As reported on WebMD.com, researchers in Italy have discovered that people with obstructive sleep apnea (OSA), may be able to increase their volume of brain gray matter through CPAP (continuous positive airway pressure) therapy.
In a study involving 17 patients with OSA and 15 healthy people, principal researcher Vincenza Castronovo of the University Vita-Salute San Raffaele and San Raffaele Scientific Institute in Milan, Italy found that patients with OSA had reductions of gray matter volume and an associated decrease in neuropsychologic performance.
After three months of CPAP therapy, the OSA patients showed a significant increase in gray matter volume and in neuropsychologic testing.
No further improvement in gray matter volume was noted when patients were re-evaluated after one year of CPAP therapy, writes WebMD Health News contributor Bill Hendrick.
OSA, a sleep-related breathing disorder that typically sees a decrease or temporary halt in airflow, despite an ongoing effort to breathe, occurs when muscles relax during sleep, causing soft tissue in the back of the throat to collapse and block the upper airway.
The result includes partial reductions and complete pauses in breathing that can produce abrupt reductions in blood oxygen levels and reduce blood flow to the brain.
CPAP therapy corrects low levels of oxygen in the blood and reduces pauses in breathing by providing a steady flow of air through a facemask that is worn while sleeping.
The gray matter, which refers to the cerebral cortex, is where the brain does most of its processing of information. It has a gray-colored appearance because it lacks the myelin insulation that makes most other parts of the brain look white.
In the study, researchers used magnetic resonance imaging and voxel-based morphometry, a neuroimaging analysis technique, to scan brains and describe differences in gray matter. While patients with OSA initially had reductions in gray matter volume in several regions of the brain, significant increases in gray matter volume were noted after three months of CPAP therapy in specific regions of the brain — the hippocampus and frontal areas.
Those improvments were said to specifically correlate with the improvement at neuropsychological tests of executive functioning and short-term memory, according to Dr. Castronovo, who says measuring neuropsychological performance may help doctors assess patients with obstructive sleep apnea to determine the effectiveness of treatment.
“Our results also suggest that specific neuropsychological measures are valuable tools for the assessment of therapy success and can offer to patients and physicians the evidence that adherence to treatment can lead not only to clinical but also to brain-structural recovery.” As the WebMD.com article points out, gray matter deficits in people with obstructive sleep apnea also were reported in the February 2010 issue of the journal Sleep. A French study published in the March 2009 issue of the Journal of Sleep Research reported gray matter loss in multiple brain regions in patients with obstructive sleep apnea.
Castronovo and colleagues say their study, findings of which were presented at the annual meeting of the Associated Professional Sleep Societies in San Antonio, provides evidence that CPAP therapy works and offers hope to obstructive sleep apnea patients.