About 10% of all adults have this condition, which causes extreme daytime sleepiness, anxiety, depression, and memory issues. According to a study published in PLOS ONE, the damage caused to the brains of people with sleep apnea is due to a weakened brain blood flow. Conducted at the UCLA School of Nursing, the study was funded by the National Institute of Nursing Research.
For those suffering from sleep apnea, every time they stop breathing during sleep, their blood oxygen levels in the body drop, causing extensive damage to their cells. Without treatment, this condition may lead to other problems, such as diabetes, high blood pressure, depression, stroke, and heart failure. A continuous airway pressure (CPAP) device is usually recommended for treatment, as it delivers gentle air pressure during sleep. For this particular study, researchers used a non-invasive MRI procedure to measure brain blood flow in patients with sleep apnea known as the global blood volume and oxygen dependent (BOLD) signal.
Tested on both males and females with and without sleep apnea, the study measured each participant’s BOLD signal while they were taking part in three physical tasks. These tasks were known as the Valsala maneuver, hand-grip challenge, and cold-pressor challenge. In the Valsala maneuver, participants breathed out through a small tube with force, which raised pressure in the chest. With the hand-grip challenge, they squeezed down hard with their hand, and for the cold-pressor challenge, their right foot was put into ice water for one minute. Participants that suffered from sleep apnea showed a “much weaker brain blood flow response” in the case of the hand-grip and cold-pressor challenges.
Because of the brain injury from sleep apnea, high brain areas that control muscle movement and sensation are compromised. As a result, signals from nerves in the arms and legs that need to be processed through those high brain areas could not function properly. Researchers also found that this issue is more prevalent in women with sleep apnea than men, which might be the reason why women often experience worse apnea-related outcomes. There are other studies from the same college that indicate brain injuries as a result of sleep apnea are much worse in women.