Aim Muscle weakness, fatigue and speech problems can occur in neurofibromatosis type 1 (NF1). The pathogenesis of these symptoms is unclear, likely multifactorial. We examined motor function in limb and speech muscles in NF1 patients. Methods We evaluated NF1 and control groups aged 4–18 years for muscle strength, tone and mobility using standard manual testing, joint motion and Beighton score measurements. Speech and language functions were assessed by speech articulation and resonance. As a marker of muscle tissue turnover, we determined collagen degradation products in urine before and after submaximal exercise. Results NF1 patients had reduced strength in proximal limb muscles compared to control subjects. Speech articulation problems and hypernasality were more common in NF1 (47% and 38%, respectively). Collagen products excreted in urine correlated with gluteal and biceps muscle strength. Conclusion Muscle dysfunction can be detected in some children with NF1 and may explain certain clinical features including fatigue, speech and articulation problems. If confirmed by further research, these findings may be relevant to the management of this condition.

Purpose: Muscle weakness and delays in motor development are more common problems in children with neurofibromatosis type 1. Gross Motor Function Measurement-88 is widely used tool to evaluate motor functions in children with developmental disabilities. We aimed to investigate validity of the Gross Motor Function Measurement-88 in a sample of Turkish children with neurofibromatosis type 1. Methods: Aged between 5 to 17 years 40 (20 male/20 female) children with neurofibromatosis type 1. participated in this study. To asses validity of Gross Motor Function Measurement-88, Manual Muscle Test was done seven muscle groups in upper and lower limbs bilaterally by a physical therapist. Results: The mean age was 9.7 ± 3.81 years. A positive moderate to strong correlation was found between Manual Muscle Test and Gross Motor Function Measurement-88 subdomains (r = 0.317-0.668; p <0.05). Conclusion: Gross Motor Function Measurement-88 is a valid measurement for evaluating gross motor functions in children with neurofibromatosis type 1. Identifying motor developmental delays in children with neurofibromatosis type 1 will be a guide for establishing early intervention programs and determining symptom-specific rehabilitation goals. We recommend the use of Gross Motor Function Measurement-88 in children with neurofibromatosis type 1 for evaluating gross motor function.

Purpose: To assess physical fitness, gross motor capacity, and their relationship in children with neurofibromatosis type 1 (NF1). Materials and Methods: Children with NF1 (n=40, age 6-17, mean 9.70±3.8 years) and typically developing children (TDC) (n= 28, age 5,5-17,5, mean 11.35±3.0 years) were evaluated by the six-minute walking test, sit-up test, sit-and-reach test, flamingo balance test and body mass index. Gross motor capacity was assessed with the Gross Motor Function Measure D and E subdimensions. Results: Physical fitness and gross motor capacity differed significantly between NF1 and TDC (p