Cynthia Gagnon1, Isabelle Lessard2, Bernard Brais3, Isabelle Côté4, Caroline Lavoie4, Matthis Synofzik5, Jean Mathieu4. 1. Charles-Le-Moyne-Saguenay-Lac-St-Jean Research Center, Faculty of Medicine and Health Sciences, University of Sherbrooke, QC, Canada; Groupe de Recherche Interdisciplinaire Sur Les Maladies Neuromusculaires, Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-St-Jean, QC, Canada. Electronic address: cynthia.gagnon4@usherbrooke.ca. 2. Charles-Le-Moyne-Saguenay-Lac-St-Jean Research Center, Faculty of Medicine and Health Sciences, University of Sherbrooke, QC, Canada; Groupe de Recherche Interdisciplinaire Sur Les Maladies Neuromusculaires, Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-St-Jean, QC, Canada. 3. Montreal Neurological Institute, McGill University, QC, Canada. 4. Groupe de Recherche Interdisciplinaire Sur Les Maladies Neuromusculaires, Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-St-Jean, QC, Canada. 5. Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; German Center for Neurodegenerative Diseases, Tübingen, Germany.
Abstract
OBJECTIVE: To document in adults affected by autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) the intra- and interrater reliability, standard error of measurement, agreement, minimal detectable change, and construct validity of the 9-Hole Peg Test (NHPT), the Standardized Finger-to-Nose Test (SFNT), and grip strength. DESIGN: Metrologic study. SETTING: Neuromuscular rehabilitation clinic. PARTICIPANTS: Genetically confirmed adult patients with ARSACS (N=42; 21 women; mean age, 38.6y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Intra- and interrater reliability was determined using the intraclass correlation coefficient (ICC). Construct validity was determined by assessing the capacity of the NHPT, the SFNT, and grip strength to distinguish between participants based on sex, mobility stages, and age groups, and on performance on the Archimedes spiral and fast alternating hand movements tests. RESULTS: All 3 tests have shown excellent reliability (ICC=.90-.98). However, the limit of agreement was influenced by the participant's performance on the NHPT, and the minimal detectable change was very different for both hands (right=9.7 vs left=28.0). Construct validity was confirmed for the SFNT and NHPT, but it was not demonstrated for grip strength. CONCLUSIONS: Given the metrologic properties assessed in this study, the SFNT is an excellent measure to assess upper limb coordination, whereas the NHPT must be used with caution. The grip strength is reliable but does not seem to reflect disease severity.
OBJECTIVE: To document in adults affected by autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) the intra- and interrater reliability, standard error of measurement, agreement, minimal detectable change, and construct validity of the 9-Hole Peg Test (NHPT), the Standardized Finger-to-Nose Test (SFNT), and grip strength. DESIGN: Metrologic study. SETTING: Neuromuscular rehabilitation clinic. PARTICIPANTS: Genetically confirmed adult patients with ARSACS (N=42; 21 women; mean age, 38.6y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Intra- and interrater reliability was determined using the intraclass correlation coefficient (ICC). Construct validity was determined by assessing the capacity of the NHPT, the SFNT, and grip strength to distinguish between participants based on sex, mobility stages, and age groups, and on performance on the Archimedes spiral and fast alternating hand movements tests. RESULTS: All 3 tests have shown excellent reliability (ICC=.90-.98). However, the limit of agreement was influenced by the participant's performance on the NHPT, and the minimal detectable change was very different for both hands (right=9.7 vs left=28.0). Construct validity was confirmed for the SFNT and NHPT, but it was not demonstrated for grip strength. CONCLUSIONS: Given the metrologic properties assessed in this study, the SFNT is an excellent measure to assess upper limb coordination, whereas the NHPT must be used with caution. The grip strength is reliable but does not seem to reflect disease severity.