HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mathieu, J. Articles by Bégin, P. Search for Related Content PubMed PubMed Citation Articles by Mathieu, J. Articles by Bégin, P.

Assessment of a disease-specific muscular impairment rating scale in myotonic dystrophy

From the Neuromuscular Clinic (Drs. Mathieu, Gaudreault, and Bégin, and H. Boivin and D. Meunier), Centre Régional de Réadaptation en Déficience Physique, Jonquière; Complexe Hospitalier de la Sagamie (Drs. Mathieu, Gaudreault, and Bégin), Chicoutimi; and Research Center (Drs. Mathieu and Bégin), Centre Hospitalier de l’Université de Montréal, Quebec, Canada.

Address correspondence and reprint requests to Dr. J. Mathieu, Neuromuscular Clinic, Centre Régional de Réadaptation en Déficience Physique, Centre Hospitalier Jonquière, 2230 rue de l’Hôpital, Jonquière, Quebec, Canada G7X 7X2; e-mail: jmathieu{at}saglac.qc.ca

OBJECTIVE: To document the intra/interrater reliability and the construct validity of the Muscular Impairment Rating Scale (MIRS) in assessing patients with myotonic dystrophy type 1 (DM1). The MIRS is a ordinal five-point rating scale, established in accordance with the clinically recognized distal to proximal progression of the muscular involvement in DM1, based partly on a manual muscle testing (MMT) of 11 muscle groups.

METHODS: To assess the reliability of the MIRS, 55 patients with DM1 were examined by three different observers, one of them evaluating each patient twice. Intra- and interobserver reliability of the MIRS was measured using Cohen’s weighted . To assess the construct validity of the MIRS, correlations were made with the Functional Status Index (FSI) and eight timed functional tasks.

RESULTS: The intraobserver reliability of the MIRS was excellent (weighted = 0.84), and the interobserver reliability was interpreted as a substantial agreement (weighted = 0.77 to 0.79). The correlation coefficients between MMT scores and MIRS grades were all highly significant (r_s = -0.81 to -0.88, p < 0.001). The FSI showed a significant progressive increase of the total median dependence score in activities of daily living from 0 in MIRS grade 1 to 39 in MIRS grade 5 (p < 0.001). The time needed to perform the eight functional tasks was also found to significantly increase in relation with the progression of the MIRS grades.

CONCLUSION: The MIRS is a quick, simple, and reliable measurement of muscular impairment in DM1. The FSI questionnaire and the timed motor activities supported its construct validity. The MIRS is useful to monitor major stages of DM1 progression, to study the natural history of the disease, and to identify homogeneous groups of patients for clinical trials.

This article has been cited by other articles:

				I. Penisson-Besnier, M. Devillers, R. Porcher, D. Orlikowski, V. Doppler, C. Desnuelle, X. Ferrer, M. -C.A. Bes, F. Bouhour, C. Tranchant, et al. Dehydroepiandrosterone for myotonic dystrophy type 1 Neurology, August 5, 2008; 71(6): 407 - 412. [Abstract] [Full Text] [PDF]

				W. J. Groh, M. R. Groh, C. Saha, J. C. Kincaid, Z. Simmons, E. Ciafaloni, R. Pourmand, R. F. Otten, D. Bhakta, G. V. Nair, et al. Electrocardiographic Abnormalities and Sudden Death in Myotonic Dystrophy Type 1 N. Engl. J. Med., June 19, 2008; 358(25): 2688 - 2697. [Abstract] [Full Text] [PDF]

				E. Ciafaloni, E. Mignot, V. Sansone, J. E. Hilbert, L. Lin, X. Lin, L. C. Liu, W. R. Pigeon, M. L. Perlis, and C. A. Thornton The hypocretin neurotransmission system in myotonic dystrophy type 1 Neurology, January 15, 2008; 70(3): 226 - 230. [Abstract] [Full Text] [PDF]

				M. -E. Arsenault, C. Prevost, A. Lescault, C. Laberge, J. Puymirat, and J. Mathieu Clinical characteristics of myotonic dystrophy type 1 patients with small CTG expansions Neurology, April 25, 2006; 66(8): 1248 - 1250. [Abstract] [Full Text] [PDF]

				A. Mankodi, X. Lin, B. C. Blaxall, M. S. Swanson, and C. A. Thornton Nuclear RNA Foci in the Heart in Myotonic Dystrophy Circ. Res., November 25, 2005; 97(11): 1152 - 1155. [Abstract] [Full Text] [PDF]

				L Laberge, C Gagnon, S Jean, and J Mathieu Fatigue and daytime sleepiness rating scales in myotonic dystrophy: a study of reliability J. Neurol. Neurosurg. Psychiatry, October 1, 2005; 76(10): 1403 - 1405. [Abstract] [Full Text] [PDF]

				A. Modoni, G. Silvestri, M. Grazia Pomponi, F. Mangiola, P. A. Tonali, and C. Marra Characterization of the Pattern of Cognitive Impairment in Myotonic Dystrophy Type 1 Arch Neurol, December 1, 2004; 61(12): 1943 - 1947. [Abstract] [Full Text] [PDF]

				G Antonini, C Mainero, A Romano, F Giubilei, V Ceschin, F Gragnani, S Morino, M Fiorelli, F Soscia, A Di Pasquale, et al. Cerebral atrophy in myotonic dystrophy: a voxel based morphometric study J. Neurol. Neurosurg. Psychiatry, November 1, 2004; 75(11): 1611 - 1613. [Abstract] [Full Text] [PDF]