Sleep apnea is characterized by reductions or pauses (10 seconds or more) in breathing during sleep. Sleep apnea is more common in men than women before age 50 and the same after age 50. It is more common with obesity (maybe as high as 70 percent), heart disease (30-50 percent), and stroke (60 percent). Estimates suggest that only 10 percent of those with sleep apnea receive treatment. Untreated sleep apnea is associated with increased accidents at work and while driving.
Sleep apnea induces daytime fatigue and sleepiness, headache upon awakening and insomnia. It also affects mental functions including poor concentration, impaired attention and poor memory. It contributes to irritability and anxiety. Those with sleep apnea may exhibit loud snoring and abrupt awakenings with shortness of breath. If you have this constellation of symptoms, consult your doctor who may order a sleep study to definitively diagnose sleep apnea.
There are also long-term risks resulting from untreated sleep apnea. These include exacerbation of hypertension, heart disease, heart attack, stroke, or disturbances of heart rhythms.
The memory loss from sleep apnea may result from atrophy of the mammillary bodies, which are involved in recognition memory (a different kind of memory loss than that found in Alzheimer’s disease which affects the hippocampus and short-term memory). Mammillary bodies are bilateral structures of the limbic system and are involved in attention, memory and emotion. Imaging studies have demonstrated shrinkage of the mammillary bodies in those with moderate to severe sleep apnea. The atrophy is believed to be caused by the repeated drops in oxygen.
Fortunately, sleep apnea is treatable. The most common treatment is to use a machine that provides continuous positive airway pressure (hence the name CPAP) via a face mask that is worn while sleeping. A recent study demonstrated that using this device for about six hours per night improved scores on tests of memory, decision making, and attention after 18 months of treatment when compared to baseline scores before using the apparatus. Participants in the study also reported improved quality of life.
Treating sleep apnea is not a cure all for memory loss and the type and severity of the memory loss is different from that associated with dementing conditions. Sleep apnea should be considered in cases of mild memory loss. Treatment involves using the CPAP device, weight loss, and avoidance or limited use of alcohol, tranquilizers, and sleep aids (all of which also impair memory).
Dr. Beckwith is a neuropsychologist, speaker, and author of “Managing Your Memory: Practical Solutions for Forgetting.” He has an office in Naples and can be reached at firstname.lastname@example.org or 591-6226. Visit Dr. Beckwith on Facebook at the Life and Memory Center or at www.lifeandmemorycenter.com.