RESUMEN
Rationale and objectives: This study examined the brain effects of mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection which are incompletely understood. Our objective was to ascertain within-person changes associated with mild coronavirus disease 2019 (COVID-19) in otherwise healthy adults. Materials and methods: We leveraged existing pre-pandemic baseline neuroimaging and neurocognitive data, and collected follow-up data from uninfected controls and individuals with prior mild COVID-19, during December 2020 and January 2021, when vaccines were not yet available. We compared change during follow-up in patients (n = 5) versus controls (n = 15). Results: We identified a decrease of intracellular volume fraction (ICVF), decrease of isotropic volume fraction (ISO) and decrease of orientation dispersion index (ODI) in multiple inferior frontal regions of interest in COVID-19 patients; this longitudinal change was significantly different from the control group which demonstrated increases in equivalent measures. This pattern suggests injury with neuronal loss and/or inflammation as underlying mechanisms. Neurocognitive studies identified a pattern of cognitive decline (processing speed, executive function, verbal learning, working memory) in patients, that did not reach significance. Conclusion: Our pilot data suggests that mild COVID-19 may result in brain pathology and impact neurocognitive function in younger adults in a manner parallel to prior findings in older individuals. Though findings may not generalize to other SARS-CoV-2 variants, larger longitudinal studies of mild COVID-19 should be undertaken to understand the potential clinical implications of these findings over the longer term.
RESUMEN
Hormonal contraception has been widely prescribed for decades. Although safety and efficacy are well-established, much uncertainty remains regarding brain effects of hormonal contraception. We systematically review human and animal studies on the brain effects of hormonal contraception which employed neuroimaging techniques such as MRI, PET and EEG, as well as animal studies which reported on neurotransmitter and other brain biochemical effects. We screened 1001 articles and ultimately extracted data from 70, comprising 51 human and 19 animal studies. Of note, there were no animal studies which employed structural or functional MRI, MRS or PET. In summary, our review shows hormonal contraceptive associations with changes in the brain have been documented. Many questions remain and more studies are needed to describe the effects of hormonal contraception on the brain.