Reliability of the modified hammersmith functional motor scale in young children with spinal muscular atrophy

• Published in: Muscle & nerve 2011-08, Vol.44 (2), p.246-251
• Main Authors: Krosschell, Kristin J., Scott, Charles B., Maczulski, Jo Anne, Lewelt, Aga J., Reyna, Sandra P., Swoboda, Kathryn J.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Child, Preschool; Diseases of striated muscles. Neuromuscular diseases; Female; Fundamental and applied biological sciences. Psychology; Humans; Infant; Male; Medical sciences; MHFMS; Modified Hammersmith Functional Motor Scale; Modified Hammersmith Functional Motor Scale, outcome, spinal muscular atrophy, test–retest reliability; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor Skills - physiology; Neurology; outcome; Reproducibility of Results; Spinal Muscular Atrophies of Childhood - physiopathology; spinal muscular atrophy; test-retest reliability; Vertebrates: nervous system and sense organs
• ISSN: 0148-639X; 1097-4598
• DOI: 10.1002/mus.22040

Introduction: The test–retest reliability of the Modified Hammersmith Functional Motor Scale (MHFMS) in children with spinal muscular atrophy (SMA) ≤30 months of age was assessed. The age at which typically developing children (TD) achieve maximum MHFMS scores was also studied. Methods: Twenty‐two children with SMA type II [mean age (SD) = 20 (5) months, range 9–30 months) were tested twice using the MHFMS. Twenty‐five TD children [mean age (SD) = 18 (7) months, range 9–30 months) were tested once. Results: The average difference between MHFMS scores for SMA children was 0.18 [first assessment: mean (SD) = 12.8 (9.8); second assessment: mean (SD) = 13.0 (8.8)]. Reliability was excellent (ICC1,3 = 0.96, SEM 1.86). TD participants had MHFMS scores ranging from 36 to 40 [mean (SD) = 39.2 (1.2)] and achieved maximum test scores at 12 months of age. Discussion: MHFMS scores in young children with SMA type II showed excellent test–retest stability. This suggests that the MHFMS can be used reliably in this younger population for clinical trials and follow‐up. Muscle Nerve, 2011