In a recent article published in Acta Neuropathologica Communications, a team of researchers from the University of California San Francisco reported a case of a patient with a rapid progressive adult onset scoliosis due to late-onset axial myopathy associated with multiple somatic mtDNA abnormalities but without chronic myopathic features typically observed in primary axial myopathies.
Based on results of the case outcomes the researchers suggested that the case demonstrates that adult spinal deformity may be secondary to a previously undiagnosed neuromuscular pathology and that primary axial myopathy can be due to an apparently isolated mitochondrial myopathy.
In their articled titled “Axial mitochondrial myopathy in a patient with rapidly progressive adult-onset scoliosis,” Marta Margeta from the Department of Pathology, University of California San Francisco and colleagues report a case of a woman aged 69 years old with family history of scoliosis. The condition also affected both her son and her mother who over the course 4 years had quick, progressive scoliosis development.
Since adolescence, the patient had a history of stable scoliosis that got progressively worse at age of 65, leading to low back pain and radiculopathy. Results from a paraspinal muscle biopsy revelaed morphologic evidence of a mitochondrial myopathy.
Mitochondrial myopathies are a group of neuromuscular diseases caused by damage to the mitochondria, energy-producing structures in cells that serve as power plants. Nerve and muscle cells require a great deal of energy and are particularly impaired by mitochondrial dysfunction.
Assessment with standard bioassays revealed no deficiencies of electron transport chain enzymes however but mitochondrial immunofluorescence demonstrated many deficiencies in muscle fibers. Using massively parallel sequencing of paraspinal muscle mtDNA, the clinicians were able to detect multiple deletions.
The observed mitochondrial abnormalities were not identified in the blood of either the patient or her son, suggesting that the patient’s quick progress in late onset scoliosis was because of an acquired paraspinal mitochondrial myopathy; the cause of non-progressive scoliosis in the other two family members presently remains inexplicable.
Based on the clinical assessment, the research team concluded that isolated mitochondrial myopathy can underlie rapidly progressive adult-onset scoliosis and should be considered in the differential diagnosis of the primary axial myopathy.