New method a dream come true for sleep apnea patients

Researchers from the University of Sydney have found the first hard evidence that the special masks doctors prescribe to patients with sleep apnea - a disorder that can cause interrupted breathing leading to choking and even death while asleep - actually work.

Dr Jong-Won Kim and colleagues from the University of Sydney's Brain Dynamics Group statistically analysed the sleep patterns of patients by polysomonography - recording a person's brain signals, heartbeat, muscle and eye movement - then analysing the results using a mathematical model know as the Markov process.

"Continuous Positive Airways Pressure (CPAP) masks are a common treatment to improve sleep of apneic patients" Dr Kim said. "Special masks to assist with breathing have been prescribed for patients with this disorder for several years, but the feedback from the patients as to their effectiveness was subjective."

Dr Kim and his team analysed sleep patterns of 113 patients with and without the masks, finding that the masks helped improve sleeping patterns in 70 per cent of cases. "Interestingly, from this we found that patients with sleep apnea have a subtle but different brain activity when asleep," Kim says.

People who suffer from sleep apnea toss and turn and wake more frequently than non-sufferers. They are also more likely to snore, wake-up frequently, be obese and are older in age. They are dominantly male with moderate alcohol consumption, daytime sleepiness, hypertension, stroke and metabolic syndrome. Children as young as one or two years can also have the disorder, which can be very worrying for their parents and families.

"Sleep apnea in children may be related to death and loss of brain cells that lead to underdevelopment. So it is vital that medical doctors definitely know that their prescribed method will provide a sound sleep for their patients," Dr Kim commented. "By wearing the mask people can sleep comfortably and without fear of choking in their sleep."

Dr Jong-Won Kim and his team are currently studying 5,000 patients at Seoul Hospital to see if their method might be helpful in diagnosing other sleep disorders.

Dr Jong-Won Kim, Dr J.S. Lee, Prof. P.A. Robinson and Prof. D.U. Jeong's paper - Markov Analysis of Sleep Dynamics - will be published in Physical Review Letters on 8 May, 2009.