Responses of the human brain to mild dehydration and rehydration explored in vivo by 1H-MR imaging and spectroscopy

• Verfasst von: Biller, Armin [VerfasserIn]
• Verfasst von: Reuter, M. [VerfasserIn]
• Verfasst von: Patenaude, B. [VerfasserIn]
• Verfasst von: Homola, G. A. [VerfasserIn]
• Verfasst von: Breuer, F. [VerfasserIn]
• Verfasst von: Bendszus, Martin [VerfasserIn]
• Verfasst von: Bartsch, Andreas J. [VerfasserIn]
• Titel: Responses of the human brain to mild dehydration and rehydration explored in vivo by 1H-MR imaging and spectroscopy
• Verf.angabe: A. Biller, M. Reuter, B. Patenaude, G.A. Homola, F. Breuer, M. Bendszus, and A.J. Bartsch
• E-Jahr: 2015
• Jahr: May 6, 2015
• Umfang: 8 S.
• Fussnoten: Gesehen am 26.05.2020
• Titel Quelle: Enthalten in: American journal of neuroradiology
• Ort Quelle: Oak Brook, Ill. : Soc., 1980
• Jahr Quelle: 2015
• Band/Heft Quelle: 36(2015), 12, Seite 2277-2284
• ISSN Quelle: 1936-959X
• DOI: doi:10.3174/ajnr.A4508
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1698806922

Abstract

BACKGROUND AND PURPOSE: As yet, there are no in vivo data on tissue water changes and associated morphometric changes involved in the osmo-adaptation of normal brains. Our aim was to evaluate osmoadaptive responses of the healthy human brain to osmotic challenges of de- and rehydration by serial measurements of brain volume, tissue fluid, and metabolites. - MATERIALS AND METHODS: Serial T1-weighted and 1H-MR spectroscopy data were acquired in 15 healthy individuals at normohydration, on 12 hours of dehydration, and during 1 hour of oral rehydration. Osmotic challenges were monitored by serum measures, including osmolality and hematocrit. MR imaging data were analyzed by using FreeSurfer and LCModel. - RESULTS: On dehydration, serum osmolality increased by 0.67% and brain tissue fluid decreased by 1.63%, on average. MR imaging morphometry demonstrated corresponding decreases of cortical thickness and volumes of the whole brain, cortex, white matter, and hypothalamus/thalamus. These changes reversed during rehydration. Continuous fluid ingestion of 1 L of water for 1 hour within the scanner lowered serum osmolality by 0.96% and increased brain tissue fluid by 0.43%, on average. Concomitantly, cortical thickness and volumes of the whole brain, cortex, white matter, and hypothalamus/thalamus increased. Changes in brain tissue fluid were related to volume changes of the whole brain, the white matter, and hypothalamus/thalamus. Only volume changes of the hypothalamus/thalamus significantly correlated with serum osmolality. - CONCLUSIONS: This is the first study simultaneously evaluating changes in brain tissue fluid, metabolites, volume, and cortical thickness. Our results reflect cellular volume regulatory mechanisms at a macroscopic level and emphasize that it is essential to control for hydration levels in studies on brain morphometry and metabolism in order to avoid confounding the findings.