Skeletal Muscle Magnetic Resonance Imaging of the Lower Limbs in Late-onset Lipid Storage Myopathy with Electron Transfer Flavoprotein Dehydrogenase Gene Mutations.
BACKGROUND
Lipid storage myopathy (LSM) is a genetically heterogeneous group with variable clinical phenotypes. Late-onset multiple acyl-coenzyme A dehydrogenation deficiency (MADD) is a rather common form of LSM in China. Diagnosis and clinical management of it remain challenging, especially without robust muscle biopsy result and genetic detection. As the noninvasion and convenience, muscle magnetic resonance imaging (MRI) is a helpful assistant, diagnostic tool for neuromuscular disorders. However, the disease-specific MRI patterns of muscle involved and its diagnostic value in late-onset MADD have not been systematic analyzed.


METHODS
We assessed the MRI pattern and fat infiltration degree of the lower limb muscles in 28 late-onset MADD patients, combined with detailed clinical features and gene spectrum. Fat infiltration degree of the thigh muscle was scored while that of gluteus was described as obvious or not. Associated muscular atrophy was defined as obvious muscle bulk reduction.


RESULTS
The mean scores were significantly different among the anterior, medial, and posterior thigh muscle groups. The mean of fat infiltration scores on posterior thigh muscle group was significantly higher than either anterior or medial thigh muscle group (P < 0.001). Moreover, the mean score on medial thigh muscle group was significantly higher than that of anterior thigh muscle group (P < 0.01). About half of the patients displayed fat infiltration and atrophy in gluteus muscles. Of 28 patients, 12 exhibited atrophy in medial and/or posterior thigh muscle groups, especially in posterior thigh muscle group. Muscle edema pattern was not found in all the patients.


CONCLUSIONS
Late-onset MADD patients show a typical muscular imaging pattern of fat infiltration and atrophy on anterior, posterior, and medial thigh muscle groups, with major involvement of posterior thigh muscle group and gluteus muscles and a sparing involvement of anterior thigh compartment. Our findings also suggest that muscle MRI of lower limbs is a helpful tool in guiding clinical evaluation on late-onset MADD.
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China.
Xin-Yi
XY
Liu
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China.
Ming
M
Jin
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005; Fujian Key Laboratory of Molecular Neurology, Fuzhou, Fujian 350005, China.
Zhi-Qiang
ZQ
Wang
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China.
Dan-Ni
DN
Wang
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China.
Jun-Jie
JJ
He
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China.
Min-Ting
MT
Lin
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China.
Hong-Xia
HX
Fu
Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005; Fujian Key Laboratory of Molecular Neurology, Fuzhou, Fujian 350005, China.
Ning
N
Wang
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D044927:Electron-Transferring Flavoproteins / Q000235:genetics*; D005260:Female; D006801:Humans; D008052:Lipid Metabolism, Inborn Errors / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D035002:Lower Extremity / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology*; D009133:Muscular Atrophy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009136:Muscular Dystrophies / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D055815:Young Adult
D044927:Electron-Transferring Flavoproteins