Evaluating repetitive transcranial magnetic stimulation for neurogenic overactive bladder management in stroke survivors: A randomized sham-controlled trial protocol.

BACKGROUND: Neurogenic overactive bladder (OAB) is a distressing condition in stroke. Existing neurogenic OAB management is expensive, unstandardized regimens, or invasive. Evaluating the effectiveness of repetitive transcranial magnetic stimulation (rTMS) remains crucial. We aimed to (1) compare the effectiveness of active-rTMS with sham-rTMS on neurogenic OAB symptoms, (2) analyze whether rTMS is cost-effective, and (3) explore the rTMS's experiences on participants' symptoms. METHODS: This is a randomized, sham-controlled, double-blinded trial with embedded qualitative and cost-effectiveness studies. A total of 110 stroke survivors with neurogenic OAB symptoms were screened for eligibility; 60 participants were eligible for inclusion and were randomly assigned to either the active (n = 30) or sham-rTMS (n = 30) groups using a computer-generated randomization schedule. The active-rTMS group received low-frequency rTMS of 1200 pulses per session lasting 20 min thrice weekly to pelvic floor muscle representation at the contralesional primary motor cortex. The sham-rTMS group received low-frequency stimulation at a 20 % resting motor threshold using the same coil as the active-rTMS but was configured to reduce the TMS-induced electrical fields significantly. The primary and secondary outcome measures were assessed at baseline, post-intervention (week 4) and follow-up (week 8). The analysis of covariance (ANCOVA) analysis compared changes in the study groups. Quality-adjusted life-years (QALY) were measured to evaluate the cost-effectiveness while EQ-5D-5L estimated QALY changes. Additionally, the focus group discussion data were thematically analyzed. CONCLUSIONS: The findings from this rTMS intervention study will be useful in alleviating neurogenic OAB symptoms and enhancing patient satisfaction in a cost-effective way.

Stigma and the use of umbrellas, hiking poles and walking sticks to aid walking in Hong Kong.

Background: The use of walking aids is widely acknowledged as one of the most relied-on forms of assistive technology. Using stick-shaped devices, such as a cane, is often the entrance for many people to the world of assistive technologies, often accompanied by the negative stigma associated with ageing and disability. Objectives: This study investigated the perception of disability and needs of the Hong Kong population using walking aids, aiming to inform device design and service provision. Methods: We observed 391 individuals using cane-like devices in their natural environment and conducted semi-structured interviews with 28 participants to understand stigma, barriers to acquisition, training, and design requirements. Results: Half of the interviewees (50%, n = 14) did not feel disabled when using a walking stick, while 39% felt slightly disabled. 56% of the observed sample used non-medical-looking aids like hiking poles or umbrellas. Most interviewees (79%) purchased off-the-shelf devices, but less than half received seller support in choosing appropriate aids. Conclusion: The feelings associated with using walking sticks and similar devices are mostly positive. There is a preference in Hong Kong for using devices without a medical appearance to aid walking, such as umbrellas and hiking poles. There is a need to raise awareness of the risks of using umbrellas to aid walking and empower the user to make informed decisions when purchasing walking aid devices. In addition, there is a need to support the supply chain of walking aids, including umbrellas and hiking poles, to provide more information on device use, misuse, training, and maintenance.

Theta burst stimulation for enhancing upper extremity motor functions after stroke: a systematic review of clinical and mechanistic evidence.

This systematic review aimed to evaluate the effects of different theta burst stimulation (TBS) protocols on improving upper extremity motor functions in patients with stroke, their associated modulators of efficacy, and the underlying neural mechanisms. We conducted a meta-analytic review of 29 controlled trials published from January 1, 2000, to August 29, 2023, which investigated the effects of TBS on upper extremity motor, neurophysiological, and neuroimaging outcomes in poststroke patients. TBS significantly improved upper extremity motor impairment (Hedge's g = 0.646, p = 0.003) and functional activity (Hedge's g = 0.500, p < 0.001) compared to controls. Meta-regression revealed a significant relationship between the percentage of patients with subcortical stroke and the effect sizes of motor impairment (p = 0.015) and functional activity (p = 0.018). Subgroup analysis revealed a significant difference in the improvement of upper extremity motor impairment between studies using 600-pulse and 1200-pulse TBS (p = 0.002). Neurophysiological studies have consistently found that intermittent TBS increases ipsilesional corticomotor excitability. However, evidence to support the regional effects of continuous TBS, as well as the remote and network effects of TBS, is still mixed and relatively insufficient. In conclusion, TBS is effective in enhancing poststroke upper extremity motor function. Patients with preserved cortices may respond better to TBS. Novel TBS protocols with a higher dose may lead to superior efficacy compared with the conventional 600-pulse protocol. The mechanisms of poststroke recovery facilitated by TBS can be primarily attributed to the modulation of corticomotor excitability and is possibly caused by the recruitment of corticomotor networks connected to the ipsilesional motor cortex.

Sex differences in brain excitability revealed by concurrent iTBS/fNIRS.

Sex differences have been claimed an imperative factor in the optimization of psychiatric treatments. Intermittent theta-burst stimulation (iTBS), a patterned form of repetitive transcranial magnetic stimulation, is a promising non-invasive treatment option. Here, we investigated whether the real-time neural response to iTBS differs between men and women, and which mechanisms may mediate these differences. To this end, we capitalized on a concurrent iTBS/functional near-infrared spectroscopy setup over the left dorsolateral prefrontal cortex, a common clinical target, to test our assumptions. In a series of experiments, we show (1) a biological sex difference in absolute hemoglobin concentrations in the left dorsolateral prefrontal cortex in healthy participants; (2) that this sex difference is amplified by iTBS but not by cognitive tasks; and (3) that the sex difference amplified by iTBS is modulated by stimulation intensity. These results inform future stimulation treatment optimizations towards precision psychiatry.

The Effects of Immersive Virtual Reality-Assisted Experiential Learning on Enhancing Empathy in Undergraduate Health Care Students Toward Older Adults With Cognitive Impairment: Multiple-Methods Study.

BACKGROUND: Immersive virtual reality (IVR)-assisted experiential learning has the potential to foster empathy among undergraduate health care students toward older adults with cognitive impairment by facilitating a sense of embodiment. However, the extent of its effectiveness, including enhancing students' learning experiences and achieving intended learning outcomes, remains underexplored. OBJECTIVE: This study aims to evaluate the impacts of IVR-assisted experiential learning on the empathy of undergraduate health care students toward older people with cognitive impairment as the primary outcome (objective 1) and on their learning experience (objective 2) and their attainment of learning outcomes as the secondary outcomes (objective 3). METHODS: A multiple-methods design was used, which included surveys, focus groups, and a review of the students' group assignments. Survey data were summarized using descriptive statistics, whereas paired 2-tailed t tests were used to evaluate differences in empathy scores before and after the 2-hour IVR tutorial (objective 1). Focus groups were conducted to evaluate the impacts of IVR-assisted experiential learning on the empathy of undergraduate health care students toward older people with cognitive impairment (objective 1). Descriptive statistics obtained from surveys and thematic analyses of focus groups were used to explore the students' learning experiences (objective 2). Thematic analysis of group assignments was conducted to identify learning outcomes (objective 3). RESULTS: A total of 367 undergraduate nursing and occupational therapy students were recruited via convenience sampling. There was a significant increase in the students' empathy scores, measured using the Kiersma-Chen Empathy Scale, from 78.06 (SD 7.72) before to 81.17 (SD 8.93) after (P<.001). Students expressed high satisfaction with the IVR learning innovation, with a high satisfaction mean score of 20.68 (SD 2.55) and a high self-confidence mean score of 32.04 (SD 3.52) on the Student Satisfaction and Self-Confidence scale. Students exhibited a good sense of presence in the IVR learning environment, as reflected in the scores for adaptation (41.30, SD 6.03), interface quality (11.36, SD 3.70), involvement (62.00, SD 9.47), and sensory fidelity (31.47, SD 5.23) on the Presence Questionnaire version 2.0. In total, 3 major themes were identified from the focus groups, which involved 23 nursing students: enhanced sympathy toward older adults with cognitive impairment, improved engagement in IVR learning, and confidence in understanding the key concepts through the learning process. These themes supplement and align with the survey results. The analysis of the written assignments revealed that students attained the learning outcomes of understanding the challenges faced by older adults with cognitive impairment, the importance of providing person-centered care, and the need for an age-friendly society. CONCLUSIONS: IVR-assisted experiential learning enhances students' knowledge and empathy in caring for older adults with cognitive impairment. These findings suggest that IVR can be a valuable tool in professional health care education.

Computational simulation of transcranial magnetic stimulation-induced electric fields in the dorsolateral prefrontal cortex of heavy cannabis using individuals.

We aimed to investigate the influence of demographic and clinical modulators on the strength of transcranial magnetic stimulation (TMS)-induced electric fields (EFs) in the left dorsolateral prefrontal cortex (lDLPFC) in heavy cannabis using individuals. Structural T1-weighted magnetic resonance imaging scans of 20 heavy cannabis using individuals and 22 non-cannabis users (the controls) in the age range of 18-25 were retrieved. Computational simulations of TMS-induced EFs in the lDLPFC were performed. No significant difference in the strength of TMS-induced EFs was observed between heavy cannabis using individuals and the controls. A negative correlation between the scalp-to-cortex distance demonstrated and the strength of the induced EFs. The severity of cannabis use related problems did not correlate with the induced EFs in the lDLPFC of heavy cannabis using individuals. However, the severity of alcohol use related problems was negatively correlated with the induced EF in the lDLPFC localized by the 5-cm method in the whole sample. Early adulthood seems related to an increase in the induced EFs in the lDLPFC. In conclusion, the dominant factor influencing TMS-induced EFs was the scalp-to-cortex distance. In early adulthood, the interaction between age and comorbid substance use may influence with the magnitude of TMS-induced EFs, thereby complicating the treatment effect of TMS in young people with substance use disorders.

Resting-state cortical electroencephalogram rhythms and network in patients after chronic stroke.

OBJECTIVE: To investigate the resting-state cortical electroencephalogram (EEG) rhythms and networks in patients with chronic stroke and examine their correlation with motor functions of the hemiplegic upper limb. METHODS: Resting-state EEG data from 22 chronic stroke patients were compared to EEG data from 19 age-matched and 16 younger-age healthy controls. The EEG rhythmic powers and network metrics were analyzed. Upper limb motor functions were evaluated using the Fugl-Meyer assessment-upper extremity scores and action research arm test. RESULTS: Compared with healthy controls, patients with chronic stroke showed hemispheric asymmetry, with increased low-frequency activity and decreased high-frequency activity. The ipsilesional hemisphere of stroke patients exhibited reduced alpha and low beta band node strength and clustering coefficient compared to the contralesional side. Low beta power and node strength in the delta band correlated with motor functions of the hemiplegic arm. CONCLUSION: The stroke-affected hemisphere showed low-frequency oscillations and decreased influence and functional segregation in the brain network. Low beta activity and redistribution of delta band network between hemispheres were correlated with motor functions of hemiplegic upper limb, suggesting a compensatory mechanism involving both hemispheres post-stroke.

'Smart reminder': A feasibility pilot study on the effects of a wearable device treatment on the hemiplegic upper limb in persons with stroke.

INTRODUCTION: Emerging literature suggests that wearable devices offer a promising option for self-directed home-based upper limb training for persons with stroke. However, little research is available to explore integrating smartphone applications with wearable devices to provide upper limb telerehabilitation to stroke survivors at home. This study examined the feasibility and potential therapeutic effects of a wearable device integrated with a smartphone-based telerehabilitation system to provide upper limb rehabilitation to stroke survivors at home. METHODS: Twelve stroke survivors from community support groups participated in a treatment consisting of 4-week telerehabilitation using a wearable device and 4-week conventional therapy successively in a single-blind, randomised crossover study. A 3-week washout period was administered between the two 4-week treatments. The primary outcome measures were the Fugl Meyer Assessment, the Action Research Arm Test, and the active range of motion (ROM) of the upper limb. Secondary outcome measures included the Motor Activity Log and exercise adherence. RESULTS: Results showed that the active ROM of participants' hemiplegic shoulder improved more significantly after 4 weeks of telerehabilitation with the wearable device than with conventional therapy. No significant differences were found in other outcome measures. CONCLUSIONS: A 4-week telerehabilitation programme using a wearable device improves the hemiplegic upper limb in community-dwelling stroke survivors and may be feasible as an effective intervention for self-directed upper limb rehabilitation at home.

Rationale and protocol paper for the Asia Pacific Network for inherited eye diseases.

PURPOSE: There are major gaps in our knowledge of hereditary ocular conditions in the Asia-Pacific population, which comprises approximately 60% of the world's population. Therefore, a concerted regional effort is urgently needed to close this critical knowledge gap and apply precision medicine technology to improve the quality of lives of these patients in the Asia-Pacific region. DESIGN: Multi-national, multi-center collaborative network. METHODS: The Research Standing Committee of the Asia-Pacific Academy of Ophthalmology and the Asia-Pacific Society of Eye Genetics fostered this research collaboration, which brings together renowned institutions and experts for inherited eye diseases in the Asia-Pacific region. The immediate priority of the network will be inherited retinal diseases (IRDs), where there is a lack of detailed characterization of these conditions and in the number of established registries. RESULTS: The network comprises 55 members from 35 centers, spanning 12 countries and regions, including Australia, China, India, Indonesia, Japan, South Korea, Malaysia, Nepal, Philippines, Singapore, Taiwan, and Thailand. The steering committee comprises ophthalmologists with experience in consortia for eye diseases in the Asia-Pacific region, leading ophthalmologists and vision scientists in the field of IRDs internationally, and ophthalmic geneticists. CONCLUSIONS: The Asia Pacific Inherited Eye Disease (APIED) network aims to (1) improve genotyping capabilities and expertise to increase early and accurate genetic diagnosis of IRDs, (2) harmonise deep phenotyping practices and utilization of ontological terms, and (3) establish high-quality, multi-user, federated disease registries that will facilitate patient care, genetic counseling, and research of IRDs regionally and internationally.

Clinical tools for evaluating the severity of overactive bladder: A systematic review of psychometric properties.

OBJECTIVES: To systematically evaluate the evidence describing the psychometric properties of clinical measures for assessing overactive bladder symptoms (urinary urgency with or without urge urinary incontinence, urinary frequency and nocturia). To evaluate the quality of this evidence-base using the COnsensus-based Standards for selecting health status Measurement INstruments (COSMIN) checklist and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tools. DATA SOURCES: Five electronic databases (CINAHL, EMBASE, MEDLINE, Scopus and Web of Science) were searched from dataset inception to August 2023. REVIEW METHODS: Study screening, data extraction and quality appraisal were performed by two independent authors. Inclusion criteria were studies testing one or more psychometric properties of clinical tools for the assessment of overactive bladder symptoms among adults aged 18 years and older for both sexes. The methodological quality and quality of the evidence were evaluated using the COSMIN checklist and GRADE tools, respectively. RESULTS: The search identified 40 studies totalling 10,634 participants evaluating the psychometric properties of 15 clinical tools. The COSMIN methodological quality was rated good for most measures, and the GRADE quality of evidence ranged from low (13%) to high (33%). The Overactive Bladder Symptom Score, Overactive Bladder Questionnaire and Neurogenic Bladder Symptom Score were of good methodological and high-GRADE evidence qualities. CONCLUSION: Overactive Bladder Symptom Score, the Overactive Bladder Questionnaire and the Neurogenic Bladder Symptoms Score are promising psychometrically sound measures. The Overactive Bladder Symptom Score has been applied to the most culturally diverse populations supported by studies of good methodological and high-GRADE evidence quality.

Measures of quality of life of people with neurogenic overactive bladder: A systematic review of psychometric properties.

OBJECTIVE: To identify psychometrically robust quality-of-life (QOL) outcome measures for evaluating QOL among people with neurogenic overactive bladder (OAB). STUDY DESIGN: Electronic databases (CINAHL, EMBASE, MEDLINE, Scopus and Web of Science) were searched from inception to January 2023. Two independent reviewers participated in study screening, data extraction and quality appraisal. Studies were included if they validated at least one psychometric property of a QOL outcome measure among adults (age ≥ 18 years) with neurogenic OAB. The COnsensus-based Standards for selecting health status Measurement INstruments (COSMIN) checklist and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool were used to evaluate the methodological quality and quality of evidence, respectively, for each included study. RESULTS: Database searches identified 47 studies that tested the psychometric properties of 15 QOL measures in a total of 19,994 participants with stroke, spinal cord injury, Parkinson's disease or multiple sclerosis. The Incontinence Quality of Life Questionnaire (I-QOL), King's Health Questionnaire, Overactive Bladder Questionnaire and Qualiveen were the best validated measures, with strong reliability, validity and responsiveness. I-QOL was the most robust, cross-culturally administered and psychometrically strong measure. The COSMIN checklist indicated sufficient methodological quality for 70% of measures, and the modified GRADE tool indicated quality of evidence ranging from moderate (67%) to high (33%). CONCLUSIONS: This review identified the I-QOL as a culturally diverse measure with robust reliability, validity and responsiveness for assessing QOL among people with neurogenic OAB. These findings are supported by studies with good methodological quality (COSMIN) and high-quality evidence (GRADE).

Rapid online correction of reach-to-manipulate movements in children with developmental coordination disorder: A pilot kinematic comparison study.

BACKGROUND: Children with developmental coordination disorder show difficulties in making rapid online corrections, and this has been demonstrated in experiments where reaching/pointing movements were employed. However, typical hand movements in real-life contexts involve subsequent movements, such as grasping and manipulating objects after reaching. This study aimed to reinvestigate online correction of reaching movements that were connected with grasping and object manipulation and to explore its impact on the coordination of subsequent hand movements in children with developmental coordination disorder. METHODS: Five children with developmental coordination disorder and five children with typical development were recruited. Their reach-to-manipulate movements in a double-step task were recorded using motion analysis. The manipulative movements included simple and complex forms of pencil rotation. Movement time, movement velocity, and correlation coefficients between finger joints were derived to quantify their motor performances. FINDINGS: Children with developmental coordination disorder showed longer movement time and deceleration phases during online correction of reaching movement than children without developmental coordination disorder. In subsequent grasping and manipulation movements after online correction, they also exhibited lower correlation coefficients in four to five finger joint couplings that are essential for movement completion, compared to children without developmental coordination disorder. INTERPRETATION: Our findings from the current pilot study suggest that children with developmental coordination disorder have impairments in online correction when reaching for objects and may also have reduced coordination of some finger movements that are important for subsequent grasping and object manipulation. Future studies with larger sample sizes are warranted to confirm these findings.

Validity and Reliability of Upper Limb Kinematic Assessment Using a Markerless Motion Capture (MMC) System: A Pilot Study.

OBJECTIVE: To investigate the validity and test-retest reliability of a customized markerless motion capture (MMC) system that used iPad Pros with a Light Detection And Ranging scanner at two different viewing angles to measure the active range of motion (AROM) and the angular waveform of the upper-limb-joint angles of healthy adults performing functional tasks. DESIGN: Participants were asked to perform shoulder and elbow actions for the investigator to take AROM measurements, followed by four tasks that simulated daily functioning. Each participant attended 2 experimental sessions, which were held at least 2 days and at most 14 days apart. SETTING: A Vicon system and 2 iPad Pros installed with our MMC system were placed at 2 different angles to the participants and recorded their movements concurrently during each task. PARTICIPANTS: Thirty healthy adults (mean age: 28.9, M/F ratio: 40/60). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The AROM and the angular waveform of the upper-limb-joint angles. RESULTS: The iPad Pro MMC system underestimated the shoulder joint and elbow joint angles in all four simulated functional tasks. The MMC demonstrated good to excellent test-retest reliability for the shoulder joint AROM measurements in all 4 tasks. CONCLUSIONS: The maximal AROM measurements calculated by the MMC system had consistently smaller values than those measured by the goniometer. An MMC in iPad Pro system might not be able to replace conventional goniometry for clinical ROM measurements, but it is still suggested for use in home-based and telerehabilitation training for intra-subject measurements because of its good reliability, low cost, and portability. Further development to improve its performance in motion capture and analysis in disease populations is warranted.

Determining the Optimal Stimulation Sessions for TMS-Induced Recovery of Upper Extremity Motor Function Post Stroke: A Randomized Controlled Trial.

To find out the optimal treatment sessions of repetitive transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) for upper extremity dysfunction after stroke during the 6-week treatment and to explore its mechanism using motor-evoked potentials (MEPs) and resting-state functional magnetic resonance imaging (rs-fMRI), 72 participants with upper extremity motor dysfunction after ischemic stroke were randomly divided into the control group, 10-session, 20-session, and 30-session rTMS groups. Low-frequency (1 Hz) rTMS over the contralesional M1 was applied in all rTMS groups. The motor function of the upper extremity was assessed before and after treatment. In addition, MEPs and rs-fMRI data were analyzed to detect its effect on brain reorganization. After 6 weeks of treatment, there were significant differences in the Fugl-Meyer Assessment of the upper extremity and the Wolf Motor Function Test scores between the 10-session group and the 30-session group and between the 20- and 30-session groups and the control group, while there was no significant difference between the 20-session group and the 30-session group. Meanwhile, no significant difference was found between the 10-session group and the control group. The 20-session group of rTMS decreased the excitability of the contralesional corticospinal tract represented by the amplitudes of MEPs and enhanced the functional connectivity of the ipsilesional M1 or premotor cortex with the the precentral gyrus, postcentral gyrus, and cingulate gyrus, etc. In conclusion, the 20-session of rTMS protocol is the optimal treatment sessions of TMS for upper extremity dysfunction after stroke during the 6-week treatment. The potential mechanism is related to its influence on the excitability of the corticospinal tract and the remodeling of corticomotor functional networks.

Considerable effects of lateralization and aging in intracortical excitation and inhibition.

Introduction: Findings based on the use of transcranial magnetic stimulation and electromyography (TMS-EMG) to determine the effects of motor lateralization and aging on intracortical excitation and inhibition in the primary motor cortex (M1) are inconsistent in the literature. TMS and electroencephalography (TMS-EEG) measures the excitability of excitatory and inhibitory circuits in the brain cortex without contamination from the spine and muscles. This study aimed to investigate the effects of motor lateralization (dominant and non-dominant hemispheres) and aging (young and older) and their interaction effects on intracortical excitation and inhibition within the M1 in healthy adults, measured using TMS-EMG and TMS-EEG. Methods: This study included 21 young (mean age = 28.1 ± 3.2 years) and 21 older healthy adults (mean age = 62.8 ± 4.2 years). A battery of TMS-EMG measurements and single-pulse TMS-EEG were recorded for the bilateral M1. Results: Two-way repeated-measures analysis of variance was used to investigate lateralization and aging and the lateralization-by-aging interaction effect on neurophysiological outcomes. The non-dominant M1 presented a longer cortical silent period and larger amplitudes of P60, N100, and P180. Corticospinal excitability in older participants was significantly reduced, as supported by a larger resting motor threshold and lower motor-evoked potential amplitudes. N100 amplitudes were significantly reduced in older participants, and the N100 and P180 latencies were significantly later than those in young participants. There was no significant lateralization-by-aging interaction effect in any outcome. Conclusion: Lateralization and aging have independent and significant effects on intracortical excitation and inhibition in healthy adults. The functional decline of excitatory and inhibitory circuits in the M1 is associated with aging.

Case Report: Spectrum of interesting ocular manifestations following COVID-19 vaccination: a case series of real-world presentations.

Purpose: We report the ocular findings that patients experienced after receiving the coronavirus disease 2019 (COVID-19) vaccination in three different eye centers in Malaysia. Observations: A total of four cases were reported. Three patients received the Pfizer-BioNTech vaccine, while the other received the Oxford AstraZeneca type. Ocular symptoms occurred after the first vaccine dose in two patients and after the second vaccine dose in the other two. Three out of four patients required active treatment for their vision complications postvaccination. The first patient had acute-onset retinal pigment epitheliitis within 3 h of vaccination and was treated conservatively. The second patient developed unilateral choroidal neovascularization 3 days after vaccination and required intravitreal antivascular endothelial growth factor injection. The third patient presented with bilateral acute multifocal placoid pigment epitheliopathy a week after vaccination and responded to intravenous methylprednisolone. The fourth patient presented with herpes zoster infection and unilateral anterior nongranulomatous uveitis 2 weeks after vaccination and was treated with oral acyclovir and topical corticosteroids. All patients reported some amount of visual recovery. Conclusions and importance: Visual symptoms and various ocular adverse events can occur following COVID-19 vaccination, which warrants further investigation and urgent intervention if necessary. We would suggest patients receiving the COVID-19 vaccination be aware of possible ocular complications and report any symptoms, regardless of severity.

Cortical Contributions to Imagined Power Grip Task: An EEG-Triggered TMS Study.

Previous studies have demonstrated that motor imagery leads to desynchronization in the alpha rhythm within the contralateral primary motor cortex. However, the underlying electrophysiological mechanisms responsible for this desynchronization during motor imagery remain unclear. To examine this question, we conducted an investigation using EEG in combination with noninvasive transcranial magnetic stimulation (TMS) during index finger abduction (ABD) and power grip imaginations. The TMS was administered employing diverse coil orientations to selectively stimulate corticospinal axons, aiming to target both early and late synaptic inputs to corticospinal neurons. TMS was triggered based on the alpha power levels, categorized in 20th percentile bins, derived from the individual alpha power distribution during the imagined tasks of ABD and power grip. Our analysis revealed negative correlations between alpha power and motor evoked potential (MEP) amplitude, as well as positive correlations with MEP latency across all coil orientations for each imagined task. Furthermore, we conducted functional network analysis in the alpha band to explore network connectivity during imagined index finger abduction and power grip tasks. Our findings indicate that network connections were denser in the fronto-parietal area during imagined ABD compared to power grip conditions. Moreover, the functional network properties demonstrated potential for effectively classifying between these two imagined tasks. These results provide functional evidence supporting the hypothesis that alpha oscillations may play a role in suppressing MEP amplitude and latency during imagined power grip. We propose that imagined ABD and power grip tasks may activate different populations and densities of axons at the cortical level.