This study intends to examine the utility of a home-use EEG-based sleep monitor for the diagnosis and evaluation of disorders of excessive sleepiness, specifically the neurological disorder Narcolepsy Type 1.

Diagnosing hypersomnia conditions (including narcolepsy type 1 [NT1], narcolepsy type 2 [NT2], and idiopathic hypersomnia [IH]) and differentiating them from other conditions is often challenging as symptoms including excessive daytime sleepiness, daytime napping, and disturbed nocturnal sleep are nonspecific and current diagnostic tests are limited. Unfortunately, patients with hypersomnia often demonstrate a discrepancy between self-reported sleep duration and quantitative assessment. This complicates both diagnosis and management, as objective sleep assessment is typically not available over multiple periods. A more natural approach would be to monitor sleep and wakefulness serially and with monitoring, including assessment of total sleep time, rapid eye movement (REM) latency, daytime sleep attacks, daytime sleep/nap duration, and consolidated/non-consolidated nocturnal sleep.

This validation study evaluates the ability of Dreem 3S to capture multiple days of continuous sleep and wake measures in subjects with hypersomnia, particularly in NT1. Primary outcomes will include usability of Dreem 3S by patients with hypersomnia, patient compliance with longitudinal data collection using Dreem 3S at-home, and fidelity of sleep staging of Dreem 3S data to synchronously recorded gold-standard nocturnal PSG and MSLT.

Dreem 3S is an FDA cleared class II medical device, under the OLZ/OLV (PSG devices) product codes for home sleep staging in patients with disturbed sleep.

Inclusion Criteria:

• Patients must be ≥ 18 years old.
• Patients must be scheduled for an MSLT for a potential diagnosis of hypersomnia (Arm A only).
• Patients are able/willing to consent and willing to undergo the nocturnal PSG, MSLT, and Dreem 3S monitoring described in the protocol.
• (for Known NT1 arm [Arm B] only) Deemed safe to discontinue prohibited medications as per protocol.
• (for Known NT1 arm [Arm B] only) Agree to discontinue driving and operating heavy machinery while untreated for their condition and according to the PI's judgement.

Exclusion Criteria:

• Patients under 18 years old.
• If a patient is taking a wake promoting drug and is unsafe to temporarily reduce or discontinue the drug during the 2 weeks prior to nocturnal PSG and MSLT due to their occupation, need to drive or operate heavy machinery, role as a primary caretaker, medical risk of temporarily discontinuing from drug therapy, or any other reason at the discretion of the subject's treating physician or study physicians/PIs.
• Patients suffering from mental and/or physical disorders that could interfere with the study protocol or the interpretation of the results (exclusion based on clinical judgment).
• Shift workers or patients working unusual hours will be excluded. 5. Patients with a history of stroke or epilepsy.
• Patients with an implanted hypoglossal nerve stimulator or a diagnosis of moderate to severe sleep apnea (Apnea-Hypopnea Index (AHI) 3% >15) not adherent on positive airway pressure therapy (usage 30-day window prior to enrollment date reveals <70% days use at least hours; patients treated with non-PAP treatments will not be eligible).
• Patients who are unable to sign an informed consent form, or unable to have a legal guardian who is able to sign along with the patient's assent.
• Patients who are deemed ineligible by the site PI or treating physician for any other reason.

Patients with diagnosed Narcolepsy or suspected Narcolepsy

Identifiable participant data will not be shared. Only deidentified data will be shared (EEG data, and related sleep metrics).