Brain tissue integrity mapping in adults with obstructive sleep apnea using T1-weighted and T2-weighted images

Bhaswati Roy; Ashish K Sahib; Daniel Kang; Ravi S Aysola; Rajesh Kumar

doi:10.1177/17562864221137505

Brain tissue integrity mapping in adults with obstructive sleep apnea using T1-weighted and T2-weighted images

Ther Adv Neurol Disord. 2022 Nov 19:15:17562864221137505. doi: 10.1177/17562864221137505. eCollection 2022.

Authors

Bhaswati Roy¹, Ashish K Sahib¹, Daniel Kang², Ravi S Aysola², Rajesh Kumar^{3

4

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Affiliations

¹ Department of Anesthesiology, University of California, Los Angeles, Los Angeles, CA, USA.
² Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
³ Department of Anesthesiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, 56-141 CHS, 10833 Le Conte Ave., Los Angeles, CA 90095-1763, USA.
⁴ Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, USA.
⁵ Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, USA.
⁶ Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA.

Abstract

Background: Obstructive sleep apnea (OSA) is accompanied by both gray and white matter differences in brain areas that regulate autonomic, cognitive, and mood functions, which are deficient in the condition. Such tissue changes have been examined through diffusion tensor and diffusion kurtosis imaging-based procedures. However, poor in-plane spatial resolution of these techniques precludes precise determination of the extent of tissue injury. Tissue texture maps derived from the ratio of T1-weighted and T2-weighted images can provide more adequate in-plane assessment of brain tissue differences.

Objectives: To examine brain tissue integrity in recently diagnosed, treatment-naïve OSA subjects, relative to age- and sex-comparable control subjects using T1-weighted and T2-weighted images.

Design: A cross-sectional study.

Methods: We examined the extent of tissue changes in 106 OSA over 115 control subjects using high-resolution T1- and T2-weighted images collected from a 3.0-Tesla scanner (analysis of covariance; covariates: age, sex, body-mass-index, Pittsburgh sleep quality index, Epworth sleepiness scale, Beck Anxiety Inventory, and Beck Depression Inventory II; false discovery rate corrected; p < 0.01).

Results: OSA subjects showed significantly lowered tissue integrity in several brain regions, including the frontal, cingulate and insular cortices, cingulum bundle, thalamus, corpus callosum, caudate and putamen, pons, temporal, occipital, and parietal sites, cerebellar peduncles, and medial medullary sites, compared with controls.

Conclusion: OSA subjects show widespread lowered tissue integrity in autonomic, mood, and cognitive control sites over healthy controls. The pathological processes contributing to the alterations may include repetitive hypoxic and hypercarbic processes and excitotoxic injury, leading to altered brain tissue integrity in OSA.

Keywords: autonomic; cognition; hippocampus; insula; mood; tissue injury.