Selective microstructural integrity impairments of the anterior corpus callosum are associated with cognitive deficits in obstructive sleep apnea.

Biao Zhang,Yu Zhang,Ying Yang,Jiajia Zhu,Dao‐Min Zhu,Wenming Zhao,Yongqiang Yu,Cun Zhang

doi:10.1002/brb3.1482

Abstract

BackgroundThere is some evidence that obstructive sleep apnea (OSA) patients have white matter integrity abnormality in the corpus callosum (CC). However, whether the CC subregions are differentially affected in OSA is largely unknown.MethodsTwenty patients with OSA and 24 well‐matched healthy controls were enrolled and underwent diffusion tensor imaging (DTI) and clinical and cognitive assessments. DTI tractography was used to reconstruct the CC which was divided into five subregions. Intergroup differences in multiple diffusion metrics of each CC subregion and their correlations with clinical and cognitive parameters were tested.ResultsIn comparison with healthy controls, OSA patients exhibited white matter integrity alterations in the anterior CC, characterized by increased radial diffusivity (RD) in the subregion 1 and decreased fractional anisotropy (FA) along with increased mean diffusivity (MD) and RD in the subregion 2. Moreover, we found that the lower microstructural integrity in the anterior CC was correlated with worse prospective memory and sustained attention in OSA patients.ConclusionsThese findings indicate that the selective impairments of the anterior CC may help clarify the neural correlates of cognitive impairments in OSA.

Highlights

Obstructive sleep apnea (OSA) is a chronic disorder characterized by frequent events of complete or partial obstruction of the upper airway during sleep, resulting in intermittent nocturnal hypoxia and sleep fragmentation (Young, Peppard, & Gottlieb, 2002)
Given the vital role of the corpus callosum (CC) in interhemispheric communication linked to cognitive functioning (Doron & Gazzaniga, 2008), it is reasonable to assume that the CC microstructural disruption is a characteristic brain impairment of obstructive sleep apnea (OSA), which may be responsible for cognitive impairments in this disorder
Pearson's correlation coefficients were measured to investigate the associations between diffusion metrics exhibiting significant intergroup differences and clinical and cognitive parameters (i.e., apnea/hypopnea index (AHI), Mean oxygen saturation (SaO2), Nadir SaO2, Epworth Sleepiness Scale (ESS), eventbased prospective memory (EBPM), time-based prospective memory (TBPM), and Continuous Performance Task-Identical Pairs (CPT-IP)) in the patient group

Summary

| INTRODUCTION

Obstructive sleep apnea (OSA) is a chronic disorder characterized by frequent events of complete or partial obstruction of the upper airway during sleep, resulting in intermittent nocturnal hypoxia and sleep fragmentation (Young, Peppard, & Gottlieb, 2002). Despite considerable variation in the findings, both global and regional white matter microstructural alterations in OSA patients have been revealed by using diffusion tensor imaging (DTI) technique (Castronovo et al, 2014; Chen et al, 2015; Kumar et al, 2012, 2014; Macey et al, 2008; Macey, Kumar, Yan-Go, Woo, & Harper, 2012; Xiong et al, 2017). Our aims were (a) to investigate the microstructural integrity change pattern of each CC subregion in OSA patients by using tractography and multiple diffusion metrics, and (b) to test the correlations between CC alterations and clinical and cognitive parameters in OSA patients

| Participants

Findings

| DISCUSSION