Snoring may destroy grey matter

By Dr. Ananya Mandal, MDOct 21 2010

A new Australian study has found that snoring and troubled nights could be a warning of brain damage occurring while sleeping. The team looked at brain scans of 60 people, aged in their mid-40s and recently diagnosed with a common sleep disorder – obstructive sleep apnea. Obstructive sleep apnea often affects overweight and the obese and leads to snoring. Results showed “decreased amount of grey matter” when compared to healthy sleepers.

Sleep physician Dr Fergal O'Donoghue from the Institute for Breathing and Sleep at Melbourne's Austin Health said that “90 per cent of cases are undiagnosed.” He explained that at least four per cent of Australian men, and two per cent of women in this age group were thought to have the condition. “Usually it's a consistent snorer who seems to stop breathing in sleep, or complains of waking up with a feeling of choking, or being tired during the day…Those would be the red flags that this could be a problem with sleep apnea,” he said.

In these cases there is a collapse of the airways during the night, causing a pause in breathing that forces them to rouse from deep sleep. This rousing could occur “many hundreds of times across the night” resulting in times when the brain was deprived of oxygen as well as “surges in blood pressure”.

For this study Dr O'Donoghue said, “What specific part of sleep apnea might cause these changes we can't say, but we can see the changes that have occurred… There was a decreased amount of grey matter, so less brain cells in those areas.” Damage was seen in two specific parts of the brain. One was near a part that handles memory and the other in a region known to process smooth movement as well as changes in attention during complex tasks. This could explain the fact why people with sleep apnea have more car accidents Dr O'Donoghue said. Fatigue from routine lack of sleep would also play a role, he added.

“The take home message is if you complain of these sort of symptoms it is not a good idea to ignore it, you should seek help…Snoring in itself, there are some suggestions that it may cause problems but by no means has that been shown to be definitely so…So it's snoring plus stopping breathing during sleep, or snoring plus waking up with a feeling of ‘Gee, I've been chocking’…Snoring and being sleepy during the day ... that's sleep apnea,” he concluded.

The study was presented at the 22nd Annual Scientific Meeting of the Australasian Sleep Association and Australasian Sleep Technologists Association conference, in Christchurch, New Zealand.