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Objective To investigate temperature changes in prefrontal cortex and hippocampus of heroin addicts with magnetic resonance spectroscopy (MRS).Methods 18 heroin addicts in the withdrawal state and 18 healthy volunteers (control group) were performed with MRS scan.First, resting-state MRS scan was performed on all subjects, and then did MRS scan again under visual stimulation while subjects were asked to carefully watch the heroin-related cue images.Measurements of NAA of the identified regions (the prefrontal cortex, bilateral hippocampus) were obtained from all subjects.Brain temperatures were calculated by the modified brain temperature-chemical shift equation.Results In resting state, the temperature of prefrontal cortex in heroin addicts group was higher than the control group, the difference was statistically significant (P0.05).Conclusion MRS can be used to measure brain temperature noninvasively.Temperature change of brain may be helpful for exploring the mechanism of drug addiction and craving.
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Hypothalamic temperature (Thy) alteration is one of the important stimuli that brings about thermoregulatory measures including the changes in wakefulness and muscular activity. The role of the lateral preoptic area (lPOA) in thermoregulation and sleep is well documented. But it is not known whether the integrity of the lPOA is essential for bringing about the changes in sleep-wakefulness (S-W) and thermoregulation in cold ambient temperature (Ta). Neurotoxic lesion of the lPOA resulted in an increase in wake period and core body temperature (Tb) and no change in Thy. Unlike, normal animals, as reported earlier, there was further increase in Tb of the lPOA lesioned rats on acute cold exposure, but the Thy remained unaltered throughout the 28 days of continued cold exposure. The findings demonstrate that the lPOA lesioned rats have lost the ability to reset Thy which may be necessary for thermoregulation during cold exposure. Moreover, increased wake period lasted only 7 days in lesioned, compared to 14 days in normal animals. Less efficient restoration of Tb, and less prolonged wake period during continued cold exposure, are probably the result of the inability of the lPOA lesioned rats to lower Thy, which is necessary to bring about the thermoregulatory measures.
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OBJECTIVE: The brain temperature is about 0.4-1 degrees C higher than that of the other peripheral body area. But most of these results have been obtained in normothermic condition. The objective of this study is to evaluate the temperature difference between the brain and axilla, in patients under hypothermia. METHODS: Sixty-three patients(37 women and 26 men) who underwent craniotomy with implantation of the thermal diffusion flowmetry sensor were included in this study. The temperature of the cerebral cortex and axilla was measured every 2 hours, simultaneously. The patient group was divided according to axillary temperature hyperthermia(over 38 degrees C), normothermia(36-38 degrees C) and hypothermia(under 36 degrees C). Total 1671 paired sample data were collected and analyzed. RESULTS: The temperature difference between the cerebral cortex and the axilla was 0.45+/-1.04 degrees C in hyperthermic patients, 0.97+/-1.1 degrees C in normothermic patients and 1.04+/-0.81 degrees C in hypothermic patients. The temperature difference has statistical significance in each group(unpaired t-test, p<0.05). CONCLUSION: From our study the temperature difference between the brain and the axilla in hypothermic condition increased more than that of normothermic state. And in hyperthermic condition, the temperature difference decreased.
Assuntos
Feminino , Humanos , Axila , Encéfalo , Córtex Cerebral , Craniotomia , Febre , Hipotermia , Reologia , Difusão TérmicaRESUMO
No abstract available.