Cataplexy, hypnagogic hallucinations and sleep paralysis can also be present in narcolepsy. The DSM-5 refers to narcolepsy without cataplexy as hypersomnolence disorder. Cataplexy without narcolepsy is rare and the cause is unknown. The diagnosis of narcolepsy and cataplexy is usually made by symptom presentation. Family history is more common in narcolepsy with cataplexy. Zimelidine was able to improve cataplexy without causing daytime sleepiness. The prevalence of narcolepsy (with cataplexy) is estimated between 1/3,300 and 1/5,000. He was the first physician to provide a clinical description of narcolepsy and cataplexy (1877). Other scientists have also linked OBEs to cases of hypnagogia and sleep paralysis (cataplexy). See also laughter-induced syncope, cataplexy, and Bezold-Jarisch reflex. Cataplexy may be mistaken for seizures. Cataplexy due to brainstem lesions is uncommon particularly when seen in isolation. Secondary cataplexy is associated with specific lesions located primarily in the lateral and posterior hypothalamus. This cataplexy is able to be triggered through social interaction, wheel running, and ultrasonic vocalizations. The attacks of cataplexy in dogs can involve partial or full collapse.