title: Adult-onset of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome presenting as acute meningoencephalitis: a case report.
abstract: BACKGROUND
  Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a rare mitochondrial disorder with a wide range of multisystemic symptoms. Epileptic seizures are common features of both MELAS and meningoencephalitis and are typically treated with anticonvulsants.
  
  
  OBJECTIVE
  To provide the reader with a better understanding of MELAS and the adverse effects of valproic acid.
  
  
  METHODS
  A 47-year-old man with a history of diabetes, hearing loss, sinusitis, and otitis media was brought to our emergency department due to acute onset of fever, headache, generalized seizure, and agitation. Because acute meningoencephalitis was suspected, the patient was treated with antibiotics on an empirical basis. The seizure activity was aggravated by valproic acid and abated after its discontinuation. MELAS was suspected and the diagnosis was confirmed by the presence of a nucleotide 3243 A→G mutation in the mitochondrial DNA.
  
  
  CONCLUSIONS
  Detailed history-taking and systematic review help emergency physicians differentiate MELAS from meningoencephalitis in patients with the common presentation of epileptic seizures. Use of valproic acid to treat epilepsy in patients suspected of having mitochondrial disease should be avoided. Underlying mitochondrial disease should be suspected if seizure activity worsens with valproic acid therapy.
authors.affiliation: Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Yu-Chuan
authors.initials: YC
authors.lastname: Hsu
authors.forename: Fu-Chi
authors.initials: FC
authors.lastname: Yang
authors.forename: Cherng-Lih
authors.initials: CL
authors.lastname: Perng
authors.forename: An-Chen
authors.initials: AC
authors.lastname: Tso
authors.forename: Lee-Jun C
authors.initials: LJ
authors.lastname: Wong
authors.forename: Chang-Hung
authors.initials: CH
authors.lastname: Hsu
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects*; D004272:DNA, Mitochondrial / Q000235:genetics; D003937:Diagnosis, Differential; D006801:Humans; D017241:MELAS Syndrome / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D008590:Meningoencephalitis / Q000175:diagnosis / Q000188:drug therapy; D008875:Middle Aged; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D014635:Valproic Acid / Q000009:adverse effects*
chemical_list: D000927:Anticonvulsants; D004272:DNA, Mitochondrial; D014635:Valproic Acid