were noticed in any of the patients. Both RG and CG showed significant (p < 0.05) improvement in all clinical motor-outcomes except Modified Ashworth Scale in CG. RG showed significantly (p < 0.05) higher improvement over CG in Modified Ashworth Scale, Active Range of Motion and Fugl-Meyer scale and FM Wrist-/Hand component. An increase in cortical-excitability in ipsilesional-hemisphere was found to be statistically significant (p < 0.05) in RG over CG, as indexed by a decrease in Resting Motor Threshold and increase in the amplitude of Motor Evoked Potential. No significant changes were shown by the contralesional-hemisphere. Interhemispheric RMT-asymmetry evidenced significant (p < 0.05) changes in RG over CG indicating increased cortical-excitability in ipsilesional-hemisphere along with interhemispheric changes.ConclusionRobotic-exoskeleton training showed improvement in motor outcomes and cortical-excitability in patients with stroke. Neurophysiological changes in RG could most likely be a consequence of plastic reorganization and use-dependent plasticity.Trial registry number: ISRCTN95291802

Dorsolateral prefrontal cortex excitability assessed using TMS‐EEG and its relationship with neuropsychiatric symptoms in Alzheimer’s dementia

AbstractBackgroundNeuropsychiatric symptoms (NPS) are common in patients with Alzheimer’s Dementia (AD) and cause substantial distress to patients and caregivers. Mechanisms underlying NPS are not well known. Studies have found increased cortical excitability in patients with AD. Studies in other neuropsychiatric disorders have found increased cortical excitability in association with NPS. We hypothesized that cortical excitability will be negatively associated with cognition and positively associated with NPS in AD.MethodThis cross‐sectional study included participants diagnosed with probable AD using the NIA‐AA core clinical criteria. Cognition was assessed using Montreal Cognitive Assessment (MoCA) and NPS were assessed using the Neuropsychiatric Inventory‐Questionnaire (NPI‐Q). NPIQ agitation‐hyperactivity domain scores were calculated by combining scores on agitation, aggression, anxiety, disinhibition and irritability domains. Motor threshold and Transcranial Magnetic Stimulation (TMS) intensity sufficient to induce 1 millivolt (mV) peak to peak motor evoked potential were calculated as per established methods. TMS at the 1mV intensity was applied to the dorsolateral prefrontal cortex (DLPFC) at a frequency of 0.1 Hz. Electroencephalography was collected during TMS. Cortical excitability was assessed using rectified area under the curve (AUC) for TMS‐evoked potential (TEP) during early (25‐80 ms) and late phases (80 – 200 ms). Individual TEP peak amplitudes were also calculated.ResultThe study included 25 participants (female = 17, Mean (SD) age = 74.3(7.1) Years, Mean (SD) MoCA score = 17.5 (4.6)). There was a negative correlation between MoCA and the TEP early AUC at the DLPFC site of stimulation (Spearman’s rs = ‐ 0.589, n = 24, p = 0.002). In contrast there was a positive correlation between NPI‐Q agitation ‐ hyperactivity domain scores and the TEP early AUC (Spearman’s rs = 0.422, n = 24, p = 0.04). There was also a positive correlation between total NPIQ and early TEP (P30) amplitude.ConclusionCortical excitability in the DLPFC is inversely associated with cognition and positively associated with NPS in AD. Specifically, increased excitability found during the early TEP duration suggests potential role of aberrant glutamatergic transmission and overall gamma amino butyric acid and glutamate imbalance. These findings may have important implications for developing treatment interventions targeting cortical excitability in AD.

Effect of psychotropic drugs on cortical excitability of patients with major depressive disorders: A transcranial magnetic stimulation study

Transcranial magnetic stimulation (TMS) can be used to evaluate the effects of pharmacological interventions. The aim of this study was to assess the impact of the selective serotonin reuptake inhibitor, sertraline, and the atypical antipsychotic drugs quetiapine and olanzapine, on cortical excitability in unmedicated patients with major depressive disorder (MDD). The study included 45 medication-free MDD patients diagnosed according to DSM V. They were divided randomly into three groups who received a single oral dose of one of the three drugs sertraline (50 mg), quetiapine (100 mg) and olanzapine (10 mg). Psychological evaluation was conducted using the Mini-Mental State Examination (MMSE) and Beck Depression Inventory Scale (BDI). Resting and active motor thresholds (rMT and aMT) together with contralateral and ipsilateral cortical silent periods (cSP, and iSP) were measured for each participant before and at the time of maximum concentration of drug intake. There was significant increase in excitability of motor cortex after sertraline without changes in GABAB neurotransmission. Quetiapine and olanzapine potentiated inhibitory GABAB neurotransmission (prolongation of cSP); olanzapine additionally prolonged the iSP. Thus TMS can differentiate between the impact of different psychotropic drugs on excitatory and inhibitory transmission in motor cortex.

Effect of electrical stimulation with bilateral scalp acupuncture on time parameters in video fluoroscopic swallowing study and cortical excitability in patients with dysphagia after cortical stroke

To investigate the effect of electrical stimulation with bilateral scalp acupuncture on time parameters in video fluoroscopic swallowing study and cortical excitability in patients with dysphagia after cortical stroke, as well as its possible mechanism of action. A total of 84 patients with dysphagia after cortical stroke were randomly divided into control group with 41 patients and observation group with 43 patients. The patients in the control group were given acupuncture based on acupoint selection for pseudobulbar palsy, and in addition to the treatment in the control group, the patients in the observation group were given electrical stimulation of bilateral scalp acupuncture, with acupuncture and pulse acupuncture at the lower 2/5 of the bilateral anterior oblique parietotemporal lines[on the line connecting Qianshencong (EX-HN1) to Xuanli (GB6)] and the lower 2/5 of the bilateral posterior oblique parietotemporal lines [on the line connecting Baihui (GV20)and Qubin (GB7)], with a needle retaining time of 30 minutes, once a day and 6 times a week for 3 weeks. Before treatment and after 3 weeks of treatment, oral delay time (ODT), oral transit time (OTT), pharyngeal delay time (PDT), and pharyngeal transit time (PTT) were compared between the two group; the Rosenbek Penetration-Aspiration Scale was used to evaluate penetration-aspiration and appro-ximate entropy (ApEn) of EEG nonlinear index. After treatment, both groups had significant reductions in ODT, OTT, PDT, PTT, and Rosenbek Penetration-Aspiration score and a significant increase in ApEn (P<0.05). Compared with the control group after treatment, the observation group had significant reductions in ODT and OTT (P<0.05) and significant increases in the ApEn values of bilateral central, parietal, and posterior temporal regions (P<0.05), while there were no significant differences in PDT, PTT, and Rosenbek Penetration-Aspiration score between the two groups (P>0.05). In addition to body acupuncture, electrical stimulation with bilateral scalp acupuncture can improve ODT and OTT in the treatment of patients with dysphagia after cortical stroke, which may be associated with the increased excitability of the swallowing cortex.

钠通道阻滞剂对局灶性癫痫患者皮层兴奋性的影响

钠通道阻滞剂对局灶性癫痫患者皮层兴奋性的影响

Effects of rhythmic auditory cueing on stepping in place in patients with Parkinson's disease.

Background:Stepping in place (SIP) is a useful locomotor training intervention. The purpose of this study was to investigate the effects of single auditory-cued SIP training on cortical excitability, rhythmic movements and walking ability in patients with Parkinson's disease(PD).Methods:Cross-over randomized control trial. Each participant completed two interventions with at least one-week washout period in between: (1) SIP with concurrent auditory cues (AC condition) and (2) SIP without auditory cues (NC condition).Results:In the primary outcome, the cortical silent period (CSP) duration increased (P = .005), whereas short intracortical inhibition (SICI) decreased after training (P = .001). Freezers demonstrated enhanced inhibition in the resting motor threshold and CSP duration. SICI and intracortical facilitation were modulated in both groups under the AC condition. In the secondary outcomes, the stepping variability decreased significantly (AC: P = .033; NC: P = .009), whereas walking cadence increased after training (AC: P = .019; NC: P = .0023).Conclusions:Auditory-cued SIP training improved the lower-limb movement variability and modulated the cortical excitability in patients with PD. Freezers may benefit more from this training than nonfreezers.

Changes of motor cortical excitability and response inhibition in patients with obsessive–compulsive disorder

Deficits in cortical inhibitory processes have been suggested as underlying pathophysiological mechanisms of obsessive–compulsive disorder (OCD). We examined whether patients with OCD have altered cortical excitability using paired-pulse transcranial magnetic stimulation (TMS). We also tested associations between TMS indices and OCD-related characteristics, including age of onset and response inhibition in the go/no-go paradigm, to examine whether altered cortical excitability contributes to symptom formation and behavioural inhibition deficit in patients with OCD. We assessed motor cortex excitability using paired-pulse TMS in 51 patients with OCD and 39 age-matched healthy controls. We also assessed clinical symptoms and response inhibition in the go/nogo task. All patients were undergoing treatment with serotonin reuptake inhibitors. We performed repeated-measures multivariate analysis of covariance to compare TMS indices between patients with OCD and controls. Compared to controls, patients with OCD showed a shorter cortical silent period and decreased intracortical facilitation. However, we found no significant difference between groups for resting motor threshold or short-interval intracortical inhibition. In the OCD group, the shortened cortical silent period was associated with a prompt reaction time in the go/no-go task and with early onset of OCD. We could not exclude the influence of medications on motor cortex excitability. These findings suggest abnormal cortical excitability in patients with OCD. The associations between cortical silent period and response inhibition and age of onset further indicate that altered cortical excitability may play an important role in the development of OCD.