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High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) remains a promising strategy for neurorehabilitation. The stimulation intensity (SI) influences the aftereffects observed. Here, we examined whether single sessions of a 15 Hz rTMS protocol, administered at suprathreshold SI, can be safely administered to able-bodied (AB) individuals. Six right-handed men were included in this pilot study. HF-rTMS was delivered over the right M1, in 10 trains of 75 biphasic stimuli at 15 Hz, at 105-120% of the individual resting motor threshold (RMT). To assess safety, electromyography (EMG) was monitored to control for signs of spread of excitation and brief EMG burst (BEB) after stimulation. Additionally, TMS side effects questionnaires and the numeric rating scale (NRS) were administered during each session. We assessed corticospinal excitability (CSE) and motor performance changes with measures of resting (rMEP) and active (aMEP) motor evoked potential and grip strength and box and blocks test (BBT) scores, respectively. Overall, the sessions were tolerated and feasible without any pain development. However, EMG analysis during 15 Hz rTMS administration revealed increased BEB frequency with SI. Statistical models revealed an increase of CSE at rest (rMEP) but not during active muscle contraction (aMEP). No linear relationship was observed between 15 Hz rTMS SI and rMEP increase. No significant changes were highlighted for motor performance measures. Although feasible and tolerable by the AB individuals tested, the results demonstrate that when administered at suprathreshold intensities (≥ 105% RMT) the 15 Hz rTMS protocol reveals signs of persistent excitation, suggesting that safety precautions and close monitoring of participants should be performed when testing such combinations of high-intensity and high-frequency stimulation protocols. The results also give insight into the nonlinear existent relationship between the SI and HF-rTMS effects on CSE.NEW & NOTEWORTHY The results of this pilot study show the effects of a therapeutically promising 15 Hz repetitive transcranial magnetic stimulation (rTMS) protocol, administered at different suprathreshold intensities in able-bodied individuals. Although tolerable and feasible with a neuromodulatory potential, 15 Hz rTMS might result in persistent excitability that needs to be closely monitored if administered at suprathreshold stimulation intensity. These results reaffirm the importance of feasibility studies, especially in translational animal-to-human research.
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Corteza Motora , Estimulación Magnética Transcraneal , Masculino , Humanos , Estimulación Magnética Transcraneal/efectos adversos , Proyectos Piloto , Corteza Motora/fisiología , Electromiografía/métodos , Potenciales Evocados Motores/fisiologíaRESUMEN
BACKGROUND: It has been demonstrated that in young and healthy individuals, there is a strong association between the amplitude of EEG-derived motor activity-related cortical potential or EEG spectral power (ESP) and voluntary muscle force. This association suggests that the motor-related ESP may serve as an index of central nervous system function in controlling voluntary muscle activation Therefore, it may potentially be used as an objective marker to track changes in functional neuroplasticity due to neurological disorders, aging, and following rehabilitation therapies. To this end, the relationship between the band-specific ESP-combined spectral power of EEG oscillatory and aperiodic (noise) components-and voluntary elbow flexion (EF) force has been analyzed in elder and young individuals. METHODS: 20 young (22.6 ± 0.87 year) and 28 elderly (74.79 ± 1.37 year) participants performed EF contractions at 20%, 50%, and 80% of maximum voluntary contraction (MVC) while high-density EEG signals were recorded. Both the absolute and relative ESPs were computed for the EEG frequency bands of interest. RESULTS: The MVC force generated by the elderly was foreseeably lower than that of the young participants. Compared to young, the elderly cohort's (1) total ESP was significantly lower for the high (80% MVC) force task; (2) relative ESP in beta band was significantly elevated for the low and moderate (20% MVC and 50% MVC) force tasks; (3) absolute ESP failed to have a positive trend with force for EEG frequency bands of interest; and (4) beta-band relative ESP did not exhibit a significant decrease with increasing force levels. CONCLUSIONS: As opposed to young subjects, the beta-band relative ESP in elderly did not significantly decrease with increasing EF force values. This observation suggests the use of beta-band relative ESP as a potential biomarker for age-related motor control degeneration.
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Articulación del Codo , Músculo Esquelético , Humanos , Anciano , Electromiografía , Músculo Esquelético/fisiología , Envejecimiento/fisiología , Electroencefalografía , Contracción Isométrica/fisiologíaRESUMEN
BACKGROUND: Persistent post-mastectomy pain (PPMP) is common after surgery. Although multiple modalities have been used to treat this type of pain, including medications, physical therapy, exercise interventions, cognitive-behavioral psychology, psychosocial interventions, and interventional approaches, managing PPMP may be still a challenge for breast cancer survivors. Currently, serratus plane block (SPB) as a novel regional anesthetic technique shows promising results for controlling chronic pain. METHODS: We report four cases of patients with PPMP that were treated using superficial serratus plane block (SSPB) at our clinic. A retrospective review of effect of pain relief was collected through postprocedure interviews. RESULTS: We found that two of our patients were successfully treated with SSPB for pain after treatment for breast cancer. The third patient had an intercostobrachial nerve block that produced incomplete pain relief but had adequate pain relief with a SSPB. However, the fourth patient reported no pain relief after SSPB. CONCLUSION: These cases illustrate that the patients with PPMP could benefit from SSPB. Particularly, we find patients with a subjective sense of "tightness" relating to reconstructive surgeries may be a good candidate for SSPB. Further studies are warranted to evaluate this block for PPMP, as it is low risk and relatively simple to perform.
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Neoplasias de la Mama , Bloqueo Nervioso , Neoplasias de la Mama/cirugía , Femenino , Humanos , Mastectomía/efectos adversos , Dolor Postoperatorio/terapia , Estudios Retrospectivos , Ultrasonografía IntervencionalRESUMEN
Traumatic brain injury (TBI) often results in balance impairment, increasing the risk of falls, and the chances of further injuries. However, the underlying neural mechanisms of postural control after TBI are not well understood. To this end, we conducted a pilot study to explore the neural mechanisms of unpredictable balance perturbations in 17 chronic TBI participants and 15 matched healthy controls (HC) using the EEG, MRI, and diffusion tensor imaging (DTI) data. As quantitative measures of the functional integration and segregation of the brain networks during the postural task, we computed the global graph-theoretic network measures (global efficiency and modularity) of brain functional connectivity derived from source-space EEG in different frequency bands. We observed that the TBI group showed a lower balance performance as measured by the center of pressure displacement during the task, and the Berg Balance Scale (BBS). They also showed reduced brain activation and connectivity during the balance task. Furthermore, the decrease in brain network segregation in alpha-band from baseline to task was smaller in TBI than HC. The DTI findings revealed widespread structural damage. In terms of the neural correlates, we observed a distinct role played by different frequency bands: theta-band modularity during the task was negatively correlated with the BBS in the TBI group; lower beta-band network connectivity was associated with the reduction in white matter structural integrity. Our future studies will focus on how postural training will modulate the functional brain networks in TBI.
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Lesiones Traumáticas del Encéfalo/patología , Lesiones Traumáticas del Encéfalo/fisiopatología , Ondas Encefálicas/fisiología , Conectoma , Electroencefalografía , Equilibrio Postural/fisiología , Sustancia Blanca/patología , Adulto , Lesiones Traumáticas del Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Sustancia Blanca/diagnóstico por imagenRESUMEN
The neurophysiological mechanism of cancer-related fatigue (CRF) remains poorly understood. EEG was examined during a sustained submaximal contraction (SC) task to further understand our prior research findings of greater central contribution to early fatigue during SC in CRF. Advanced cancer patients and matched healthy controls performed an elbow flexor SC until task failure while undergoing neuromuscular testing and EEG recording. EEG power changes over left and right sensorimotor cortices were analyzed and correlated with brief fatigue inventory (BFI) score and evoked muscle force, a measure of central fatigue. Brain electrical activity changes during the SC differed in CRF from healthy subjects mainly in the theta (4-8 Hz) and beta (12-30 Hz) bands in the contralateral (to the fatigued limb) hemisphere; changes were correlated with the evoked force. Also, the gamma band (30-50 Hz) power decrease during the SC did not return to baseline after 2 min of rest in CRF, an effect correlated with BFI score. In conclusion, altered brain electrical activity during a fatigue task in patients is associated with central fatigue during SC or fatigue symptoms, suggesting its potential contribution to CRF during motor performance. This information should guide the development and use of rehabilitative interventions that target the central nervous system to maximize function recovery.
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Electroencefalografía/métodos , Fatiga/diagnóstico , Fatiga/fisiopatología , Fuerza de la Mano/fisiología , Neoplasias/diagnóstico , Neoplasias/fisiopatología , Anciano , Fatiga/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/complicacionesRESUMEN
Background and Purpose: Cancer-related fatigue (CRF) is widely recognized as one of the most common symptoms and side effects of cancer and/or its treatment. However, neuropathological mechanisms contributing to CRF are largely unknown, and the lack of knowledge makes CRF difficult to treat. Recent research has shown dissociation between changes in the brain and muscle signals during voluntary motor performance in cancer survivors with CRF, and this dissociation may be caused by an interruption in functional coupling (FC) of the two signals. The goal of this study was to assess the FC between EEG (cortical signal) and EMG (muscular signal) in individuals with CRF and compare the FC with that of healthy controls during a motor task that led to progressive muscle fatigue. Method: Eight cancer survivors with CRF and nine healthy participants sustained an isometric elbow flexion contraction (at 30% maximal level) until self-perceived exhaustion. The entire duration of the EEG and EMG recordings was divided into the first-half (less-fatigue stage) and second-half (more-fatigue stage) artifact-free epochs without overlapping. The EEG-EMG coupling (measured by coherence of the two signals) in each group and stage was computed. Coherence values at different frequencies were statistically analyzed using a repeated-measure general linear model. Results: The results demonstrated that compared to healthy controls, CRF participants sustained the contraction for a significantly shorter time and exhibited robust and significantly lower EEG-EMG coherence at the alpha (8~14 Hz) and beta (15~35 Hz) frequency bands. Both the CRF and healthy control groups exhibited significantly decreased EEG-EMG coherence from the less-fatigue to more-fatigue stages at the alpha and beta frequency bands, indicating fatigue-induced weakening of functional corticomuscular coupling. Conclusion: Impaired functional coupling between the brain and muscle signals could be a consequence of cancer and/or its treatment, and it may be one of the contributing factors to the abnormal feeling of fatigue that caused the early failure of sustaining a prolonged motor task.
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Encéfalo/fisiopatología , Fatiga/fisiopatología , Contracción Isométrica/fisiología , Fatiga Muscular/fisiología , Músculo Esquelético/fisiopatología , Neoplasias/fisiopatología , Adulto , Anciano , Mapeo Encefálico , Supervivientes de Cáncer , Electroencefalografía , Electromiografía , Fatiga/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/complicacionesRESUMEN
Motor overflow, typically described in the context of unimanual movements, refers to the natural tendency for a 'resting' limb to move during movement of the opposite limb and is thought to be influenced by inter-hemispheric interactions and intra-cortical networks within the 'resting' hemisphere. It is currently unknown, however, how motor overflow contributes to asymmetric force coordination task accuracy, referred to as bimanual interference, as there is need to generate unequal forces and corticospinal output for each limb. Here, we assessed motor overflow via motor evoked potentials (MEPs) and the regulation of motor overflow via inter-hemispheric inhibition (IHI) and short-intra-cortical inhibition (SICI) using transcranial magnetic stimulation in the presence of unimanual and bimanual isometric force production. All outcomes were measured in the left first dorsal interosseous (test hand) muscle, which maintained 30% maximal voluntary contraction (MVC), while the right hand (conditioning hand) was maintained at rest, 10, 30, or 70% of its MVC. We have found that as higher forces are generated with the conditioning hand, MEP amplitudes at the active test hand decreased and inter-hemispheric inhibition increased, suggesting reduced motor overflow in the presence of bimanual asymmetric forces. Furthermore, we found that subjects with less motor overflow (i.e., reduced MEP amplitudes in the test hemisphere) demonstrated poorer accuracy in maintaining 30% MVC across all conditions. These findings suggest that motor overflow may serve as an adaptive substrate to support bimanual asymmetric force coordination.
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Potenciales Evocados Motores/fisiología , Lateralidad Funcional/fisiología , Mano , Corteza Motora/fisiología , Movimiento/fisiología , Desempeño Psicomotor/fisiología , Adulto , Análisis de Varianza , Electromiografía , Femenino , Humanos , Masculino , Inhibición Neural/fisiología , Tractos Piramidales/fisiología , Estadística como Asunto , Estimulación Magnética Transcraneal , Adulto JovenRESUMEN
The present study examined functional connectivity (FC) between functional MRI (fMRI) signals of the primary motor cortex (M1) and each of the three subcortical neural structures, cerebellum (CB), basal ganglia (BG), and thalamus (TL), during muscle fatigue using the quantile regression technique. Understanding activation relation between the subcortical structures and the M1 during prolonged motor performance should help delineate how central motor control network modulates acute perturbations at peripheral sensorimotor system such as muscle fatigue. Ten healthy subjects participated in the study and completed a 20-minute intermittent handgrip motor task at 50% of their maximal voluntary contraction (MVC) level. Quantile regression analyses were carried out to compare the FC between the contralateral (left) M1 and CB, BG, and TL in the minimal (beginning 100 s) versus significant (ending 100 s) fatigue stages. Widespread, statistically significant increases in FC were found in bilateral BG, CB, and TL with the left M1 during significant versus minimal fatigue stages. Our results imply that these subcortical nuclei are critical components in the motor control network and actively involved in modulating voluntary muscle fatigue, possibly, by working together with the M1 to strengthen the descending central command to prolong the motor performance.
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Mapeo Encefálico , Actividad Motora/fisiología , Fatiga Muscular/fisiología , Músculo Esquelético/fisiología , Vías Nerviosas/fisiología , Adulto , Cerebelo/fisiología , Fuerza de la Mano/fisiología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Corteza Motora/fisiologíaRESUMEN
PURPOSE: To study whether inconsistent findings in voxel-based morphometry (VBM) in amyotrophic lateral sclerosis (ALS) brain are due to use of different data preprocessing and statistical methods in two software packages. MATERIALS AND METHODS: T1-weighted magnetic resonance imaging (MRI) was obtained during routine clinical imaging at 1.5T in ALS patients with frontotemporal dementia (ALS-FTD) (n=18) and in unaffected neurologic controls (n=15). Gray matter (GM) VBM analysis was carried out using FMRIB software library (FSL) 4.1.5 and statistical parametric mapping 8 (SPM8). Comparison of processing steps segmentation, registration, and statistical methods (nonparametric vs. parametric) between the two softwares was performed by subjecting the same dataset through standard VBM processing pipelines. RESULTS: GM volume was significantly (P<0.05) reduced in motor and extramotor regions of ALS-FTD when compared to controls. Percentage of atrophied GM voxels in the entire brain that reached statistical significance using FSL was 22.52% compared to 0.81% in SPM. Similarly, 0.81% (3308 voxels) reached statistical significance using nonparametric statistics when compared to parametric statistics (0.50%, 2056 voxels). CONCLUSION: The differences in GM volume atrophy measures found by FSL and SPM analytic methods indicate that variable results in previous VBM studies may arise from differences in their image processing algorithms and statistical models.
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Algoritmos , Esclerosis Amiotrófica Lateral/patología , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética , Modelos Estadísticos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Persona de Mediana Edad , Programas InformáticosRESUMEN
PURPOSE: Persistent fatigue and cognitive dysfunction are poorly understood potential long-term effects of adjuvant chemotherapy. In this pilot study, we assessed the value of electroencephalogram (EEG) power measurements as a means to evaluate physical and mental fatigue associated with chemotherapy. PATIENTS AND METHODS: Women planning to undergo adjuvant chemotherapy for breast cancer and healthy controls underwent neurophysiologic assessments at baseline, during the time of chemotherapy treatment, and at 1 year. Repeated measures analysis of variance was used to analyze the data. RESULTS: Compared with controls, patients reported more subjective fatigue at baseline that increased during chemotherapy and did not entirely resolve by 1 year. Performance on endurance testing was similar in patients versus controls at all time points; however, values of EEG power increased after a physical task in patients during chemotherapy but not controls. Compared with controls, subjective mental fatigue was similar for patients at baseline and 1 year but worsened during chemotherapy. Patients performed similarly to controls on formal cognitive testing at all time points, but EEG activity after the cognitive task was increased in patients only during chemotherapy. CONCLUSION: EEG power measurement has the potential to provide a sensitive neurophysiologic correlate of cancer treatment-related fatigue and cognitive dysfunction.
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Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/psicología , Trastornos del Conocimiento/inducido químicamente , Trastornos del Conocimiento/diagnóstico , Electroencefalografía/métodos , Fatiga/inducido químicamente , Fatiga/diagnóstico , Estudios de Casos y Controles , Quimioterapia Adyuvante , Femenino , Humanos , Persona de Mediana Edad , Examen Neurológico/métodos , Proyectos PilotoRESUMEN
The fractal dimension is a morphometric measure that has been used to investigate the changes of brain shape complexity in aging and neurodegenerative diseases. This chapter reviews fractal dimension studies in aging and neurodegenerative disorders in the literature. Research has shown that the fractal dimension of the left cerebral hemisphere increases until adolescence and then decreases with aging, while the fractal dimension of the right hemisphere continues to increase until adulthood. Studies in neurodegenerative diseases demonstrated a decline in the fractal dimension of the gray matter and white matter in Alzheimer's disease, amyotrophic lateral sclerosis, and spinocerebellar ataxia. In multiple sclerosis, the white matter fractal dimension decreases, but conversely, the fractal dimension of the gray matter increases at specific stages of disease. There is also a decline in the gray matter fractal dimension in frontotemporal dementia and multiple system atrophy of the cerebellar type and in the white matter fractal dimension in epilepsy and stroke. Region-specific changes in fractal dimension have also been found in Huntington's disease and Parkinson's disease. Associations were found between the fractal dimension and clinical scores, showing the potential of the fractal dimension as a marker to monitor brain shape changes in normal or pathological processes and predict cognitive or motor function.
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Enfermedades Neurodegenerativas , Humanos , Adulto , Enfermedades Neurodegenerativas/diagnóstico por imagen , Enfermedades Neurodegenerativas/patología , Fractales , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/patología , Envejecimiento , Cerebelo/diagnóstico por imagen , Cerebelo/patologíaRESUMEN
Background: Balance impairment is one of the most debilitating consequences of Traumatic Brain Injury (TBI). To study the neurophysiological underpinnings of balance impairment, the brain functional connectivity during perturbation tasks can provide new insights. To better characterize the association between the task-relevant functional connectivity and the degree of balance deficits in TBI, the analysis needs to be performed on the data stratified based on the balance impairment. However, such stratification is not straightforward, and it warrants a data-driven approach. Approach: We conducted a study to assess the balance control using a computerized posturography platform in 17 individuals with TBI and 15 age-matched healthy controls. We stratified the TBI participants into balance-impaired and non-impaired TBI using k-means clustering of either center of pressure (COP) displacement during a balance perturbation task or Berg Balance Scale (BBS) score as a functional outcome measure. We analyzed brain functional connectivity using the imaginary part of coherence across different cortical regions in various frequency bands. These connectivity features are then studied using the mean-centered partial least squares correlation (MC-PLSC) analysis, which is a multivariate statistical framework with the advantage of handling more features than the number of samples, thus making it suitable for a small-sample study. Main Results: Based on the nonparametric significance testing using permutation and bootstrap procedure, we noticed that the theta-band connectivity strength in the following regions of interest significantly contributed to distinguishing balance impaired from non-impaired population, regardless of the type of stratification: left middle frontal gyrus, right paracentral lobule, precuneus, and bilateral middle occipital gyri. Significance: Identifying neural regions linked to balance impairment enhances our understanding of TBI-related balance dysfunction and could inform new treatment strategies. Future work will explore the impact of balance platform training on sensorimotor and visuomotor connectivity. .
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The Coronavirus disease 2019 (COVID-19), an illness caused by a SARS-CoV-2 viral infection, has been associated with neurological and neuropsychiatric disorders, revealing its impact beyond the respiratory system. Most related research involved individuals with post-acute or persistent symptoms of COVID-19, also referred to as long COVID or Post-Acute Sequelae of COVID-19 (PASC). In this longitudinal unique report, we aimed to describe the acute supraspinal and corticospinal changes and functional alterations induced by a COVID-19 infection using neuroimaging, neurophysiological and clinical assessment of a participant during acute infection, as compared to three other visits where the participant had no COVID-19. The results favor a multisystem impairment, impacting cortical activity, functional connectivity, and corticospinal excitability, as well as motor and cardiovascular function. The report suggests pathophysiological alteration and impairment already present at the acute stage, that if resolved tend to lead to a full clinical recovery. Such results could be also insightful into PASC symptomatology.
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COVID-19 , Síndrome Post Agudo de COVID-19 , Humanos , COVID-19/complicaciones , COVID-19/fisiopatología , Estudios Longitudinales , Masculino , SARS-CoV-2 , Femenino , Enfermedad Aguda , Persona de Mediana Edad , Adulto , Imagen por Resonancia MagnéticaRESUMEN
Muscle weakness associated with aging implicates central neural degeneration. However, role of the primary motor cortex (M1) is poorly understood, despite evidence that gains in strength in younger adults are associated with its adaptations. We investigated whether weakness of biceps brachii in aging analogously relates to processes in M1. We enrolled 20 young (22.6 ± 0.87 yr) and 28 old (74.79 ± 1.37 yr) right-handed participants. Using transcranial magnetic stimulation, representation of biceps in M1 was identified. We examined the effect of age and sex on strength of left elbow flexion, voluntary activation of biceps, corticospinal excitability and output, and short-interval intracortical and interhemispheric inhibition. Interhemispheric inhibition was significantly exaggerated in the old (P = 0.047), while strength tended to be lower (P = 0.075). Overall, women were weaker (P < 0.001). Processes of M1 related to strength or voluntary activation of biceps, but only in older adults. Corticospinal excitability was lower in weaker individuals (r = 0.38), and corticospinal output, intracortical inhibition and interhemispheric inhibition were reduced too in individuals who poorly activated biceps (r = 0.43, 0.54 and 0.38). Lower intracortical inhibition may reflect compensation for reduced corticospinal excitability, allowing weaker older adults to spread activity in M1 to recruit synergists and attempt to sustain motor output. Exaggerated interhemispheric inhibition, however, conflicts with previous evidence, potentially related to greater callosal damage in our older sample, our choice of proximal vs. distal muscle and differing influence of measurement of inhibition in rest vs. active states of muscle. Overall, age-specific relation of M1 to strength and muscle activation emphasizes that its adaptations only emerge when necessitated, as in a weakening neuromuscular system in aging.
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Envejecimiento/fisiología , Corteza Motora/fisiología , Fuerza Muscular , Músculo Esquelético/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Contracción Muscular , Músculo Esquelético/inervación , Inhibición Neural , Tractos Piramidales/fisiología , Factores Sexuales , Estimulación Magnética TranscranealRESUMEN
OBJECT: Dual-echo fast spin-echo (FSE) sequences are used in T2 relaxometry studies of neurological disorders because of shorter clinical scanning times and protocol simplicity. However, FSE sequences have possible spatial frequency-dependent effects, and derived T2 values may include errors that depend on the spatial frequency characteristics of the brain region of interest. MATERIALS AND METHODS: Dual-echo FSE and multi-echo spin-echo (MESE) sequences were acquired in nine subjects. The T2 decay curves for FSE and MESE sequences were estimated and percent error maps were generated. T2 error values were obtained along each patient's corticospinal tract (CST). Whole-brain white matter (WM) and gray matter (GM) T2 error values were also obtained. The paired t test was performed to evaluate differences in T2 values in the CST between FSE and MESE sequences. RESULTS: Histograms of error values in CST and in whole-brain WM and GM structures revealed systematic errors in FSE sequences. Significant differences (P < 0.001) in CST T2 values were also observed between FSE and MESE sequences. CONCLUSION: Our findings indicate that T2 values derived from FSE sequences are prone to large errors, even in low spatial frequency regions such as the CST, when compared to MESE sequences. Future studies should be aware of this limitation of FSE sequences.
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Encéfalo/patología , Imagen Eco-Planar/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Anciano , Anciano de 80 o más Años , Esclerosis Amiotrófica Lateral/patología , Imagen de Difusión Tensora/métodos , Progresión de la Enfermedad , Análisis de Fourier , Humanos , Imagen por Resonancia Magnética/métodos , Persona de Mediana Edad , Tractos Piramidales/patología , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
Following spinal cord injury (SCI), upper extremity (UE) weakness may impede one's ability to carry out activities of daily living (ADLs). Such a limitation drastically lowers a person's level of independence. Additionally, therapy and the field of assistive technology continue to place a strong premium on the restoration of UE motor function in patients with SCI. The main objective of this study was to assess the benefits of an UE myoelectric-powered wearable orthosis (MPWO) produced by MyoMo, Inc. (Boston, MA) on improving UE motor function in order to enhance ADLs and quality of life in individuals with subacute SCI. A 43-year-old man with subacute incomplete SCI (iSCI), American Spinal Injury Association (ASIA) Impairment Scale (AIS) C grade received 18 sessions (over a period of six weeks) of UE mobility therapy utilizing the MPWO. The MPWO was used to enhance active range of motion (AROM) of the hand and elbow, and associated muscle activations. After training with the MPWO, hand and elbow AROM and muscle activations were enhanced. These preliminary findings imply that UE-MPWO device-assisted rehabilitation may increase participants' UE activities, leading to improved function.Clinical Relevance- These preliminary findings from a person with iSCI in the subacute phase indicate that training with UE-MPWO assistive devices may enhance UE use during ADLs for people with muscle weakness but still having some residual voluntary muscle activation ability.
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Actividades Cotidianas , Traumatismos de la Médula Espinal , Masculino , Humanos , Adulto , Calidad de Vida , Traumatismos de la Médula Espinal/rehabilitación , Extremidad Superior , Aparatos OrtopédicosRESUMEN
Objective: The objective of this review was to evaluate the efficacy of mental imagery training (MIT) in promoting bilateral transfer (BT) of motor performance for healthy subjects. Data sources: We searched 6 online-databases (Jul-Dec 2022) using terms: "mental practice," "motor imagery training," "motor imagery practice," "mental training," "movement imagery," "cognitive training," "bilateral transfer," "interlimb transfer," "cross education," "motor learning," "strength," "force" and "motor performance." Study selection and data extraction: We selected randomized-controlled studies that examined the effect of MIT on BT. Two reviewers independently determined if each study met the inclusion criteria for the review. Disagreements were resolved through discussion and, if necessary, by a third reviewer. A total of 9 articles out of 728 initially identified studies were chosen for the meta-analysis. Data synthesis: The meta-analysis included 14 studies for the comparison between MIT and no-exercise control (CTR) and 15 studies for the comparison between MIT and physical training (PT). Results: MIT showed significant benefit in inducing BT compared to CTR (ES = 0.78, 95% CI = 0.57-0.98). The effect of MIT on BT was similar to that of PT (ES = -0.02, 95% CI = -0.15-0.17). Subgroup analyses showed that internal MIT (IMIT) was more effective (ES = 2.17, 95% CI = 1.57-2.76) than external MIT (EMIT) (ES = 0.95, 95% CI = 0.74-1.17), and mixed-task (ES = 1.68, 95% CI = 1.26-2.11) was more effective than mirror-task (ES = 0.46, 95% CI = 0.14-0.78) and normal-task (ES = 0.56, 95% CI = 0.23-0.90). No significant difference was found between transfer from dominant limb (DL) to non-dominant limb (NDL) (ES = 0.67, 95% CI = 0.37-0.97) and NDL to DL (ES = 0.87, 95% CI = 0.59-1.15). Conclusion: This review concludes that MIT can serve as a valuable alternative or supplement to PT in facilitating BT effects. Notably, IMIT is preferable to EMIT, and interventions incorporating tasks that have access to both intrinsic and extrinsic coordinates (mixed-task) are preferred over those that involve only one of the two coordinates (mirror-task or normal-task). These findings have implications for rehabilitation of patients such as stroke survivors.
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In this study functional Magnetic Resonance Imaging (fMRI) was used to evaluate cortical motor network adaptation after a rehabilitation program for upper extremity motor function in chronic stroke patients. Patients and healthy controls were imaged when they attempted to perform shoulder-elbow and wrist-hand movements in a 1.5 T Siemens scanner. We perform fMRI analysis at both single- and group-subject levels. Activated voxel counts are calculated to quantify brain activation in regions of interest. We discuss several candidate regression models for making inference on the count data, and propose an application of a generalized negative-binomial model (GNBM) with structured dispersion in the study. The effects of inappropriate statistical models that ignore the nature of data are addressed through Monte Carlo simulations. Based on the GNBM, significant activation differences are observed in a number of cortical regions for stroke versus control and as a result of treatment; notably, these differences are not detected when the data are analyzed using a conventional linear regression model. Our findings provide an improved functional neuroimaging data analysis protocol, specifically for pixel/voxel counts.
Asunto(s)
Mapeo Encefálico/métodos , Encéfalo/fisiopatología , Interpretación de Imagen Asistida por Computador/métodos , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Análisis de Regresión , Accidente Cerebrovascular/fisiopatologíaRESUMEN
Fatigue caused by sustaining submaximal-intensity muscle contraction(s) involves increased activation in the brain such as primary motor cortex (M1), primary sensory cortex (S1), premotor and supplementary motor area (PM&SMA) and prefrontal cortex (PFC). The synchronized increases in activation level in these cortical areas suggest fatigue-related strengthening of functional coupling within the motor control network. In the present study, this hypothesis was tested using the cross-correlation based functional connectivity (FC) analysis method. Ten subjects performed a 20-minute intermittent (3.5s ON/6.5s OFF, 120 trials total) handgrip task using the right hand at 50% maximal voluntary contraction (MVC) force level while their brain was scanned by a 3 T Siemens Trio scanner using echo planar imaging (EPI) sequence. A representative signal time course of the left M1 was extracted by averaging the time course data of a 2-mm cluster of neighboring voxels of local maximal activation foci, which was identified by a general linear model. Two FC activation maps were created for each subject by cross-correlating the time course data of the minimal (the first 10 trials) and significant (the last 10 trials) fatigue stages across all the voxels in the brain to the corresponding representative time course. Histogram and quantile regression analysis were used to compare the FC between the minimal and significant fatigue stages and the results showed a significant increase in FC among multiple cortical regions, including right M1 and bilateral PM&SMA, S1 and PFC. This strengthened FC indicates that when muscle fatigue worsens, many brain regions increase their coupling with the left M1, the primary motor output control center for the right handgrip, to compensate for diminished force generating capability of the muscle in a coordinated fashion by enhancing the descending command for greater muscle recruitment to maintain the same force.
Asunto(s)
Encéfalo/fisiología , Imagen por Resonancia Magnética , Fatiga Muscular/fisiología , Adulto , Mapeo Encefálico , Femenino , Humanos , MasculinoRESUMEN
PURPOSE: A systematic review and meta-analysis to examine the effect of music interventions on psychological and physical outcome measures in cancer patients. METHODS: We searched six English-language databases and three major Chinese-language databases in March 2011. Nine databases were reviewed from 1966 or the start of the database to March 2011. All randomized controlled trials comparing music intervention with standard care, other interventions, or placebo for psychological and physical outcomes in cancer were included. Study quality was evaluated by the Grading of Recommendations Assessment, Development, and Evaluation Working Group. We then performed a meta-analysis of music interventions for psychological and physical outcomes in cancer. RESULTS: Of 322 total studies found, 32 randomized trials (3181 participants) met the inclusion criteria. Seven high-quality studies indicated music had positive effects on coping anxiety assessed by the Self-Rating Anxiety Scale. Two moderate-quality studies suggested music reduced anxiety assessed by the Hamilton Anxiety Scale. Eight moderate-quality studies revealed music lowered anxiety assessed by the Spielberger State-Trait Anxiety Inventory. Seven moderate-quality studies demonstrated that music improved depression. Seven moderate-quality studies observed that music had positive effects on pain management. Two moderate-quality studies suggested music worsened fatigue. Four moderate-quality studies indicated music lowered heart rate. Three low-quality studies suggested music could reduce respiratory rate. Two moderate-quality studies indicated that music improved quality of life. CONCLUSIONS: Individual randomized trials suggest that music intervention is accepted by patients and associated with improved psychological outcomes. The effects of music on vital signs especially blood pressure are small. High-quality trials are needed to further determine the effects of music intervention.