Responses of human primary sensorimotor and supplementary motor areas to internally triggered unilateral and simultaneous bilateral one‐digit movements. A high‐resolution EEG study

We modelled the responses of human primary sensorimotor areas and supplementary motor area to simple, self-initiated unilateral and simultaneous bilateral middle finger movements using a novel high-resolution electroencephalography technology. The results support the view that these cortical motor areas are involved in parallel and present similar activity in the preparation, initiation, and execution of the contralateral and bilateral movements. Furthermore, the left primary sensorimotor area (dominant hemisphere) appears to be activated more than the right primary sensorimotor area during the preparation and performance of the ipsilateral movements.     

不同重复经颅磁刺激模式对脑卒中后上肢运动功能障碍干预效果的网状Meta分析

背景 上肢运动功能障碍是脑卒中后常见的后遗症之一,严重影响患者日常生活能力。重复经颅磁刺激（rTMS）作为常见的神经电生理技术对治疗脑卒中后上肢运动功能障碍有较好的疗效,但临床对不同rTMS干预模式的选择仍缺乏循证依据。目的 采用网状Meta分析方法比较rTMS的4种模式对脑卒中后上肢运动功能障碍患者的临床疗效。方法 计算机检索PubMed、Embase、Cochrane Library、Web of Science、中国生物医学文献数据库、中国知网、万方数据知识服务平台、维普网中有关rTMS治疗脑卒中后上肢运动功能障碍的随机对照试验,并通过追溯Meta分析的参考文献作为补充。检索时间均为建库至2022年2月,采用主题词和自由词结合方式进行。2名研究者进行文献筛选、资料提取及质量评价。采用RevMan 5.0软件和Stata 16.0软件进行统计学分析。结果 最终纳入17篇文献,790例患者,共涉及6种干预措施：高频rTMS(HF-rTMS)、低频rTMS(LF-rTMS)、间断性theta节律刺激（iTBS）、连续性theta节律刺激（cTBS）、假刺激、常规疗法。网状Meta分析结...     

Comparison of mathematically determined blood lactate and heart rate “threshold” points and relationship with performance

Summary The purpose of this study was to investigate the relationship between threshold points for heart rate ( ) and blood lactate (Th_1a) as determined by two objective mathematical models. The models used were the mono-segmental exponential (EXP) model of Hughson et al. and the log-log (LOG) model of Beaver et al. Inter-correlations of these threshold points and correlations with performance were also studied. Seventeen elite runners (mean, SD = 27.5, 6.5 years; 1.73, 0.05 m; 63.8, 7.3 kg; and maximum oxygen consumption of 67.8, 3.7 ml · kg^–1 · min^–1) performed two maximal multistage running field tests on a 183.9-m indoor track with inclined turns. The initial speed of 9 km · h^–1 (2.5 m · s^–1) was increased by 0.5 km · h^–1 (0.14 m · s^–1) every lap for thef _c test and by 1 km · h^–1 (0.28 m · s^–1) every 4 min for the la test. After fitting the la or thef _c data to the two mathematical models, the threshold speed was assessed in the LOG model from the intersection of the two linear segments (LOG-1a; LOG-f _c) and in the EXP model from a tangent point (TI-1a; TI-f _c). Th_1a and speeds computed with the two models were significantly different (P<0.001) and poorly correlated (LOG-1a vs LOG-f _c:r=0.36, TI-1a vs TI-f _c:r=0.13). In general, were less well correlated with performance than Th_1a. With two different objective mathematical models, this study has shown significant differences and poor correlations between Th_1a and . Thus thef _c inflection point with Conconi's protocol is a poor indicator of the la breakpoint with a conventional multistage protocol and a weaker indicator of running performance.     

Surface EMG in the recording of fasciculations.

The usefulness of multichannel surface recording of fasciculations was evaluated by a retrospective study of 116 patients with various neurological disorders. Eight channels of a conventional electroencephalograph were used with plate electrode recordings from the upper arms and legs. Wide-spread fasciculations (defined as five or more of the eight muscle groups) were recorded in 48 of 54 patients with motor neuron disease, spinal muscular atrophy or postpolio syndrome, but noted on routine clinical examination at presentation in only 6. Eleven of 23 patients with peripheral neuropathy or myelopathy had fasciculations in five or more leads compared to one clinically, and 3 of 39 with other neurological diseases had fasciculations electrically but in only one were they clinically observed. The method is a noninvasive and sensitive adjunct to clinical examination for detecting fasciculations. Its diagnostic value is limited by the relatively high incidence of fasciculations in neuropathies and myelopathies. However, this study suggests that "false negatives" are rare and that the diagnosis of motor neuron disease should be reconsidered when less than five leads shows fasciculations.     

Quantification of motor deficit in Parkinson's disease with a motor performance test series

Summary It was the purpose of the present study to quantify the expected motor deficit in parkinsonian patients with the computer assisted Motor Performance Test Series (MPS), version 05.87 by Schuhfried (1987) and to examine which of the motor test variables found correlate at a significance level of p<0.01 with items of motor examination recorded at neurological examination and activities of daily living of the Unified Parkinson's Disease Rating Scale (UPDRS), version 3.0.38 patients with idiopathic Parkinson's disease (PD) stages I–IV according to Hoehn and Yahr, aged 41 to 73 years were studied. The study design, i.e. initial rating by the physician followed immediately by testing of motor function with MPS was strictly adhered to in each patient.Physician's rating of rigor and the scores of the semiquantitative tests (finger taps, hand movements and alternating movements) as expression of hypokinesia and the activities of daily living correlated with the 3 factors of the Motor Performance Test Series at a highly significant level independent of disease stage. Tremor is only partly and never significantly reflected in the motor data measured. Stages I–II and II–IV (Hoehn and Yahr) differ significantly in the representative data of the Motor Performance Test Series.The results of the study support the assumption that MPS is a valid instrument for quantitative measurement of the motor deficit in parkinsonian patients, but that only some subtests are pathognomonic.     

Cerebellar connections with the motor cortex and the arcuate premotor area: an analysis employing retrograde transneuronal transport of WGA-HRP

We have employed transneuronal transport to examine the anatomical relationships between the deep cerebellar nuclei and 2 cortical motor areas: the primary motor cortex and the arcuate premotor area (APA). In the same animals, we have also examined the patterns of labeling in the thalamus and the red nucleus to provide evidence for the potential routes of transneuronal transport to the cerebellum. When the appropriate technical procedures were employed, cortical injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) resulted in transneuronal labeling within portions of the contralateral deep cerebellar nuclei. Injections into the primary motor cortex labeled neurons in the dentate and in the 2 subdivisions of the interpositus. Injections into the APA labeled neurons in the dentate and in only the posterior subdivision of the interpositus. In most instances, dentate neurons were more intensely labeled following the cortical injections than interpositus neurons. The transneuronal labeling observed in the dentate nucleus was topographically organized. The dentate region that was labeled following injections into the "arm area" of the APA was caudal and ventral to the dentate region that was labeled following injections into the "arm area" of the primary motor cortex. This observation provides evidence for two "arm areas" in the dentate: one anatomically related to the APA, and the other related to the primary motor cortex. More than one route of transport may be responsible for the labeling of cerebellar neurons. We propose that the labeling observed in the dentate nucleus reflects the pattern of connections in the cerebellothalamocortical pathways that link the dentate with the cerebral cortex. Thus, our observations support the concept proposed by Schell and Strick (J. Neurosci. 4:539-560, '84)--that the cortical targets of the dentate nucleus include both the primary motor cortex and the APA.     

Plateau potentials evoked by climbing-fibre stimulation are restricted to the Purkinje cell dendrites of the cat

The present study investigated the duration of afterdepolarizations in Purkinje cell somata following climbing-fibre activation. Intracellular recordings revealed that, in cells with membrane potentials more negative than -50 mV and with normal spike-generating capabilities, climbing-fibre activation resulted in somatic responses with short afterdepolarizations. As the cell deteriorated and the resting membrane potential became more positive, the duration and form of the climbing-fibre response resembled the plateau potentials recorded from proximal dendrites. The absence of plateau potentials in undamaged Purkinje cell somata was confirmed by extracellular recording of test spike amplitudes following evoked climbing-fibre responses.     

Conventional anticonvulsant drugs in the guinea pig kindling model of partial seizures: effects of acute phenobarbital,valproate, and ethosuximide

This study addressed the anticonvulsant effects of phenobarbital, valproate, and ethosuximide in the amygdala of kindled guinea pigs to further validate this model for the screening of anticonvulsant drugs. Behavioral toxic effects were assessed at 30 min following drug administration using quantitative locomotor tests, as well as scores on a sedation and muscle relaxation rating index. The anticonvulsant efficacy of the drugs were evaluated from measurements of afterdischarge threshold (ADT), afterdischarge duration (ADD), and behavioral seizure severity (SS) during early and late phases of kindling acquisition, and in kindled guinea pigs. ADD and SS were also measured in response to both threshold and suprathreshold kindling stimulation. All drugs exerted slight to moderate sedative effects in guinea pigs on both the behavioral tests and rating index. We found that phenobarbital exhibited effective anticonvulsant properties in guinea pigs by consistently reducing ADD and SS in response to both threshold and suprathreshold kindling stimulation. Valproate exhibited effective anticonvulsant properties at threshold stimulation and less effective properties at suprathreshold stimulation. Lastly, we found that ethosuximide lacked effective anticonvulsant action at either threshold or suprathreshold kindling stimulation. Our results indicate that the guinea pig kindling model correctly predicted the actions of phenobarbital, valproate, and ethosuximide in the treatment of partial seizures. Guinea pig amygdala kindling appears to serve as a useful and valid model for partial epilepsy.     

Prolyl-leucyl-glycinamide shares some effects with oxytocin but decreases oxytocin levels

Oxytocin treatment in rats induces long-lasting antistress and growth promoting effects. This study investigated whether prolyl-leucyl-glycinamide (PLG) (the c-terminal tripeptide of oxytocin) or tocinoic acid (the ring structure of oxytocin) could induce some of these effects in male rats. For this purpose, PLG (2 or 10 mg/kg, s.c.) or tocinoic acid (1 mg/kg, s.c.) was administered to rats once a day for 3 or 5 days. Blood pressure, heart rate, spontaneous motor activity, nociceptive thresholds, and the survival of ischaemic musculocutaneous flaps were measured. In addition, endogenous oxytocin levels and plasma levels of some hormones known to be influenced by oxytocin were determined. PLG (2 mg/kg, s.c., but not 10 mg/kg, s.c.) decreased diastolic blood pressure (p<0.05) and locomotor activity (p<0.05). PLG (10 mg/kg, s.c.) decreased gastrin (p<0.05) and endogenous oxytocin levels in plasma (p<0.01). Tocinoic acid decreased locomotor activity (p<0.05), but did not affect any of the other parameters measured. In conclusion, this study showed that both PLG and tocinoic acid decrease locomotor activity. In addition, PLG also induced some other effects similar to those induced by oxytocin treatment but when administered in high doses it decreased oxytocin levels.     

Repeated measurement of the gas exchange threshold: relative size of measurement and biological variabilities

If an individual's gas exchange threshold (GET) is measured on several separate occasions, without a change in aerobic fitness, a random variability will be observed. However, it is not known how much of this variability is biologically determined and how much results from variability in the calibration and measurement processes. The statistical re-sampling technique of Bootstrapping was used to estimate the variability of the GET on a single occasion. This analysis provides the first estimate of the combined contribution of breath-by-breath measurement and calibration processes (6%), to the total between-occasion random variability, leaving biological variability to account for the remainder of the imprecision in the measurement of the GET.