[Advances in the diagnosis and treatment of narcolepsy-cataplexy syndrome].

INTRODUCTION

Narcolepsy is a disabling sleep disorder that is characterised by excessive daytime sleepiness and abnormal manifestations in REM (rapid eye movement) sleep that include, among other symptoms, cataplexy (the sudden loss of muscle tone triggered by strong emotions). Studies on the prevalence of narcolepsy-cataplexy in Europe and the United States have yielded a figure of 0.013-0.067% in the general population. Although its prevalence is low, it is probably under-diagnosed for a number of different reasons, the most important perhaps being the difficulties involved in its diagnosis.

DEVELOPMENT

Because its diagnosis is essentially clinical, complementary tests can often be very helpful. Today, it is one of the most extensively studied sleep disorders at the molecular level. Human narcolepsy is associated with diminished hypocretin/orexin concentrations, unlike the case of canine narcolepsy, where mutations in the Hcrt receptor have been found. The treatment of narcolepsy must be tailored to meet the needs of each patient after an individual analysis of his or her symptoms. Daytime sleepiness can be controlled by drugs that stimulate the central nervous system, the most common being methylphenidate and modafinil. Cataplexy is usually treated with tricyclic antidepressants and selective serotonin reuptake inhibitors. The appearance of new drugs like sodium oxybate sheds a ray of light on the dark horizon of patients with narcolepsy-cataplexy syndrome.

CONCLUSION

Early identification of excessive daytime sleepiness by primary care physicians and specialists is essential for a better management and follow-up of these patients.