Related Experiment Video
Updated: Jun 2, 2026
Measurements of Motor Function and Other Clinical Outcome Parameters in Ambulant Children with Duchenne Muscular Dystrophy
Published on: January 12, 2019
Quantitative Muscle MRI of the Lower Extremities Reveals Different Patterns of Involvement in Classic Infantile and
Jan J A van den Dorpel1, Mechteld E Guldemond1, Kevin R Keene2
1Department of Pediatrics, Center for Lysosomal and Metabolic Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands.
Insights
Quantitative MRI reveals distinct lower limb muscle involvement patterns in infantile and late-onset Pompe disease, correlating with motor function deficits. This aids in understanding disease progression and targeted therapies.
Area of Science:
- Neurology
- Medical Imaging
- Genetics
Background:
- Enzyme replacement therapy has improved survival in Pompe disease, leading to distinct clinical phenotypes.
- Classic infantile Pompe disease often presents with distal muscle weakness, while late-onset forms typically show proximal weakness.
Purpose of the Study:
- To characterize lower limb muscle involvement using quantitative MRI in classic infantile and young late-onset Pompe disease patients.
- To compare muscle involvement patterns between patient groups and healthy controls.
- To examine the relationship between MRI findings and motor function.
Main Methods:
- Quantitative MRI (3-point Dixon, multi-echo spin-echo at 3T) assessed fat fraction (FF) and water T2 (T2water) in leg muscles.
- Eight classic infantile, 12 late-onset Pompe patients, and 13 healthy controls were studied.
- MRI findings were correlated with Quick Motor Function Test (QMFT) and Medical Research Council (MRC) scores.
Main Results:
- Both Pompe patient groups exhibited fat replacement and T2water abnormalities in numerous muscles.
- Classic infantile patients showed more frequent lower leg involvement (80%), while late-onset patients had predominant thigh involvement (40%).
- Extensive thigh involvement correlated with lower QMFT scores; foot dorsiflexion weakness was linked to tibialis anterior involvement in infantile patients.
Conclusions:
- Quantitative MRI reveals phenotype-specific patterns of lower limb muscle involvement in Pompe disease.
- Combining FF and T2water measurements is valuable for detecting muscle involvement in Pompe disease.
- These findings support tailored therapeutic strategies based on disease presentation.
Abstract:
With increased survival due to enzyme replacement therapy, children with classic infantile Pompe disease tend to develop a clinical phenotype with pronounced distal muscle weakness, while late-onset patients typically exhibit proximal muscle weakness. This MRI study aimed to characterize lower limb muscle involvement in classic infantile and young late-onset Pompe patients compared to healthy controls, and examine its relationship with motor function. Quantitative MRI (3-point Dixon and multi-echo spin-echo at 3T) was used to assess fat fraction (FF) and water T2 (T2water) in the leg muscles of eight classic infantile patients (6.6-15.0 years), 12 late-onset patients (6.8-27.3 years), and 13 healthy controls (6.5-26.9 years). Group comparisons were performed (Kruskal-Wallis, post hoc Dunn), and FF and T2water values were combined to identify the most frequently affected muscles. MRI findings were correlated with Quick Motor Function Test (QMFT) scores for thigh involvement and Medical Research Council (MRC) scores for foot dorsiflexion strength. MRI showed fat replacement and T2water abnormalities in numerous muscles in both patient groups. Fat replacement was generally mild (< 20%) but reached 69% in some cases. T2water values ranged from 21 to 37 ms. Classic infantile patients showed more frequent lower leg involvement (80% vs. 40%), while late-onset patients had predominant thigh involvement, particularly in the adductors. Extensive thigh involvement correlated with lower QMFT scores. Foot dorsiflexion weakness occurred only in classic infantile patients with tibialis anterior involvement. This data suggests a phenotype-specific pattern of muscle involvement and demonstrates the value of combining FF and T2water via quantitative MRI for detection of muscle involvement in Pompe disease.
