EMBARGOED FOR RELEASE UNTIL 4 PM ET, January 09, 2006
Surgery Can Ease Sleep Problems for Those with Brain Malformations
St. Paul, Minn. -
People with a brain defect called Arnold-Chiari Malformation often develop sleep apnea, a disorder that causes breathing interruptions during sleep and can lead to daytime sleepiness. In Arnold-Chiari Malformation, abnormalities cause the cerebellum portion of the brain to protrude through the bottom of the skull against the spinal cord. This protrusion can cause compression on the brain stem, including the areas that control breathing. A new study, published in the January 10, 2006, issue of Neurology, the scientific journal of the American Academy of Neurology, shows that surgery to remove the compression on the brain stem can also improve sleep apnea. “Our study shows that more than 70 percent of people with Chiari Malformations have sleep apnea and problems with daytime sleepiness,” said study author Frédéric Gagnadoux, MD, of Central University Hospital in Angers, France. “These problems can be significantly improved by surgery.” The study involved 16 people with Arnold-Chiari Malformation type I and a related condition called syringomyelia. In syringomyelia, cerebrospinal fluid enters the spinal cord. The fluid then forms a cavity in the spinal cord known as a syrinx. All of the participants underwent an overnight sleep study. Out of the 16 people, 12 had sleep apnea. Of those, half were a rare type of sleep apnea called central sleep apnea. Much less common than obstructive sleep apnea, central sleep apnea is caused by problems with the brain’s mechanisms that control breathing. Eight of the 12 people with sleep apnea had decompression surgery. Six people had another overnight sleep study an average of about seven months after the surgery. After the surgery, the number of central sleep apnea occurrences decreased by more than 90 percent, from an average of 15 episodes per hour of sleep to an average of one episode per hour of sleep. The number of micro-arousals, or partial awakenings from sleep, also decreased by 30 percent. “Anyone with Chiari Malformation who is experiencing daytime sleepiness should do an overnight sleep study to check for sleep apnea,” Gagnadoux said.