Amyotrophic lateral sclerosis caused by the expansion in Norway - prevalence, ancestry, clinical characteristics and sociodemographic status.

Objective: The most common genetic cause of amyotrophic lateral sclerosis (ALS) is the expansion. A high incidence of this expansion has been detected in Sweden and Finland. This Norwegian population-based study aimed to identify the prevalence, geographic distribution, ancestry, and relatedness of ALS patients with a expansion (C9).

Repeat expansions in , , and in Norwegian patients diagnosed with amyotrophic lateral sclerosis.

Genetic repeat expansions cause neuronal degeneration in amyotrophic lateral sclerosis as well as other neurodegenerative disorders such as spinocerebellar ataxia, Huntington's disease and Kennedy's disease. Repeat expansions in the same gene can cause multiple clinical phenotypes. We aimed to characterize repeat expansions in a Norwegian amyotrophic lateral sclerosis cohort.

Incidence of cancer in multiple sclerosis before and after the treatment era- a registry- based cohort study.

Background: Whether disease-modifying therapies (DMTs) influence cancer in multiple sclerosis (MS) is uncertain.

Objectives: Assess incidence of cancer diagnosis among Norwegian MS patients compared to the general population in 1953 to 1995 and 1996 to 2017-reflecting era before and after introduction of DMTs.

Methods: We performed a nationwide cohort study comprising 6949 MS patients and 37,922 controls, matched on age, sex and county.

Risk of cancer among multiple sclerosis patients, siblings, and population controls: A prospective cohort study.

Background: Risk of cancer in multiple sclerosis (MS) patients compared to their siblings is unknown.

Objective: The objective was to prospectively investigate the risk of cancer among MS patients compared to siblings without MS and to population controls.

Methods: We retrieved data on MS patients born between 1930 and 1979 from the Norwegian Multiple Sclerosis Registry and population studies and on cancer diagnosis from the Cancer Registry of Norway.

Vitamin D supplementation and neurofilament light chain in multiple sclerosis.

Objectives: The effect of vitamin D supplementation on the disease course of multiple sclerosis (MS) is not established. Neurofilament light chain (NFL) is a sensitive marker of axonal degeneration. The aim of this study was to establish whether high-dose vitamin D supplementation reduces serum levels of NFL.

High dose vitamin D supplementation does not affect biochemical bone markers in multiple sclerosis - a randomized controlled trial.

Background: People with multiple sclerosis have high risk of osteoporosis and fractures. A poor vitamin D status is a risk factor for MS, and vitamin D supplementation has been recommended both to prevent MS progression and to maintain bone health.

Methods: We assessed the effect of 20,000 IU vitamin D weekly compared to placebo on biochemical markers of bone metabolism in 68 persons with relapsing remitting multiple sclerosis.

Full Implementation of Screening for Nutritional Risk and Dysphagia in an Acute Stroke Unit: A Clinical Audit.

Background And Purpose: In patients with acute stroke, undernutrition and aspiration pneumonia are associated with increased mortality and length of hospital stay. Formal screening for nutritional risk and dysphagia helps to ensure optimal nutritional management in all patients with stroke and to reduce the risk of aspiration in patients with dysphagia. We developed a national guideline for nutritional and dysphagia screening in acute stroke, which was introduced in our stroke unit on June 1, 2012.

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.

Effect of high-dose vitamin D supplementation on antibody responses against Epstein-Barr virus in relapsing-remitting multiple sclerosis.

Background: Elevated antibody levels against Epstein-Barr virus (EBV) and a poor vitamin D status are environmental factors that may interact in relapsing-remitting multiple sclerosis (RRMS) aetiology.

Objectives: To examine effects of high-dose oral vitamin D supplementation on antibody levels against EBV nuclear antigen 1 (EBNA1) in RRMS.

Methods: Serum 25-hydroxyvitamin D (25(OH)D) and immunoglobulin G antibody levels against EBNA1 (whole protein and amino acid 385-420 fragment), EBV viral capsid antigen (VCA), cytomegalovirus (CMV) and varicella zoster virus (VZV) were measured in 68 RRMS patients enrolled in a 96-week randomised double-blinded placebo-controlled clinical trial of oral vitamin D supplementation (20,000 IU/week) (NCT00785473).

Level of education and multiple sclerosis risk over a 50-year period: Registry-based sibling study.

Background: The conflicting results from studies on socioeconomic status (SES) and multiple sclerosis (MS) risk might be due to a change in the distribution of environmental exposures over time or to methodological limitations in previous research.

Objective: To examine the association between SES and MS risk during 50 years.

Methods: We included patients registered in Norwegian MS registries and prevalence studies born between 1930 and 1979, and identified their siblings and parents using the Norwegian Population Registry.

Vitamin D supplementation and systemic inflammation in relapsing-remitting multiple sclerosis.

Observational studies have suggested that vitamin D may reduce inflammation in relapsing-remitting multiple sclerosis (RRMS), but this has not been clearly confirmed in randomized controlled trials. To further explore the possible anti-inflammatory effects of vitamin D in RRMS, we examined the effect of high-dose oral vitamin D3 on eleven markers of systemic inflammation in 68 RRMS patients enrolled in a double-blinded randomized placebo-controlled trial of vitamin D3 supplementation (20,000 IU/week) (NCT00785473). Serum inflammation markers and 25-hydroxyvitamin D (25(OH)D) were measured at baseline and week 96, and no restrictions were set on additional standard immunomodulatory treatment for RRMS.

Level of education and multiple sclerosis risk after adjustment for known risk factors: The EnvIMS study.

Background: Several recent studies have found a higher risk of multiple sclerosis (MS) among people with a low level of education. This has been suggested to reflect an effect of smoking and lower vitamin D status in the social class associated with lower levels of education.

Objective: The objective of this paper is to investigate the association between level of education and MS risk adjusting for the known risk factors smoking, infectious mononucleosis, indicators of vitamin D levels and body size.

The EnvIMS Study: Design and Methodology of an International Case-Control Study of Environmental Risk Factors in Multiple Sclerosis.

Background: Multiple sclerosis (MS) is a chronic disease of the central nervous system, often resulting in significant neurological disability. The causes of MS are not known; however, the incidence of MS is increasing, thereby suggesting that changes in lifestyle and/or environmental factors may be responsible. On this background, the Environmental Risk Factors in MS Study or EnvIMS study was designed to further explore the etiology of MS.

Timing of use of cod liver oil, a vitamin D source, and multiple sclerosis risk: The EnvIMS study.

Background: Low vitamin D levels have been associated with an increased risk of multiple sclerosis (MS), although it remains unknown whether this relationship varies by age.

Objective: The objective of this paper is to investigate the association between vitamin D3 supplementation through cod liver oil at different postnatal ages and MS risk.

Methods: In the Norwegian component of the multinational case-control study Environmental Factors In Multiple Sclerosis (EnvIMS), a total of 953 MS patients with maximum disease duration of 10 years and 1717 controls reported their cod liver oil use from childhood to adulthood.

Month of birth and risk of multiple sclerosis: confounding and adjustments.

A month of birth effect on multiple sclerosis (MS) risk has been reported from different countries. Recent critics have suggested that this finding is caused by confounding and that adequately adjusting for year and place of birth would markedly reduce this effect. All inhabitants in Norway are registered in the Norwegian Population Registry (Statistics Norway), making this an ideal area for performing adjusted analyses.

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.

Sun exposure and multiple sclerosis risk in Norway and Italy: The EnvIMS study.

Objectives: The objective of this paper is to estimate the association between multiple sclerosis (MS) and measures of sun exposure in specific age periods in Norway and Italy.

Methods: A total of 1660 MS patients and 3050 controls from Italy and Norway who participated in a multinational case-control study (EnvIMS) reported sun habits during childhood and adolescence.

Results: A significant association between infrequent summer outdoor activity and increased MS risk was found in Norway and in Italy.

Season of infectious mononucleosis and risk of multiple sclerosis at different latitudes; the EnvIMS Study.

Background: Seasonal fluctuations in solar radiation and vitamin D levels could modulate the immune response against Epstein-Barr virus (EBV) infection and influence the subsequent risk of multiple sclerosis (MS).

Methods: Altogether 1660 MS patients and 3050 controls from Norway and Italy participating in the multinational case-control study of Environmental Factors In Multiple Sclerosis (EnvIMS) reported season of past infectious mononucleosis (IM).

Results: IM was generally reported more frequently in Norway (p=0.

Sex ratio of multiple sclerosis in persons born from 1930 to 1979 and its relation to latitude in Norway.

A remarkable increase in female to male ratio of multiple sclerosis (MS) is recognised in high incidence areas. Norway is a high-risk area for MS, spanning latitudes 58-71 °N. We studied whether the sex ratio has changed over time and whether it differs by clinical phenotype or by latitude.

Month of birth as a latitude-dependent risk factor for multiple sclerosis in Norway.

Objective: We aimed to determine if the risk of Multiple Sclerosis (MS) is associated with month of birth in Norway and to explore a possible latitudinal gradient.

Methods: All patients with MS born between 1930 and 1979 registered in the Norwegian MS Registry or ascertained in Norwegian prevalence studies were included (n = 6649). The latitude gradient was divided in Southern, Middle and Northern Norway, according to the estimated regional yearly mean vitamin D effective UV dose.

Vitamin D in multiple sclerosis: implications for assessment and treatment.

Epidemiological and experimental evidence suggest that a poor vitamin D status is associated with an increased risk of developing multiple sclerosis (MS), and also an unfavorable disease course. Vitamin D may exert relevant effects both on the immune system and on resident cells within the CNS. The data from clinical trials is, however, restricted, and does not allow any conclusion on the effect of high-dose vitamin D supplementation on disease course.