A Case of Narcolepsy Misdiagnosed as Schizophrenia

Abstract

Narcolepsy is a chronic neurological disease with five domains of symptoms including excessive daytime sleepiness (EDS), cataplexy, hypnagogic/hypnopompic hallucinations, sleep paralysis, and sleep fragmentation. Several overlapping symptoms of schizophrenia and narcolepsy often make it challenging to differentiate between the two conditions. A 23-year-old African American female was diagnosed with schizophrenia based on a two-year history of auditory and visual hallucinations. The patient was referred to a sleep physician for excessive daytime sleepiness. She has been sleepy since her teenage years taking 1–2 naps daily (Epworth sleepiness scale (ESS) was 14). She also complained of occasional sudden loss of muscle tone, which was triggered by strong emotions. In addition, she had episodes of inability to move her body in the morning, feeling as if someone was sitting on her chest. A full “hypersomnia workup” was scheduled including a nocturnal polysomnography (PSG) followed by a multiple sleep latency test (MSLT). The MSLT was positive for narcolepsy with cataplexy, or type 1 narcolepsy. She was prescribed modafinil 200 mg daily for EDS and venlafaxine 75 mg was added for cataplexy. In two weeks her ESS improved from 14 to 8. This case illustrates the potential of narcolepsy being misdiagnosed as schizophrenia in patients who have excessive daytime sleepiness and symptoms mimicing psychosis.