Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases
Background: Single-fiber electromyography (SFEMG) abnormality in the extensor digitorum communis (EDC) was reported in ocular myasthenia gravis (OMG), which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC an...
Main Authors: | , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Wolters Kluwer
2015-01-01
|
Series: | Chinese Medical Journal |
Subjects: | |
Online Access: | http://www.cmj.org/article.asp?issn=0366-6999;year=2015;volume=128;issue=20;spage=2783;epage=2786;aulast=Guan |
id |
doaj-c6636a59b7d94b26bfaec388e4f89c30 |
---|---|
record_format |
Article |
spelling |
doaj-c6636a59b7d94b26bfaec388e4f89c302020-11-25T02:14:51ZengWolters KluwerChinese Medical Journal0366-69992015-01-01128202783278610.4103/0366-6999.167354Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 CasesYu-Zhou GuanLi-Ying CuiMing-Sheng LiuJing-Wen NiuBackground: Single-fiber electromyography (SFEMG) abnormality in the extensor digitorum communis (EDC) was reported in ocular myasthenia gravis (OMG), which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC and the probability for OMG to develop generalized myasthenia gravis (GMG) is unknown. This retrospective study aimed to determine the predictive value of abnormality of SFEMG in EDC of OMG patients. Methods: One-hundred and two OMG patients underwent standard clinical diagnosis process and SFEMG test in EDC muscle when diagnosed and were clinically followed up for 5 years. The SFEMG data were compared between different clinical groups according to thymus status, onset age, and different outcome of OMG developing. Chances of progressing to GMG were compared between two different groups according to SFEMG and repetitive nerve stimulation (RNS) results, acetylcholine receptor antibody (AchRAb) titer, thymus status, and onset age. Results: Abnormal SFEMG results were observed in 84 (82.4%) patients. The mean jitter, percentage of jitter >55 μs (%), and blocking were higher in OMG patients than in healthy volunteers. There were no statistical differences in jitter analysis between thymoma group and non-thymoma group (P = 0.65), or between the later OMG group and the later GMG group (P = 0.31), including mean jitter, percentage of jitter >55 μs (%), and blocking. Elderly group (≥45 years old) had a higher mean jitter than younger group (t = 2.235, P = 0.028). Total 55 OMG developed GMG, including 47 in abnormal SFEMG group while 8 in normal SFEMG group. There was no statistical difference in the conversion rates between the two groups (χ2 = 0.790, P = 0.140). RNS abnormality, AchRab titer, or onset age had no correlation with OMG prognosis (P = 0.150, 0.070, 0.120, respectively) while thymoma did (χ2 = 0.510, P = 0.020). Conclusion: SFEMG test in the EDC showed high abnormality in OMG, suggesting subclinical involvement other than extraocular muscles. Nevertheless, the abnormal jitter analysis did not predict the prognosis of OMG according to clinical follow-up.http://www.cmj.org/article.asp?issn=0366-6999;year=2015;volume=128;issue=20;spage=2783;epage=2786;aulast=GuanExtensor Digitorum Communis; Generalized Myasthenia Gravis; Ocular Myasthenia Gravis; Prognosis; Single-fiber Electromyography |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Yu-Zhou Guan Li-Ying Cui Ming-Sheng Liu Jing-Wen Niu |
spellingShingle |
Yu-Zhou Guan Li-Ying Cui Ming-Sheng Liu Jing-Wen Niu Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases Chinese Medical Journal Extensor Digitorum Communis; Generalized Myasthenia Gravis; Ocular Myasthenia Gravis; Prognosis; Single-fiber Electromyography |
author_facet |
Yu-Zhou Guan Li-Ying Cui Ming-Sheng Liu Jing-Wen Niu |
author_sort |
Yu-Zhou Guan |
title |
Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases |
title_short |
Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases |
title_full |
Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases |
title_fullStr |
Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases |
title_full_unstemmed |
Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases |
title_sort |
single-fiber electromyography in the extensor digitorum communis for the predictive prognosis of ocular myasthenia gravis: a retrospective study of 102 cases |
publisher |
Wolters Kluwer |
series |
Chinese Medical Journal |
issn |
0366-6999 |
publishDate |
2015-01-01 |
description |
Background: Single-fiber electromyography (SFEMG) abnormality in the extensor digitorum communis (EDC) was reported in ocular myasthenia gravis (OMG), which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC and the probability for OMG to develop generalized myasthenia gravis (GMG) is unknown. This retrospective study aimed to determine the predictive value of abnormality of SFEMG in EDC of OMG patients.
Methods: One-hundred and two OMG patients underwent standard clinical diagnosis process and SFEMG test in EDC muscle when diagnosed and were clinically followed up for 5 years. The SFEMG data were compared between different clinical groups according to thymus status, onset age, and different outcome of OMG developing. Chances of progressing to GMG were compared between two different groups according to SFEMG and repetitive nerve stimulation (RNS) results, acetylcholine receptor antibody (AchRAb) titer, thymus status, and onset age.
Results: Abnormal SFEMG results were observed in 84 (82.4%) patients. The mean jitter, percentage of jitter >55 μs (%), and blocking were higher in OMG patients than in healthy volunteers. There were no statistical differences in jitter analysis between thymoma group and non-thymoma group (P = 0.65), or between the later OMG group and the later GMG group (P = 0.31), including mean jitter, percentage of jitter >55 μs (%), and blocking. Elderly group (≥45 years old) had a higher mean jitter than younger group (t = 2.235, P = 0.028). Total 55 OMG developed GMG, including 47 in abnormal SFEMG group while 8 in normal SFEMG group. There was no statistical difference in the conversion rates between the two groups (χ2 = 0.790, P = 0.140). RNS abnormality, AchRab titer, or onset age had no correlation with OMG prognosis (P = 0.150, 0.070, 0.120, respectively) while thymoma did (χ2 = 0.510, P = 0.020).
Conclusion: SFEMG test in the EDC showed high abnormality in OMG, suggesting subclinical involvement other than extraocular muscles. Nevertheless, the abnormal jitter analysis did not predict the prognosis of OMG according to clinical follow-up. |
topic |
Extensor Digitorum Communis; Generalized Myasthenia Gravis; Ocular Myasthenia Gravis; Prognosis; Single-fiber Electromyography |
url |
http://www.cmj.org/article.asp?issn=0366-6999;year=2015;volume=128;issue=20;spage=2783;epage=2786;aulast=Guan |
work_keys_str_mv |
AT yuzhouguan singlefiberelectromyographyintheextensordigitorumcommunisforthepredictiveprognosisofocularmyastheniagravisaretrospectivestudyof102cases AT liyingcui singlefiberelectromyographyintheextensordigitorumcommunisforthepredictiveprognosisofocularmyastheniagravisaretrospectivestudyof102cases AT mingshengliu singlefiberelectromyographyintheextensordigitorumcommunisforthepredictiveprognosisofocularmyastheniagravisaretrospectivestudyof102cases AT jingwenniu singlefiberelectromyographyintheextensordigitorumcommunisforthepredictiveprognosisofocularmyastheniagravisaretrospectivestudyof102cases |
_version_ |
1724899388782804992 |