title: Brain temperature measured by 1H-magnetic resonance spectroscopy in acute and subacute carbon monoxide poisoning.
abstract: BACKGROUND
  Brain temperature (BT) is associated with the balance between cerebral blood flow and metabolism according to the "heat-removal" theory. The present study investigated whether BT is abnormally altered in acute and subacute CO-poisoned patients by using (1)H-magnetic resonance spectroscopy (MRS).
  
  
  METHODS
  Eight adult CO-poisoned patients underwent 3-T magnetic resonance imaging in the acute and subacute phases after CO exposure. MRS was performed on deep cerebral white matter in the centrum semiovale, and MRS-based BT was estimated by the chemical shift difference between water and the N-acetyl aspartate signal. We defined the mean BT + 1.96 standard deviations of the BT in 15 healthy controls as the cutoff value for abnormal BT increases (p < 0.05) in CO-poisoned patients.
  
  
  RESULTS
  BT of CO-poisoned patients in both the acute and subacute phases was significantly higher than that of the healthy control group. However, BT in the subacute phase was significantly lower than in the acute phase. On the other hand, no significant difference in body temperature was observed between acute and subacute CO-poisoned patients. BT weakly correlated with body temperature, but this correlation was not statistically significant (rho = 0.304, p = 0.2909).
  
  
  CONCLUSIONS
  The present results suggest that BT in CO-poisoned patients is abnormally high in the acute phase and remains abnormal in the subacute phase. BT alteration in these patients may be associated with brain perfusion and metabolism rather than other factors such as systemic inflammation and body temperature.
authors.affiliation: Department of Neurosurgery, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan. shunfuji@iwate-med.ac.jp.
authors.forename: Shunrou
authors.initials: S
authors.lastname: Fujiwara
authors.affiliation: Laboratory of Biofunctional Imaging, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Yoshioka
authors.affiliation: MR Applications and Workflow Asia Pacific, GE Healthcare Japan, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsuda
authors.affiliation: Department of Neurosurgery, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nishimoto
authors.affiliation: Department of Neurosurgery, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Murakami
authors.affiliation: Department of Neurosurgery, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ogawa
authors.affiliation: Department of Neurosurgery, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan.
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Ogasawara
authors.affiliation: Department of Neurosurgery, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan.|Department of Hyperbaric Medicine, Iwate Medical University, Iwate, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Beppu
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature; D001921:Brain / Q000503:physiopathology*; D002249:Carbon Monoxide Poisoning / Q000175:diagnosis*; D006801:Humans; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged
chemical_list: D006859:Hydrogen
keywords: Brain metabolism; Brain temperature; CO poisoning; Delayed neuropsychiatric sequelae; Magnetic resonance spectroscopy