Researchers from the UCLA School of Nursing examined clinical records and magnetic resonance imaging brain scans of patients who were recently diagnosed with obstructive sleep apnea (OSA) and discovered several apparent connections between thinning of the brain’s cerebral cortex and apnea symptoms.

Using high-resolution magnetic resonance imaging scans, the researchers looked at cortex thickness of 12 women and 36 men who had diagnoses of mild to severe OSA (who were not being treated for their condition) and compared those findings to 40 male and 22 female controls (who did not have OSA). The researchers then compared clinical findings of each patient with evidence of cortex thinning.

The researchers discerned distinct changes in brain structures and concurrent symptoms that differed between men and women. For example, more regions of the superior frontal lobe were thinner in women with OSA than men or control groups, which might explain enhanced cognitive deficits among women with the disorder.

No OSA patients showed any thickening of the cerebral cortex. In addition, overall cortical thinning could possibly lead to impaired regulation of the autonomic nervous system and associated impaired breathing function through the upper airway in these patients.

The study underscores significant clinical differences between men and women with OSA and points to the need for different treatment approaches to address these varied symptoms. The greater cortex injury in cognitive centers of women’s brains may underlie their more common cognitive problems compared with men, while thinning associated with both men and women who have OSA may be behind the disordered breathing seen between both. It is not clear whether these physical brain changes precede the sleep apnea disorder, or worsen sleep apnea’s symptoms as the disorder progresses.

The research is published online in the journal PLOS ONE. Paul Macey, PhD, is lead author.