Narcolepsy with cataplexy and comorbid immunopathological diseases

Evidence suggests that autoimmune diseases tend to co-occur so that patients with an autoimmune disorder are at higher risk of a second autoimmune disease. The association between allergic and autoimmune diseases is also of considerable interest. There are no reports on the association between sporadic or familial narcolepsy with cataplexy and other non-neurological immune-mediated diseases. This study reported on the comorbid immunopathological diseases associated with narcolepsy. One-hundred and fifty six narcoleptic patients with a mean age at diagnosis of 39.1 ± 17.8 years (range, 6-70 years) were assessed using the clinical history, physical and neurological examinations, sleep questionnaires, neuroimaging and human leucocyte antigen typing. Diagnosis was confirmed by polysomnography followed by a multiple sleep latency test or by measuring hypocretin-1 levels. Patients with immunopathological diseases were matched for gender and age at the onset of narcoleptic symptoms with narcoleptic patients without immunopathological diseases. Twenty-six patients (16.6%; 50% women; one familial, 25 sporadic) had one or more immunopathological diseases associated: autoimmune diseases, such as idiopathic thrombocytopenic purpura, multiple sclerosis, systemic lupus erythematosus, psoriasis, Crohn's disease, ulcerative colitis, autoimmune thyroid disease, Peyronie's disease and idiopathic recurrent facial palsy; other immunopathological diseases, like atopic dermatitis, allergic asthma and allergic rhinitis. Although not significant, the age at diagnosis of narcolepsy was 9.3 years earlier in patients with narcolepsy + immunopathological diseases. The results demonstrate that the prevalence of comorbid immunopathological diseases is high in narcolepsy, and cataplexy is significantly more severe in patients with narcolepsy + immunopathological diseases.

[The role of slow wave sleep in the homeostatic regulation of sleep]

OBJECTIVES

The homeostatic regulation of sleep is based on the model devised by Borb ly in 1982. During the sleep waking cycle there is an interaction between the natural tendency to sleep, which increase as the vigil is prolonged (S process) and the circadian variation (C process). In this study, we aimed to find how slow activity (0.5 4.5 Hz) during sleep (SWA), mainly registered in phases 3 and 4, may be an indicator of process S.

PATIENTS AND METHODS

We compared two groups of persons: 10 with chronic sleep deprivation (CSD) (less than 6 hours of sleep/day) as compared with 10 persons who slept more than 6 hours per day, using spectral analysis of their delta activity during sleep.

RESULTS

There was a predominance of delta activity in the group of persons with CSD as compared with the control group.

CONCLUSIONS

An increase in SWA was accompanied by an increased tendency to sleep and may therefore be considered to be a marker for this. This marker allows conditions associated with hypersomnolence due to alteration of process S to be identified.

[Epileptic channelopathies]

OBJECTIVE

At the present time the study of epileptogenesis is becoming increasingly interested in the function of ionic channels in which localization of new gene sites and mutations have been aetiopathogenically related to certain syndromes involving epilepsy. The pathology of these channels known as channelopathies is responsible for a certain number of conditions affecting the central nervous and neuromuscular systems. Its clinical expression is often paroxystic. The mutations cause inactivation of the channel, which depending on the degree, conditions the phenotype of the process.

DEVELOPMENT

We studied the main epileptic channelopathies related to idiopathic epilepsy syndromes. To date it has been possible to codify four genes responsible for: benign familial neonatal convulsions, generalized epilepsy with febrile convulsions plus and frontal lobe nocturnal dominant autosomal epilepsy, together with other syndromes in which potentially related mutations have arisen.

CONCLUSIONS

Ionic channels, both voltage and receptor dependent, are involved in the genesis of idiopathic epilepsy syndromes. Their importance is due to the contribution made to understanding epileptogenesis and the application of this in the investigation of drugs which act by modifying the initial cause of the seizure. Today it may be said that the idiopathic epilepsies, or at least some of them, make up a family of channelopathies.