Kleine-Levin Syndrome (KLS) is a rare and complex form of neurological disorder characterized by recurring periods of excessive amounts of sleep, altered behavior, as well as a reduced understanding of the world.
The disorder affects mainly adolescents, although it may occur in younger children as well as adults. At the onset of an episode, the person becomes progressively drowsy and sleeps for most of the day and night, at times waking only to eat or use the bathroom. Each episode lasts days, weeks, or even months during which time all usual daily activities cease. People are unable to care for themselves or attend school or work. In between episodes, people with KLS seem to be in perfect health with no evidence of behavioral or physical dysfunction. Episodes of KLS may continue for ten years or more. KLS is sometimes referred to as, 'Sleeping Beauty,' syndrome.
Along with excessive sleep, a person with KLS's whole demeanor is changed. They often times appear to be, 'spacey,' or childlike. While awake, the person experiences disorientation, confusion, a complete lack of energy, as well as a lack of emotions. The majority of people with KLS report that everything seems to be out of focus and that they are hypersensitive to light and noise. In some instances, food cravings are a part of the symptoms they experience. Instances of uninhibited hyper-sexuality during an episode have been reported by people with KLS.
Episodes of Kleine-Levin syndrome (KLS) are cyclical. When present, the symptoms of KLS can persist for days, weeks, or even months - during which time all of the person's usual daily activities stop. People with KLS are unable to attend school, work, or to provide care for themselves. Most people with this syndrome are bedridden, tired, as well as uncommunicative, even when they are awake. Not everyone affected by KLS experiences all of the symptoms associated with the syndrome.
People with KLS might go for weeks, months or even years at a time without experiencing any symptoms at all, then symptoms reappear with little warning. In between episodes, people with KLS seem to be in perfect health with no evidence of either behavioral or physical dysfunction. They do; however, function on a daily basis with the reality that they could become sick again at any time. Episodes of KLS might continue to reoccur for a decade or more with devastating effects on the person's life and family. KLS takes large pieces of the person's life, one episode at a time.
The mean diagnostic delay for proper KLS diagnosis is around four years. What this means is that it takes the average person with KLS about four years before they receive an accurate diagnosis. The cause of Kleine-Levin syndrome remains unknown at this time.
Symptoms of KLS
There is no medical test that may be used to confirm Kleine-Levin syndrome. As with any medical condition, there are atypical instances that do not fall within the classic definition. The length of episodes and period of time between them in some instances are known to be outside of the periods that are average. A person with KLS may experience symptoms which include:
Causes of KLS
In 18 people, KLS-like symptoms were observed in association with post-traumatic brain maematoma or stroke, genetic or developmental disease, multiple sclerosis, hydrocephalus, paraneoplasia in the context of a carcinoma of the cervix utero, an autoimmune encephalitis, or a severe infectious encephalitis. The types of stroke reported were a multi-infarct dementia, a thalamic ischaemic stroke and traumatic hemorrhages of the right hemisphere.
The genetic diseases were heterogeneous and included an instance of, 'mosaicism,' with Robert's syndrome, phocomelia, mild intellectual disability, optic atrophy, bilateral facial palsy, an instance of Prader-Willi syndrome, an unidentified disease with intellectual disability, a complex instance of consanguinity, intellectual disability, an ectodermal disorder, acanthosis nigricans, hereditary exostosis, developmental Asperger's syndrome in two people - one with cortical dysplasia and retinitis pigmentosa. In three people with infectious encephalitis of unknown origin, one experienced acute viral meningo-encephalitis and high CSF lymphocyte counts. Another had a meningo-encephalitis with neurological sequels, to include left-hypo-sensitively, central facial palsy, concentric loss of visual fields and bilateral facial spasms. KLS also occurred in a context of gastrointestinal symptoms in a woman with recurrent episodes of variable hypersomnia, at times severe insomnia, as well as diarrhea lasting over a thirty year period of time.
The evaluation of treatment, based upon case-reports, was difficult to assess because of the unpredictable spontaneous course of the syndrome and the absence of placebo-controlled studies. It was evaluated in a large population of people and the results were extremely disappointing. Amphetamine-stimulants significantly improved sleepiness, yet not the other more serious symptoms, suggesting a very imperfect therapeutic approach.
The potential benefit of lithium at preventing relapses, administered in only 29 instances, if confirmed should be balanced against its known difficulty of use and unfavorable side-effects. Anti-seizure mood stabilizers, particularly carbamezapine, were commonly prescribed, yet results were similar to no medication treatment - strongly suggesting the practice has no justification. Antidepressant therapies were also ineffective. Therapeutic trials of other medications such as antiviral agents and immunosuppressives with double-blind placebo-controlled approaches may be warranted.
KLS Triggering Factors
The occurrence of an infection at the onset of the syndrome in more than two-thirds of those affected seems too frequent and closely associated with KLS to be due to mere chance. In rare instances where an infectious agent was identified, it differed from one person to another. The agents may therefore de-compensate a previously existing disease, or a coexisting infection with another as yet undetected infectious agents might be responsible.
More work related to KLS is clearly needed as the studies of some notable infectious agents are known to cause confusion, hypersomnia and various neuro-psychiatric symptoms such as Whipple's disease, California encephalitis, malaria or encephalitis. Infection, alcohol and head trauma are all known to increase the blood-brain barrier permeability and may therefore facilitate the passage of a circulating pathogenic agent or immunoglobulin to a person's brain.
NINDS Kleine-Levin Syndrome Information
Kleine-Levin syndrome: Etiology, diagnosis, and treatment
Kleine-Levin Syndrome (KLS)