We aimed to investigate the influence of environmental risk factors for multiple sclerosis (MS) in different genetic contexts, and study if interactions between environmental factors and human leucocyte antigen (HLA) genes differ in magnitude according to heterozygocity and homozygocity for . Using population-based case-control studies (6985 cases, 6569 controls), subjects with different genotypes and smoking, EBNA-1 status and adolescent Body Mass status, were compared regarding MS risk, by calculating OR with 95% CI employing logistic regression. The interaction between different genotypes and each environmental factor was evaluated on the additive scale. The effect of each allele on MS risk was additive on the log-odds scale for each additional allele. Interaction between and each assessed environmental factor was of similar magnitude regardless of the number of alleles, although ORs were affected. When any of the environmental factors were present in carriers without the protective allele, a three-way interaction occurred and rendered high ORs, especially among homozygotes (OR 20.0, 95% CI 13.1 to 30.5 among smokers, OR 21.9, 95% CI 15.0 to 31.8 among those with elevated EBNA-1 antibody levels, and OR 44.3, 95% CI 13.5 to 145 among those who reported adolescent overweight/obesity). The strikingly increased MS risk among homozygotes exposed to any of the environmental factors is a further argument in favour of these factors acting on immune-related mechanisms. The data further reinforce the importance of preventive measures, in particular for those with a genetic susceptibility to MS. The strikingly increased MS risk among DRB*1501 homozygotes exposed to any of the environmental factors is a further argument in favour of these factors acting on immune-related mechanisms. The data further reinforce the importance of preventive measures, in particular for those with a genetic susceptibility to MS. To identify early clinical and paraclinical factors that may help predict later conversion to multiple sclerosis (MS) in patients presenting with isolated myelitis (ie, 'transverse myelitis' without clinical or radiological evidence of inflammation/demyelination elsewhere in the central nervous system). In this retrospective cohort study, we included patients with isolated myelitis who were followed clinically and radiologically at our specialised myelopathy clinic. We excluded patients with MS at the onset, aquaporin-4-IgG seropositivity, myelin oligodendrocyte glycoprotein-IgG seropositivity or other identified aetiology. Logistic regression was used to identify factors predictive of conversion to MS (defined by the 2017 McDonald criteria). We included 100 patients, followed for a median of 4.3 years. Conversion to MS occurred in 25 of 77 patients (32%) with short-segment myelitis (longest lesion spanning <3 vertebral segments on MRI) as compared with 0 of 23 patients (0%) with longitudinally extensive myelitis (p=0.002). Among patients with short-segment myelitis, factors identified as highly predictive of conversion to MS using multivariate logistic regression included cerebrospinal fluid (CSF)-restricted oligoclonal bands (OCB) (OR (OR) 9.2, 95% CI 2.1 to 41.0, p=0.004), younger age (OR 1.1 for each year younger, 95% CI 1.0 to 1.1, p=0.04) and longer follow-up (OR 1.3 for each year longer, 95% CI 1.0 to 1.6, p=0.04). Conversion to MS occurred at a median of 2.8 years after myelitis onset. Short-segment MRI cord lesion(s), CSF-restricted OCB, younger age and longer follow-up are all factors predictive of conversion to MS in patients presenting with isolated myelitis. Short-segment MRI cord lesion(s), CSF-restricted OCB, younger age and longer follow-up are all factors predictive of conversion to MS in patients presenting with isolated myelitis. Venous thromboembolism is common in patients with solid malignancies and brain metastases. Whether to anticoagulate such patients is controversial given the possibility of intracerebral haemorrhage (ICH). We evaluated the added risk of ICH in patients with brain metastases receiving therapeutic anticoagulation. We performed a matched, retrospective cohort study of 291 patients (100 receiving therapeutic anticoagulation vs 191 controls) with brain metastases managed at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 1998 and 2015. For each patient, all MRI studies of the brain were reviewed to identify ICH. Propensity score matching and multivariable Cox regression were used to mitigate confounding. The risk of ICH was comparable in patients receiving anticoagulation versus controls preanticoagulation Postanticoagulation, we observed significant or borderline-significant associations between anticoagulation and development of any ICH (HR 1.31, 95% CI 0.96 to 1.79, p=0.09), ICH as iden of intracerebral bleeding should be considered on an individual basis among such patients. Traumatic brain injury (TBI) is a leading cause of epilepsy. Our aim was to characterise the risk of epilepsy in adults after hospitalisation for TBI. Register-based cohort study. All individuals aged 18-100 with a first hospitalisation for TBI in the comprehensive national patient register in Sweden between 2000 and 2010 (n=111 947) and three controls per exposed (n=325 881), matched on age and sex were included. Exposed individuals were categorised according to TBI severity. Kaplan-Meier curves were used to estimate the risk of epilepsy and Cox regression to estimate the hazard in univariate or multivariate regression. The 10-year risk of epilepsy was 12.9% (95% CI 11.7% to 14.1%) for focal cerebral injuries, 8.1% (95% CI 7.5% to 8.7%) for diffuse cerebral injuries, 7.3% (95% CI 6.9% to 7.7%) for extracerebral injuries, 2.8% (95% CI 2.4% to 3.2%) for skull fractures and 2.6% (95% CI 2.4% to 2.8%) for mild TBI. The risk of epilepsy after any TBI was 4.0% (95% CI 3.8% to 4.2%). The corresponding 10-year risk for controls was 0.9% (95% CI 0.9% to 0.9%). The HR increased with a more severe injury, from 3.0 (95% CI 2.8 to 3.2) for mild injury to 16.0 (95% CI 14.5 to 17.5) for focal cerebral injury. Multivariable analyses identified central nervous system (CNS) comorbidities as risk factors, but TBI remained significant also after adjustment for these. https://www.selleckchem.com/products/larotrectinib.html Other identified risk factors were male sex, age, mechanical ventilation and seizure during index hospitalisation. The risk of post-traumatic epilepsy is considerable, also with adjustments for CNS comorbidities. The risk of post-traumatic epilepsy is considerable, also with adjustments for CNS comorbidities.