Sleep Disorders and the Brain

Brain chemistry and different sleep disordersappear linked, according to 2 studies publishedin Neurology (July 8, 2004). The studies lookedat the same 13 individuals with multiple systematrophy (MSA), a fatal, degenerative neurologicaldisorder that is almost always accompaniedby sleep disorders. All the MSA patients in thestudy also had obstructive sleep apnea andrapid eye movement (REM) behavior disorder.The purpose of the study was to explore thelinks between these sleeping disorders and theneurotransmitters dopamine and acetylcholine.

The 13 participants, along with 27 healthycontrol participants, slept in a clinical researchcenter for 2 nights, hooked up to machinery thatmeasured neurotransmitter levels, brain waves,eye movements, and more.

The focus of the first study was to determineif dopamine was related to REM sleep behaviordisorder. "We found a very tight correlation [betweenthe severity of REM sleep behavior disorderand the level of decrease in dopamine], sothis suggests that there's a causal effect," saidSid Gilman, MD, FRCP, chairman of the departmentof neurology at the University of MichiganSchool of Medicine.

The second study looked to see if there wasa relationship between the severity of obstructivesleep apnea and the degree of decrease ofacetylcholine. "Here again, we found a goodcorrelation. It's not allowing us to conclude butit's certainly suggesting that there might be acausative relationship between obstructivesleep apnea and this neurotransmitter," saidDr. Gilman.