-
1.
Moving forward: methodological considerations for assessing corticospinal excitability during rhythmic motor output in humans.
Lockyer, EJ, Compton, CT, Forman, DA, Pearcey, GE, Button, DC, Power, KE
Journal of neurophysiology. 2021;(1):181-194
Abstract
The use of transcranial magnetic stimulation to assess the excitability of the central nervous system to further understand the neural control of human movement is expansive. The majority of the work performed to-date has assessed corticospinal excitability either at rest or during relatively simple isometric contractions. The results from this work are not easily extrapolated to rhythmic, dynamic motor outputs, given that corticospinal excitability is task-, phase-, intensity-, direction-, and muscle-dependent (Power KE, Lockyer EJ, Forman DA, Button DC. Appl Physiol Nutr Metab 43: 1176-1185, 2018). Assessing corticospinal excitability during rhythmic motor output, however, involves technical challenges that are to be overcome, or at the minimum considered, when attempting to design experiments and interpret the physiological relevance of the results. The purpose of this narrative review is to highlight the research examining corticospinal excitability during a rhythmic motor output and, importantly, to provide recommendations regarding the many factors that must be considered when designing and interpreting findings from studies that involve limb movement. To do so, the majority of work described herein refers to work performed using arm cycling (arm pedaling or arm cranking) as a model of a rhythmic motor output used to examine the neural control of human locomotion.
-
2.
Migraine and Its Association with Hyperactivity of Cell Membranes in the Course of Latent Magnesium Deficiency-Preliminary Study of the Importance of the Latent Tetany Presence in the Migraine Pathogenesis.
Cegielska, J, Szmidt-Sałkowska, E, Domitrz, W, Gaweł, M, Radziwoń-Zaleska, M, Domitrz, I
Nutrients. 2021;(8)
Abstract
So far, there is no consistent and convincing theory explaining the pathogenesis of migraines. Vascular disorders, the effect of oxidative stress on neurons, and the contribution of magnesium-calcium deficiencies in triggering cortical depression and abnormal glutaminergic neurotransmission are taken into account. However, there are no reliable publications confirming the role of dietary deficits of magnesium and latent tetany as factors triggering migraine attacks. The aim of the study was to evaluate the influence of latent magnesium deficiency assessed with the electrophysiological tetany test on the course of migraine. The study included: a group of 35 patients (29 women and six men; in mean age 41 years) with migraine and a control group of 24 (17 women and seven men; in mean age 39 years) healthy volunteers. Migraine diagnosis was based on the International Headache Society criteria, 3rd edition. All patients and controls after full general and neurological examination were subjected to a standard electrophysiological ischemic tetany test. Moreover, the level of magnesium in blood serum was tested and was in the normal range in all patients. Then, the incidence of a positive tetany EMG test results in the migraine group and the results in the subgroups with and without aura were compared to the results in the control group. Moreover, the relationship between clinical markers of spasmophilia and the results of the tetany test was investigated in the migraine group. As well as the relationship between migraine frequency and tetany test results. There was no statistically significant difference in the occurrence of the electrophysiological exponent of spasmophilia between the migraine and control group. Neither correlation between the occurrence of clinical symptoms nor the frequency of migraine attacks and the results of the tetany test was stated (p > 0.05). However, there was an apparent statistical difference between the subgroup of migraine patients with aura in relation to the control group (p < 0.05). The result raises hope to find a trigger for migraine attacks of this clinical form, the more that this factor may turn out to be easy to supplement with dietary supplementation.
-
3.
Quantitative Analysis of EEG Power Spectrum and EMG Median Power Frequency Changes after Continuous Passive Motion Mirror Therapy System.
Park, T, Lee, M, Jeong, T, Shin, YI, Park, SM
Sensors (Basel, Switzerland). 2020;(8)
Abstract
Robotic mirror therapy (MT), which allows movement of the affected limb, is proposed as a more effective method than conventional MT (CMT). To improve the rehabilitation effectiveness of post-stroke patients, we developed a sensory stimulation-based continuous passive motion (CPM)-MT system with two different operating protocols, that is, asynchronous and synchronous modes. To evaluate their effectiveness, we measured brain activation through relative and absolute power spectral density (PSD) changes of electroencephalogram (EEG) mu rhythm in three cases with CMT and CPM-MT with asynchronous and synchronous modes. We also monitored changes in muscle fatigue, which is one of the negative effects of the CPM device, based on median power frequency (MPF) and root mean square (RMS). Relative PSD was most suppressed when subjects used the CPM-MT system under synchronous control: 22.11%, 15.31%, and 16.48% on Cz, C3, and C4, respectively. The absolute average changes in MPF and RMS were 1.59% and 9.78%, respectively, with CPM-MT. Synchronous mode CPM-MT is the most effective method for brain activation, and muscle fatigue caused by the CPM-MT system was negligible. This study suggests the more effective combination rehabilitation system for MT by utilizing CPM and magnetic-based MT task to add action execution and sensory stimulation compared with CMT.
-
4.
Diagnosis and treatment of myasthenia gravis.
Mantegazza, R, Cavalcante, P
Current opinion in rheumatology. 2019;(6):623-633
Abstract
PURPOSE OF REVIEW This article provides an update on the most recent advances in diagnostic procedures and therapeutic approaches for myasthenia gravis, spanning from autoantibody and neuroelectrophysiological tests as diagnostic tools, to innovative and promising treatments based on biological drugs. RECENT FINDINGS Novel studies performed by cell-based assays (CBAs) indicate an improvement in the chance of identifying serum autoantibodies in myasthenic patients. Clinical trials on the use of biological drugs were recently concluded, providing important data on safety and efficacy of eculizumab, efgartigimod and amifampridine phosphate: the first, a complement blocker, showed long-term safety and efficacy in acetylcholine receptor (AChR)-positive myasthenic patients with refractory generalized disease; the second, the neonatal Fc receptor blocker, was well tolerated and clinically effective in both AChR-specific and muscle-specific kinase receptor (MuSK)-positive patients; the third, a blocker of presynaptic potassium channels, was found to be well tolerated and effective in MuSK-positive patients. SUMMARY CBAs can lead to a significant reduction of seronegative patients, improving myasthenia gravis diagnostic process. New biological drugs offer innovative approaches to treat myasthenic patients with generalized disease, promising to change the paradigm of treatment and to significantly enhance therapeutic success within a precision medicine framework.
-
5.
Differences in Knee and Hip Adduction and Hip Muscle Activation in Runners With and Without Iliotibial Band Syndrome.
Baker, RL, Souza, RB, Rauh, MJ, Fredericson, M, Rosenthal, MD
PM & R : the journal of injury, function, and rehabilitation. 2018;(10):1032-1039
Abstract
BACKGROUND Iliotibial band syndrome has been associated with altered hip and knee kinematics in runners. Previous studies have recommended further research on neuromuscular factors at the hip. The frontal plane hip muscles have been a strong focus in strength comparison but not for electromyography investigation. OBJECTIVE To compare hip surface electromyography, and frontal plane hip and knee kinematics, in runners with and without iliotibial band syndrome. DESIGN Observational cross-sectional study. SETTING Biomechanics research laboratory within a university. PARTICIPANTS Thirty subjects were recruited consisting of 15 injured runners with iliotibial band syndrome and 15 gender-, age-, and body mass index-matched controls. In each group, 8 were male runners and 7 were female runners. Inclusion criteria for the injured group were pain within 2 months related to iliotibial band syndrome and a positive Noble compression test. Participants were excluded if they reported other lower extremity diagnoses within the last year or active lower extremity or low back pain not related to iliotibial band syndrome. Controls were excluded if they reported a history of iliotibial band syndrome. Convenience sampling was used based on referrals from local running clinics and orthopedic clinics. METHODS Three-dimensional motion capture was performed with 10 high-speed cameras synchronized with wireless surface electromyography during a 30-minute run. The first data point was at 3 minutes, using a constant speed of 2.74 meters per second. A second data point was at 30 minutes, using a self-selected pace by the participant to allow for a challenging run until completion at 30 minutes. MAIN OUTCOME MEASUREMENTS Motion capture was reported as peak kinematic values from heel strike to peak knee flexion for hip adduction and knee adduction. Surface electromyography was reported as a percentage of maximal voluntary contraction for the gluteus maximus, gluteus medius and tensor fascia latae muscles. RESULTS Injured runners demonstrated increased knee adduction compared with control runners at 30 minutes (P = .002, control = -1.48°, injured = 3.74°). Tensor fasciae latae muscle activation in injured runners was increased compared with control runners at 3 minutes (P = .017, control = 7% maximal voluntary isometric contraction, injured = 11% maximal voluntary isometric contraction). CONCLUSION The results of this study suggest that lateral knee pain in runners localized to the distal iliotibial band is associated with increased knee adduction at 30 minutes. Increased tensor fasciae latae muscle activation at 3 minutes is noted, but more investigation is needed to better understand the clinical meaning. These findings are consistent with but not conclusive evidence supporting the theory that neuromuscular factors of the hip muscles may contribute to increased knee adduction in runners with iliotibial band syndrome. We advise caution using these findings to support treatments intended to modify tensor fasciae latae activation, given the small differences of 4% in muscle activation. Increased knee adduction in runners at 30 minutes was over 5° and beyond the minimal detectable difference. Additional research is needed to confirm whether the degree of knee adduction changes earlier versus later in a run and whether fatigue is a clinically relevant factor. LEVEL OF EVIDENCE III.
-
6.
A pilot study on disturbed gastric myoelectric activity in obstructed defecation syndrome.
Farid, M, Emile, SH, Haleem, M, El-Hak, NG
The Journal of surgical research. 2018;:95-100
Abstract
BACKGROUND Electrogastrography (EGG) is a noninvasive technique for recording gastric myoelectric activity. The aim of this study was to measure and record gastric myoelectric activity in patients with obstructed defecation syndrome (ODS) and to compare their results with those of normal individuals. METHODS Forty-two patients (22 male) with ODS and a mean age of 41.02 y were enrolled in this prospective study after thorough clinical and physiologic assessment. Eleven normal subjects (six female) with a mean age of 39.2 ± 8.4 y were assigned to the control group. Both patients and controls were subjected to surface EGG in fasting and postprandial states. Data were recorded and analyzed via a computer system to reveal the EGG pattern in both groups. RESULTS Abnormalities in the EGG were found in 24 (57.1%) of the 42 patients with ODS. EGG in ODS patients showed alterations in the fasting state in the form of a significant decrease of the normal gastric slow wave (P = 0.03) and a nonsignificant increase in gastric dysrhythmias. The EGG alterations of ODS patients were significantly improved in the postprandial state as the normal gastric slow waves significantly (P = 0.006) increased and the gastric bradycardia declined significantly (P = 0.02). No significant differences were observed in the power distribution between the ODS patients and the healthy controls. CONCLUSIONS Patients with ODS showed an altered EGG pattern compared with that of healthy control subjects. The alterations in ODS patients were more clearly observed during the fasting state and improved significantly after eating.
-
7.
Effects of Velocity on Electromyographic, Mechanomyographic, and Torque Responses to Repeated Eccentric Muscle Actions.
Hill, EC, Housh, TJ, Camic, CL, Smith, CM, Cochrane, KC, Jenkins, ND, Cramer, JT, Schmidt, RJ, Johnson, GO
Journal of strength and conditioning research. 2016;(6):1743-51
Abstract
The purposes of this study were to examine the effects of the velocity of repeated eccentric muscle actions on the torque and neuromuscular responses during maximal isometric and eccentric muscle actions. Twelve resistance-trained men performed 30 repeated, maximal, eccentric, isokinetic muscle actions at randomly ordered velocities of 60, 120, or 180°·s on separate days. Maximal voluntary isometric contractions (MVICs) were performed before (pretest) and after (posttest) the repeated eccentric muscle actions on each day. Eccentric isokinetic peak torque (EIPT) values were the averages of the first 3 and last 3 repetitions of the 30 repeated eccentric muscle actions. During the EIPT and MVIC muscle actions, electromyographic (EMG) and mechanomyographic (MMG) amplitude (EMG AMP and MMG AMP) and mean power frequency (EMG MPF and MMG MPF) values were assessed. These results indicated that the repeated eccentric muscle actions had no effects on EIPT, or the EMG AMP, EMG MPF, or MMG MPF values assessed during the EIPT muscle actions, but decreased MMG AMP. The repeated eccentric muscle actions, however, decreased MVIC torque, and also the EMG AMP and MMG MPF values assessed during the MVIC muscle actions, but increased MMG AMP. The results indicated that the velocity of the repeated eccentric muscle actions affected the MVIC torque responses, but not EIPT or any of the neuromuscular parameters. Furthermore, there are differences in the torque and neuromuscular responses for isometric vs. eccentric muscle actions after repeated eccentric muscle actions.
-
8.
Characteristics of EMG frequency bands in temporomandibullar disorders patients.
Politti, F, Casellato, C, Kalytczak, MM, Garcia, MB, Biasotto-Gonzalez, DA
Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. 2016;:119-125
Abstract
The aim of the present study was to determine whether any specific frequency bands of surface electromyographic (sEMG) signals are more susceptible to alterations in patients with temporomandibular disorders (TMD), when compared with healthy subjects. Twenty-seven healthy adults (19 women and eight men; mean age: 23±6.68years) and 27 TMD patients (20 women and seven men; mean age: 24±5.89years) voluntarily participated in the experiment. sEMG data were recorded from the right and left masseter muscles (RM and LM) and the right and left anterior temporalis muscles (RT and LT) as the participants performed tests of chewing (CHW) and maximal clenching effort (MCE). Frequency domain analysis of the sEMG signal was used to analyze differences between TMD patients and healthy subjects in relation to the Power Spectral Density Function (PSDF). The analysis focused on the median frequency (MDF) of the sEMG signal and PSDF frequency bands after the EMG spectrum was divided into twenty-five frequency band of 20Hz each. The Mann-Whitney test was used to compare MDF between TMD patients and healthy subjects and the frequency bands were analyzed using three-way ANOVA with three factors: frequency band, muscle and group. The results of the analysis confirmed that the median frequency values in TMD patients were significantly higher (p<0.05) than those recorded for healthy subjects in the two experimental conditions (MCE and CHW), for all of the muscles assessed (RM, LM, RT and LT). In addition, frequency content between 20 and 100Hz of the normalized PSDF range was significantly lower (p<0.05) in TMD patients than in healthy. This study contributes to quantitatively identify TMD dysfunctions, by non-invasive sEMGs; this assessment is clinically important and still lacking nowadays.
-
9.
The effect of early physiotherapy on the recovery of mandibular function after orthognathic surgery for class III correction. Part II: electromyographic activity of masticatory muscles.
Ko, EW, Teng, TT, Huang, CS, Chen, YR
Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery. 2015;(1):138-43
Abstract
The study was conducted to evaluate the effect of early physical rehabilitation by comparing the differences of surface electromyographic (sEMG) activity in the masseter and anterior temporalis muscles after surgical correction of skeletal class III malocclusion. The prospective study included 63 patients; the experimental groups contained 31 patients who received early systematic physical rehabilitation; the control group (32 patients) did not receive physiotherapy. The amplitude of sEMG in the masticatory muscles reached 72.6-121.3% and 37.5-64.6% of pre-surgical values in the experimental and control groups respectively at 6 weeks after orthognathic surgery (OGS). At 6 months after OGS, the sEMG reached 135.1-233.4% and 89.6-122.5% of pre-surgical values in the experimental and control groups respectively. Most variables in the sEMG examination indicated that recovery of the masticatory muscles in the experimental group was better than the control group as estimated in the early phase (T1 to T2) and the total phase (T1 to T3); there were no significant differences between the mean recovery percentages in the later phase (T2 to T3). Early physical rehabilitative therapy is helpful for early recovery of muscle activity in masticatory muscles after OGS. After termination of physical therapy, no significant difference in recovery was indicated in patients with or without early physiotherapy.
-
10.
Conventional versus implant-retained overlay dentures: a pilot study of masseter and anterior temporalis electromyography.
Dakhilalian, M, Rismanchian, M, Fazel, A, Basiri, K, Azadeh, H, Mahmoodi, M, Fayazi, S, Sadr-Eshkvari, P
The Journal of oral implantology. 2014;(4):418-24
Abstract
Implant-supported overlay dentures (ISODs) have been widely accepted among patients using conventional removable complete dentures (CRCDs). The present study aimed to comparatively study conventional and ISODs in terms of function and coordination of masticatory muscles using electromyograms. Included were 10 patients with ISODs (each with 2 implants in the intercanine area). The mean wave range (MWR) and frequency (MWF) of masseter and temporalis were recorded with (ISOD) and without (CRCD) ball attachments while maximum clenching on cotton rolls (cotton roll clenching), maximum intercuspal clenching (clenching), and unilateral gum chewing (chewing) using electromyography. Data were analyzed in SPAW using t-paired for matched groups and independent-sample t tests for unmatched ones. The MWF differences were not statistically significant with or without attachments (P > .05). Without attachments in place, the MWF of both masseter and temporalis muscles significantly decreased when patients clenched on cotton rolls (P = .01 and .02, respectively) and when chewing unilaterally (both P = .01). With attachments present, the right and left temporalis muscles did not show identical mean wave ranges while chewing (P = .01). Without attachments, this disharmony was seen in the left and right masseter muscles (P = .03). The MWR of masseter was higher in men while chewing with attachments (P = .02). Without attachments, the MWR of temporalis was higher in women while cotton roll clenching (P = .03) and chewing (P = .02). These findings are seemingly in favor of improved masticatory function and coordination in edentulous patients with the application of ISODs.