Responses of the human brain to mild dehydration and rehydration explored in vivo by 1H-MR imaging and spectroscopy
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 mea...
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| Main Authors: | , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
May 6, 2015
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| In: |
American journal of neuroradiology
Year: 2015, Volume: 36, Issue: 12, Pages: 2277-2284 |
| ISSN: | 1936-959X |
| DOI: | 10.3174/ajnr.A4508 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.3174/ajnr.A4508 Verlag, lizenzpflichtig, Volltext: http://www.ajnr.org/content/36/12/2277 
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| Author Notes: | A. Biller, M. Reuter, B. Patenaude, G.A. Homola, F. Breuer, M. Bendszus, and A.J. Bartsch |
| Summary: | 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. |
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| Item Description: | Gesehen am 26.05.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1936-959X |
| DOI: | 10.3174/ajnr.A4508 |