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.

Background: Speech is the most common method of communication. Videobased clinical communication evaluation is a requirement for children with speech-language impairments living in rural areas, and those who have limited mobility. Aims: To determine the validity and reliability of the Turkish version of the Viking Speech Scale (VSS-T) via live and video-based observation for children with cerebral palsy (CP) aged 4-18 years. Methods & Procedures:A total of 142 children (mean age 8.18 ± 3.98 years; 68 female) with CP were included in this study. Their motor, communication, visual and eating-drinking function levels and comorbidities (dental, swallowing, cognitive impairments and epilepsy) were recorded. The Intelligibility in Context Scale (ICS), the Pediatric Evaluation of Disability Inventory-Social Function (PEDI-SF), and the Functional Independence Measure for Children-Communication (WeeFIM-C) were assessed to examine the concurrent validity of the VSS-T. The interrater reliability of the VSS-T was analysed between parents, physical therapists, and speech and language therapists from live and video-based observation. Intra-rater reliability was calculated from ratings made from live and video-based observations taken 3 weeks apart. Outcomes & Results:The VSS-T was strongly related to the ICS (r = -0.830), PEDI-SF (r = -0.819), WeeFIM-C (r = -0.643), other functional classifications (r > 0.432), and the comorbidities (Cramer's V > 0.284, p < 0.001). Good to excellent interrater reliability (κ w ≥ 0.838) and intra-rater reliability (intraclass correlation coefficient (ICC) = 0.848-0.995) were found between parents and therapists.Conclusions & Implications: Speech and language therapists, physical therapists, and parents can use the VSS-T as a valid and reliable classification system to describe speech intelligibility of 4-18-year-old children with CP. Both live and video-based observations can be used to administer the VSS-T.