Some studies have shown changes in the white and gray matter of the brain from untreated obstructive sleep apnea (OSA). The gray matter refers to cell bodies in the brain and is generally on the outer surface. White matter is the connections between the cell bodies and some of the supporting cell types - it's deeper in the brain, meaning below the gray matter.
This study sought to evaluate white matter changes and impact on cognition in patients with OSA, and if the changes were reversible with CPAP therapy. The researchers studied 17 patients with severe OSA and compared them to similar patients that did not have OSA. The treated patients were evaluated at baseline, 3 months, and at 12 months - however, the controls were only evaluated at baseline. CPAP use was monitored objectively with downloads from each unit.
Results showed changes in white matter in the untreated OSA patients. There was only limited improvement with 3 months of CPAP, but there was significant improvement at 12 months of CPAP. This is an exciting study because it suggests that the brain damage inflicted by untreated severe OSA may be reversible with regular, prolonged CPAP treatment.