Infectious agents and Alzheimer's disease.

Alzheimer's disease (AD) is the leading cause of dementia worldwide. Individuals affected by the disease gradually lose their capacity for abstract thinking, understanding, communication and memory. As populations age, declining cognitive abilities will represent an increasing global health concern. While AD was first described over a century ago, its pathogenesis remains to be fully elucidated. It is believed that cognitive decline in AD is caused by a progressive loss of neurons and synapses that lead to reduced neural plasticity. AD is a multifactorial disease affected by genetic and environmental factors. The molecular hallmarks of AD include formation of extracellular ß amyloid (Aß) aggregates, neurofibrillary tangles of hyperphosphorylated tau protein, excessive oxidative damage, an imbalance of biothiols, dysregulated methylation, and a disproportionate inflammatory response. Recent reports have shown that viruses (e.g., Herpes simplex type 1, 2, 6A/B; human cytomegalovirus, Epstein-Barr virus, hepatitis C virus, influenza virus, and severe acute respiratory syndrome coronavirus 2, SARS-CoV-2), bacteria (e.g., Treponema pallidum, Borrelia burgdorferi, Chlamydia pneumoniae, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, Aggregatibacter actinomycetemcmitans, Eikenella corrodens, Treponema denticola, and Helicobacter pylori), as well as eukaryotic unicellular parasites (e.g., Toxoplasma gondii) may factor into cognitive decline within the context of AD. Microorganisms may trigger pathological changes in the brain that resemble and/or induce accumulation of Aß peptides and promote tau hyperphosphorylation. Further, the mere presence of infectious agents is suspected to induce both local and systemic inflammatory responses promoting cellular damage and neuronal loss. Here we review the influence of infectious agents on the development of AD to inspire new research in dementia based on these pathogens.

Costs of Stroke and Incidence of First Diagnosis of Atrial Fibrillation at Time of Stroke. Neurology Ward Hospital Poznan, Poland 2018.

Stroke is a major cause of morbidity in industrialized countries, representing 8% of total deaths across Europe in 2017. It is also a very costly disorder, frequently caused by atrial fibrillation. We aimed to calculate the cost of stroke hospitalization in 2018 in Poznan (Poland). We also intended to present patients with the first AF diagnosis at the time of stroke. The study was conducted from January 2019 to July 2020. Data were obtained from hospital records and from the hospital accounting department. Out of 164 patients included in the study, 41 had AF and in 18 cases AF was first diagnosed at the time of stroke. The cost of hospitalization in Poznan was EUR 139,257.21 (x¯= EUR 849.13). Among those with concomitant AF, the general cost of inpatient care was EUR 33,859.18 (x¯= EUR 825.83). Considering those who had AF first diagnosed during hospitalization the cost was EUR 16,248.97 (x¯= EUR 906.24). Stroke is associated with high costs of inpatient care, which turned out to be higher among those with AF first diagnosed at the time of stroke. The number of patients who used oral anticoagulants at the time of admission was relatively low. The most frequently used NOAC was dabigatran.