Brain Temperature in Neonates with Hypoxic-Ischemic Encephalopathy during Therapeutic Hypothermia

Brain Temperature Is Increased During the First Days of Life in Asphyxiated Newborns: Developing Brain Injury Despite Hypothermia Treatment

“…On the basis of the princi-ple that temperature affects the hydrogen bonding between water molecules, 9 which leads to a shift in the spectral position of the water signal relative to a reference metabolite that has less sensitivity to temperature changes-such as N-acetyl aspartate-on MR spectroscopy, 11,17,25,26 brain temperature was derived by analyzing the chemical shift differences (␦ ppm) between the water peak and the NAA spectrum. 19 This method has been demonstrated previously to have an accuracy of Ϯ0.5°C and a precision of 0.3°C. 14,17,26 The chemical shift differences were plotted against the temperature to obtain the calibration line for estimating the brain temperature of the neonates.…”

“…15 However, until now, brain thermometry has been used only a few times with neonates, 16,17 and even more rarely with neonates with hypoxic-ischemic encephalopathy. 18,19 Bainbridge et al 18 have demonstrated the feasibility of this technique with neonates using single-voxel MR spectroscopy placed in the thalamus and/or white matter to show the correlation between brain and rectal temperatures in healthy neonates; in addition, in their study, only 9 neonates had brain temperature measurements during hypothermia treatment. Wu et al 19 studied 18 neonates with hypoxic-ischemic encephalopathy treated with hypothermia with single-voxel MR spectroscopy placed in the thalamus, basal ganglia, and/or cortical gray matter.…”

“…18,19 Bainbridge et al 18 have demonstrated the feasibility of this technique with neonates using single-voxel MR spectroscopy placed in the thalamus and/or white matter to show the correlation between brain and rectal temperatures in healthy neonates; in addition, in their study, only 9 neonates had brain temperature measurements during hypothermia treatment. Wu et al 19 studied 18 neonates with hypoxic-ischemic encephalopathy treated with hypothermia with single-voxel MR spectroscopy placed in the thalamus, basal ganglia, and/or cortical gray matter. They found that the initial degree of encephalopathy seemed to influence brain temperature measurements during and after hypothermia.…”

The effects of therapeutic hypothermia on cerebral metabolism in neonates with hypoxic-ischemic encephalopathy: An in vivo 1H-MR spectroscopy study

“…In an earlier report, we demonstrated that there is variability in cerebral temperature across patients and brain regions during hypothermia and after rewarming. 22 It remains to be determined whether long-term neurodevelopmental outcomes can be enhanced by optimizing hypothermia protocols to achieve targeted brain temperatures in neonates with HIE. Furthermore, neurodevelopmental follow-up is ongoing in the present cohort.…”

“…During the first MRI, whole-body hypothermia was maintained using the same blanketcooling device as above, modified with extension tubing. 22,23 Rectal temperature was continuously monitored throughout both examinations and recorded via an MR compatible temperature probe (Invivo Corporation, Gainesville, FL). MR data were acquired on a 3 T MR system (Philips Medical, Best, The Netherlands, Achieva, Ver.…”