SALT LAKE CITY – The combination of obstructive sleep apnea and increased age may have an overwhelming effect on the brain's compensatory mechanisms, and early diagnosis and treatment of OSA in older patients may be important for preserving brain function, reported Liat Ayalon, Ph.D.
In a study Dr. Ayalon presented at the annual meeting of the Associated Professional Sleep Societies, 12 untreated OSA patients and 12 healthy good sleepers were studied with polysomnography and functional magnetic resonance imaging. The interaction between group and age in regard to effects on brain function during a verbal learning task was analyzed.
Imaging studies showed that patients' brains were able to recruit additional resources to maintain intact performance and compensate for either age or OSA. Increased brain activation was noted in both older patients and those with OSA, compared with controls, specifically in the left inferior parietal lobe, thalamus, caudate, middle temporal gyrus, and fusiform; in the right anterior cingulate; and in the bilateral precuneus and cerebellum.
But when patients had both increased age and OSA, decreased brain activation was noted, compared with younger patients, specifically in the right superior temporal gyrus and anterior cingulate, and in the bilateral parahippocampal gyri, caudate, precuneus, cerebellum, and fusiform gyrus, said Dr. Ayalon of the University of California, San Diego.
Patients ranged in age from 25 to 59 years. The groups were similar in age, gender, and body mass index. Average apnea-hypopnea index score–a measure of sleep apnea severity–was 35.1 in the OSA patients and 1.9 in the control group.
The findings suggest that OSA in older patients is associated with decreased functioning, as evidenced by deficiencies in word recall in this study.
Studies to address effects in even older patients (as this was a relatively young study population) and the effects of OSA treatment on brain function are planned, Dr. Ayalon said.