Background: We report a 46-year-old woman with implications regarding pathogenesis of strokelike episodes in MELAS (mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes). She had a 10-month history of episodic seizures, strokes, cognitive decline, vomiting, and ileus. She also had sensorineural hearing loss, insulin-dependent diabetes mellitus of several years' duration, and persistent lactic acidosis. Family history was pertinent for a similar syndrome in her deceased mother (onset in her sixties), for hearing loss and diabetes mellitus in two brothers, and for hearing loss in her only child, a son.
Case Description: Serial MRIs of the brain revealed severe but evanescent cerebral cortical abnormalities. A left temporal brain biopsy was performed to exclude encephalitis. Light microscopy revealed a diffuse fibrillary gliosis with abundant reactive gemistocytes, focal evidence of ischemic neuronal injury, and edema. Electron microscopy revealed bizarre enlarged mitochondria and changes consistent with cellular edema. Succinate dehydrogenase staining was strongly reactive within cerebral blood vessels and within neurons. A point mutation was subsequently found at nt 3243 of the mitochondrial tRNA(Leu(UUR) gene in peripheral leukocytes and in brain, confirming the clinical diagnosis of MELAS. Quantitation revealed that 82% of brain mitochondria carried the disease mutation, indicating that most, if not all, tissues were affected.
Conclusions: Our findings suggest that strokelike episodes in MELAS result from defects in neuronal metabolism, as well as in cerebral vasculature.
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http://dx.doi.org/10.1161/01.str.27.8.1420 | DOI Listing |
Orphanet J Rare Dis
January 2025
Ophthalmology Department, Centro Hospitalar e Universitário de Coimbra (CHUC), Hospitais da Universidade de Coimbra (HUC), ULS Coimbra, Praceta Prof. Mota Pinto, 3000-075, Coimbra, Portugal.
Background: Syndromic genetic disorders affecting vision can also cause hearing loss, and Usher syndrome is by far the most common etiology. However, many other conditions can present dual sensory impairment. Accurate diagnosis is essential for providing patients with genetic counseling, prognostic information, and appropriate resources.
View Article and Find Full Text PDFEur Heart J Case Rep
January 2025
Department of Cardiology, National University Heart Center Singapore, 5 Lower Kent Ridge Rd, Singapore, Singapore 119074.
Background: Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a rare and progressive mitochondrial disorder characterized by multi-systemic involvement. This disease manifests in various clinical manifestations, with heart and kidney disorders being among the most common. Accurate diagnosis of MELAS often necessitates a range of complex investigations.
View Article and Find Full Text PDFAJNR Am J Neuroradiol
January 2025
Department of Pediatric Radiology and Neuroradiology (C.D., F.A., C.P., A.R.), Children's Hospital V. Buzzi, Milan, Italy.
Glucose transporter type 1 deficiency syndrome (GLUT1-DS) is an uncommon condition represented by an infantile-onset disorder, frequently arising from heterozygous mutations in the gene. Individuals with GLUT1-DS may present with early-onset seizures (typically manifesting before 4 years of age), developmental delay, and complex movement disorders. In fewer cases, stroke-like events or hemiplegic migraine-like symptoms are also reported, defined by unilateral paresis affecting 1 side of the body and/or one-half of the face, occasionally accompanied by speech impairment.
View Article and Find Full Text PDFBiomolecules
November 2024
Departments of Pediatrics, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06229, Republic of Korea.
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a complex mitochondrial disorder characterized by a wide range of systemic manifestations. Key clinical features include recurrent stroke-like episodes, seizures, lactic acidosis, muscle weakness, exercise intolerance, sensorineural hearing loss, diabetes, and progressive neurological decline. MELAS is most commonly associated with mutations in mitochondrial DNA, particularly the m.
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