What Is Kleine-Levin Syndrome (KLS)?

Kleine-Levin syndrome, or KLS, is a rare disorder associated with extreme fatigue and excessive sleepiness, causing patients to sleep as much as 20 hours a day. Other characteristics include bouts of intense hunger and strong sexual desire. Symptoms are intermittent, coming and going in phases for months or years at a time. Though sometimes called “sleeping beauty disease,” KLS most often affects adolescent males. The overriding quality of its symptoms makes it difficult for sufferers to participate in normal day-to-day activities.

What Are the Symptoms of Kleine-Levin Syndrome?

Kleine-Levin syndrome is marked by a number of symptoms, mostly behavioral in nature. The most common is an unshakeable drowsiness, leading to long periods of sleep and grogginess and fatigue when awake. The medical term for this condition is hypersomnia.

Other potential symptoms include:

• A heightened sense of hunger (hyperphagia)
• Intensified carnal desire (hypersexuality)
• Irritable disposition
• Childish behaviors
• Emotional withdrawal
• Disorientation
• Hallucinations

KLS is highly unpredictable. Though symptoms tend to diminish with age, sufferers can experience relapses without warning, years after the previous episode.

Medical researchers are uncertain as to the cause or causes of KLS. A number of theories have been put forth:

• Injury to the hypothalamus: The hypothalamus is a portion of the brain involved in sensory perception, body temperature, and the regulation of conscious and unconscious states of mind. A dysfunctional hypothalamus might lessen the mind’s ability to switch between periods of alertness and sleep.
• Viral triggers: There is some evidence suggesting that the initial onset of KLS may be caused or accompanied by flu or flu-like symptoms. Possibly implicated in this connection are viruses such as herpes zoster, varicella zoster, Influenza A, and Epstein-Barr.
• Genetic factors: It’s also possible that there is a heritable aspect to Kleine-Levin syndrome. This is unproven, however, because the rarity of KLS has limited data collection and slowed progress in researching the disease.

KLS can affect people of all ages and either sex but occurs most frequently in teenage boys. About 70 percent of all reported cases involve males.

How Is Kleine-Levin Syndrome Diagnosed?

Kleine-Levin syndrome shares symptoms with other medical conditions, making it a challenge to properly diagnose. Its primary characteristic, excessive sleepiness, is sometimes demonstrated by diabetes, hypothyroidism, other sleep disorders, neurological conditions such as multiple sclerosis, and mood disorders, including depression.

Because of this, physicians typically run a variety of medical tests to identify a case of KLS. These might include bloodwork, imaging tests, and sleep studies. The goal of these tests is to successively eliminate alternative diagnoses until arriving at KLS as the best fit for the symptoms being experienced by the patient.

This process can take a long time – as much as four years. In addition to medical tests, it may also include a mental-health exam, because of KLS’s similarity to bipolar disorder (“manic depression”).

How Is Kleine-Levin Syndrome Treated?

There is no known cure for Kleine-Levin syndrome. The current approach to care focuses on controlling symptoms and reducing their severity and duration through medication. This approach may include:

• Pharmaceutical stimulants: Stimulants can increase alertness and limit the desire to sleep. A downside to stimulant consumption is an increase in irritability. Commonly prescribed stimulants include modafinil (Provigil) and methylphenidate (Ritalin and Concerta).
• Mood-disorder medications: KLS’s depression-like characteristics mean that sufferers sometimes respond positively to mood-disorder medications. These might include carbamazepine (Tegretol) or lithium (Lithane).

Patients can sometimes learn to recognize the onset of a KLS episode and act to limit potentially harmful consequences. The good news is that KLS tends to fade with time, while leading to very little dysfunction during periods of remission. Sufferers are considered free of the disease when six or more years have elapsed since their last episode.

Learn More About Kleine-Levin Syndrome from Baptist Health

Kleine-Levin Syndrome can be conquered. Start by scheduling an appointment with a Baptist Health primary care or sleep specialist today.