A bizarre, but thankfully, rare disorder has received a lot of press in the past few months and one of my patients asked me about it this week worried that her son was sleeping too much and that he had “that sleeping sickness.”

Kleine-Levin syndrome is marked by recurrent periods of excessive sleepiness during which the patient can sleep for 24-48 hours, getting up only to urinate and often to eat. In fact, other than hypersomnia, that is, the excessive sleepiness with long sleep times, this disorder is characterized by compulsive eating, called megaphagia, hypersexuality, and almost all patients have cognitive and mood dysfunction.

In 2005, Dr. Isabelle Arnulf published a large case series of the 186 known cases worldwide. The first known report of the disorder was more than 150 years ago. We do not know what causes it, but approximately half of the reported cases were preceded by a mild infection such as a cold or gastroenteritis. It is postulated that the infection then triggers an autoimmune reaction. It usually presents during the teens or early 20s and it twice as common in males as in females.

The excessive sleepiness lasts more than two days and less than four weeks and is intermixed with long intervals of normal alertness. The excessive sleepiness recurs at least once a year and is almost always accompanied cognitive dysfunction and irritability while the person is awake. The compulsive overeating and the hypersexuality were observed in only half the cases. The average course of the disease was eight years.

There is no diagnostic test. Treatment with stimulants, anti-depressants and anti-seizure medications have all been disappointing.

The good news is that this is quite rare, and if, like my patient, you have a teenager who is seems to sleeping all the time, the explanation probably lies elsewhere.

Common causes of excessive sleepiness in teens or young adults: sleep deprivation, circadian rhythm disturbance such as delayed sleep phase syndrome, obstructive sleep apnea, restless legs syndrome, periodic limb movement disorder, narcolepsy, idiopathic hypersomnia and depression.

http://thechart.blogs.cnn.com/2011/0...e-rare/?hpt=C2