THE DANGER OF DIAGNOSING NARCOLEPSY WITH CATAPLEXY ON HISTORY ALONE IN NEUROLOGY OUTPATIENTS

Abstract

Narcolepsy with cataplexy is a chronic sleep disorder characterised by excessive daytime sleepiness, and is associated with sleep paralysis, hypnagogic hallucinations, disrupted nocturnal sleep, and sleep attacks. It is a relatively uncommon condition, with a prevalence of 0.01–0.05%, and can be difficult to diagnose with significant long term impact on an individual9s health. Current guidelines suggest that narcolepsy with cataplexy can be diagnosed on history alone, without the need for further investigations. Objectives To determine the rate of misdiagnosis of narcolepsy with cataplexy in a general neurology clinic. Methods Case notes were reviewed for patients referred to a new sub-specialty neurology sleep clinic with a potential diagnosis of narcolepsy with cataplexy over a 2 year period. Results Of 10 patients referred who had been diagnosed with narcolepsy and prescribed pharmacological treatment, other diagnoses were established in 5 patients following specialist sleep assessment and where appropriate, objective testing. These diagnoses include obstructive sleep apnoea, COPD, Circadian phase reversal, delayed sleep phase syndrome and behavioural sleep problems. Conclusion The use of history alone to establish a diagnosis of narcolepsy with cataplexy is insufficient in a general neurology clinic. We argue that objective testing, including actigraphy, polysomnography and multiple sleep latency testing in conjunction with a detailed history is the most effective method of establishing a correct diagnosis.