Associations between obesity, a composite risk score for probable long COVID, and sleep problems in SARS-CoV-2 vaccinated individuals.

BACKGROUND: Preliminary data suggests that obesity might hasten the decline in mRNA vaccine-induced immunity against SARS-CoV-2. However, whether this renders individuals with obesity more susceptible to long COVID symptoms post-vaccination remains uncertain. Given sleep's critical role in immunity, exploring the associations between obesity, probable long COVID symptoms, and sleep disturbances is essential. METHODS: We analyzed data from a survey of 5919 adults aged 18 to 89, all of whom received two SARS-CoV-2 mRNA vaccinations. Participants were categorized into normal weight, overweight, and obesity groups based on ethnicity-specific BMI cutoffs. The probability of long COVID was evaluated using the Post-Acute Sequelae of SARS-CoV-2 (PASC) score, as our survey did not permit confirmation of acute SARS-CoV-2 infection through methods such as antibody testing. Additionally, sleep patterns were assessed through questionnaires. RESULTS: Participants with obesity exhibited a significantly higher adjusted odds ratio (OR) of having a PASC score of 12 or higher, indicative of probable long COVID in our study, compared to those with normal weight (OR: 1.55, 95% CI: 1.05, 2.28). No significant difference was observed for overweight individuals (OR: 0.92 [95% CI: 0.63, 1.33]). Both obesity and probable long COVID were associated with increased odds of experiencing a heightened sleep burden, such as the presence of obstructive sleep apnea or insomnia (P < 0.001). However, no significant interaction between BMI and probable long COVID status was found. CONCLUSIONS: Even post-vaccination, individuals with obesity may encounter a heightened risk of experiencing prolonged COVID-19 symptoms. However, confirming our observations necessitates comprehensive studies incorporating rigorous COVID infection testing, such as antibody assays - unavailable in our anonymous survey. Additionally, it is noteworthy that the correlation between probable long COVID and sleep disturbances appears to be independent of BMI.

Nightmare frequency is a risk factor for suicidal ideation during the COVID-19 pandemic.

The association between nightmare frequency (NMF) and suicidal ideation (SI) is well known, yet the impact of the COVID-19 pandemic on this relation is inconsistent. This study aimed to investigate changes in NMF, SI, and their association during the COVID-19 pandemic. Data were collected in 16 countries using a harmonised questionnaire. The sample included 9328 individuals (4848 women; age M[SD] = 46.85 [17.75] years), and 17.60% reported previous COVID-19. Overall, SI was significantly 2% lower during the pandemic vs. before, and this was consistent across genders and ages. Most countries/regions demonstrated decreases in SI during this pandemic, with Austria (-9.57%), Sweden (-6.18%), and Bulgaria (-5.14%) exhibiting significant declines in SI, but Italy (1.45%) and Portugal (2.45%) demonstrated non-significant increases. Suicidal ideation was more common in participants with long-COVID (21.10%) vs. short-COVID (12.40%), though SI did not vary by COVID-19 history. Nightmare frequency increased by 4.50% during the pandemic and was significantly higher in those with previous COVID-19 (14.50% vs. 10.70%), during infection (23.00% vs. 8.10%), and in those with long-COVID (18.00% vs. 8.50%). The relation between NMF and SI was not significantly stronger during the pandemic than prior (rs = 0.18 vs. 0.14; z = 2.80). Frequent nightmares during the pandemic increased the likelihood of reporting SI (OR = 1.57, 95% CI 1.20-2.05), while frequent dream recall during the pandemic served a protective effect (OR = 0.74, 95% CI 0.59-0.94). These findings have important implications for identifying those at risk of suicide and may offer a potential pathway for suicide prevention.

Kleine-Levin syndrome is associated with birth difficulties and genetic variants in the TRANK1 gene loci.

Kleine-Levin syndrome (KLS) is a rare disorder characterized by severe episodic hypersomnia, with cognitive impairment accompanied by apathy or disinhibition. Pathophysiology is unknown, although imaging studies indicate decreased activity in hypothalamic/thalamic areas during episodes. Familial occurrence is increased, and risk is associated with reports of a difficult birth. We conducted a worldwide case-control genome-wide association study in 673 KLS cases collected over 14 y, and ethnically matched 15,341 control individuals. We found a strong genome-wide significant association (rs71947865, Odds Ratio [OR] = 1.48, P = 8.6 × 10-9) within the 3'region of TRANK1 gene locus, previously associated with bipolar disorder and schizophrenia. Strikingly, KLS cases with rs71947865 variant had significantly increased reports of a difficult birth. As perinatal outcomes have dramatically improved over the last 40 y, we further stratified our sample by birth years and found that recent cases had a significantly reduced rs71947865 association. While the rs71947865 association did not replicate in the entire follow-up sample of 171 KLS cases, rs71947865 was significantly associated with KLS in the subset follow-up sample of 59 KLS cases who reported birth difficulties (OR = 1.54, P = 0.01). Genetic liability of KLS as explained by polygenic risk scores was increased (pseudo R2 = 0.15; P < 2.0 × 10-22 at P = 0.5 threshold) in the follow-up sample. Pathway analysis of genetic associations identified enrichment of circadian regulation pathway genes in KLS cases. Our results suggest links between KLS, circadian regulation, and bipolar disorder, and indicate that the TRANK1 polymorphisms in conjunction with reported birth difficulties may predispose to KLS.

Sleep symptoms are essential features of long-COVID - Comparing healthy controls with COVID-19 cases of different severity in the international COVID sleep study (ICOSS-II).

Many people report suffering from post-acute sequelae of COVID-19 or "long-COVID", but there are still open questions on what actually constitutes long-COVID and how prevalent it is. The current definition of post-acute sequelae of COVID-19 is based on voting using the Delphi-method by the WHO post-COVID-19 working group. It emphasizes long-lasting fatigue, shortness of breath and cognitive dysfunction as the core symptoms of post-acute sequelae of COVID-19. In this international survey study consisting of 13,628 subjects aged 18-99 years from 16 countries of Asia, Europe, North America and South America (May-Dec 2021), we show that post-acute sequelae of COVID-19 symptoms were more prevalent amongst the more severe COVID-19 cases, i.e. those requiring hospitalisation for COVID-19. We also found that long-lasting sleep symptoms are at the core of post-acute sequelae of COVID-19 and associate with the COVID-19 severity when COVID-19 cases are compared with COVID-negative cases. Specifically, fatigue (61.3%), insomnia symptoms (49.6%) and excessive daytime sleepiness (35.8%) were highly prevalent amongst respondents reporting long-lasting symptoms after hospitalisation for COVID-19. Understanding the importance of sleep-related symptoms in post-acute sequelae of COVID-19 has a clinical relevance when diagnosing and treating long-COVID.

Associations between changes in habitual sleep duration and lower self-rated health among COVID-19 survivors: findings from a survey across 16 countries/regions.

BACKGROUND: Self-rated health (SRH) is widely recognized as a clinically significant predictor of subsequent mortality risk. Although COVID-19 may impair SRH, this relationship has not been extensively examined. The present study aimed to examine the correlation between habitual sleep duration, changes in sleep duration after infection, and SRH in subjects who have experienced SARS-CoV-2 infection. METHODS: Participants from 16 countries participated in the International COVID Sleep Study-II (ICOSS-II) online survey in 2021. A total of 10,794 of these participants were included in the analysis, including 1,509 COVID-19 individuals (who reported that they had tested positive for COVID-19). SRH was evaluated using a 0-100 linear visual analog scale. Habitual sleep durations of < 6 h and > 9 h were defined as short and long habitual sleep duration, respectively. Changes in habitual sleep duration after infection of ≤ -2 h and ≥ 1 h were defined as decreased or increased, respectively. RESULTS: Participants with COVID-19 had lower SRH scores than non-infected participants, and those with more severe COVID-19 had a tendency towards even lower SRH scores. In a multivariate regression analysis of participants who had experienced COVID-19, both decreased and increased habitual sleep duration after infection were significantly associated with lower SRH after controlling for sleep quality (ß = -0.056 and -0.058, respectively, both p < 0.05); however, associations between current short or long habitual sleep duration and SRH were negligible. Multinomial logistic regression analysis showed that decreased habitual sleep duration was significantly related to increased fatigue (odds ratio [OR] = 1.824, p < 0.01), shortness of breath (OR = 1.725, p < 0.05), diarrhea/nausea/vomiting (OR = 2.636, p < 0.01), and hallucinations (OR = 5.091, p < 0.05), while increased habitual sleep duration was significantly related to increased fatigue (OR = 1.900, p < 0.01). CONCLUSIONS: Changes in habitual sleep duration following SARS-CoV-2 infection were associated with lower SRH. Decreased or increased habitual sleep duration might have a bidirectional relation with post-COVID-19 symptoms. Further research is needed to better understand the mechanisms underlying these relationships for in order to improve SRH in individuals with COVID-19.

Immunocyte single cell analysis of vaccine-induced narcolepsy.

Increased incidence of narcolepsy type 1 (NT1) was observed following Pandemrix®-vaccination, initiated as a preventive measure against the 2009 Influenza pandemic. Here, single cell analysis was conducted to suggest a lower number of CD8+ CD27+ T cells among these patients. These findings provide understanding into the autoimmune pathogenesis of NT1.

Narcolepsy treatment in Sweden: An observational study.

OBJECTIVES: To describe the pharmacological treatments (2005-2017) and the healthcare utilization (1997-2016) for patients with narcolepsy in Sweden in order to create a framework for future organizational and economic analyses. MATERIAL & METHODS: Patients of all ages with a diagnosis of narcolepsy registered in the National Patient Registry in specialist care in Sweden were included and information on treatments for narcolepsy was retrieved from The Swedish Prescribed Drug Register. RESULTS: We collected 2508 patients with narcolepsy, 43,3% men and 56,7% women and 47,9% were prescribed modafenil, 33,8% metylphenidate and 26,2% amphetamine. In total, 3817 treatments were initiated. Patients treated with amphetamine had a higher mean age. More women than men used modafinil, methylphenidate, amphetamine and antidepressants. The narcolepsy population had more outpatient than inpatient healthcare. Patients treated with sodium oxybate had more outpatient visits than other narcolepsy patients, before and during treatment (p = .00). CONCLUSIONS: This study gives valuable information on pharmaceutical treatments and healthcare utilization for patients with narcolepsy and can be used to estimate the healthcare cost in the future. Patients with sodium oxybate treatment had more outpatient visits than other patients before and during treatment which may be due to the need to monitor potentially severe side-effects or may indicate that patients with sodium oxybate treatment have a severe disease. The number of included patients was less than expected; however, this may depend on patients escaping our collection of data, which does not contain information from primary care.

Autologous haematopoietic stem cell transplantation compared with alemtuzumab for relapsing-remitting multiple sclerosis: an observational study.

OBJECTIVE: To compare outcomes after treatment with autologous haematopoietic stem cell transplantation (AHSCT) and alemtuzumab (ALZ) in patients with relapsing-remitting multiple sclerosis. METHODS: Patients treated with AHSCT (n=69) received a conditioning regimen of cyclophosphamide (200 mg/kg) and rabbit anti-thymocyte globulinerG (6.0 mg/kg). Patients treated with ALZ (n=75) received a dose of 60 mg over 5 days, a repeated dose of 36 mg over 3 days after 1 year and then as needed. Follow-up visits with assessment of the expanded disability status scale score, adverse events and MR investigations were made at least yearly. RESULTS: The Kaplan-Meier estimates of the primary outcome measure 'no evidence of disease activity' was 88% for AHSCT and 37% for ALZ at 3 years, p<0.0001. The secondary endpoint of annualised relapse rate was 0.04 for AHSCT and 0.1 for ALZ, p=0.03. At last follow-up, the proportions of patients who improved, were stable or worsened were 57%/41%/1% (AHSCT) and 45%/43%/12% (ALZ), p=0.06 Adverse events grade three or higher were present in 48/69 patients treated with AHSCT and 0/75 treated with ALZ in the first 100 days after treatment initiation. The most common long-term adverse event was thyroid disease with Kaplan-Meier estimates at 3 years of 21% for AHSCT and 46% for ALZ, p=0.005. CONCLUSIONS: In this observational cohort study, treatment with AHSCT was associated with a higher likelihood of maintaining 'no evidence of disease activity'. Adverse events were more frequent with AHSCT in the first 100 days, but thereafter more common in patients treated with ALZ.

Proenkephalin Decreases in Cerebrospinal Fluid with Symptom Progression of Huntington's Disease.

OBJECTIVE: Identifying molecular changes that contribute to the onset and progression of Huntington's disease (HD) is of importance for the development and evaluation of potential therapies. METHODS: We conducted an unbiased mass-spectrometry proteomic analysis on the cerebrospinal fluid of 12 manifest HD patients (ManHD), 13 pre-manifest (preHD), and 38 controls. A biologically plausible and significant possible biomarker was validated in samples from a separate cohort of patients and controls consisting of 23 ManHD patients and 23 controls. RESULTS: In ManHD compared to preHD, 10 proteins were downregulated and 43 upregulated. Decreased levels of proenkephalin (PENK) and transthyretin were closely linked to HD symptom severity, whereas levels of 15 upregulated proteins were associated with symptom severity. The decreased PENK levels were replicated in the separate cohort where absolute quantitation was performed. CONCLUSIONS: We hypothesize that declining PENK levels reflect the degeneration of medium spiny neurons (MSNs) that produce PENK and that assays for PENK may serve as a surrogate marker for the state of MSNs in HD. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Multiple sclerosis and COVID-19: The Swedish experience.

The COVID-19 pandemic has brought challenges for healthcare management of patients with multiple sclerosis (MS). Concerns regarding vulnerability to infections and disease-modifying therapies (DMTs) and their complications have been raised. Recent published guidelines on the use of DMTs in relation to COVID-19 in MS patients have been diverse between countries with lack of evidence-based facts. In Sweden, there exists a particular interest in anti-CD20 therapy as a possible risk factor for severe COVID-19 due to the large number of rituximab-treated patients off-label in the country. Rapid responses from the Swedish MS Association (SMSS) and the Swedish MS registry (SMSreg) have resulted in national guidelines on DMT use for MS patients and implementation of a COVID-19 module in the SMSreg. Recently updated guidelines also included recommendations on COVID-19 vaccination with regard to the different DMTs. Social distancing policies forced implementation of telemedicine consultation to replace in-person consultations as part of regular MS health care. Patient-reported outcome measures (PROMs) in SMSreg have been useful in this respect. This paper reports our experiences on the progress of national MS health care during the COVID-19 pandemic, in addition to offering an overview of the present scientific context.

Validating the diagnosis of multiple sclerosis using Swedish administrative data in Värmland County.

OBJECTIVES: Multiple sclerosis (MS) is a chronic neurodegenerative disease of the central nervous system. Identifying MS at the population level is important for disease surveillance and allocation of resources. The Swedish National Patient Registry (NPR) has been used to study the epidemiology of MS, but the accuracy of this resource is not known. We aimed to validate a definition of MS using the Swedish NPR in Värmland County using a longitudinal cohort design. MATERIALS AND METHODS: Data were extracted from the NPR, the Total Population Register, the Swedish MS Register, and medical records for the years 2001-2013. Fifteen algorithms of hospitalizations and clinic visits for MS were developed and compared with findings in medical records, which acted as the "gold standard" definition. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were estimated. RESULTS: Of 805 eligible persons identified in the NPR, 763 had MS (94.8%) according to medical records. Of these, 544 (71.3%) were also registered in the SMSreg. The case definition that had a well-balanced sensitivity and specificity required three or more clinic or hospital visits for MS (sensitivity of 85.3% (95% CI: 82.6-87.8) and specificity of 81.0% (95%CI: 65.9-91.4). CONCLUSIONS: Multiple case definitions with high sensitivity and moderate specificity were found, suggesting that the NPR can be used to accurately identify persons with MS.

Aniridia with PAX6 mutations and narcolepsy.

PAX6 gene mutations cause a variety of eye and central nervous system (CNS) abnormalities. Aniridia is often accompanied by CNS abnormalities such as pineal gland atrophy or hypoplasia, leading to disturbed circadian rhythm and sleep disorders. Less is known on the coincidence of narcolepsy in this patient group. We aimed to find out whether the circadian rhythm or sleep-wake structure was affected in patients with aniridia. Four members of a family segregating with congenital aniridia in two generations were included in the study. The patients were subjected to genetic testing for a PAX6 mutation, multiple sleep latency test, whole-brain magnetic resonance imaging (MRI), hypocretin-1 in cerebrospinal fluid, and Human Leukocyte Antigen DQ beta1*06:02. All four members were heterozygous for the pathogenic c.959-1G>A mutation in the PAX6 gene. Sleep disturbance was observed in all family members. The index patient was diagnosed with narcolepsy. MRI showed a hypoplastic pineal gland in all members. We describe the first case of a patient with PAX6 haploinsufficiency, aniridia and pineal gland hypoplasia diagnosed with narcolepsy type-1, suggesting a complex sleep disorder pathogenesis.

The cost utility of pitolisant as narcolepsy treatment.

OBJECTIVES: The cost-effectiveness of available pharmacological treatments for narcolepsy is largely unknown. Available pharmacological treatments are associated with tolerability, abuse, and adherence issues. Pitolisant is the first inverse agonist of the histamine H3 receptor to be prescribed for the treatment of narcolepsy with and without cataplexy. Studies suggest that pitolisant is both as effective as previously introduced drugs and is associated with fewer adverse effects. The objective in this study was to estimate the cost-effectiveness of pitolisant as monotherapy, and pitolisant as an adjunctive treatment to modafinil, compared with standard treatment. MATERIALS & METHODS: Calculations were performed using a Markov model with a 50-year time horizon. Healthcare utilization and quality-adjusted life years (QALYs) for each treatment alternative were calculated assuming no treatment effect on survival. Probabilistic sensitivity analyses were performed for treatment effectiveness and healthcare cost parameters. RESULTS: The cost per additional quality-adjusted life year was estimated at SEK 356 337 (10 SEK ≈ 1 Euro) for pitolisant monotherapy, and at SEK 491 128 for pitolisant as an adjunctive treatment, as compared to standard treatment. The cost-effectiveness measure was demonstrated to be particularly sensitive to the assumptions made concerning indirect effects on total healthcare utilization and the pitolisant treatment cost. CONCLUSIONS: The incremental cost-effectiveness ratios were below the unofficial willingness-to-pay threshold at SEK 500 000. The estimated costs per additional QALY obtained here are likely to overestimate the true cost-effectiveness ratio since significant potential indirect effects-pertaining both to labor-market and household-related productivity-of treatment are not taken into account.

Inherited Ataxia and Intrathecal Baclofen for the Treatment of Spasticity and Painful Spasms.

BACKGROUND: Intrathecal baclofen (ITB) treatment is considered a powerful tool in the management of severe spasticity in neurological conditions such as multiple sclerosis, cerebral palsy, and traumatic spinal cord and brain injury. OBJECTIVES: The objective of this study was to assess the effectiveness of the ITB in patients with inherited ataxia suffering from severe painful spasms and/or spasticity. METHOD: A total of 5 patients with spinocerebellar ataxia 3 or 7 or Friedreich's ataxia were included in this observational multicenter study. The patients were interviewed and completed outcome measures assessing pain (The Brief Pain Inventory), fatigue (Fatigue Severity Scale), and life satisfaction (LiSAT-9) before and 1 year after the treatment. Spasticity (Modified Ashworth Scale) and spasm frequency (SPFS) were measured objectively for each patient. RESULTS: The mean treatment time was 1.9 years. Evaluation of established standard forms revealed symptomatic relief from spasticity, spasms, pain, and fatigue in addition to improved body posture, sleep, and life satisfaction after ITB treatment. CONCLUSIONS: We report the potential beneficial effects of ITB treatment in patients with inherited ataxia who also suffer from spasticity/spasms. ITB treatment indication in neurological disorders allows for extension to the treatment of spasticity/ spasms in patients with hereditary ataxia.

Physical activity is associated with a decreased multiple sclerosis risk: The EnvIMS study.

BACKGROUND: The lifestyle factors smoking and obesity have been associated with the risk of multiple sclerosis (MS). Physical activity (PA) may also be of importance. OBJECTIVE: To examine the association between PA and MS risk in Italy, Norway, and Sweden and to evaluate the possible influence by established risk factors. METHODS: In this case-control study, 1904 cases and 3694 controls were asked to report their average weekly amounts of light and vigorous PA during adolescence on a scale ranging from none to more than 3 hours activity. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) and adjusted for potential confounders. RESULTS: Vigorous PA was inversely associated with MS risk in the pooled analysis ( p-trend < 0.001) with an age- and sex-adjusted OR of 0.74 (95% CI: 0.63-0.87) when comparing the highest and lowest levels. Adjusting for outdoor activity, infectious mononucleosis, body size, and smoking yielded similar results. The association was present in all countries and was not affected by exclusion of patients with early disease onset. Light PA was not associated with the risk of MS. CONCLUSION: Our findings suggest that vigorous PA can modify the risk of developing MS independent of established risk factors.

Neuroimaging in the Kleine-Levin Syndrome.

PURPOSE OF REVIEW: The purpose was to review the most recent literature on neuroimaging in the Kleine-Levin syndrome (KLS). We aimed to investigate if frontotemporal and thalamic dysfunction are key KLS signatures, and if recent research indicates other brain networks of interest that elucidate KLS symptomatology and aetiology. RECENT FINDINGS: In a comprehensive literature search, we found 12 original articles published 2013-2018. Most studies report deviations related to cerebral perfusion, glucose metabolism, or blood-oxygen-level-dependent responses in frontotemporal areas and/or the thalamus. Studies also report dysfunction in the temporoparietal junction and the oculomotor network that also were related to clinical parameters. We discuss these findings based on recent research on thalamocortical networks and brain stem white matter tracts. The hypothesis of frontotemporal and thalamic involvement in KLS was confirmed, and additional findings in the temporoparietal junction and the oculomotor system suggest a broader network involvement, which can be investigated by future high-resolution and multimodal imaging.

Lifestyle factors and disease-specific differences in subgroups of Swedish Myasthenia Gravis.

PURPOSE: To evaluate disease-specific differences between Myasthenia Gravis (MG) subgroups and compare patterns of lifestyle between MG patients and population controls. METHODS: All MG patients (n = 70) in Jönköping County, Sweden, were invited to answer a disease-specific questionnaire, containing questions about disease-specific data, lifestyle, comorbidity, and mental fatigue. The patients were clinically evaluated. Four hundred age- and gender-matched population controls were invited to answer the nondisease-specific part of the questionnaire. Disease-specific issues were compared between MG subgroups. Lifestyle-related factors and concomitant conditions were compared to the population controls. RESULTS: Forty MG patients and 188 population controls participated in the study. In the late-onset MG (LOMG; N = 18) subgroup, the male predominance was higher than previously reported. In the early-onset MG (EOMG; N = 17) subgroup, time to diagnosis was longer, fatigue was higher, and bulbar weakness was the dominant symptom (65%). Compared to their matched population controls, LOMG patients were more obese (OR = 13.7, P = 0.015), ate less fish (OR = 4.1, P = 0.012), tended to smoke more (OR = 4.1, P = 0.086), and tended to be employed as manual laborers more often (OR = 2.82, P = 0.083). Mental health problems and sickness benefits were more common among MG patients than in controls, and MG patients were less regularly doing focused physical activity. CONCLUSIONS: It is important to consider disease-specific differences when tailoring the management of individual MG patients. There is a need for improved knowledge on how to apply primary and secondary prevention measures to lifestyle disorders in MG patients without risk of deterioration.

Negative interaction between smoking and EBV in the risk of multiple sclerosis: The EnvIMS study.

BACKGROUND: Results from previous studies on a possible interaction between smoking and Epstein-Barr virus (EBV) in the risk of multiple sclerosis (MS) are conflicting. OBJECTIVES: To examine the interaction between smoking and infectious mononucleosis (IM) in the risk of MS. METHODS: Within the case-control study on Environmental Factors In Multiple Sclerosis (EnvIMS), 1904 MS patients and 3694 population-based frequency-matched healthy controls from Norway, Italy, and Sweden reported on prior exposure to smoking and history of IM. We examined the interaction between the two exposures on the additive and multiplicative scale. RESULTS: Smoking and IM were each found to be associated with an increased MS risk in all three countries, and there was a negative multiplicative interaction between the two exposures in each country separately as well as in the pooled analysis ( p = 0.001). Among those who reported IM, there was no increased risk associated with smoking (odds ratio (OR): 0.95, 95% confidence interval (CI): 0.66-1.37). The direction of the estimated interactions on the additive scale was consistent with a negative interaction in all three countries (relative excess risk due to interaction (RERI): -0.98, 95% CI: -2.05-0.15, p = 0.09). CONCLUSION: Our findings indicate competing antagonism, where the two exposures compete to affect the outcome.

New hypothesis on pontine-frontal eye field connectivity in Kleine-Levin syndrome.

Previous studies have indicated involvement of the thalamus and the pons in Kleine-Levin syndrome. In the present study, functional connectivity of the thalamus and the pons was investigated in asymptomatic patients with Kleine-Levin syndrome and healthy controls. Twelve patients and 14 healthy controls were investigated by functional magnetic resonance imaging during rest. Resting state images were analysed using seed regions of interest in the thalamus and the pons. The results showed significantly lower functional connectivity between the pons and the frontal eye field in persons with Kleine-Levin syndrome compared with healthy controls. There were no connectivity differences involving the thalamus. Based on these findings, a relation is proposed between the sleep disorder Kleine-Levin syndrome and cerebral control of eye movements, which in turn is related to visual attention and working memory. This hypothesis has to be tested in future studies of oculomotor control in Kleine-Levin syndrome.

Body size and the risk of multiple sclerosis in Norway and Italy: the EnvIMS study.

BACKGROUND: Obesity may be a risk factor for developing multiple sclerosis (MS). OBJECTIVE: We examined if body size influences the risk of MS in a population-based, case control study. METHODS: A total of 953 cases and 1717 controls from Norway and 707 cases and 1333 controls from Italy reported their body size by choosing a silhouette 1 to 9 (largest) every fifth year from age 5 to 30 and at time of study. The body size-related MS risk was defined by odds ratios (ORs) in logistic regression analyses adjusting for age, smoking and outdoor activity. RESULTS: In Norway a large body size (silhouettes 6-9) compared to silhouette 3 increased the risk of MS, especially at age 25 (OR 2.21; 95% CI 1.09-4.46 for men and OR 1.43; 95% CI 0.90-2.27 for women). When comparing silhouette 9 to 1, we found a significant dose-response from age 10 until age 30 peaking at age 25 (sex-adjusted OR 2.83; 95% CI 1.68-4.78). The association was present for at least 15 years prior to disease onset. No significant associations were found in Italy. CONCLUSIONS: Obesity from childhood until young adulthood is a likely risk factor for MS with a seemingly stronger effect in Norway than in Italy.