Altered Cerebral Glucose Metabolism in a Family With Clinical Features Resembling Mitochondrial Neurogastrointestinal Encephalomyopathy Syndrome in Association With Multiple Mitochondrial DNA Deletions

Abstract

To determine the involvement of cerebral metabolism in 2 siblings with mitochondrial neurogastrointestinal encephalomyopathy syndrome (MNGIE)-like disease with multiple mitochondrial DNA (mtDNA) deletions. Case report. Department of Neurology at a university medical center. Two siblings with MNGIE-like disease with multiple mtDNA deletions. Clinical, biochemical, genetic, and imaging findings, including cerebral magnetic resonance imaging, proton magnetic resonance spectroscopy, and positron emission tomography with fluorine 18-labeled deoxyglucose (FDG-PET). Genetic analysis of muscle DNA revealed multiple mtDNA deletions, while no mutations were detected in ECGF1, POLG1, ANT1, or Twinkle. Cerebral magnetic resonance imaging and proton magnetic resonance spectroscopy findings were unremarkable. Reduced regional glucose metabolism was found in a patchy and asymmetrical pattern predominantly in the frontotemporal region in both siblings by means of FDG-PET. The discrepancy between absence of clinical signs of cerebral involvement and the substantial impairment of glucose metabolism reflects a chronic subclinical encephalopathy. To our knowledge, the predominantly frontotemporal distribution has not been described previously in mitochondrial disorders.