Characteristic findings of skeletal muscle MRI in caveolinopathies

• Published in: Neuromuscular disorders : NMD 2018-10, Vol.28 (10), p.857-862
• Main Authors: Ishiguro, Kumiko, Nakayama, Takahiro, Yoshioka, Masaru, Murakami, Terumi, Kajino, Sachiko, Shichiji, Minobu, Sato, Takatoshi, Hino-Fukuyo, Naomi, Kuru, Satoshi, Osawa, Makiko, Nagata, Satoru, Okubo, Mariko, Murakami, Nobuyuki, Hayashi, Yukiko K, Nishino, Ichizo, Ishigaki, Keiko
• Format: Article
• Language: English
• Subjects: Caveolin-3; Caveolinopathy; Life Sciences; Limb-girdle muscular dystrophy 1C; Polymerase I and transcript release factor; Rippling muscle disease; Skeletal muscle magnetic resonance imaging
• ISSN: 0960-8966; 1873-2364
• DOI: 10.1016/j.nmd.2018.07.010

•This is a report on muscle MRI findings in childhood-onset caveolinopathies.•Skeletal muscle MRI images showed peripheral involvement of the rectus femoris.•Secondary CAV3 deficiency due to PTRF mutations showed same patterns of involvement. Caveolinopathies, caused by CAV3 mutations, can include several phenotypes such as rippling muscle disease, limb-girdle muscular dystrophy type 1C, distal myopathy, familial hypertrophic cardiomyopathy, and idiopathic hyperCKemia. Here we present characteristic skeletal muscle imaging findings in four patients with genetically defined childhood-onset RMD caused by CAV3 mutations and in one patient with congenital generalized lipodystrophy type 4 with muscular dystrophy due to polymerase I and transcript release factor (PTRF) mutations, which may have caused secondary deficiency of caveolin-3. Muscle MRI revealed that the rectus femoris and semitendinosus muscles were most commonly affected in the rippling muscle disease patients. Peripheral changes in the rectus femoris were specific and observed even in one of the younger patients in this study. Furthermore, muscle involvement extended to the semitendinosus muscles, biceps femoris, and gracilis with disease progression or increase in its severity. Similar patterns of involvement were observed on reviewing skeletal muscle images of various previously reported phenotypes of caveolinopathy; interestingly, patients with secondary deficiency of caveolin due to PTRF mutations revealed the same pattern. Thus, primary caveolinopathies and secondary deficiency of caveolin demonstrated specific findings on skeletal muscle imaging, regardless of the broad phenotypic spectrum of these two conditions.