Reshaping the Cortical Connectivity Gradient by Long-Term Cognitive Training During Development / 神经科学通报·英文版

The organization of the brain follows a topological hierarchy that changes dynamically during development. However, it remains unknown whether and how cognitive training administered over multiple years during development can modify this hierarchical topology. By measuring the brain and behavior of school children who had carried out abacus-based mental calculation (AMC) training for five years (starting from 7 years to 12 years old) in pre-training and post-training, we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology. We observed the development-induced emergence of the default network, AMC training-promoted shifting, and regional changes in cortical gradients. Moreover, the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery strategy. We found that gradient-based features can predict the math ability within groups. Our findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.

The Secondary Motor Cortex-striatum Circuit Contributes to Suppressing Inappropriate Responses in Perceptual Decision Behavior / 神经科学通报·英文版

The secondary motor cortex (M2) encodes choice-related information and plays an important role in cue-guided actions. M2 neurons innervate the dorsal striatum (DS), which also contributes to decision-making behavior, yet how M2 modulates signals in the DS to influence perceptual decision-making is unclear. Using mice performing a visual Go/No-Go task, we showed that inactivating M2 projections to the DS impaired performance by increasing the false alarm (FA) rate to the reward-irrelevant No-Go stimulus. The choice signal of M2 neurons correlated with behavioral performance, and the inactivation of M2 neurons projecting to the DS reduced the choice signal in the DS. By measuring and manipulating the responses of direct or indirect pathway striatal neurons defined by M2 inputs, we found that the indirect pathway neurons exhibited a shorter response latency to the No-Go stimulus, and inactivating their early responses increased the FA rate. These results demonstrate that the M2-to-DS pathway is crucial for suppressing inappropriate responses in perceptual decision behavior.

Study on after-effect of electroacupuncture with different time intervals on corticospinal excitability in primary motor cortex / 中国针灸

OBJECTIVES@#To compare the effects of electroacupuncture (EA) with different time intervals on corticospinal excitability of the primary motor cortex (M1) and the upper limb motor function in healthy subjects and observe the after-effect rule of acupuncture.@*METHODS@#Self-comparison before and after intervention design was adopted. Fifteen healthy subjects were included and all of them received three stages of trial observation, namely EA0 group (received one session of EA), EA6h group (received two sessions of EA within 1 day, with an interval of 6 h) and EA48h group (received two sessions of EA within 3 days, with an interval of 48 h). The washout period among stages was 1 week. In each group, the needles were inserted perpendicularly at Hegu (LI 4) on the left side, 23 mm in depth and at a non-acupoint, 0.5 cm nearby to the left side of Hegu (LI 4), separately. Han's acupoint nerve stimulator (HANS-200A) was attached to these two needles, with continuous wave and the frequency of 2 Hz. The stimulation intensity was exerted higher than the exercise threshold (local muscle twitching was visible, and pain was tolerable by healthy subjects, 1-2 mA ). The needles were retained for 30 min. Using the single pulse mode of transcranial magnetic stimulation (TMS) technique, before the first session of EA (T0) and at the moment (T1), in 2 h (T2) and 24 h (T3) after the end of the last session of EA, on the left first dorsal interosseous muscle, the amplitude, latency (LAT), resting motor threshold (rMT) of motor evoked potentials (MEPs) and the completion time of grooved pegboard test (GPT) were detected. Besides, in the EA6h group, TMS was adopted to detect the excitability of M1 (amplitude, LAT and rMT of MEPs) before the last session of EA (T0*).@*RESULTS@#The amplitude of MEPs at T1 and T2 in the EA0 group, at T0* in the EA6h group and at T1, T2 and T3 in the EA48h group was higher when compared with the value at T0 in each group separately (P<0.001). At T1, the amplitude of MEPs in the EA0 group and the EA48h group was higher than that in the EA6h group (P<0.001, P<0.01); at T2, it was higher in the EA0 group when compared with that in the EA6h group (P<0.01); at T3, the amplitude in the EA0 group and the EA6h group was lower than that of the EA48h group (P<0.001). The LAT at T1 was shorter than that at T0 in the three groups (P<0.05), and the changes were not obvious at the rest time points compared with that at T0 (P > 0.05). The GPT completion time of healthy subjects in the EA0 group and the EA48h group at T1, T2 and T3 was reduced in comparison with that at T0 (P<0.001). The completion time at T3 was shorter than that at T0 in the EA6h group (P<0.05); at T2, it was reduced in the EA48h group when compared with that of the EA6h group (P<0.05). There were no significant differences in rMT among the three groups and within each group (P>0.05).@*CONCLUSIONS@#Under physiological conditions, EA has obvious after-effect on corticospinal excitability and upper limb motor function. The short-term interval protocol (6 h) blocks the after-effect of EA to a certain extent, while the long-term interval protocol (48 h) prolongs the after-effect of EA.

Effects of electroacupuncture on cardiac function and local field potential of sensory and motor cortices in mice with stress cardiomyopathy / 中国针灸

OBJECTIVE@#To observe the effects of electroacupuncture (EA) on cardiac function and local field potential (LFP) in sensory and motor cortices in mice with stress cardiomyopathy (SC), and to explore the possible mechanism of EA in improving SC.@*METHODS@#Twenty-seven female C57BL/6 mice were randomized into a blank group, a model group and an EA group, 9 mice in each group. In the model group and the EA group, SC model was established by continuous intraperitoneal injection of isoproterenol (ISO) for 14 days. At the same time of modeling, EA was applied at "Neiguan" (PC 6) and "Shenmen" (HT 7) in the EA group, with disperse-dense wave, in frequency of 2 Hz/15 Hz, 15 min each time, once a day for 14 days. After intervention, the total movement distance, the number of crossing grid and the number of crossing central grid of open field test within 5 minutes were observed; the left ventricular function indexes (left ventricular diameter of end-diastole [LVIDd], left ventricular diameter of end-systole [LVIDs], left ventricular volume of end-diastole [LVEDV], left ventricular volume of end-systole [LVESV], ejection fraction [EF] and fraction shortening [FS]) were detected by echocardiography; the changes in ST-segment amplitude and PR interval of electrocardiogram were observed; the morphology of myocardial tissue was observed by HE staining; the serum levels of cortisol (CORT), cardiac troponin T (cTnT) and brain natriuretic peptide (BNP) were detected by ELISA; the changes of LFP in sensory and motor cortices were recorded by Plexon multi-channel acquisition system.@*RESULTS@#Compared with the blank group, in the model group, the total movement distance, the number of crossing grid and the number of crossing central grid of open field test were decreased (P<0.05); LVIDd, LVIDs, LVEDV and LVESV were increased (P<0.05), EF and FS were decreased (P<0.05); ST-segment amplitude was increased (P<0.05) and PR interval was prolonged (P<0.05); irregular myocardial fiber arrangement, interstitial edema and inflammatory cell infiltration were observed; the serum levels of CORT, cTnT and BNP were increased (P<0.05); in the sensory cortex, the ratios of delta, theta, alpha and beta frequency bands were increased (P<0.05), the maximum energy spectrum of theta and beta frequency bands was increased (P<0.05), the power spectral density (PSD) of delta, theta, alpha, beta and gamma frequency bands was increased (P<0.05); in the motor cortex, the ratios of delta, theta, alpha and beta frequency bands were increased (P<0.05), the maximum energy spectrum as well as PSD of delta, theta, alpha, beta and gamma frequency bands were increased (P<0.05). Compared with model group, in the EA group, the total movement distance, the number of crossing grid and the number of crossing central grid of open field test were increased (P<0.05); LVIDd, LVIDs, LVEDV and LVESV were decreased (P<0.05), EF and FS were increased (P<0.05); ST-segment amplitude was decreased (P<0.05), and the PR interval was shortened (P<0.05); myocardial fiber injury and inflammatory cell infiltration were reduced; the serum levels of CORT, cTnT and BNP were decreased (P<0.05); in the sensory cortex, the ratios of theta, alpha and beta frequency bands were decreased (P<0.05), the ratio of gamma frequency band was increased (P<0.05), the maximum energy spectrum of theta frequency band as well as the PSD of theta, alpha, beta and gamma frequency bands were decreased (P<0.05); in the motor cortex, the ratios of theta, alpha and beta frequency bands were decreased (P<0.05) and the ratio of gamma frequency band was increased (P<0.05), the maximum energy spectrum of delta frequency band was increased (P<0.05), the maximum energy spectrum of theta frequency band as well as the PSD of theta and gamma frequency bands were decreased (P<0.05).@*CONCLUSION@#EA can improve cardiac function in mice with stress cardiomyopathy, and its mechanism may be related to the regulation of local field potentials in sensory and motor cortices.

Neural Mechanism Underlying Task-Specific Enhancement of Motor Learning by Concurrent Transcranial Direct Current Stimulation / 神经科学通报·英文版

The optimal protocol for neuromodulation by transcranial direct current stimulation (tDCS) remains unclear. Using the rotarod paradigm, we found that mouse motor learning was enhanced by anodal tDCS (3.2 mA/cm2) during but not before or after the performance of a task. Dual-task experiments showed that motor learning enhancement was specific to the task accompanied by anodal tDCS. Studies using a mouse model of stroke induced by middle cerebral artery occlusion showed that concurrent anodal tDCS restored motor learning capability in a task-specific manner. Transcranial in vivo Ca2+ imaging further showed that anodal tDCS elevated and cathodal tDCS suppressed neuronal activity in the primary motor cortex (M1). Anodal tDCS specifically promoted the activity of task-related M1 neurons during task performance, suggesting that elevated Hebbian synaptic potentiation in task-activated circuits accounts for the motor learning enhancement. Thus, application of tDCS concurrent with the targeted behavioral dysfunction could be an effective approach to treating brain disorders.

From Parametric Representation to Dynamical System: Shifting Views of the Motor Cortex in Motor Control / 神经科学通报·英文版

In contrast to traditional representational perspectives in which the motor cortex is involved in motor control via neuronal preference for kinetics and kinematics, a dynamical system perspective emerging in the last decade views the motor cortex as a dynamical machine that generates motor commands by autonomous temporal evolution. In this review, we first look back at the history of the representational and dynamical perspectives and discuss their explanatory power and controversy from both empirical and computational points of view. Here, we aim to reconcile the above perspectives, and evaluate their theoretical impact, future direction, and potential applications in brain-machine interfaces.

O uso da estimulação transcraniana por corrente contínua em crianças com paralisia cerebral: uma revisão sistemática / The use of transcranial direct current stimulation in children with cerebral palsy: a systematic review

Estimulação Transcraniana por Corrente Contínua (ETCC) é um recurso terapêutico não invasivo ao paciente, de baixo custo, baseado na alteração da excitabilidade do córtex motor. Técnica capaz de influenciar no mecanismo autônomo do SNC, aumentando a eficiência sináptica e favorecendo o aprendizado motor. Objetivo: Sistematizar evidências científicas sobre a ETCC como recurso terapêutico no processo de reabilitação de crianças com paralisia cerebral. Métodos: Revisão sistematizada seguindo recomendações do PRISMA e a busca estratégica PICO diante da indicação da ETCC, como recurso terapêutico no processo de reabilitação de crianças com paralisia cerebral. Incluídos ensaios clínicos controlados e randomizados, publicados nos últimos 10 anos, disponíveis em cinco relevantes bases de dados em saúde nos idiomas inglês, espanhol e português. Resultados: Foram encontrados 604 estudos, dos quais, após aplicação dos critérios de elegibilidade, quatro deles foram selecionados. Os resultados de tais estudos se mostraram benéficos no tratamento de crianças com paralisia cerebral, incluindo aquelas com mais de 70% de presença de espasticidade. Conclusão: ETCC constitui recurso promissor no tratamento da criança com paralisia cerebral, aceito pelas crianças visto ser indolor e apresentar reações leves como vermelhidão e formigamento no local da aplicação. Os efeitos favoráveis destacados foram: melhora no desempenho funcional e da marcha. (AU)

Neuronavegación asociada a resonancia funcional motora, validación por estimulación cortical directa en cirugías de tumores de área motora / Neuronavigation associated with functional motor resonance, validation by direct cortical stimulation in motor area tumor surgeries

Objetivo: Determinar la confiabilidad de rm funcional motora (rmfm) en la localización de la corteza motora primaria en condiciones patológicas causadas por la proximidad de lesiones expansivas cerebrales con el uso intraoperatorio de electro estimulación cortical directa (ecd) Material y método: Se incluyeron 48 pacientes portadores de tumores intra axiales (nº 25) y extraaxiales (nº23) próximas al área motora, con capacidad de realizar la tarea funcional motora por rmf, y que fueron sometidos a cirugía con ecd. Durante la cirugía se realizaron 220 registros de ecd en total de la población de pacientes estudiados. La población estuvo constituida por una serie consecutiva de casos, el estudio se planificó de manera prospectiva entre los años 2007-2019, y tiene como objetivo la evaluación de la eficacia de pruebas diagnósticas (stard 2015).Se realizó una comparación sitio por sitio entre la imagen por rmfm y la ecm con la ayuda del neuronavegador. Discusión: Los resultados estadísticos de la prueba fueron: sensibilidad 82.2%, Especificidad: 76,5%, lr+:3.49, Lr-: 0,23; vpp: 74.8%, Vpn: 83.5%; Odds Postest+:2.96, Odds postest-: 0,19 y fueron publicados acordes con los standards stard 2015. Conclusiones: Las técnicas de rmfm basadas en tareas, no son suficientes para la toma de decisiones críticas intraoperatorias. No obstante, la integración de la rmfm por neuronavegación implica una planificación espacial muy confiable que permite asociar el área de activación bold a la topografía del tumor y a la tractografía, de esta forma orientar una validación por ecd rápida y segura en la resección de los tumores cerebrales

Effect of electroacupuncture combined with motor training on motor learning and motor cortex excitability / 中国针灸

OBJECTIVE@#To compare the effect of electroacupuncture (EA), motor training (MT) and EA combined with MT on motor learning and motor cortex excitability in healthy subjects, and to explore the effect of EA combined with MT on synaptic metaplasticity.@*METHODS@#Using self-control design, 12 healthy subjects were assigned into an EA group, a motor training group (MT group) and an EA plus motor training group (EA+MT group) successively, wash-out period of at least 2 weeks was required between each group. EA was applied at left Hegu (LI 4) in the EA group for 30 min, with continuous wave, 2 Hz in frequency and 0.5-1 mA in density. Motor training of left hand was adopted in the MT group for 30 min. EA and motor training were adopted in the EA+MT group successively. The time of finishing grooved pegboard test (GPT) was observed, and the average amplitude of motor evoked potentials (MEPs), the rest motor threshold (rMT) and the latency were recorded by transcranial magnetic stimulation technique before intervention (T0), after intervention (T1) and 30 min after EA (T3) in the EA group and the EA+MT group, T0 and T1 in the MT group.@*RESULTS@#Compared with T0, the time of finishing GPT was shortened at T1 in the MT group and at T2 in the EA group and the EA+MT group (@*CONCLUSION@#In physiological state, electroacupuncture combined with motor training have a synergistic effect on motor learning, while have no such effect on excitability of cerebral motor cortex.

An improved maximal information coefficient algorithm applied in the analysis of functional corticomuscular coupling for stroke patients / 生物医学工程学杂志

The functional coupling between motor cortex and effector muscles during autonomic movement can be quantified by calculating the coupling between electroencephalogram (EEG) signal and surface electromyography (sEMG) signal. The maximal information coefficient (MIC) algorithm has been proved to be effective in quantifying the coupling relationship between neural signals, but it also has the problem of time-consuming calculations in actual use. To solve this problem, an improved MIC algorithm was proposed based on the efficient clustering characteristics of K-means ++ algorithm to accurately detect the coupling strength between nonlinear time series. Simulation results showed that the improved MIC algorithm proposed in this paper can capture the coupling relationship between nonlinear time series quickly and accurately under different noise levels. The results of right dorsiflexion experiments in stroke patients showed that the improved method could accurately capture the coupling strength of EEG signal and sEMG signal in the specific frequency band. Compared with the healthy controls, the functional corticomuscular coupling (FCMC) in beta (14~30 Hz) and gamma band (31~45 Hz) were significantly weaker in stroke patients, and the beta-band MIC values were positively correlated with the Fugl-Meyers assessment (FMA) scale scores. The method proposed in this study is hopeful to be a new method for quantitative assessment of motor function for stroke patients.

Subthalamic Nucleus: Neuroanatomical Review

Discovered in 1865 by Jules Bernard Luys, the subthalamic nucleus is a set of small nuclei located in the diencephalon, inferior to the thalamus and superior to the substantia nigra, that can be visualized in a posterior coronal section. Histologically, it consists of neurons compactly distributed and filled with a large number of blood vessels and sparse myelinated fibers. This review presents an analysis of this anatomical region, considering what is most recent in the literature. Subthalamic neurons are excitatory and use glutamate as the neurotransmitter. In healthy individuals, these neurons are inhibited by nerve cells located in the side globus pallidus. However, if the fibers that make up the afferent circuit are damaged, the neurons become highly excitable, thus causing motor disturbances that can be classified as hyperkinetic, for example ballism and chorea, or hypokinetic, for example Parkinson disease (PD). The advent of deep brain stimulation has given the subthalamic nucleus great visibility. Studies reveal that the stimulation of this nucleus improves themotor symptoms of PD.

Parálisis pseudoperiférica: claves en su identificación semiológica / Pseudo-peripheral paralysis: keys in its semiological identification

RESUMEN La parálisis pseudoperiférica es una presentación infrecuente del ataque cerebrovascular (ACV) isquémico, que suele llevar a un diagnóstico erróneo de patología de nervio periférico. Se caracteriza por una presentación clínica consistente en paresia de la mano o de un grupo de dedos y alteración de la sensibilidad que puede simular el compromiso de un nervio periférico. Se reporta el caso clínico de un paciente que cursó con parálisis pseudoperiférica, con compromiso motor predominantemente cubital asociado a hipoestesia multimodal en la región hipotenar, lo cual ilustrando la dificultad de la localización topográfica para explicar el compromiso motor y sensitivo por un síndrome mononeuropático, troncular, radicular o medular. Se resalta la importancia de una adecuada evaluación semiológica, que permita hacer aproximaciones diagnósticas acertadas para dar un manejo adecuado de acuerdo con el estudio topográfico en las patologías neurológicas.

SUMMARY Pseudo-peripheral palsy is an infrequent presentation of ischemic stroke, which often leads to a misdiagnosis of peripheral nerve pathology. It is characterized by palsy of the hand or a group of fingers and altered sensitivity which can simulate peripheral nerve damage. We report a case of a patient who had pseudo-peripheral palsy with predominantly ulnar motor involvement, associated with multimodal hypoesthesia in the hypothenar region; illustrating the difficulty of topographic localization to explain motor and sensory involvement by a mononeuropathic, radicular or spinal syndrome. We highlight the importance of an adequate semiological evaluation to accurately diagnose and manage these pathologies.

Effects of Repetitive High Frequency Motor Cortex Transcranial Magnetic Stimulation and Cortical Disinhibition in Diabetic Patients with Neuropathic Pain: A Case Control Study

OBJECTIVE: To investigate the cortical disinhibition in diabetic patients with neuropathic pain and without pain. In addition, we assessed the cortical disinhibition and pain relief after repetitive transcranial magnetic stimulation (rTMS).METHOD: We recruited diabetic patients with neuropathic pain (n = 15) and without pain (n = 15). We compared the TMS parameters such as motor evoked potential (MEP) amplitude, cortical silent period (CSP), intracortical inhibition (ICI %) and intracortical facilitation (ICF %) between two groups. Moreover, we evaluated the changes of pain and TMS parameters after five consecutive high frequency (10 Hz) rTMS sessions in diabetic patients with neuropathic pain. The neuropathic pain intensity (visual analog scale) and TMS parameters were assessed on pre-rTMS, post-rTMS 1day, and post-rTMS 5 day.RESULTS: The comparison of the CSP, ICI % revealed significant differences between two groups (p<0.01). After rTMS sessions, the decrease in pain intensity across the three time points revealed a pattern of significant differences (p<0.01). The change of CSP and ICI % across the three test points revealed a pattern of significant differences (p<0.01). The ICI % revealed immediate increase after first rTMS application and significant increase after five rTMS application (p<0.01) in diabetic patients with neuropathic pain. The MEP amplitude and ICF % did not reveal any significant changes.CONCLUSION: Our findings demonstrate that cortical inhibition was decreased in diabetic patients with neuropathic pain compared with patients without pain. Furthermore, we also identified that five daily rTMS sessions restored the defective intracortical inhibition which related to improvement of neuropathic pain in diabetic patients.

Research progress on analysis methods in electroencephalography-electromyography synchronous coupling / 生物医学工程学杂志

The motor nervous system transmits motion control information through nervous oscillations, which causes the synchronous oscillatory activity of the corresponding muscle to reflect the motion response information and give the cerebral cortex feedback, so that it can sense the state of the limbs. This synchronous oscillatory activity can reflect connectivity information of electroencephalography-electromyography (EEG-EMG) functional coupling. The strength of the coupling is determined by various factors including the strength of muscle contraction, attention, motion intention etc. It is very significant to study motor functional evaluation and control methods to analyze the changes of EEG-EMG synchronous coupling caused by different factors. This article mainly introduces and compares coherence and Granger causality of linear methods, the mutual information and transfer entropy of nonlinear methods in EEG-EMG synchronous coupling, and summarizes the application of each method, so that researchers in related fields can understand the current research progress on analysis methods of EEG-EMG synchronous systematically.

Seed-Based Resting-State Functional MRI for Presurgical Localization of the Motor Cortex: A Task-Based Functional MRI-Determined Seed Versus an Anatomy-Determined Seed

OBJECTIVE: For localization of the motor cortex, seed-based resting-state functional MRI (rsfMRI) uses the contralateral motor cortex as a seed. However, research has shown that the location of the motor cortex could differ according to anatomical variations. The purpose of this study was to compare the results of rsfMRI using two seeds: a template seed (the anatomically expected location of the contralateral motor cortex) and a functional seed (the actual location of the contralateral motor cortex determined by task-based functional MRI [tbfMRI]). MATERIALS AND METHODS: Eight patients (4 with glioma, 3 with meningioma, and 1 with arteriovenous malformation) and 9 healthy volunteers participated. For the patients, tbfMRI was performed unilaterally to activate the healthy contralateral motor cortex. The affected ipsilateral motor cortices were mapped with rsfMRI using seed-based and independent component analysis (ICA). In the healthy volunteer group, both motor cortices were mapped with both-hands tbfMRI and rsfMRI. We compared the results between template and functional seeds, and between the seed-based analysis and ICA with visual and quantitative analysis. RESULTS: For the visual analysis, the functional seed showed significantly higher scores compared to the template seed in both the patients (p = 0.002) and healthy volunteers (p < 0.001). Although no significant difference was observed between the functional seed and ICA, the ICA results showed significantly higher scores than the template seed in both the patients (p = 0.01) and healthy volunteers (p = 0.005). In the quantitative analysis, the functional seed exhibited greater similarity to tbfMRI than the template seed and ICA. CONCLUSION: Using the contralateral motor cortex determined by tbfMRI as a seed could enhance visual delineation of the motor cortex in seed-based rsfMRI.

A Man Presenting with Sudden Weakness and Pain of the Right Hand, by Non-Small Cell Lung Cancer with Brain Metastases

Unexplained pain and weakness, i.e., without obvious predisposing factors, are often encountered by physiatrists and efforts should be made to determine the cause. A 63-year-old male presented with radiating pain in his right arm and mild weakness of the right hand. An electrodiagnostic examination revealed distal symmetric sensory polyneuropathy in the upper and lower extremities, and denervation potentials in the forearm muscles, which were inconsistent with the cervical spine MRI images and symptoms. A predisposing undiscovered disease was revealed, i.e., squamous cell carcinoma in the lung; brain metastasis affecting the left primary motor cortex was also detected. Therefore, we concluded that the pain and weakness were related to paraneoplastic syndrome and brain metastases of the hand knob. The observed denervation potentials were characterized as trans-synaptic changes in the brain metastasis. This case highlights the importance of unexplainable focal pain and weakness in the increasing prevalence of cancer.

Repetitive Transcranial Magnetic Stimulation Enhances Recovery in Central Cord Syndrome Patients

OBJECTIVE: To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on neurological and functional recovery in patients with central cord syndrome (CCS) involving the upper extremities between the treated and non-treated sides of the treated group and whether the outcomes are comparable to that of the untreated control group. METHODS: Nineteen CCS patients were treated with high-frequency (20 Hz) rTMS over the motor cortex for 5 days. The stimulation side was randomly selected, and all the subjects received conventional occupational therapy during the rTMS-treatment period. Twenty CCS patients who did not receive rTMS were considered as controls. Clinical assessments, including those by the International Standard for Neurological Classification of Spinal Cord Injury, the Jebsen-Taylor Hand Function Test, and the O'Connor Finger Dexterity Test were performed initially and followed up for 1 month after rTMS treatment or 5 weeks after initial assessments. RESULTS: The motor scores for upper extremities were increased and the number of improved cases was greater for the treated side in rTMS-treated patients than for the non-treated side in rTMS-treated patients or controls. The improved cases for writing time and score measured on the Jebsen-Taylor Hand Function Test were also significantly greater in number on the rTMS-treated side compared with the non-treated side and controls. There were no adverse effects during rTMS therapy or the follow-up period. CONCLUSION: The results of the application of high-frequency rTMS treatment to CCS patients suggest that rTMS can enhance the motor recovery and functional fine motor task performance of the upper extremities in such individuals.

Motor Recovery after Seizure Induced by Repetitive Transcranial Magnetic Stimulation

Despite the low incidence, seizures induced by repetitive transcranial magnetic stimulation (rTMS) have been studied as they may cause neurological and functional regression. Seizures may predict poor outcomes in stroke patients, with no reports of improved neurological status after seizures. This is the first Korean report of a seizure induced by rTMS, and the first report in the literature of prompt motor recovery following a seizure induced by high-frequency rTMS of the primary motor cortex in a stroke patient. A 43-year-old man with left hemiplegia due to infarction in the right basal ganglia was enrolled 10 sessions of rTMS (each session consisted of 15 trains, with each train consisting of 5 seconds of stimulation at 20 Hz and 90% of resting motor threshold for each session followed by 55 seconds of rest). The self-limited seizure occurred within 5 seconds after the 10th session. It lasted for 60 seconds, with generalized tonic features in all four extremities and the trunk and loss of consciousness followed by prompt improvement in left hand muscle strength and coordination. Though the seizure is known to usually cause neurologic regression, this case showed neurologic improvement after rTMS even after the rTMS-induced seizure.

Effect of Anodal Transcranial Direct Current Stimulation over the Motor Cortex for Cognition

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that modulates cortical excitability and influences cognition. The role of the primary motor cortex (M1) in cognition is controversial. Here, we investigated the offline effects of anodal and sham tDCS over M1 on cognitive tasks that require comparable motor skills, but different levels of working memory and attention. Twenty healthy young female adults received anodal tDCS and sham tDCS to the M1 on two separate testing days in a counter balanced order. The cognitive functions outcome variables were the response time from the Attention Switching Task (AST) and Motor Screening Task (MST) tests using the Cambridge Neuropsychological Test Automated Battery before and after the anodal/sham tDCS. Anodal tDCS significantly improved AST response times from baseline in congruent and incongruent condition and MST mean correct latency (all p < 0.05). There was a significant difference for AST tasks variable include AST Switching cost (mean, correct), AST Mean correct latency, in congruent, incongruent, blocks 3, 5 (non-switching blocks), block 7 (switching block) (p < 0.01) and MST mean latency (p < 0.05) between anodal and sham conditions. These results indicate that tDCS is a promising tool to an improvement in response time in task related attention and motor speed. However, this study warrants further research to determine the long-term effect on other cognitive functions and in different age and gender groups.

Reflex and Spontaneous Movements of Patients in the Process of Determining Brain Death

Brain death is a clinical diagnosis that implies irreversible loss of function of the entire brain, including the brainstem and both hemispheres. It is not uncommon for reflex and spontaneous movements to occur in patients with impending brain death during the process of determining brain death. When physicians charged with judging brain death witness such movements during this period, unless they know how common these movements are and what they mean, it will be difficult for them to make an appropriate determination of brain death. Movements following brain death have been reported in previous studies of various types, including cohort studies and case series or reports. However, only a few studies have employed verified diagnostic tools and neurological examinations as a standard protocol when diagnosing brain death. According to previous reports, the frequency of these movements ranges from 19.2% to 75.0% of all brain death cases. These reports have also described which movements are commonly seen. However, it is difficult to determine conclusively where these movements originate, i.e., in the spinal cord or in the cerebral motor cortex, and how such information should be considered in determining brain death. Although limited information is available on the characteristics and pathophysiological mechanism of these movements, it will help physicians to diagnose brain death correctly if they obtain sufficient knowledge about them.