"Clustering Index method": A new technique for differentiation between neurogenic and myopathic changes using surface EMG
2011 (English)In: Clinical Neurophysiology, ISSN 1388-2457, E-ISSN 1872-8952, Vol. 122, no 5, 1032-1041 p.Article in journal (Refereed) Published
Objective: To establish a non-invasive and quantitative analysis method using single-channel surface EMG (SEMG) for diagnosing neurogenic and myopathic changes.
Methods: The subjects consisted of 66 healthy controls, 12 patients with neurogenic diseases, and 18 patients with myopathic diseases. The tibialis anterior muscle was examined using a belly to the adjacent bone lead. From each subject, 20-40 signals of 1 s length were collected of various strengths. A new parameter, the "Clustering Index (CI)", was developed to quantify the uneven distribution of the SEMG signal, and was plotted against the SEMG area. The results were expressed as the Z-score of each subject calculated using linear regression from the normative data.
Results: When +/- 2.5 was used as the cut-off value of the Z-score, the specificity was 95%, whereas the sensitivity was 92% (11/12) and 61% (11/18) for the neurogenic and myopathic patients, respectively. There was no overlap of the Z-score values between the neurogenic and myopathic groups.
Conclusions: The CI method achieved a reasonably high diagnostic yield in detecting neurogenic or myopathic changes.
Significance: This is a new simple and quantitative analysis method using SEMG with good reproducibility, and is promising as a non-invasive complement to needle EMG.
Place, publisher, year, edition, pages
2011. Vol. 122, no 5, 1032-1041 p.
Surface electromyography, Quantitative analysis, Needle electromyography, Tibialis anterior, Clustering Index
Medical and Health Sciences
Research subject Clinical Neurophysiology
IdentifiersURN: urn:nbn:se:uu:diva-153352DOI: 10.1016/j.clinph.2010.08.012ISI: 000290098700026PubMedID: 20869308OAI: oai:DiVA.org:uu-153352DiVA: diva2:416369