Cognitive profile and brain morphological changes in obstructive sleep apnea

Abstract

Obstructive sleep apnea (OSA) is accompanied by neurocognitive impairment, likely mediated by injury to various brain regions. We evaluated brain morphological changes in patients with OSA and their relationship to neuropsychological and oximetric data. Sixteen patients affected by moderate-severe OSA (age: 55.8±6.7 years, 13 males) and fourteen control subjects (age: 57.6±5.1 years, 9 males) underwent 3.0 Tesla brain magnetic resonance imaging (MRI) and neuropsychological testing evaluating short and long-term memory, executive functions, language, attention, praxia and non-verbal learning. Volumetric segmentation of cortical and subcortical structures and voxel-based morphometry (VBM) were performed. Patients and controls differed significantly in Rey Auditory- Verbal Learning test (immediate and delayed recall), Stroop test and Digit span backward scores. Volumes of cortical gray matter (GM), right hippocampus, right and left caudate were smaller in patients compared to controls, with also brain parenchymal fraction (a normalized measure of cerebral atrophy) approaching statistical significance. Differences remained significant after controlling for comorbidities (hypertension, diabetes, smoking, hypercholesterolemia). VBM analysis showed regions of decreased GM volume in right and left hippocampus and within more lateral temporal areas in patients with OSA. Our findings indicate that the significant cognitive impairment seen in patients with moderate-severe OSA is associated with brain tissue damage in regions involved in several cognitive tasks. We conclude that OSA can increase brain susceptibility to the effects of aging and other clinical and pathological occurrences.

Reduced Regional Gray Matter Volume in Patients with Chronic Obstructive Pulmonary Disease: A Voxel-Based Morphometry Study

“…Our present study revealed that patients with COPD had reduced GM volume in a number of brain regions, which were mainly confined to the limbic/paralimbic structures and frontal cortices, compared with healthy controls. These findings are consistent with those in patients with obstructive sleep apnea, 18,19,24 congenital central hypoventilation syndrome, and pediatric heart failure, 25 and in high-altitude residents. 20 Moreover, patients with COPD exhibited poorer performance on visuospatial and visual reproduction tasks.…”

Associations of brain lesions at autopsy with polysomnography features before death

“…In a study of elderly women, higher AHI and duration of sleep in apnea or hypopnea were associated with cognitive impairment. 1 Prior imaging studies further support a role for OSA in the development of brain atrophy 21,22 and cerebral white matter disease. [23][24][25] SWS has not been previously examined as a risk factor for the pathologic correlates of dementia.…”

Neuropsychological Function in Patients With Acute Tetraplegia and Sleep Disordered Breathing

“…44 Younger age is protective of cognitive impairment in the presence of SDB. 45,46 Age and premorbid intelligence are important considerations in investigating the effect of SDB on neuropsychological function and likely contribute to the previously observed heterogeneity of results across the studies. In the current research, these factors were accounted for and their importance confirmed by the study data.…”