title: Effects of temperature changes on cerebral biochemistry in spontaneous intracerebral hematoma.
abstract: BACKGROUND
  Fever worsens outcome in acute brain injury, presumably by accelerating secondary damage. Improved understanding of the pathophysiological processes that occur in spontaneous intracerebral hemorrhage (ICH) may help to determine if controlled normothermia might be of clinical benefit.
  
  
  METHODS
  In this prospective observational study over a period of 18 months at the National Neuroscience Institute, Singapore, we examined the effects of temperature changes on brain biochemistry and tissue oxygenation in 25 consecutive patients with spontaneous primary putaminal hemorrhage. The patients were divided into 3 groups according to the mean brain temperature over a 72-hour monitoring period following surgery and standard medical measures to control post-operative brain swelling and secondary injury.
  
  
  RESULTS
  Patients that become spontaneously hypothermic with a mean brain temperature of less than 36 degrees centigrade (degrees C) had greater impairment in brain biochemistry as reflected by the worst brain lactate/pyruvate (L/P) ratio, glutamate and glucose dialysates. Brain tissue oxygenation, on the other hand, was highest and within normal limits in these spontaneously hypothermic patients. The hyperthemic group had similar L/P ratio, glycerol and glutamate levels when compared to the normothermic group. The glucose levels were found to be significantly different in all 3 groups.
  
  
  CONCLUSIONS
  Extremes of temperature in spontaneous ICH, in particular--spontaneous hypothermia with a mean brain temperature of less than 36 degrees C, are associated with a poor outcome. Cerebral microdialysis can be used to detect these detrimental changes that occur.
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, 11, Jalan Tan Tock Seng, Singapore 308433, Singapore.
authors.forename: Ernest
authors.initials: E
authors.lastname: Wang
authors.forename: Chi Long
authors.initials: CL
authors.lastname: Ho
authors.forename: Kah Keow
authors.initials: KK
authors.lastname: Lee
authors.forename: Ivan
authors.initials: I
authors.lastname: Ng
authors.forename: Beng Ti
authors.initials: BT
authors.lastname: Ang
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001923:Brain Chemistry / Q000502:physiology*; D001929:Brain Edema / Q000503:physiopathology; D002543:Cerebral Hemorrhage / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D007035:Hypothermia / Q000209:etiology; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019289:Pyruvic Acid / Q000378:metabolism; D018709:Statistics, Nonparametric; D013696:Temperature
chemical_list: D019344:Lactic Acid; D018698:Glutamic Acid; D019289:Pyruvic Acid