Reassessment of the risk of narcolepsy in children in England 8 years after receipt of the AS03-adjuvanted H1N1 pandemic vaccine: A case-coverage study.

BACKGROUND: Early studies of narcolepsy after AS03-adjuvanted pandemic A/H1N12009 vaccine (Pandemrix) could not define the duration of elevated risk post-vaccination nor the risk in children aged under 5 years who may not present until much older. METHODS/FINDINGS: Clinical information and sleep test results, extracted from hospital notes at 3 large pediatric sleep centers in England between September 2017 and June 2018 for narcolepsy cases aged 4-19 years with symptom onset since January 2009, were reviewed by an expert panel to confirm the diagnosis. Vaccination histories were independently obtained from general practitioners (GPs). The odds of vaccination in narcolepsy cases compared with the age-matched English population was calculated after adjustment for clinical conditions that were indications for vaccination. GP questionnaires were returned for 242 of the 244 children with confirmed narcolepsy. Of these 5 were under 5 years, 118 were 5-11 years, and 119 were 12-19 years old at diagnosis; 39 were vaccinated with Pandemrix before onset. The odds ratio (OR) for onset at any time after vaccination was 1.94 (95% confidence interval [CI] 1.30-2.89), The elevated risk period was restricted to onsets within 12 months of vaccination (OR 6.65 [3.44-12.85]) and was highest within the first 6 months. After one year, ORs were not significantly different from 1 up to 8 years after vaccination. The ORs were similar in under five-year-olds and older ages. The estimated attributable risk was 1 in 34,500 doses. Our study is limited by including cases from only 3 sleep centers, who may differ from cases diagnosed in nonparticipating centers, and by imprecision in defining the centers' catchment population. The potential for biased recall of onset shortly after vaccination in cases aware of the association cannot be excluded. CONCLUSIONS: In this study, we found that vaccine-attributable cases have onset of narcolepsy within 12 months of Pandemrix vaccination. The attributable risk is higher than previously estimated in England because of identification of vaccine-attributable cases with late diagnoses. Absence of a compensatory drop in risk 1-8 years after vaccination suggests that Pandemrix does not trigger onsets in those in whom narcolepsy would have occurred later.

Drug treatment of REM sleep behavior disorder: the use of drug therapies other than clonazepam.

STUDY OBJECTIVES: REM sleep behavior disorder (RBD) is characterized by loss of the normal muscle atonia during REM sleep associated with disruptive motor activity related to the acting out of dreams. There is frequently injury to the patient or bed partner, and treatment is usually required. Clonazepam has been the first-line therapy for many years, with 2 large case series reporting efficacy with few side effects in the majority of patients. However, long-acting hypnotics in the elderly or those with cognitive impairment can be associated with adverse events especially unacceptable daytime sedation, confusion, and exacerbation of existing sleep apnea. METHODS: We reviewed 39 patients with confirmed RBD who were treated within our regional sleep center, assessing both efficacy and side effects of drug therapies. RESULTS: Adverse effects were reported by 58% of the patients using clonazepam, with 50% either discontinuing the drug or reducing the dose. This prompted us review the side effects of clonazepam in detail and to look for alternative therapies. We report several novel and effective therapies, in particular zopiclone, in a series of patients under long-term follow-up for RBD. CONCLUSIONS: There are alternatives to clonazepam therapy for RBD which can be as effective and may be better tolerated.