In a recent study, published in Frontiers in Neurology, researchers examined cortical thickness in patients with obstructive sleep apnea (OSA) to assess brain structure changes related to excessive daytime sleepiness associated with OSA. The team used surface-based morphometry (SBM) to identify potential thinning of the cortex in a population of middle-aged, male patients.
The study’s co-lead authors, Yezhou Li and Jing Wang, reported subjective daytime sleepiness was associated with a decrease in cortical thickness, potentially leading to cognitive impairment. The researchers also noted the Epworth Sleepiness Scale (ESS) score might be a functional clinical marker of brain injury in patients with OSA.
Daytime Sleepiness May Mark Brain Degradation in OSA
Between August 2020 and June 2021, investigators enrolled 61 male patients from a single sleep center who had newly diagnosed OSA and were aged 25 to 60 years. Polysomnography and structural MRI assessments were performed on each participant, and ESS score was used to identify patients with excessive daytime sleepiness.
Notably, compared to patients without excessive daytime sleepiness, investigators found the cortical thickness of patients with OSA and sleepiness was markedly reduced in the left temporal lobe, frontal lobe, parietal lobe, and bilateral pre- and postcentral gyri (pFWE<.05).
Furthermore, researchers noted there was a strongly negative correlation between cortical thickness values and ESS score. ESS score persisted through adjustments for age, body mass index, and OSA severity as an independent predictive factor for cortical thickness of the left middle temporal lobe, transverse temporal, and temporal pole.
“In conclusion,” the authors summarized,” this study provides clear evidence of daytime sleepiness-associated cortical thinning in male OSA patients, with effects distributed across various subregions of the frontal, parietal and temporal lobes.”
Related: Dr. Ofer Jacobowitz on the Link Between Sleep Apnea and Heart Disease