Introduction: Patients with migraines, particularly those with auras, may present with stroke. Atrial fibrillation is a known risk factor for stroke. With common pathophysiological factors between migraines and atrial fibrillation, we aimed to clarify the association between migraine and atrial fibrillation in this systematic review and meta-analysis. Materials and Methods: A literature search was conducted in EMBASE, PubMed, Scopus and Cochrane electronic bibliographic databases from inception to 14th June 2021 with the following inclusion criteria: (1) cohort or cross-sectional studies, (2) patients ≥ 18-years-old, (3) studies examining association between atrial fibrillation and migraines. Exclusion criteria were case-control studies, studies including patients with prior diagnosis of atrial fibrillation or non-migrainous headache. The Newcastle Ottawa Scale was used to assess the quality of studies.  Results: 6 studies were included, demonstrating a 1.61% (95% CI 0.51, 3.29) pooled prevalence of atrial fibrillation in migraine with aura and 1.32% (95% CI 0.17, 3.41) in migraine without aura. The total prevalence of atrial fibrillation in migraine was 1.39% (95% CI 0.24, 3.46) overall. Conclusion: Overall, there was a higher prevalence of atrial fibrillation in migraine with aura compared to migraine without aura. Prevalence of atrial fibrillation in migraine patients was low.

Background: Haematological markers such as absolute lymphopenia has been associated with severe COVID-19 infection. However, the described cohorts were generally unwell with a large proportion of patients requiring intensive care stay. It is uncertain if these markers apply to a population with less severe illness. We sought to describe the haematological profile of patients with mild disease with COVID-19 that were admitted to a single centre in Singapore. Methods: We examined 554 consecutive PCR positive SARS-COV-2 patients who were admitted to a single tertiary healthcare institution from Feb 2020 to April 2020 2020. We examined patients based on their haematological profile based on full blood count obtained within 24h of presentation. Results: Patients with pneumonia had higher neutrophil percentages (66.5±11.6 vs 55.2±12.6%, p<0.001), lower absolute lymphocyte count (1.5±1.1 vs 1.9±2.1 x109/L, p<0.011) and absolute eosinophil count (0.2±0.9 vs 0.7±1.8 x109/L, p=0.002). Platelet counts (210±56 vs 230±61, p=0.020) were slightly lower in the group with pneumonia. We did not demonstrate significant differences in the neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio and platelet-lymphocyte ratio in patients with or without pneumonia. Sixty-eight patients (12.3%) had peripheral eosinophilia. This was more common in migrant workers living in dormitories. Conclusion: Neutrophilia and lymphopenia were found to be markers associated with severe COVID-19 illness. We did not find that combined haematological parameters: NLR, MLR and PLR, had any association with disease severity in our cohort of patients with mild-moderate disease. Migrant workers living in dormitories had eosinophilia which may reflect concurrent chronic parasitic infection.