| 1. |
- Askmark, H, et al.
(författare)
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Myoglobin in rat hind limb muscles after denervation and during reinnervation
- 1984
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Ingår i: Muscle and Nerve. - 0148-639X .- 1097-4598. ; 7:8, s. 656-661
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Tidskriftsartikel (refereegranskat)abstract
- Radioimmunoassay of myoglobin (Mb) was performed in rat hind limb muscles after surgical denervation and during reinnervation following cryolesion of the sciatic nerve. Muscles of the contralateral leg served as controls. After resection of the sciatic nerve, decreased Mb concentrations were noted on the fourth day in the tibialis anterior, peroneus longus, and extensor digitorum longus (EDL) muscles. Thereafter, the levels increased up to the last observation on day 32. The increases in Mb levels in the tibialis anterior and EDL muscles were considerably more pronounced (305% and 324%, respectively) than in the peroneus longus and soleus muscles (148% and 137%, respectively). After cryolesion of the sciatic nerve, the Mb concentrations in the tibialis anterior, peroneus longus, and EDL muscles increased, reaching maximal values on days 16-21. The levels then decreased and normal values were observed 2 months postoperatively. The normalization of the Mb levels during reinnervation corresponded fairly well in time with the clinical recovery and neurophysiological findings observed in a previous study.
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| 2. |
- Axelson, Hans W, et al.
(författare)
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Microdialysis and electromyography of experimental muscle fatigue in healthy volunteers and patients with mitochondrial myopathy
- 2002
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 26:4, s. 520-526
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Tidskriftsartikel (refereegranskat)abstract
- Consecutive 60-min microdialysis samples were taken from the tibial anterior muscle in 11 healthy subjects and 4 patients with mitochondrial myopathy before (2-3 samples) and after (3-4 samples, 2 controls and 1 patient excluded) sustained isometric foot dorsiflexions. Before exercise, mean concentrations of lactate, pyruvate, hypoxanthine, urate, aspartate, and glutamate did not significantly differ between controls and patients. After exercise, the controls showed significantly increased concentrations of lactate, pyruvate, and urate, decreased hypoxanthine, and no change in aspartate and glutamate. Similar findings were observed in the patients. Plasma lactate was unchanged. Exercise-induced increase in integrated electromyogram amplitude and rated subjective fatigue were correlated to increased post-exercise lactate concentrations, with no obvious difference between the groups. Microdialysis of skeletal muscle allows the detection and monitoring of biochemical changes in the interstitial space. With the exercise protocol used, however, it was not possible to demonstrate any biochemical difference between healthy controls and patients with mitochondrial myopathy.
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| 3. |
- Chan, Young, et al.
(författare)
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Reinnervation as measured by the motor unit size index is associated with preservation of muscle strength in amyotrophic lateral sclerosis, but not all muscles reinnervate
- 2022
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Ingår i: Muscle and Nerve. - : John Wiley & Sons. - 0148-639X .- 1097-4598. ; 65:2, s. 203-210
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Tidskriftsartikel (refereegranskat)abstract
- Introduction/Aims: The motor unit size index (MUSIX) may provide insight into reinnervation patterns in diseases such as amyotrophic lateral sclerosis (ALS). However, it is not known whether MUSIX detects clinically relevant changes in reinnervation, or if all muscles manifest changes in MUSIX in response to reinnervation after motor unit loss.Methods: Fifty-seven patients with ALS were assessed at 3-month intervals for 12 months in four centers. Muscles examined were abductor pollicis brevis, abductor digiti minimi, biceps brachii, and tibialis anterior. Results were split into two groups: muscles with increases in MUSIX and those without increases. Longitudinal changes in MUSIX, motor unit number index (MUNIX), compound muscle action potential amplitude, and Medical Research Council strength score were investigated.Results: One hundred thirty-three muscles were examined. Fifty-nine percent of the muscles exhibited an increase in MUSIX during the study. Muscles with MUSIX increases lost more motor units (58% decline in MUNIX at 12 months, P <.001) than muscles that did not increase MUSIX (34.6% decline in MUNIX at 12 months, P <.001). However, longitudinal changes in muscle strength were similar. When motor unit loss was similar, the absence of a MUSIX increase was associated with a significantly greater loss of muscle strength (P =.002).Discussion: MUSIX increases are associated with greater motor unit loss but relative preservation of muscle strength. Thus, MUSIX appears to be measuring a clinically relevant response that can provide a quantitative outcome measure of reinnervation in clinical trials. Furthermore, MUSIX suggests that reinnervation may play a major role in determining the progression of weakness.
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| 4. |
- Chroni, Elisabeth, et al.
(författare)
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Usefulness of assessing repeater F-waves in routine studies
- 2012
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 45:4, s. 477-485
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Repeater F-waves are sometimes seen in routine studies.METHODS: We retrospectively reviewed the clinical significance of repeater F-waves in median, ulnar, and fibular nerve recordings in 50 healthy subjects and groups of 50 patients each with diabetic polyneuropathy, amyotrophic lateral sclerosis, carpal tunnel syndrome, ulnar mononeuropathy, and L5 root lesion. The number of identical F-waves and their repetitions in samples of 20 stimuli were estimated.RESULTS: Repeater F-waves occurred significantly more frequently in all nerves and patient groups than in healthy individuals. Their persistence was negatively correlated with that of non-repeater F-waves.CONCLUSIONS: Based on the presented material and recording condition it appears that repeater F-waves differentiate between health and disease but not between different types of pathology of motor neurons or their axons. Even in routinely recorded samples of 20 traces, the index of repeater all F-waves could be used as a sign of nerve pathology.
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| 5. |
- Dengler, Reinhard, et al.
(författare)
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AANEM - IFCN Glossary of Terms in Neuromuscular Electrodiagnostic Medicine and Ultrasound
- 2020
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Ingår i: Muscle and Nerve. - : WILEY. - 0148-639X .- 1097-4598. ; 62:1, s. 10-12
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- Modern neuromuscular electrodiagnosis (EDX) and neuromuscular ultrasound (NMUS) require a universal language for effective communication in clinical practice and research and, in particular, for teaching young colleagues. Therefore, the AANEM and the IFCN have decided to publish a joint glossary as they feel the need for an updated terminology to support educational activities in neuromuscular EDX and NMUS in all parts of the world. In addition NMUS has been rapidly progressing over the last years and is now widely used in the diagnosis of disorders of nerve and muscle in conjunction with EDX. This glossary has been developed by experts in the field of neuromuscular EDX and NMUS on behalf of the AANEM and the IFCN and has been agreed upon by electronic communication between January and November 2019. It is based on the glossaries of the AANEM from 2015 and of the IFCN from 1999. The EDX and NMUS terms and the explanatory illustrations have been updated and supplemented where necessary. The result is a comprehensive glossary of terms covering all fields of neuromuscular EDX and NMUS. It serves as a standard reference for clinical practice, education and research worldwide.
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| 6. |
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| 7. |
- Hehir, Michael K., et al.
(författare)
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Myasthenia gravis patient and physician opinions about immunosuppressant reduction
- 2020
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 61:6, s. 767-772
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionTo reduce myasthenia gravis (MG) patient risk of immunosuppressant (IS) exposure adverse events (AEs), such as infections and malignancies, and to reduce treatment burden, international guidelines recommend decreasing IS dose in stable MG patients.MethodsOnline surveys were conducted of self‐identified MG patients and MG physician experts about the importance of IS dose reduction for MG patients who achieve prolonged periods of disease stability.ResultsEighty‐four percent of MG patients (n = 283) and 100% of physicians (n = 45) were concerned about long‐term IS‐associated AEs. Although both groups favored attempting IS reduction, they raised concerns including MG relapse, hospitalization, and uncertainty about the future. Presented with an estimated 12% significant relapse rate with IS dose reduction, 76% of patients would be willing to enroll in a randomized IS dose reduction trial.DiscussionPatients and physicians favor considering IS dose reduction but are also concerned about potential negative sequelae.
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| 8. |
- Higashihara, Mana, et al.
(författare)
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Evaluation of spinal and bulbar muscular atrophy by the clustering index method
- 2011
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 44:4, s. 539-546
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: A reliable electrophysiological marker for clinical trials is increasingly needed in spinal and bulbar muscular atrophy (SBMA). We previously developed a quantitative analysis method for surface electromyography (SEMG), the clustering index (CI) method. Our purpose was to test the utility of the CI method for evaluating lower motor neuron involvement in SBMA patients. Methods: Subjects included 29 SBMA patients and 27 healthy controls. The recording electrode was placed over the abductor digiti minimi (ADM) muscle with a proximal reference. The Z-score, based on the CI method, was compared with compound muscle action potential (CMAP) amplitude and motor unit number estimation (MUNE), with regard to sensitivity. Results: The Z-scores of the CI method, CMAP amplitude, and MUNE were abnormal in 100%, 72%, and 93% of the patients, respectively. Interrater reliability of the CI method was sufficiently high. Conclusion: The CI method is promising as a non-invasive electrophysiological marker in SBMA.
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| 9. |
- Hokkoku, Keiichi, et al.
(författare)
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Electromyographs of the flexor digitorum profundus muscle are useful for the diagnosis of inclusion body myositis
- 2012
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 46:2, s. 181-186
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The frequent observation of high-amplitude and long-duration motor unit potentials (MUPs) in inclusion body myositis (IBM) is problematic, because it may lead to a misdiagnosis of amyotrophic lateral sclerosis (ALS).Objective: To document the diagnostic utility of EMG from the flexor digitorum profundus (FDP) muscle for IBM. Methods: Quantitative analyses of MUP parameters were performed in the FDP and biceps brachii (BB) muscles from 7 biopsy-confirmed IBM patients.Results: In the FDP muscle, all MUP parameters were significantly decreased in IBM patients, which indicated the predominance of low-amplitude and short-duration MUPs in this muscle. In the BB muscle, most parameters were increased, suggesting the frequent contamination of high-amplitude and long-duration MUPs.Conclusions: Low-amplitude MUPs in the FDP muscle indicate the presence of an advanced myopathy in this muscle that was extremely weak for all subjects. Examining the FDP muscle would reduce the chance of misdiagnosing IBM as ALS.
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| 10. |
- Kouyoumdjian, Joao A., et al.
(författare)
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Concentric needle jitter in stimulated frontalis in 20 healthy subjects
- 2012
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 45:2, s. 276-278
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Tidskriftsartikel (refereegranskat)abstract
- Normative data for jitter parameters using a disposable concentric needle have been presented in a few studies. Jitter, expressed as the mean consecutive difference (MCD), was measured in the frontalis muscle in 20 subjects by percutaneous bar stimulation of the temporal nerve branch. The mean MCD for individual studies (20) and for all potentials (600) were 16.05 +/- 2.73 mu s and 16.05 +/- 5.96 mu s, respectively. The suggested limit for mean MCD is 22 mu s and for outliers is 28 mu s.
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