Adolescent idiopathic scoliosis without limb weakness: a differential diagnosis of core myopathy?

Abstract

BackgroundCore myopathies are a clinically and genetically heterogeneous group of congenital myopathies with the common defined histopathological feature of focally reduced oxidative activity on muscle biopsy. It has a low incidence, however, recent articles show broad clinical spectrum, suggesting that the real incidence should be considerably larger than previously described. Due to the important association between scoliosis and paravertebral muscle imbalance, numerous authors study, by biopsy of the spinal rotator muscles, potential changes that may elucidate the etiology of adolescent idiopathic scoliosis.Case presentationTwo patients have been followed at Spine Group of Department of Orthopedics at Federal University of São Paulo, with an initial diagnosis of idiopathic scoliosis. Both patients had clinical and radiological findings compatible with it. The patients authorized, through the Term of Consent, intraoperative biopsy of muscle multifidus from the apex of the thoracic curve on concave and convex sides. After muscle biopsy was performed a histopathological analysis. As regard to the histopathological features: in both patients were identified, the presence of core structures in extensive areas with reduced oxidative activity running along the muscle fiber.ConclusionsAll patients with ‘idiopathic’ scoliosis deserve a careful neurological evaluation, even if they have minimal muscle symptoms in the extremities. The frequent occurrence of scoliosis in patients with CORE Myopathies, supports the thesis that the change in the paravertebral muscle fiber must be the underlying pathogenic factor in scoliosis and may help us understand the onset and progression of curves in patients previously diagnosed with idiopathic scoliosis.

Genetic ACE I/D and ACTN3 R577X polymorphisms and adolescent idiopathic scoliosis

“…In addition, atrophy, and core presence, also occur in these muscles in patients with AIS. However, there is disparity in the literature as to whether these changes are the cause or an effect of the deformity (Chagas et al, 1993;Meier et al, 1997;Luciano et al, 2015;Wajchenberg et al, 2015).…”

Neuromuscular Scoliosis: A Neurological Point of View

“…39 Congenital myopathies, although rare and non-progressive, can also cause scoliosis over the years. 40…”

Special Pathologic Features of Adolescent Idiopathic Scoliosis: Could There be a New Type of Muscular Dystrophinopathy?

“…Moth-eaten bers were indicated by the aky and irregular loss of oxidase in staining, and could be present near the center or the edge of muscle bers. Their presence near the center of muscle bers could resemble the presentation of core myopathy, and must be differentiated by clinical manifestations and genetics (7,8). Furthermore, patients with severe scoliosis tended to have more NADH de ciency than patients with mild scoliosis (P = 0.053, although there was no statistically signi cant difference), suggesting the metabolic dysfunction of myo bers.…”

“…According to the previous literature, AIS is often accompanied by certain but unspeci ed pathological changes in paraspinal nerves or muscles (7). In 2015, Luciano et al (8) reported cases of AIS patients who didn't show the typical symptoms of decreased limb muscle strength and of limited respiratory muscle function; however, the results of the paraspinal muscle biopsies of two patients with AIS indicated a high likelihood of core myopathy, but the patients did not develop core myopathy eventually. A hypothetical explanation is that this sort of AIS patients may be a special manifestation of the core myopathy.…”