Two Research Teams Discover The Cause Of Narcolepsy

Germantown, TN - August 29, 2000

Research teams from Stanford University and UCLA today announced that they had discovered the cause of narcolepsy in most humans. Narcolepsy is a sleep disorder that causes overwhelming sleepiness and cataplexy, a loss of muscle tone triggered by sudden strong emotions. For more information about narcolepsy, visit our Narcolepsy Home Page.

Both studies indicate that the lack of a neuropeptide called hypocretin in the brain cells of narcoleptic patients is directly linked to the sleep disorder narcolepsy. The Stanford results will be published in September 1 issue of the peer-reviewed journal Nature Medicine and the UCLA results will be available in the September 28 issue of the peer-reviewed journal Neuron.

The Stanford team, led by Dr. Emmanuel Mignot, MD, PhD, director of the Stanford Center for Narcolepsy searched for defects in the brains and genes of narcolepsy patients. They found that a small brain protein - or peptide - that is present in the brains of normal people was absent in every narcoleptic brain that they studied. The peptide, hypocretin, was identified last year when Mignot and his colleagues discovered that dogs with narcolepsy had a problem with a hypocretin gene.

In a study published in Lancet (January 1, 2000), Mignot's team reported on the first studies of cerebrospinal fluid (CSF) from narcoleptic patients, which showed that most humans with narcolepsy have no hyocretin in their spinal fluid. The follow up study looked for the presence of hypocretin in the brain.

"We think this is the cause of most human cases of narcolepsy -- that they don't have this peptide in the brain, " said Dr. Mignot. "Now we need to develop a drug that can go into the brain to replace it." Dr. Mignot offers additional insights on the implications of this research in a discussion with a Talk About Sleep reporter. See "An Interview With Dr. Emmanuel Mignot" for those comments.

The UCLA team, led by Jerome Siegel, PhD., director of the Sleep Research Team at the UCLA Medical Center followed a similar path. They found that the number of Hcrt cells (neurons containing the neuropeptide hypocretin) in narcoleptic brains was 85-95% less than that found in non-narcoleptic brains.

Dr. Siegel is enthusiastic about the findings: "The discovery of the cell loss in narcolepsy ends the first chapter in narcolepsy research - the discovery of the cause of human narcolepsy." Looking to the future, "Now attention must shift to using this knowledge to develop better diagnostic procedures and, most importantly, more effective treatments."

Future research in narcolepsy, he says, will be "determining what causes the cell loss in narcolepsy, and in testing hypocretin and hypocretin-like drugs for their effect on narcolepsy"

When asked about her response to these findings, a person with narcolepsy replied: " As a person living with Narcolepsy, every new bit of research lends me increased hope that in the future people won't have to struggle with this disease. I am thankful and grateful such renown researchers as Mignot and Siegel continue to work hard to find the answers to this quietly disabling disease."