Dr. Gert-Jan Lammers Dr. Gert-Jan Lammers

Dr. Gert-Jan Lammers
Dr. Gert-Jan Lammers

Dr. Lammers, neurologist, is the head of the Sleep-wake centre SEIN (Heemstede) and affiliated with the Leiden University Medical Centre. Lammers has been involved in sleep research for over 20 years, during which he has mainly focussed on narcolepsy. He is one of the founders of the European Narcolepsy Network, of which he currently also is president.


Those who suffer from narcolepsy are unable to remain awake during the day, but also have difficulty to stay asleep during the night. There are intriguing other symptoms such as cataplexy: muscle weakness induced by emotions, particularly laughter; hypnagogic hallucinations: vivid dream experiences usually occurring at sleep onset, and sleep paralysis: the inability to move while being awake. All these symptoms can be explained by disturbed (REM)sleep.

During the last 15 years there have been exciting discoveries regarding the pathophysiology and cause of narcolepsy. It all started with the study of a hereditary form in dogs. Currently we know that the disorder is caused by a selective destruction of hypocretin (also called orexin) containing neurons in the hypothalamus. Surprisingly, the finding turns out to have important implications for other sleep disorders such as insomnia, and also for addiction.