Muscle biopsy is not diagnostic for MELAS

With interest we read the article by Lu et al. about a histopathological study of 12 patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episode syndrome (MELAS) who were negative for ragged-red fibers (RRFs) and cytochrome-c-oxidase (COX) deficient muscle fibers (group-1) and 99 MELAS patients positive for RRFs and COX-deficient muscle fibers on muscle biopsy (group-2) [1]. Interestingly, four of the 12 patients with COX- and RRF-negative muscle biopsy had vessels on muscle biopsy which strongly stained for succinate dehydrogenase (SDH) (strongly succinate dehydrogenase positive vessels (SSVs)) [1].

Source: Journal of the Neurological Sciences - January 4, 2020 Category: Neurology Authors: Josef Finsterer Tags: Letter to the Editor Source Type: research