The diagnosis and management of preterm labor with intact membranes
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
Increased uterine contractility can be present in the absence of cervical change. Two types of uterine contractions have been identified using electromyography (159): (i) “contractures,” which are epochs of myometrial activity leading to a modest increase in intrauterine pressure and are of long duration, and (ii) “contractions,” which are of short duration but increase intrauterine pressure. A switch from a predominant “contracture pattern” to a predominant “contraction pattern” can occur during normal labor or be induced by pathologic events such as intra-abdominal surgery, infection, or food withdrawal. The molecular basis of this switch is thought to be the development of gap junctions, which increase the transmission of cell-to-cell communication in the myometrium during labor. Efforts to differentiate contractures from contractions using clinically available external tocodynamometry have failed to distinguish between the patient at risk for preterm delivery and the one who is not at risk (160). Therefore, uterine contractility alone is not sufficient to reliably diagnose preterm labor. Recent modalities that use external electro-myography may improve such a diagnosis, but these techniques are not yet clinically available (161–165).
Dislocations around the shoulder
Charles M Court-Brown, Margaret M McQueen, Marc F Swiontkowski, David Ring, Susan M Friedman, Andrew D Duckworth in Musculoskeletal Trauma in the Elderly, 2016
The most commonly involved nerve is the axillary nerve. The prevalence quoted in a large prospective study was 9.3%, compared to 4.6% in younger patients.4 However, the prevalence is increased when all patients are tested with electro-myography.13 The proportion of nerve injuries as confirmed on NCV studies is found in Table 21.1.
Some technical propositions for electromyographical human interface device
Waldemar Wójcik, Sergii Pavlov, Maksat Kalimoldayev in Information Technology in Medical Diagnostics II, 2019
However, all existing implementations of the human-device interface are rather cumbersome. For image analysis systems and systems based on the Doppler effect, you must be at a fixed distance from the device. Systems based on surface myography have an advantage among known systems, since they perform a direct analysis of the work of muscles.
Reversible sub-acute motor neuron syndrome after mushroom intoxication masquerading as amyotrophic lateral sclerosis
Published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 2022
Emmeline Lagrange, Elisa de la Cruz, Florence Esselin, Jean-Paul Vernoux, Nicolas Pageot, Guillaume Taieb, William Camu
On electroneuromyography (ENMG), motor conduction velocities (CV) and F waves were normal, no conduction blocks were found. Distal latency of the left median nerve was increased (4.32 ms), suggesting an associated carpal tunnel syndrome. Sensory potential amplitudes were diminished (2.5 and 3.5µV for median and sural nerves respectively) and median sensory CV reduced at 28m/s, either due to diabetes or to the carpal tunnel syndrome (this patient was a manual worker). Myography showed active and severe denervation on the four limbs, tongue and facial muscles, demonstrated by the presence of fibrillation potentials, increased amplitude and firing rate of the motor unit potentials, and severe loss of recruitment. Complete biological work-up for ALS differential diagnosis was normal, including HIV serology and immunological testing, as was brain MRI. However, general biochemistry showed mild increase of ALAT, GGT and CRP, at 73UI (normal value <41), 62UI (normal value <60) and 6.5 (normal value <0.5), respectively. Amyotrophic lateral sclerosis functional rating scale-revised (ALSFRS-r) score was 34/48, SVC was 80% of the normal value and weight was 91kgs (6). Blood gases and thoraco-abdominal CT-scan were normal. A diagnosis of definite ALS according to the revised El Escorial criteria was made and riluzole treatment was started (2). Genetic analysis was done as this patient was adopted and thus had no information about his family. This study was carried out on the main ALS genes, C9ORF72, SOD1, TARDBP and FUS, and was normal.
Role of P38 mitogen-activated protein kinase on Cx43 phosphorylation in cerebral vasospasm after subarachnoid hemorrhage
Published in International Journal of Neuroscience, 2019
Chao Lei, Yutian Ruan, Changcheng Cai, Bao He, Dong Zhao
To evaluate the degree of CVS, we used one of the functional modules of the pressure myograph system instead of performing angiography. This system is a highly sensitive device designed by Mulvany and Halpern to investigate the responsiveness of small blood vessels to different stimuli and hormones [24]. We were able to perform pressure myograph measurement under isobaric pressure conditions and simulate the internal environments without performing procedures that may disrupt vascular activity. This device can record the amplitude of changes intuitively and accurately in the diameter of the artery. Although it is not easy to compare the difference in the basilar artery diameter before and after SAH, this measurement method is believed to be relatively accurate in evaluating the degree of CVS and the severity of vascular contraction. In this study, the results of the pressure myograph analysis showed the severe narrowing of the basilar artery after SAH. Moreover, SB203580 increased the diameter of the basilar artery to a nearly normal level. These results suggest that SB203580 treatment attenuates CVS.
The emerging significance of circadian rhythmicity in microvascular resistance
Published in Chronobiology International, 2022
Jeffrey T. Kroetsch, Darcy Lidington, Steffen-Sebastian Bolz
Unfortunately, while considerable progress has been made in elucidating the molecular mechanisms that drive myogenic vasoconstriction, the research field has yet to explore rhythmic aspects with the same resolve. Of note, microvascular research is a resource-intensive field: (i) the techniques (e.g. resistance artery pressure myography) are time consuming and technically demanding, (ii) biochemical assessments are limited by small tissue sample sizes and (iii) molecular manipulations are generally limited to genetically modified mice. Undoubtedly, the additional complexity linked to incorporating the dimension of time has discouraged the expansion of microvascular research into the circadian field. As a result and to our best knowledge, only mesenteric arteries have so far been examined for rhythms in myogenic reactivity to date (Xie et al. 2015).
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