http://www.medicalnewstoday.com/articles/290623.php
They think the antibodies are autoimmune.
Following the [H1N1 flu] vaccination campaign [in Finland], the incidence of narcolepsy shot up to 16 times the average, says Prof. Shoenfeld.
The team had also become aware of a study reported by a group of sleep researchers in Japan who had discovered antibodies in the brain that appear to attack "tribbles" - small granules that contain brain cells that produce orexin, a brain chemical that helps maintain the delicate balance between sleep and wakefulness.
Prof. Shoenfeld says they have noticed how patients and animals with narcolepsy have less orexin in the brain, resulting in an imbalance between sleep and wakefulness, which leads to attacks of narcolepsy.
They think the antibodies are autoimmune.