Clinical, muscle imaging and electrophysiological features of oculopharyngodistal myopathy / 中国神经精神疾病杂志

Objective To investigate the clinical manifestation and electrophysiological, muscle imaging and pathological, molecular features of oculopharyngodistal myopathy (OPDM). Methods The clinical electrophysiological, muscle imaging and pathological, molecular data was collected from a case of OPDM. Data analysis was conducted together with a literature. Results The onset age of the patient was 25 years old. The sequential order of involved muscle was upper eyelid muscle, external ocular, laryngopharyngeal, facial, distal limb muscle and proximal upper limb. Serum creatine kinase was mildly elevated. Electromyography revealed myogenic changes with demyelinating peripheral neuropathy. Myopathological findings showed myopathic changes with rimmed vacuoles . Muscle image showed that fatty replacement of was more severe in lower legs than in thigh. Posterior muscle was severely involved in lower legs. All known genes responsible for distal and myofibrillar myopathies, vacuolar myopathies, and muscular dystrophies were excluded by targeted next-generation sequencing. Conclusion The case is a sporadic case. OPDM is a disease with a unique phenotype which not only affects muscle but also involves multiple system (demyelinating peripheral neuropathy、heart disease and so on).

Clinical, pathological, imaging and genetic analysis of two cases of central core disease with different inheritance modes / 中国神经精神疾病杂志

Objective To study the clinical, pathological, imaging features of two cases of central core disease (CCD) with different inheritance and to explore the similarities and differences between autosomal recessive CCD (AR-CCD) and autosomal dominant CCD (AD-CCD). Methods Clinical manifestations, family history, muscle MRI and muscle biopsy were collected. Targeted next generation sequencing (NGS) and sanger sequencing were applied for genetic analysis. Co-segregation analysis was further conducted in one family. Results Their common clinical manifestations included childhood early-onset proximal limbs muscle weakness and dystrophy accompanied with facial involvement. The MRI revealed extensive muscular dystrophy and fatty filtration in the both thighs, but not in rectus femoris. Pathology of skeletal muscle showed typical central cores in type Ⅰ muscle fibers and eccentric cores only in AR-CCD. Targeted NGS identified 3 missense mutations in RYR1, including one novel mutation. Conclusion The present study has described clinical and pathological features of two typical CCD patients with different inheritance, which may be associated with the different mutations in RYR1 gene. Targeted NGS apparently improves the genetic diagnosis of CCD.

Whole-Body Muscle MRI in Patients with Hyperkalemic Periodic Paralysis Carrying the SCN4A Mutation T704M: Evidence for Chronic Progressive Myopathy with Selective Muscle Involvement

BACKGROUND AND PURPOSE: Hyperkalemic periodic paralysis (hyperKPP) is a muscle sodium-ion channelopathy characterized by recurrent paralytic attacks. A proportion of affected individuals develop fixed or chronic progressive weakness that results in significant disability. However, little is known about the pathology of hyperKPP-induced fixed weakness, including the pattern of muscle involvement. The aim of this study was to characterize the patterns of muscle involvement in hyperKPP by whole-body magnetic resonance imaging (MRI). METHODS: We performed whole-body muscle MRI in seven hyperKPP patients carrying the T704M mutation in the SCN4A skeletal sodium-channel gene. Muscle fat infiltration, suggestive of chronic progressive myopathy, was analyzed qualitatively using a grading system and was quantified by the two-point Dixon technique. RESULTS: Whole-body muscle MRI analysis revealed muscle atrophy and fatty infiltration in hyperKPP patients, especially in older individuals. Muscle involvement followed a selective pattern, primarily affecting the posterior compartment of the lower leg and anterior thigh muscles. The muscle fat fraction increased with patient age in the anterior thigh (r=0.669, p=0.009), in the deep posterior compartment of the lower leg (r=0.617, p=0.019), and in the superficial posterior compartment of the lower leg (r=0.777, p=0.001). CONCLUSIONS: Our whole-body muscle MRI findings provide evidence for chronic progressive myopathy in hyperKPP patients. The reported data suggest that a selective pattern of muscle involvement-affecting the posterior compartment of the lower leg and the anterior thigh-is characteristic of chronic progressive myopathy in hyperKPP.