Sleep / Wake

Idiopathic Hypersomnia

Idiopathic hypersomnia (IH) is a rare and debilitating sleep disorder that can significantly disrupt daily functioning. IH is characterized by excessive daytime sleepiness (EDS) despite sufficient or even long sleep time. Other symptoms include unrefreshed sleep, difficulty in awakening, cognitive dysfunction, and autonomic symptoms.

IH is usually not alleviated by naps, longer sleep, or more efficient sleep. People living with IH experience significant EDS along with prolonged difficulty waking up from sleep and “brain fog.” While the cause of IH is unknown, many patients have a family history of similar symptoms, and IH is likely due to alterations in areas of the brain that stabilize states of sleep and wakefulness.

Approximately 80,000 people in the US are believed to be affected by IH, with 40,000 currently having been diagnosed.

Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a rare genetic neurological disorder with many of the symptoms resulting from hypothalamic dysfunction.

The hypothalamus is an area of the brain that controls both sleep-wake state stability as well as the balance between hunger and satiety. The main symptoms of PWS include: hyperphagia (an intense persistent sensation of hunger accompanied by food preoccupations, an extreme drive to consume food, food-related behavior problems, and a lack of normal satiety); excessive daytime sleepiness (EDS); and behavioral symptoms. Other features include low muscle tone, short stature, and cognitive impairment.

Approximately 15,000 to 20,000 people in the US are living with PWS, the majority experiencing behavioral symptoms and more than half with EDS. There is currently no FDA-approved treatment for EDS in this patient population.

Myotonic Dystrophy Type 1

Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder that causes muscle weakness and is the most common form of adult-onset muscular dystrophy. It is an inherited disorder that is caused by a genetic mutation, and onset often occurs in an individual’s 20s and 30s. DM1 also affects multiple systems including the heart, eyes, endocrine system, and central nervous system.

Latest estimates suggest a prevalence of about 1 per 2,100 people with the genetic defect for DM1, which equates to about 150,000 people in the US. Estimates suggest there are 40,000 people currently diagnosed with DM1 in the US, with up to 90% of them reporting excessive daytime sleepiness (EDS) and fatigue and over 60% of them experiencing cognitive dysfunction.

Narcolepsy

Narcolepsy is a rare, chronic, debilitating neurological disorder of sleep-wake state instability. Narcolepsy impacts approximately 170,000 Americans and is primarily characterized by excessive daytime sleepiness, cataplexy, and other manifestations of REM sleep dysregulation, which intrude into wakefulness. In most patients, it is caused by the loss of hypocretin, a neuropeptide in the brain that supports sleep-wake state stability.

This disorder affects men and women equally, with typical symptom onset in adolescence or young adulthood; however, it can take up to a decade to be properly diagnosed. Narcolepsy can cause significant burden on patients and their families, affecting their ability to perform routine tasks, limit achievement at school and work, impact social relationships, and cause impairment in overall quality of life.