Objective To assess whether risk factors for Parkinson’s disease and Dementia with Lewy bodies increase rate of defined neurodegenerative disease in idiopathic REM sleep behavior disorder Methods 12 centers administered a detailed questionnaire assessing risk factors for neurodegenerative synucleinopathy to patients with idiopathic REM sleep behavior disorder. Variables included demographics, lifestyle factors, pesticide exposures, occupation, co-morbid conditions, medication use, family history, and autonomic/motor symptoms. After 4-years follow-up, patients were assessed for dementia or parkinsonism. Disease risk was assessed with Kaplan-Meier analysis, and epidemiologic variables were compared between convertors and those still idiopathic using logistic regression. Results Of 305 patients, follow-up information was available for 279, of whom 93 (33.3%) developed defined neurodegenerative disease. Disease risk was 25% at 3 years, and 41% after 5 years. Patients who converted were older (difference=4.5 years, p<0.001), with similar sex distribution. Neither caffeine, smoking, nor alcohol exposure predicted conversion. Although occupation was similar between groups, those who converted had a lower likelihood of pesticide exposure (occupational insecticide=2.3% vs. 9.0%). Convertors were more likely to report family history of dementia (OR=2.09), without significant differences in Parkinson’s disease or sleep disorders. Medication exposures and medical history were similar between groups. Autonomic and motor symptoms were more common among those who converted. Risk factors for primary dementia and parkinsonism were generally similar, except for a notably higher clonazepam use in dementia convertors (OR=2.6). Interpretation Patients with idiopathic RBD are at very high risk of neurodegenerative synucleinopathy. Risk factor profiles between convertors and non-convertors have both important commonalities and differences.

Bimodal distribution of age at onset of narcolepsy was found in two independent patient populations. Our data suggest that age at onset is genetically determined.

Objective: To determine the role of CSF hypocretin-1 in narcolepsy with and without cataplexy, KleineLevin syndrome (KLS), idiopathic and other hypersomnias, and several neurological conditions. Patients: 26 narcoleptic patients with cataplexy, 9 narcoleptic patients without cataplexy, 2 patients with abnormal REM-sleep-associated hypersomnia, 7 patients with idiopathic hypersomnia, 2 patients with post-traumatic hypersomnia, 4 patients with KLS, and 88 patients with other neurological disorders. Results: 23 patients with narcolepsy-cataplexy had low CSF hypocretin-1 levels, while one patient had a normal hypocretin level (HLA-DQB1*0602 negative) and the other two had intermediate levels (familial forms). One narcoleptic patient without cataplexy had a low hypocretin level. One patient affected with post-traumatic hypersomnia had intermediate hypocretin levels. The KLS patients had normal hypocretin levels while asymptomatic, but one KLS patient (also affected with Prader-Willi syndrome) showed a twofold decrease in hypocretin levels during a symptomatic episode. Among the patients without hypersomnia, two patients with normal pressure hydrocephalus and one with unclear central vertigo had intermediate levels.Conclusion: Low CSF hypocretin-1 is highly specific (99.1%) and sensitive (88.5%) for narcolepsy with cataplexy. Hypocretin ligand deficiency appears not to be the major cause for other hypersomnias, with a possible continuum in the pathophysiology of narcolepsy without cataplexy and idiopathic hypersomnia. However, partial hypocretin lesions without low CSF hypocretin-1 consequences cannot be definitely excluded in those disorders. The existence of normal hypocretin levels in narcoleptic patients and intermediate levels in other rare aetiologies needs further investigation, especially for KLS, to establish the functional significance of hypocretin neurotransmission alterations.

Objective. To assess objective and subjective evidence of sleep disturbances in patients with rheumatoid arthritis (RA) and to examine correlations between parameters of inflammatory activity and sleep pathology. Methods. Nineteen RA patients and 19 age‐matched healthy control subjects underwent all‐night polysomnography on 2 consecutive nights. RA patients were also evaluated for daytime sleepiness by mean sleep latency test and responded to a self‐report questionnaire on their first night. Results. Whereas normal sleep architecture is conserved in RA, we confirmed former findings of severe sleep fragmentation and an enhanced presence of primary sleep disorders. No correlation exists between RA activity and the sleep disorders. Subjective assessment was not consistent with the objective evidence of sleep disruption, unlike the findings in patients with fibrositis. Conclusion. Sleep is severly disturbed in patients with RA, regardless of the inflammatory disease activity. the specificity of the sleep disorders assessed needs confirmation, as does specific sleep therapy for these patients.