Magnetic stimulation in the treatment of urinary retention after spinal cord injury / 中华物理医学与康复杂志

Objective:To observe any effect of magnetic stimulation of the primary motor cortex and sacral nerve roots on urinary retention after spinal cord injury.Methods:Forty patients experiencing urine retention after a spinal cord injury were randomly divided into an experimental group and a control group, each of 20. Both groups received conventional treatment and repeated magnetic stimulation of the roots of the sacral nerve. The experimental group also received repeated magnetic stimulation of the bilateral primary motor cortices (M1 region). Bladder capacity and pressure indices, residual urine volume and life quality were evaluated in both groups before and after 8 weeks of treatment.Results:After the treatment, the average maximum bladder pressure, first sensation capacity, residual urine volume and life quality score of both groups had improved significantly, but the improvements in average first sensation capacity, residual urine volume and life quality score of the experimental group were significantly greater than those of the control group. There was, however, no significant difference in the groups′ average maximum bladder pressure after the treatment.Conclusion:Magnetic stimulation of the primary motor cortex and sacral nerve roots can significantly improve the sensory function of the bladder, reduce residual urine volume and improve the life quality of persons experiencing urinary retention after a spinal cord injury.

Dyskinesia is Closely Associated with Synchronization of Theta Oscillatory Activity Between the Substantia Nigra Pars Reticulata and Motor Cortex in the Off L-dopa State in Rats / 神经科学通报·英文版

Excessive theta (θ) frequency oscillation and synchronization in the basal ganglia (BG) has been reported in elderly parkinsonian patients and animal models of levodopa (L-dopa)-induced dyskinesia (LID), particularly the θ oscillation recorded during periods when L-dopa is withdrawn (the off L-dopa state). To gain insight into processes underlying this activity, we explored the relationship between primary motor cortex (M1) oscillatory activity and BG output in LID. We recorded local field potentials in the substantia nigra pars reticulata (SNr) and M1 of awake, inattentive resting rats before and after L-dopa priming in Sham control, Parkinson disease model, and LID model groups. We found that chronic L-dopa increased θ synchronization and information flow between the SNr and M1 in off L-dopa state LID rats, with a SNr-to-M1 flow directionality. Compared with the on state, θ oscillational activity (θ synchronization and information flow) during the off state were more closely associated with abnormal involuntary movements. Our findings indicate that θ oscillation in M1 may be consequent to abnormal synchronous discharges in the BG and support the notion that M1 θ oscillation may participate in the induction of dyskinesia.

Metabolism Levels in Precentral Gyrus of Patients after Spinal Cord Injury / 中国康复理论与实践

Objective:To investigate the changes of metabolite concentration in the precentral gyrus (primary motor cortex, M1) in spinal cord injury (SCI) patients. Methods:From December, 2018 to October, 2019, 20 SCI patients and 15 healthy controls were scaned with magnetic resonance spectroscopy to measure the concentrations of N-acetylaspartate (NAA), choline (Cho), creatine (Cr) and myo-inositol (MI) in region of interest (ROI) of left M1. Results:Concentration of MI was more in the patients than in the controls (t = 3.745, P < 0.01). There was no significant difference in the concentrations of NAA, Cho and Cr, as well as the ratios of NAA/Cr, Cho/Cr, Cho/NAA between the patients and the controls (t < 1.431, P > 0.05). Conclusion:There may be hyperplasia of glial cells in M1 of SCI patients, indicating compensatory repair in cerebral motor cortex.

Modulation of Beta Oscillations for Implicit Motor Timing in Primate Sensorimotor Cortex during Movement Preparation / 神经科学通报·英文版

Motor timing is an important part of sensorimotor control. Previous studies have shown that beta oscillations embody the process of temporal perception in explicit timing tasks. In contrast, studies focusing on beta oscillations in implicit timing tasks are lacking. In this study, we set up an implicit motor timing task and found a modulation pattern of beta oscillations with temporal perception during movement preparation. We trained two macaques in a repetitive visually-guided reach-to-grasp task with different holding intervals. Spikes and local field potentials were recorded from microelectrode arrays in the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. We analyzed the association between beta oscillations and temporal interval in fixed-duration experiments (500 ms as the Short Group and 1500 ms as the Long Group) and random-duration experiments (500 ms to 1500 ms). The results showed that the peak beta frequencies in both experiments ranged from 15 Hz to 25 Hz. The beta power was higher during the hold period than the movement (reach and grasp) period. Further, in the fixed-duration experiments, the mean power as well as the maximum rate of change of beta power in the first 300 ms were higher in the Short Group than in the Long Group when aligned with the Center Hit event. In contrast, in the random-duration experiments, the corresponding values showed no statistical differences among groups. The peak latency of beta power was shorter in the Short Group than in the Long Group in the fixed-duration experiments, while no consistent modulation pattern was found in the random-duration experiments. These results indicate that beta oscillations can modulate with temporal interval in their power mode. The synchronization period of beta power could reflect the cognitive set maintaining working memory of the temporal structure and attention.

Is the omega sign a reliable landmark for the neurosurgical team? An anatomical study about the central sulcus region / O sinal do ômega é um reparo anatômico confiável para a equipe neurocirúrgica? Estudo anatômico sobre a regiāo do sulco central

ABSTRACTThe central sulcus region is an eloquent area situated between the frontal and parietal lobes. During neurosurgical procedures, it is sometimes difficult to understand the cortical anatomy of this region.Objective Find alternative ways to anatomically navigate in this region during neurosurgical procedures.Method We analyzed eighty two human hemispheres using a surgical microscope and completed a review of the literature about central sulcus region.Results In 68/82 hemispheres, the central sulcus did not reach the posterior ramus of the lateral sulcus. A knob on the second curve of the precentral gyrus was reliably identified in only 64/82 hemispheres.Conclusion The morphometric data presented in this article can be useful as supplementary method to identify the central sulcus region landmarks.

RESUMOA região do sulco central é uma área eloquente posicionada entre os lobos frontal e parietal. Durante procedimentos neurocirúrgicos, em algumas ocasiões, torna-se difícil compreender a anatomia cortical desta região.Objetivo Encontrar métodos alternativos para uma navegaçāo anatômica desta regiāo durante procedimentos neurocirúrgicos.Método Analisamos oitenta e dois hemisférios humanos usando um microscópio cirúrgico, além de fazer uma revisão da literatura.Resultados Em 68/82 hemisférios, o sulco central não atingiu o ramo posterior do sulco lateral. Uma dilatação na segunda curva do giro precentral foi encontrada em apenas 64/82 hemisférios.Conclusão Os dados morfométricos apresentados neste artigo podem ser úteis como método suplementar para identificação dos reparos anatômicos na região do sulco central.

Low frequency (0.5Hz) rTMS over the right (non-dominant) motor cortex does not affect ipsilateral hand performance in healthy humans / A inibição do córtex motor não-dominante por meio da estimulação magnética transcraniana a 0, 5Hz não interfere no desempenho manual ipsilateral de sujeitos hígidos

Reduction of excitability of the dominant primary motor cortex (M1) improves ipsilateral hand function in healthy subjects. In analogy, inhibition of non-dominant M1 should also improve ipsilateral performance. In order to investigate this hypothesis, we have used slow repetitive transcranial magnetic stimulation (rTMS) and the Purdue Pegboard test. Twenty-eight volunteers underwent 10 minutes of either 0.5Hz rTMS over right M1 or sham rTMS (coil perpendicular to scalp). The motor task was performed before, immediately after, and 20 minutes after rTMS. In both groups, motor performance improved significantly throughout the sessions. rTMS inhibition of the non-dominant M1 had no significant influence over ipsilateral or contralateral manual dexterity, even though the results were limited by unequal performance between groups at baseline. This is in contrast to an improvement in left hand function previously described following slow rTMS over left M1, and suggests a less prominent physiological transcallosal inhibition from right to left M1.

A redução da excitabilidade do córtex motor primário (M1) dominante melhora o desempenho manual ipsilateral: a inibição do M1 não-dominante poderia, analogamente, aprimorar a função manual direita. Para investigar esta hipótese, utilizou-se a estimulação magnética transcraniana repetitiva (EMTr) de baixa frequência e o teste Purdue Pegboard. Submetemos 28 voluntários a 10 minutos de EMTr sobre o M1 direito (0,5 Hz) ou a EMTr placebo (bobina perpendicular ao escalpo). O teste foi executado antes, imediatamente após e 20 minutos após a EMTr. Nos dois grupos, o desempenho manual mostrou significativa melhora entre as sessões. A inibição do M1 não-dominante não influenciou significativamente a destreza motora ipsi ou contralateral, apesar da conclusão limitada pelo desempenho discrepante dos grupos na primeira sessão. Este resultado contrasta com a melhora da função manual esquerda descrita após a EMTr sobre o M1 esquerdo e sugere uma inibição transcalosa fisiológica menos intensa do M1 direito para o esquerdo.

Immunohistochemical Study on the Changes of Neuropeptide Y Immunoreactive Neurons in the Corpus Striatum and Motor System of Aged Rat / 대한해부학회지

Decreased number of the Neuropeptide-Y[NPY] immunoreactive neurons in the corpus striatum and primary motor cortex of aged rat was detected by the immunohistochemical method. The animals were categorized into control and aged group and we used 10 Sprague-Dawley rat weighing 250-300gm for control group. 10 Sprague-Dawley rat weighing over 600gm for aged group. The number of NPY-immunoreactive neurons in corpus striatum and primary motor cortex were counted under the light microscope and the following results were obtained. 1. The NPY-immunoreactive neurons were evenly distributed in corpus striatum and in the primaty motor cortex, the NPY-immunoreactive neurons were concentrated within the layer II, III and layer V, VI. The typical NPY-immunoreactive perikarya was multipolar shape. 2. Decreased number of NPY-immunoreactive neurons were detected in some areas of corpus striatum and primary mortor cortex of the aged rat. 3. Decrease of NPY-immunoreactive neurons were most prominent in the caudate-putamen and there were moderate decrease of NPY-immunoreactive neurons in the primary motor cortex, mild decrease of NPY-immunoreactive neurons in the nucleus accumbens but the NPY-immunoreactive neurons were not observed in the globus pallidus in both control and aged rat. NPY is supposed to act as a neurotransmitter of local circuit neurons in the striatum and may exert its potent vasoconstrictor effects on cerebral vessels which influences on the microcirculation of cerebral cortex and striatum. So our results seems to provide an important data on change of the function in the striatum and primary motor cortex of aged rat brain.