The diagnosis may be suspected on clinical grounds. On blood testing the creatinine kinase may be raised. Imaging with ultrasound or MRI will show abnormalities in the affected muscles but these changes are not diagnostic. The diagnostic test is a muscle biopsy. On biopsy type 1 fibres predominate. The sarcomeres are disorganised and the mitochondria depleted. Necrosis and fibrosis are absent. Within the fibres<unk> ple cores are visible. Differential diagnosis * Central core disease * Centronuclear myopathy * Congenital muscular dystrophy with rigidity of the spine
Multi/minicore myopathy
Nemaline myopathy
Brody myopathy
Inflammatory myopathy
Metabolic myopathy
Polyneuropathy
Tick paralysis
Centronuclear myopathy