Morphological characteristics of paravertebral muscles in patients with scoliosis caused by primaryprogressive muscular dystrophies

Abstract

To identify the morphological features of paraspinal muscles in patients with spinal pathology caused by progressive muscular dystrophy. The Traumatologic-and-Orthopedic Department of Axial Skeleton Pathology examined patients with scoliotic spinal deformity due to muscular dystrophy: 1) severe Duchenne X-linked muscular dystrophy (n=7); 2) Erb-Roth's autosomal recessive muscular dystrophy (n=2); 3) Landouzy-Dejerine facioscapulohumeral muscular dystrophy (n=2). For histopathological analysis of paraspinal muscles, an excisional biopsy was performed in the region of the apex of the strain angle (the convex side), and the specimens were fixed with 10% neutral formalin. Paraffin sections were stained with hematoxylin and eosin according to the Van Gieson and Masson trichrome staining methods. The preparations were examined using an AxioScope.A1 stereo microscope and an AxioCam digital camera ('Carl Zeiss MicroImaging GmbH', Germany). Sluggish moderate paraparesis and grade IV progressive neurogenic thoracolumbar scoliosis were predominant in the clinical picture of the disease. The muscle biopsy specimens were established to have muscle fiber profiles with lost polygonality, increased diameter variability, and centrally positioned or numerous internal nuclei (myophagy) and to be characterized by fiber contractures, fatty degeneration fields, interstitial fibrosis, and signs of axonopathy of intramuscular nerve conductors. The arterial blood vessels were spastic with fibrotic t. media and t. adventicia; the venous bed vessels were dilated, thin-walled, full-blooded, which causes blood corpuscle transudation and numerous hemorrhages. The identified morphopathological characteristics of muscle tissue in patients with progressive muscular dystrophy are very similar. However, Duchenne muscular dystrophy is the most severe pathology, in which fatty degeneration and sclerotization of muscle tissue and perimysial vessels are most pronounced. To solve this problem, there is a need for the integration of geneticists, biochemists, molecular biologists, pharmacologists, and histologists.