title: Cranial nerve and cervical root enhancement in an infant with polymerase gamma mutation mitochondrial disease.
abstract: BACKGROUND
  Nuclear polymerase gamma (POLG) mutations are the most common cause of inherited mitochondrial disease. POLG mutation diseases have a broad spectrum of clinical manifestations; the lethal infantile form is myocerebrohepatopathy spectrum.
  
  
  METHODS
  A 4-month-old boy was referred for poor feeding, emesis, failure to thrive, and hypotonia.
  
  
  RESULTS
  Brain computed tomography was normal. Brain magnetic resonance imaging with and without contrast demonstrated bilateral enhancement of cranial nerves III, V-X, and the upper and midcervical nerve roots. Liver biopsy revealed early cirrhosis, steatosis, and focal necrosis. Muscle biopsy did not demonstrate specific abnormalities of mitochondrial morphology or number. Electron transport chain analysis of both fibroblasts and muscle demonstrated deficiencies. Because of suspected mitochondrial depletion disorder, testing was performed for mitochondrial abnormalities including analysis of the POLG gene, which revealed two pathogenic mutations, c.1399G>A (p.A467T) and c.3285C>G (p.S1095R).
  
  
  CONCLUSIONS
  We report abnormal gadolinium enhancement of multiple cranial nerves and cervical nerve roots in an infant with myocerebrohepatopathy spectrum disease whose brain MRI otherwise revealed only mild atrophy. Mitochondrial disease should be included in the differential diagnosis of cranial nerve enhancement. Contrast-enhanced MRI aids in the diagnostic evaluation of infants with developmental delay and suspected neurological disease.
authors.affiliation: Department of Radiology, Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Deanna M
authors.initials: DM
authors.lastname: Horst
authors.affiliation: Department of Radiology, Nationwide Children's Hospital, Columbus, Ohio; Department of Radiology, The Ohio State University College of Medicine and Public Health, Columbus, Ohio. Electronic address: lynne.ruess@nationwidechildrens.org.
authors.forename: Lynne
authors.initials: L
authors.lastname: Ruess
authors.affiliation: Department of Radiology, Nationwide Children's Hospital, Columbus, Ohio; Department of Radiology, The Ohio State University College of Medicine and Public Health, Columbus, Ohio.
authors.forename: Jerome A
authors.initials: JA
authors.lastname: Rusin
authors.affiliation: Center for Molecular and Human Genetics, Nationwide Children's Hospital Research Institute, Columbus, Ohio; Department of Pediatrics, The Ohio State University College of Medicine and Public Health, Columbus, Ohio.
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Bartholomew
mesh_terms: D001921:Brain / Q000473:pathology; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase / Q000235:genetics*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D028361:Mitochondrial Diseases / Q000235:genetics* / Q000473:pathology; D009154:Mutation / Q000235:genetics*; D013116:Spinal Cord / Q000473:pathology
chemical_list: D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase; C413027:POLG protein, human
keywords: MRI; imaging; infant; mitochondrial disease