Central core disease in China: a clinical and pathological study

Objectives: To investigate the clinical and pathological characteristics of central core disease (CCD) in China. Methods: A retrospective analysis was performed on the clinical data of 40 patients with CCD who presented at our department or other hospitals from 1986 to 2013. Muscle histochemical staining was used to study the muscular pathological characteristics of patients with CCD. Results: This study included a total of 18 reported cases and 22 cases in our department, among which 15 were sporadic cases and 25 were familial (from 6 families). There were 20 men and 20 women. 38 patients had experienced the onset of CCD during childhood or even earlier; however, only 2 patients had adult-onset CCD. All patients manifested symptoms of muscle weakness, majority of them starting with a weakness of the lower extremities. In addition to limb muscles, CCD also affected their necks, faces, and extraocular muscles to varying degrees. CCD was often accompanied by delayed motor development, bone and joint deformities, reduced fetal movement during pregnancy, or hypotonia. Except 2 patients with significantly elevated creatine kinase (CK) levels (up to 1419 U/L and 2259 U/L), the remaining patients had normal or slightly elevated CK levels. Electromyography (EMG) showed myogenic damage or no abnormalities. In the muscle pathology of all patients, NADH staining clearly showed an oxidase-deficient area, or the core region, with a clear boundary at the center of almost every muscle fiber. Besides, the core phenomenon can also be observed via a good hematoxylin and eosin (HE), modified Gomori trichrome (MGT), non-specific esterase (NSE), periodic acid shift (PAS), and oil Red “O” (ORO) staining. ATPase staining showed that the majority of fibers with cores were type I fibers. Necrotic muscle fibers, phagocytosis, and inflammatory cell infiltration were not observed, except in 3 patients with necrotic muscle fibers. Conclusions: The clinical manifestation and pathological characteristics of Chinese CCD patients are similar with that of previous reports, except with late onset age, less facial muscle involvement and eccentric cores. And the diagnosis mainly relies on the characteristic core structure revealed by muscle histochemical staining.