Muscle MRI of classic infantile pompe patients: Fatty substitution and edema-like changes.

INTRODUCTION: The aim of this study was to evaluate the muscle MRI pattern of 9 patients (median age: 6.5 ± 2.74 years) affected by classic infantile-onset Pompe disease who were treated with enzyme replacement therapy.

METHODS: We performed and qualitatively scored T1-weighted (T1-w) sequences of the facial, shoulder girdle, paravertebral, and lower limb muscles and short-tau inversion recovery (STIR) sequences of the lower limbs using the Mercuri and Morrow scales, respectively.

RESULTS: On T1-w images, mild (grade 1) or moderate (grade 2) involvement was found in the tongue in 6 of 6 patients and in the adductor magnus muscle in 6 of 9. STIR hyperintensity was detected in all areas examined and was categorized as limited to mild in 5 of 8 patients.

CONCLUSIONS: On T1-w sequences, mild/moderate adipose substitution in the adductor magnus and tongue muscles was documented. STIR edema-like alterations of thigh and calf muscles are novel findings. Correlations with biopsy findings and clinical parameters are needed to fully understand these findings. Muscle Nerve 55: 841-848, 2017.