title: [Mutism and acute behavioral disorders revealing MELAS syndrome].
abstract: BACKGROUND
  MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) is a rare genetic mitochondrial disease which can cause cerebral (cerebrovascular accident, migraine, mental deterioration..), sensorial (bilateral symmetrical deafness) and peripheral (muscular involvement, neuropathy) disorders potentially associated with diabetes, renal or cardiac disorders, or growth retardation. Eighty percent of the patients have the 3243 A>G mutation in the leucine RNA transfer gene. Clinical manifestations leading to discovery of the mutation can be extremely varied, affecting patients of different age groups.
  
  
  METHODS
  We report the case of a 49-year-old man who presented acute fits of confusion followed by mutism and praxic disorders. History taking revealed recently diagnosed type 2 diabetes, axonal neuropathy, and bilateral symmetrical deafness requiring hearing aids. The initial MRI showed FLAIR sequences with bi-parietal abnormalities, no signs of recent stroke on the DW/B10000 sequences, and basal ganglia calcifications. Blood tests and morphological findings ruled out a vascular origin. Search for lactic acidosis remained constantly negative in blood samples despite positive cerebrospinal fluid samples (N×3). The 3243 A>G mitochondrial DNA mutation was identified. The neuropsychological evaluation revealed a serious dysexecutive syndrome with a major impact on the patient's self sufficiency.
  
  
  CONCLUSIONS
  Neurocognitive disorders are not common in MELAS syndrome. Brain MRI results and the presence of extra-neurological signs can be helpful for diagnosis.
authors.affiliation: Service de Neurologie, Centre Hospitalier François-Mitterrand, 4, Boulevard Hauterive, 64046 Pau cedex, France.
authors.forename: H
authors.initials: H
authors.lastname: Coomans
authors.forename: B
authors.initials: B
authors.lastname: Barroso
authors.forename: E
authors.initials: E
authors.lastname: Bertandeau
authors.forename: M
authors.initials: M
authors.lastname: Bonnan
authors.forename: A
authors.initials: A
authors.lastname: Dakar
authors.forename: S
authors.initials: S
authors.lastname: Demasles
authors.forename: S
authors.initials: S
authors.lastname: Garraud
authors.forename: E
authors.initials: E
authors.lastname: Krim
authors.forename: M-L
authors.initials: ML
authors.lastname: Martin-Négrier
mesh_terms: D000208:Acute Disease; D003638:Deafness / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003929:Diabetic Neuropathies / Q000150:complications / Q000175:diagnosis; D006801:Humans; D017241:MELAS Syndrome / Q000150:complications / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000209:etiology; D008875:Middle Aged; D009155:Mutism / Q000175:diagnosis* / Q000209:etiology