Related Experiment Video
Updated: Apr 14, 2026
Author Spotlight: Collecting the Brain and Serum from the Same Mice Fetus to Study Brain Tumor Development
Published on: May 17, 2024
Muscle weakness in children with neurofibromatosis type 1
Kayla M D Cornett1,2, Kathryn N North3,4, Kristy J Rose1,2
1Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, Sydney, NSW, Australia.
Insights
Children with neurofibromatosis type 1 (NF1) exhibit significantly reduced muscle strength across all tested muscle groups compared to typically developing children. This weakness is evident early and persists throughout childhood, suggesting a primary myopathy associated with NF1.
Area of Science:
- Pediatric Neurology
- Muscle Physiology
- Genetics
Background:
- Neurofibromatosis type 1 (NF1) is a genetic disorder with varied clinical manifestations.
- Muscle strength deficits in children with NF1 have been an area of ongoing investigation.
- Understanding the extent of muscle weakness is crucial for comprehensive patient care.
Purpose of the Study:
- To quantitatively assess and compare muscle strength in children with NF1 versus age-matched controls.
- To determine if NF1 is associated with generalized muscle weakness in pediatric populations.
- To identify potential patterns or differences in muscle weakness across various muscle groups.
Main Methods:
- Maximal isometric strength testing of 15 upper and lower limb muscle groups.
- Inclusion of 30 children with NF1 (aged 4-16 years) and 30 matched controls.
- Utilized hand-held dynamometry for precise strength measurements, assessing both left and right sides.
Main Results:
- Children with NF1 demonstrated significantly lower muscle strength in all 15 assessed muscle groups (p<0.05).
- Strength deficits ranged from 3% to 43% compared to controls, with no significant side-to-side differences except for elbow flexion.
- Muscle weakness was observed equally in both males and females with NF1.
Conclusions:
- Children diagnosed with NF1 present with objectively reduced muscle strength compared to their typically developing peers.
- This muscle weakness is a consistent finding from early disease stages throughout childhood, irrespective of sex.
- The results corroborate emerging evidence suggesting NF1 may involve a primary myopathy.
Aim:
To investigate if children with neurofibromatosis type 1 (NF1) have reduced muscle strength compared with children with typical development.
Method:
Maximal isometric strength of 15 upper and lower limb muscle groups was evaluated in 30 children with NF1 (16 males, 14 females; aged 4-16y) and 30 age-, sex-, height-, and weight-matched controls using hand-held dynamometry by a single evaluator. Both the left and right sides were assessed.
Results:
Children with NF1 were significantly weaker than children with typical development across all 15 muscle groups assessed (p<0.05). Apart from elbow flexion, there were no differences between the left and right sides (p>0.05). Magnitude of differences between the children with NF1 compared with the controls ranged from 3% to 43%. Males and females were equally affected.
Interpretation:
This study shows that children with NF1 have reduced muscle strength compared with children with typical development. This muscle weakness is present from the earliest stages of the disease assessed and persists throughout childhood with no sex difference. These results support recent evidence from mouse studies that NF1 is associated with a primary myopathy.
More Related Videos
Related Concept Videos
01:28Disorders of the Skeletal Muscle
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
01:15Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
01:21Satellite Stem Cells and Muscular Dystrophy
01:26Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:26Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:20Myasthenia Gravis: Overview and Treatment
These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which...