Hypersomnia and extended sleep cycles in Kleine-Levin Syndrome: Identifying key characteristics of excessive daytime sleepiness
Kleine-Levin Syndrome (KLS) is a rare neurological disorder, with an estimated prevalence of 1 to 5 cases per million people worldwide. This condition is characterized by recurrent episodes of excessive sleepiness (hypersomnia), behavioral changes, and cognitive disturbances [1].
The exact cause of KLS is unknown, but growing evidence supports the hypothesis of hypothalamic dysfunction as a contributing factor in its pathophysiology. Common triggers associated with KLS include infections, head trauma, and alcohol intake, which are believed to potentially precipitate the onset of KLS episodes [1].
People of all ethnic and geographic populations can be affected by KLS, but some studies suggest a slightly higher occurrence in individuals of Ashkenazi Jewish descent, indicating a possible genetic predisposition in certain groups [1]. The disorder predominantly affects adolescents, with the average age of onset between 15 and 19 years [1]. Interestingly, it is more common in individuals assigned male at birth, accounting for approximately 70% of cases.
KLS episodes are marked by prolonged sleep periods, where patients sleep around 16 to 20 hours per day. Unlike idiopathic hypersomnia, KLS involves complete sleep episodes, rather than chronic and persistent sleepiness without a return to normalcy [1].
The disorder is further characterized by cognitive and behavioral disturbances, including hyperphagia (compulsive overeating), hypersexuality, and derealization [1]. Misdiagnosis is common due to its overlapping symptoms with mental health disorders like depression and bipolar disorder.
Diagnosing KLS can be challenging due to a lack of established diagnostic criteria and a global consensus. Polysomnography and EEG are commonly used to examine an individual's sleep patterns and brain activity, while neuroimaging studies such as fMRI and PET scans can help find any structural or functional abnormalities in the brain responsible for sleep regulation and consciousness in KLS patients [1].
Sleep diaries and actigraphy can be used to track the beginning, duration, and frequency of KLS episodes over time. However, the precise mechanisms that trigger hypersomnia and other related symptoms in KLS remain uncertain.
Further studies are needed to integrate objective diagnostic methods, elucidate the pathophysiological mechanisms, and create targeted therapies to facilitate early diagnosis and help avoid misdiagnosis. Accurate global prevalence data for KLS is not available due to inconsistent research and treatment practices worldwide, and many cases may go unrecognized.
References: [1] Hypersomnia Foundation. (n.d.). Kleine-Levin Syndrome (KLS). Retrieved from https://hypersomnifoundation.org/kls/
- The mysterious cause of Kleine-Levin Syndrome (KLS) is under investigation, with evidence pointing towards hypothalamic dysfunction as a potential factor.
- Recurring sleepiness, behavioral changes, and cognitive disturbances characterize KLS, a rare neurological disorder that can affect people of all backgrounds.
- Struggling with proper diagnosis is common for KLS, as its symptoms can overlap with other medical-conditions like depression and bipolar disorder.
- To better understand the neurological underpinnings of KLS, scientific research aims to integrate objective diagnostic methods, illuminate pathophysiological mechanisms, and develop targeted therapies to improve health-and-wellness for those afflicted.
