Electrical impedance myography in duchenne muscular dystrophy and healthy controls: A multicenter study of reliability and validity

Zaidman, Craig M.; Wang, Lucy Lu; Connolly, Anne M.; Florence, Julaine; Wong, Brenda; Parsons, Julie; Apkon, Susan; Goyal, Namita; Williams, Eugene; Escolar, Diana M.; Rutkove, Seward B.; Bohorquez, J.

doi:10.1002/mus.24611

Cited by 49 publications

(53 citation statements)

References 16 publications

(25 reference statements)

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“…Phase angle represents the time shift of a sinusoid wave when passing through the muscle, which was previously used as a major outcome measure of EIM since it is less affected by the architecture and shape of the muscle compared with R or X (37). The smaller phase angle in the SCI group is in line with the data from a multicenter study of DMD children (38) and ALS subjects (23). Reductions in cell size and the presence of more connective tissue in the muscle also reduce the EIM phase angle (16).…”

Section: Discussionsupporting

confidence: 86%

Alterations in Localized Electrical Impedance Myography of Biceps Brachii Muscles Paralyzed by Spinal Cord Injury

Stampas

Shin

et al. 2017

Front. Neurol.

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This study assessed electrical impedance myography (EIM) changes after spinal cord injury (SCI) with a localized multifrequency technology. The EIM measurement was performed on the biceps brachii muscle at rest condition of 17 cervical SCI subjects, and 23 neurologically intact subjects as control group. The results showed that there was a significant decrease in muscle reactance (X) and phase angle (θ) at selected frequencies (i.e., 50 and 100 kHz) in SCI compared to control. There was no significant difference in muscle resistance (R) between the two groups. The anisotropy examination revealed that SCI group had a decreased anisotropy ratio in resistance. In addition, the multifrequency spectrum analysis showed a decreased slope of the log(freq)-resistance regression in SCI group when compared to healthy control. Findings of the EIM changes are related to inherit muscle changes after the injury. Since EIM requires no patient effort and is quick and convenient to conduct, it may provide a useful tool for examination of paralyzed muscle changes after SCI.

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Section: Discussionsupporting

confidence: 86%

Alterations in Localized Electrical Impedance Myography of Biceps Brachii Muscles Paralyzed by Spinal Cord Injury

Stampas

Shin

et al. 2017

Front. Neurol.

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“…Training was straightforward. There was excellent inter-evaluator reliability between an experienced assay performer and a trainee (Fig 2) [35, 42, 52–54]. …”

Section: Discussionmentioning

confidence: 99%

“…EIM has been extensively used as a painless and reliable outcome measurement to study various neuromuscular diseases including amyotrophic lateral sclerosis (ALS) [20–27], spinal muscular atrophy [28], facioscapulohumeral muscular dystrophy [29], congenital muscular dystrophy [30], inflammatory myopathy [31], inclusion-body myositis [19, 32], radiculopathy [33], and disuse atrophy [34]. Of relevance to our study, EIM has been successfully used in DMD patients and mdx mice [35–42]. These studies have revealed excellent reliability and validity of EIM as a powerful noninvasive biomarker for both pre-clinical and clinical studies.…”

Section: Introductionmentioning

confidence: 99%

Non-invasive evaluation of muscle disease in the canine model of Duchenne muscular dystrophy by electrical impedance myography

et al. 2017

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Dystrophin-deficient dogs are by far the best available large animal models for Duchenne muscular dystrophy (DMD), the most common lethal childhood muscle degenerative disease. The use of the canine DMD model in basic disease mechanism research and translational studies will be greatly enhanced with the development of reliable outcome measures. Electrical impedance myography (EIM) is a non-invasive painless procedure that provides quantitative data relating to muscle composition and histology. EIM has been extensively used in neuromuscular disease research in both human patients and rodent models. Recent studies suggest that EIM may represent a highly reliable and convenient outcome measure in DMD patients and the mdx mouse model of DMD. To determine whether EIM can be used as a biomarker of disease severity in the canine model, we performed the assay in fourteen young (~6.6-m-old; 6 normal and 8 affected) and ten mature (~16.9-m-old; 4 normal and 6 affected) dogs of mixed background breeds. EIM was well tolerated with good inter-rater reliability. Affected dogs showed higher resistance, lower reactance and phase. The difference became more straightforward in mature dogs. Importantly, we observed a statistically significant correlation between the EIM data and muscle fibrosis. Our results suggest that EIM is a valuable objective measurement in the canine DMD model.

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“…43 The refinement of EIM to quantify changes in diseased muscle with subcutaneous fat lends its use to determine changes throughout the clinical spectrum in Pompe disease patients in addition to its current use in patients with related neuromuscular disorders. 41,44–48 …”

Section: Discussionmentioning

confidence: 99%

Correcting Neuromuscular Deficits With Gene Therapy in Pompe Disease

Todd

McElroy

Grange

et al. 2015

Annals of Neurology

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Objective We have recently reported on the pathology of the neuromuscular junction (NMJ) in Pompe disease, reflecting disruption of neuronal and muscle homeostasis as a result of glycogen accumulation. The aim of this study was to examine how the alteration of NMJ physiology contributes to Pompe disease pathology; we performed molecular, physiological, and histochemical analyses of NMJ-related measures of the tibialis anterior muscles of young-, mid-, and late-stage alpha-glucosidase (GAA)-deficient mice. Methods We performed intramuscular injection of an adeno-associated virus (AAV)9 vector expressing GAA (AAV9-hGAA) into the tibialis anterior muscle of Gaa–/– mice at early, mid, and severe pathological time points. We analyzed expression of NMJ-related genes, in situ muscle force production, and clearance of glycogen in conjunction with histological assessment of the NMJ. Results Our data demonstrate that AAV9-hGAA is able to replace GAA to the affected tissue and modify AChR mRNA expression, muscle force production, motor endplate area, and innervation status. Importantly, the degree of restoration for these outcomes is limited by severity of disease. Early restoration of GAA activity was most effective, whereas late correction of GAA expression was not effective in modifying parameters reflecting NMJ structure and function nor in force restoration despite resolution of glycogen storage in muscle. Interpretation Our data provide new mechanistic insight into the pathology of Pompe disease and suggest that early systemic correction to both neural and muscle tissues may be essential for successful correction of neuromuscular function in Pompe disease.

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Electrical impedance myography in duchenne muscular dystrophy and healthy controls: A multicenter study of reliability and validity

Abstract: EIM is a reliable and valid measure of disease severity in DMD. Longitudinal studies comparing EIM with other assessments over time in DMD are warranted.

Cited by 49 publications

References 16 publications

Alterations in Localized Electrical Impedance Myography of Biceps Brachii Muscles Paralyzed by Spinal Cord Injury

Alterations in Localized Electrical Impedance Myography of Biceps Brachii Muscles Paralyzed by Spinal Cord Injury

Non-invasive evaluation of muscle disease in the canine model of Duchenne muscular dystrophy by electrical impedance myography

Correcting Neuromuscular Deficits With Gene Therapy in Pompe Disease

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