scholarly journals EMG ACTIVITY OF UPPER LIMB MUSCLES IN THE CASE OF NERVOUS MUSCULAR TRANSMISSION’S PATHOLOGY IN THE HUMAN

2019 ◽  
Author(s):  
Olena Chekh ◽  
Olena Morenko ◽  
Olha Tytiuk ◽  
Alevtyna Morenko
Keyword(s):  
Upper Limb ◽  
Neuromuscular Transmission ◽  
Clinical Pathology ◽  
Propagation Rate ◽  
Emg Activity ◽  
Abductor Pollicis Brevis ◽  
Abductor Digiti Minimi ◽  
The Right ◽  
Pathological Group ◽  
Stimulation Of

In many cases of a disease or an injury of the upper extremity nerve impulses are impaired. The high level of diagnostic and tactical errors in upper limb's nerve damage often leads to poor treatment outcomes. An important, and sometimes decisive, factor in the choice of treatment is the assessment of the functional state of the nerves and muscles of the affected limb segment. The purpose of this testing is to study the features of the upper limb muscles's EMG activity in normal and in the case of clinical pathology of neuromuscular transmission. 24 volunteers between the ages of 17 and 32, both male and female, with the right profile of manual asymmetry took part in the study. While dividing into groups, the presence of the diagnosted pathology of the upper right limb's neuromuscular transmission was taken into account. Accordingly, we created a "pathological" (n = 8) and "healthy" (n = 16) groups. In both groups, we sequentially recorded the M-response of the abductor pollicis brevis during stimulation of the nerve medianus as well as the M-response of the abductor digiti minimi during stimulation of the nerve ulnaris. The M-response amplitude, residual latency (RL), and excitation propagation rate (EPR) were analyzed. It has been established that the amplitudes of the M-responce during EMG stimulation of the abductor pollicis brevis and the abductor digiti minimi were lower in pathological group than tin normal. According to our results, RL of examined muscles' M-response increased with distanting away from the stimulation point (muscle's working point). In the case of pathology we observed longer RL of M-responce than in healthy testees. In the case of stimulation of the abductor pollicis brevis EPR was comparely higher on the elbow-shoulder segment and the wrist-shoulder segment in the pathological group, wereas while stimulation of the abductor digiti minimi we established inverse relationship. EPR in all segments, namely the wrist-shoulder and elbow-shoulder, was lower in the pathologic group compared to the norm.

Electrophysiological Evaluation and Clinical Implication of Martin-Gruber Anastomosis in Healthy Subjects

2020 ◽  
Vol 25 (01) ◽  
pp. 87-94
Author(s):  
Mohamed Hefny ◽  
Asser Sallam ◽  
Maii Abdellatif ◽  
Shaimaa Okasha ◽  
Marwa Orabi
Keyword(s):  
Healthy Subjects ◽  
Anatomic Variation ◽  
Electrophysiological Study ◽  
Mean Amplitude ◽  
Sensory Loss ◽  
Abductor Pollicis Brevis ◽  
Motor Action ◽  
Compound Muscle Action Potentials ◽  
Abductor Digiti Minimi ◽  
The Right

Background: The aim of this study is to determine the prevalence of Martin-Gruber Anastomosis (MGA) in healthy Egyptian subjects, and to discuss the available literature regarding MGA subtypes and their clinical implications. Methods: An electrophysiological study was conducted in both forearms of 140 healthy subjects. This included the ulnar and median nerves. Compound muscle action potentials were recorded from abductor pollicis brevis, abductor digiti minimi, and first dorsal interosseous muscles. Other measurements included the compound motor action potential amplitude and its innervation ratio. Results: MGA was found in 56 of the 280 forearms. This included 20 men and 36 women. Type II MGA subtype was the most frequent in both genders. The MGA was bilateral in 6 subjects and more frequent on the right side. The highest mean amplitude and innervation ratio were recorded at first dorsal interosseus muscle. Conclusions: The prevalence of MGA in the studied sample of the Egyptian population is 20%. It is important for Hand, Orthopaedic and Neurosurgeons to be aware of this anatomic variation in order to explain paradoxical motor and sensory loss in patients.

scholarly journals Integration of Visual and Tactile Signals From the Hand in the Human Brain: An fMRI Study

2011 ◽  
Vol 105 (2) ◽  
pp. 910-922 ◽  
Author(s):  
Giovanni Gentile ◽  
Valeria I. Petkova ◽  
H. Henrik Ehrsson
Keyword(s):  
Upper Limb ◽  
Premotor Cortex ◽  
Brain Regions ◽  
Multisensory Perception ◽  
Tactile Information ◽  
Tactile Stimuli ◽  
Fmri Study ◽  
Subcortical Regions ◽  
The Right ◽  
Stimulation Of

In the non-human primate brain, a number of multisensory areas have been described where individual neurons respond to visual, tactile and bimodal visuotactile stimulation of the upper limb. It has been shown that such bimodal neurons can integrate sensory inputs in a linear or nonlinear fashion. In humans, activity in a similar set of brain regions has been associated with visuotactile stimulation of the hand. However, little is known about how these areas integrate visual and tactile information. In this functional magnetic resonance imaging experiment, we employed tactile, visual, and visuotactile stimulation of the right hand in an ecologically valid setup where participants were looking directly at their upper limb. We identified brain regions that were activated by both visual and tactile stimuli as well as areas exhibiting greater activity in the visuotactile condition than in both unisensory ones. The posterior and inferior parietal, dorsal, and ventral premotor cortices, as well as the cerebellum, all showed evidence of multisensory linear (additive) responses. Nonlinear, superadditive responses were observed in the cortex lining the left anterior intraparietal sulcus, the insula, dorsal premotor cortex, and, subcortically, the putamen. These results identify a set of candidate frontal, parietal and subcortical regions that integrate visual and tactile information for the multisensory perception of one's own hand.

A rare variation in the formation of the lower trunk of the brachial plexus its embryological basis and clinical importance - a case report

2012 ◽  
Vol 6 (4) ◽  
pp. 49-52
Author(s):  
N Satyanarayana ◽  
R Guha ◽  
P Sunitha ◽  
GN Reddy ◽  
G Praveen ◽  
...  
Keyword(s):  
Case Report ◽  
Brachial Plexus ◽  
Upper Limb ◽  
Clinical Importance ◽  
Medical Sciences ◽  
Nerve Roots ◽  
Rare Variation ◽  
Lower Trunk ◽  
Male Cadaver ◽  
The Right

Brachial plexus is the plexus of nerves, that supplies the upper limb.Variations in the branches of brachial plexus are common but variations in the roots and trunks are very rare. Here, we report one of the such rare variations in the formations of the lower trunk of the brachial plexus in the right upper limb of a male cadaver. In the present case the lower trunk was formed by the union of ventral rami of C7,C8 and T1 nerve roots. The middle trunk was absent. Upper trunk formation was normal. Journal of College of Medical Sciences-Nepal,2011,Vol-6,No-4, 49-52 DOI: http://dx.doi.org/10.3126/jcmsn.v6i4.6727

Phosphene perceptions and safety of chronic visual cortex stimulation in a blind subject

2020 ◽  
Vol 132 (6) ◽  
pp. 2000-2007 ◽  
Author(s):  
Soroush Niketeghad ◽  
Abirami Muralidharan ◽  
Uday Patel ◽  
Jessy D. Dorn ◽  
Laura Bonelli ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Adverse Events ◽  
Clinical Intervention ◽  
Occipital Cortex ◽  
Neuronal Population ◽  
Serious Adverse Events ◽  
Stimulation Parameters ◽  
The Right ◽  
Visual Cortical ◽  
Stimulation Of

Stimulation of primary visual cortices has the potential to restore some degree of vision to blind individuals. Developing safe and reliable visual cortical prostheses requires assessment of the long-term stability, feasibility, and safety of generating stimulation-evoked perceptions.A NeuroPace responsive neurostimulation system was implanted in a blind individual with an 8-year history of bare light perception, and stimulation-evoked phosphenes were evaluated over 19 months (41 test sessions). Electrical stimulation was delivered via two four-contact subdural electrode strips implanted over the right medial occipital cortex. Current and charge thresholds for eliciting visual perception (phosphenes) were measured, as were the shape, size, location, and intensity of the phosphenes. Adverse events were also assessed.Stimulation of all contacts resulted in phosphene perception. Phosphenes appeared completely or partially in the left hemifield. Stimulation of the electrodes below the calcarine sulcus elicited phosphenes in the superior hemifield and vice versa. Changing the stimulation parameters of frequency, pulse width, and burst duration affected current thresholds for eliciting phosphenes, and increasing the amplitude or frequency of stimulation resulted in brighter perceptions. While stimulation thresholds decreased between an average of 5% and 12% after 19 months, spatial mapping of phosphenes remained consistent over time. Although no serious adverse events were observed, the subject experienced mild headaches and dizziness in three instances, symptoms that did not persist for more than a few hours and for which no clinical intervention was required.Using an off-the-shelf neurostimulator, the authors were able to reliably generate phosphenes in different areas of the visual field over 19 months with no serious adverse events, providing preliminary proof of feasibility and safety to proceed with visual epicortical prosthetic clinical trials. Moreover, they systematically explored the relationship between stimulation parameters and phosphene thresholds and discovered the direct relation of perception thresholds based on primary visual cortex (V1) neuronal population excitation thresholds.

INFLUENCE OF RIGHT VENTRICULAR LEAD IMPLANTATION SITE CHOICE ON PACING EFFICIENCY

2020 ◽  
pp. 13-17
Author(s):  
Dmitrii Aleksandrovich Lopyn ◽  
Stanislav Valerevich Rybchynskyi ◽  
Dmitrii Evgenevich Volkov
Keyword(s):  
Heart Failure ◽  
Right Ventricular ◽  
Longitudinal Strain ◽  
Treatment Options ◽  
Global Longitudinal Strain ◽  
Optimal Method ◽  
Cardiac Stimulation ◽  
Ventricular Lead ◽  
The Right ◽  
Stimulation Of

Currently the electrophysiological treatment options have been considered to be the most effective for many patients with arrhythmogenic cardiomyopathies, as well as in those with arrhythmias on the background of heart failure. Currently, the dependence of efficiency of the pacemakers on the location of the electrodes has been proven. In order to study the effect of a myocardial dysynchrony on the effectiveness of pacing depending on the location of the right ventricular electrode, an investigation has been performed. This study comprised the patients with a complete atrioventricular block, preserved ejection fraction of the left ventricle (more than 50 %), with no history of myocardial infarction, who were implanted with the two−chamber pacemaker. It has been established that the best results were achieved with a stimulation of the middle and lower septal zone of the right ventricle, the worst ones were obtained with a stimulation of its apex. It has been found that the dynamics of the magnitude of segmental strains and a global longitudinal strain coincided with the dynamics of other parameters of the pacemaker effectiveness, which indicated the pathogenetic value of myocardial dysynchrony in the progression of heart failure after implantation of the pacemaker. Therefore it could be concluded that the studying of myocardial mobility by determining a longitudinal strain for assessing the functional state of the myocardium and the effectiveness of pacing is highly advisable. It is emphasized that the use of the latest strains−dependent techniques for cardiac performance evaluation in the patients with bradyarrhythmia have a great potential to predict the development of chronic heart failure and to choose the optimal method of physiological stimulation of the heart. Key words: right ventricular lead, cardiac stimulation, myocardial dyssynchrony.

СТИМУЛИРОВАНИЕ ПРАВОПОСЛУШНОГО ПОВЕДЕНИЯ ОСУЖДЕННЫХ В МЕСТАХ ЛИШЕНИЯ СВОБОДЫ В СОВЕТСКОМ И СОВРЕМЕННОМ РОССИЙСКОМ ЗАКОНОДАТЕЛЬСТВЕ

2020 ◽  
Author(s):  
Stanislav Kuzmin ◽  
Irina Polyanskaya
Keyword(s):  
Criminal Punishment ◽  
Personal Time ◽  
Labor Camps ◽  
Archival Documents ◽  
Legal Position ◽  
Executive System ◽  
The Right ◽  
Stimulation Of

Статья подготовлена на основе использования нормативных правовых актов и архивных документов различных исправительно-трудовых лагерей, указанных в сносках, что позволяет судить о территориальных рамках источников. Исследуется генезис становления и развития практики стимулирования правопослушного поведения осужденных посредством норм, не изменяющих их правовое положение в период отбывания уголовного наказания в виде лишения свободы на различных этапах функционирования исправительно-трудовой (уголовно-исполнительной) системы. На основе изученных документов можно сделать вывод, что в основу дифференциации поощрительных норм, распространявшихся на осужденных, положены следующие критерии: 1) поощрения, не изменяющие условия отбывания уголовного наказания в виде лишения свободы; 2) поощрения, изменяющие условия содержания осужденных. Из ранее применявшихся мер поощрений в современном уголовно-исполнительном законодательстве используются следующие: объявление благодарности с занесением в личное дело, материальное поощрение, право на дополнительную посылку, передачу и др. Среди других мер поощрения можно выделить увеличение времени ежедневной прогулки до двух часов для осужденных, содержащихся в строгих условиях отбывания наказания в колониях и тюрьмах. Также законодатель предусмотрел возможность проводить праздничные и выходные дни за пределами учреждения для осужденных, содержащихся в колониях-поселениях.The article is prepared on the basis of the use of normative legal acts and archival documents of various correctional labor camps mentioned in the footnotes, which allows to judge the territorial scope of the sources. The Genesis of formation and development of practice of stimulation of law-abiding behavior of condemned by means of the norms which are not changing their legal position during serving of criminal punishment in the form of imprisonment at various stages of functioning of correctional labor (criminal Executive) system is investigated. On the basis of the studied documents, it can be concluded that the basis for the differentiation of incentive norms that apply to convicts are the following criteria: 1) incentives that do not change the conditions of serving a criminal sentence in the form of imprisonment; 2) incentives that change the conditions of detention of convicts. Of the previously applied measures of incentives in the modern penal legislation the following are used: the announcement of gratitude with entering in personal time, material encouragement, the right to an additional parcel, transfer, etc. Among other measures of encouragement it is possible to allocate increase in time of daily walk to two hours for condemned detainees in strict conditions of serving of punishment in colonies and prisons. Also, the legislator provided the opportunity to spend holidays and weekends outside the institution for convicts held in colonies-settlements.

Força dos Músculos Rotadores do Ombro em Indivíduos Saudáveis/ Rotator Cuff Muscle Strength in Healthy Individuals

1970 ◽  
Vol 1 (1) ◽  
pp. 78-82
Author(s):  
Paulo José Oliveira Cortez ◽  
José Elias Tomazini ◽  
Mauro Gonçalves
Keyword(s):  
Rotator Cuff ◽  
Muscle Strength ◽  
Internal Rotation ◽  
Upper Limb ◽  
Statistical Difference ◽  
External Rotation ◽  
Healthy Individuals ◽  
Average Strength ◽  
Strength Tests ◽  
The Right

Introdução: A diminuição da capacidade de exercer esforços por parte dos músculos rotadores pode criar uma variedade de problemas. O conhecimento preciso do nível de força muscular de um indivíduo é importante, tanto para a avaliação da capacidade funcional ocupacional, como para uma apropriada prescrição de exercícios atléticos e de reabilitação. Percebe-se escassez de informação sobre as articulações do ombro, bem como os fatores envolvidos na força muscular dessa região. O objetivo deste estudo foi comparar a força gerada pelos músculos do manguito rotador entre o membro superior direito e o membro superior esquerdo em indivíduos saudáveis. Métodos: Participaram do estudo 22 sujeitos do sexo masculino, com idade de 18 e 19 anos, militares, saudáveis e sem história clínica de patologia ortopédica ou qualquer tipo de lesão no sistema musculoesquelético. Foram aplicados dois testes de força: Rotação Interna e Rotação Externa. Resultado : A força média de rotação interna no membro superior direito (MSD) foi maior que a força média de rotação interna no membro superior esquerdo (MSE) (p=0,723) e a força de rotação externa no MSD foi menor que a força média de rotação externa no MSE (p=0,788). Não houve diferença estatística na comparação dos valores de força de todos os testes de força isométrica. Conclusão: Para amostra estudada e metodologia utilizada na avaliação da força muscular, não houve diferença estatística na comparação da força gerada pelos músculos do manguito rotador do membro superior direito e do membro superior esquerdo.Rotator Cuff Muscle Strength in Healthy Individuals Introduction: Decreased ability to exert efforts by the rotator muscles can create a variety of problems. The precise knowledge of the level of muscular strength of an individual is important for both the functional capacity evaluation for occupational as an appropriate exercise prescription and rehabilitation of athletic. It is perceived scarcity of information on the shoulder joints as well as factors involved in muscle strength in this region. Objective: Develop a device for measuring the strength generated by the muscles of the upper limbs and the verification of efficiency and adaptability of this device through a comparative study of muscle strength in healthy subjects. Methods: The study included 22 male subjects, aged 18 and 19 years, military personnel, body mass between 57.7 and 93 kg (71.8 ± 9.45 kg) and height between 1.67 and 1.90 m (1.75 ± 0.06 m), healthy and without a history of orthopaedic disease or any kind of damage to the musculoskeletal system. Three strength tests were applied: Internal Rotation and External Rotation. For each type of effort three maximum voluntary contractions were required for 10 seconds, with an interval of 30 seconds between each contraction.  Results: Internal rotation in the right upper limb (RUL) was higher than the average strength of internal rotation in the left upper limb (LUL) (p = 0, 723) and the external rotation strength in RUL was lower than the average strength of external rotation in the LUL (p=0,788).  No statistical difference in comparing the strength values of all isometric strength tests. Conclusion: For sample and methodology used to assess muscle strength, there was no statistical difference in comparing the force generated by the muscles of the rotator cuff of the right and left upper limb.

scholarly journals Stimulation of the right entorhinal white matter enhances visual memory encoding in humans

2021 ◽  
Vol 14 (1) ◽  
pp. 131-140
Author(s):  
Emily A. Mankin ◽  
Zahra M. Aghajan ◽  
Peter Schuette ◽  
Michelle E. Tran ◽  
Natalia Tchemodanov ◽  
...  
Keyword(s):  
White Matter ◽  
Visual Memory ◽  
Memory Encoding ◽  
The Right ◽  
Stimulation Of

scholarly journals STUDIES WITH THE ELECTROCARDIOGRAPH ON THE ACTION OF THE VAGUS NERVE ON THE HUMAN HEART

1911 ◽  
Vol 14 (3) ◽  
pp. 217-234 ◽  
Author(s):  
G. Canby Robinson ◽  
George Draper
Keyword(s):  
Vagus Nerve ◽  
Mechanical Stimulation ◽  
Human Heart ◽  
Appreciable Effect ◽  
Vagus Stimulation ◽  
Ventricular Systole ◽  
Constant Change ◽  
The Right ◽  
Stimulation Of

In hearts showing auricular fibrillation mechanical stimulation of the right vagus nerve causes, as a rule, marked slowing or stoppage of ventricular rhythm, without producing any appreciable effect in the electrocardiographic record of the auricular fibrillation. The ventricular pauses are apparently due to the blocking of stimuli from the auricles. The force of ventricular systole is distinctly weakened for several beats after vagus stimulation, and ectopic ventricular systoles have been seen in several instances, apparently the result of the vagus action. There may, in some cases, be lowered excitability of the ventricles, while no constant change is seen in the size of the electrical complexes representing ventricular systole.

scholarly journals Normalization in human somatosensory cortex

2015 ◽  
Vol 114 (5) ◽  
pp. 2588-2599 ◽  
Author(s):  
Gijs Joost Brouwer ◽  
Vanessa Arnedo ◽  
Shani Offen ◽  
David J. Heeger ◽  
Arthur C. Grant
Keyword(s):  
Somatosensory Cortex ◽  
Middle Finger ◽  
Functional Magnetic Resonance ◽  
Stimulus Amplitude ◽  
Target Digit ◽  
Divisive Normalization ◽  
Postcentral Gyrus ◽  
Baseline Response ◽  
The Right ◽  
Stimulation Of

Functional magnetic resonance imaging (fMRI) was used to measure activity in human somatosensory cortex and to test for cross-digit suppression. Subjects received stimulation (vibration of varying amplitudes) to the right thumb (target) with or without concurrent stimulation of the right middle finger (mask). Subjects were less sensitive to target stimulation (psychophysical detection thresholds were higher) when target and mask digits were stimulated concurrently compared with when the target was stimulated in isolation. fMRI voxels in a region of the left postcentral gyrus each responded when either digit was stimulated. A regression model (called a forward model) was used to separate the fMRI measurements from these voxels into two hypothetical channels, each of which responded selectively to only one of the two digits. For the channel tuned to the target digit, responses in the left postcentral gyrus increased with target stimulus amplitude but were suppressed by concurrent stimulation to the mask digit, evident as a shift in the gain of the response functions. For the channel tuned to the mask digit, a constant baseline response was evoked for all target amplitudes when the mask was absent and responses decreased with increasing target amplitude when the mask was concurrently presented. A computational model based on divisive normalization provided a good fit to the measurements for both mask-absent and target + mask stimulation. We conclude that the normalization model can explain cross-digit suppression in human somatosensory cortex, supporting the hypothesis that normalization is a canonical neural computation.

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