title: Cerebral proton magnetic resonance spectroscopy demonstrates reversibility of N-acetylaspartate/creatine in gray matter after delayed encephalopathy due to carbon monoxide intoxication: a case report.
abstract: BACKGROUND
  Predictive markers for long-term outcome in carbon monoxide-intoxicated patients with late encephalopathy are desired. Here we present the first data demonstrating a full reversibility pattern of specific brain substances measured by cerebral proton magnetic resonance spectroscopy in a carbon monoxide-intoxicated victim. This may provide clinicians with important information when estimating patient outcome.
  
  
  METHODS
  We report the case of a 40-year-old Caucasian woman with severe carbon monoxide poisoning who was treated with five repetitive sessions of hyperbaric oxygen therapy in a multiplace chamber (100 percent oxygen with a ventilator, 90 minutes exposure to 2.8 atmospheres absolute). Initially, our patient recovered completely after three days of hospitalization, but became encephalopathic after a lucid interval of four weeks. An examination of the brain with cerebral proton magnetic resonance spectroscopy showed a dramatically decrease in N-acetylaspartate to total creatine ratios and elevated lactate levels in the gray matter. Subsequently, our patient received six additional sessions of hyperbaric oxygen therapy with only minimal recovery. At six-month follow-up our patient showed significant improvement in cognition and neuromuscular coordination. Extraordinarily, the cerebral proton magnetic resonance spectroscopy measurements at relapse compared to measurements at follow-up (217 days post insult) revealed full reversal of the severe abnormalities in mid-occipital gray matter and partial reversal in white matter.
  
  
  CONCLUSIONS
  The present case indicates that cerebral proton magnetic spectroscopy provides valuable information on brain metabolism in patients presenting with delayed encephalopathy after acute carbon monoxide intoxication. The full reversal of N-acetylaspartate to total creatine ratios in gray matter has, to our knowledge, never been described before and shows that severe, initial measurements may not predict poor long-term patient outcome.
authors.affiliation: Hyperbaric Oxygen Treatment Unit, Department of Anesthesia, Centre for Head and Orthopedics, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark. marco.bo.hansen.02@regionh.dk.
authors.forename: Marco Bo
authors.initials: MB
authors.lastname: Hansen
authors.forename: Daniel
authors.initials: D
authors.lastname: Kondziella
authors.forename: Else Rubæk
authors.initials: ER
authors.lastname: Danielsen
authors.forename: Vibeke Andree
authors.initials: VA
authors.lastname: Larsen
authors.forename: Erik Christian
authors.initials: EC
authors.lastname: Jansen
authors.forename: Ole
authors.initials: O
authors.lastname: Hyldegaard
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D001927:Brain Diseases / Q000139:chemically induced* / Q000378:metabolism; D002249:Carbon Monoxide Poisoning / Q000150:complications*; D003401:Creatine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D059906:Neuroimaging; D066244:Proton Magnetic Resonance Spectroscopy
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine