Transient changes in white matter microstructure during general anesthesia

• Published in: PloS one 2021-03, Vol.16 (3), p.e0247678
• Main Authors: Tang, Cheuk Y, Wang, Victoria X, Lun, Min Yin, Mincer, Joshua S, Ng, Johnny C, Brallier, Jess W, Schwartz, Arthur E, Ahn, Helen, McCormick, Patrick J, Nir, Tommer, Delman, Bradley, Sano, Mary, Deiner, Stacie G, Baxter, Mark G
• Format: Article
• Language: English
• Subjects: Adult; Age; Aged; Aged, 80 and over; Airway management; Analysis; Anesthesia; Anesthesia, General - adverse effects; Anesthesiology; Anesthetics, Inhalation - adverse effects; Anisotropy; Atrophy; Biology and Life Sciences; Biomedical data; Biomedical engineering; Blood pressure; Brain - diagnostic imaging; Brain - drug effects; Brain - pathology; Brain Mapping; Brain slice preparation; Cancer; Carbon dioxide; Case-Control Studies; Cognitive ability; Critical care; Data acquisition; Data analysis; Diffusion; Diffusion Tensor Imaging; Drafting software; Eddy currents; Editing; EKG; Engineering; Female; Funding; Gas analysis; General anesthesia; General anesthetics; Gray Matter - diagnostic imaging; Gray Matter - drug effects; Gray Matter - pathology; Humans; Image acquisition; Magnetic resonance imaging; Male; Medical imaging; Medicine; Medicine and Health Sciences; Microvasculature; Middle Aged; Nervous system; Neuroglia - drug effects; Neuroglia - pathology; Neuroimaging; Neurosciences; Oximetry; Pain; Physical Sciences; Postoperative Cognitive Complications - chemically induced; Postoperative Cognitive Complications - diagnostic imaging; Postoperative Cognitive Complications - pathology; Psychiatry; Research and Analysis Methods; Scanners; Sevoflurane - adverse effects; Signal to noise ratio; Substantia alba; Surgery; White Matter - diagnostic imaging; White Matter - drug effects; White Matter - pathology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0247678

Cognitive dysfunction after surgery under general anesthesia is a well-recognized clinical phenomenon in the elderly. Physiological effects of various anesthetic agents have been studied at length. Very little is known about potential effects of anesthesia on brain structure. In this study we used Diffusion Tensor Imaging to compare the white matter microstructure of healthy control subjects under sevoflurane anesthesia with their awake state. Fractional Anisotropy, a white mater integrity index, transiently decreases throughout the brain during sevoflurane anesthesia and then returns back to baseline. Other DTI metrics such as mean diffusivity, axial diffusivity and radial diffusivity were increased under sevoflurane anesthesia. Although DTI metrics are age dependent, the transient changes due to sevoflurane were independent of age and sex. Volumetric analysis shows various white matter volumes decreased whereas some gray matter volumes increased during sevoflurane anesthesia. These results suggest that sevoflurane anesthesia has a significant, but transient, effect on white matter microstructure. In spite of the transient effects of sevoflurane anesthesia there were no measurable effects on brain white matter as determined by the DTI metrics at 2 days and 7 days following anesthesia. The role of white matter in the loss of consciousness under anesthesia will need to be studied and MRI studies with subjects under anesthesia will need to take these results into account.