Pre-COVID-19 fear conditioning responses predict COVID-19-related anxiety: evidence from an exploratory study.

BACKGROUND AND OBJECTIVES: Fear conditioning represents the prevailing model by which organisms acquire novel threat contingencies. However, little work has been devoted to linking laboratory measures of fear conditioning to the development of real-world threat responses. To fill this gap, the present study explored whether individual differences in a laboratory-based fear conditioning measure could predict levels of COVID-19-related anxiety and avoidance assessed during the first month of the pandemic. DESIGN AND METHOD: Forty-eight undergraduate students who had previously participated in two fear conditioning experiments prior to COVID-19 completed a survey assessing COVID-19 anxiety and avoidance. The fear conditioning experiment involved learning to discriminate between a shape contingently associated with mild electric shock (CS+) and two other shapes that were not (CS-). RESULTS: Increased subjective anxiety to our laboratory CS+ prior to the pandemic predicted heightened COVID-19 anxiety. Follow-up analyses revealed that participants with high COVID-19 anxiety exhibited increased anxiety to CS+ during the final experimental block relative to participants with low COVID-19 anxiety. CONCLUSIONS: Findings from this exploratory study tentatively implicate fear conditioning in the development of real-world fear responses and underscore the importance of investigating laboratory fear conditioning as a predictor of anxiety responses to real-world threats.

Intracranial microhemorrhages in the setting of COVID-19: what we know so far.

BACKGROUND: Diffuse intracranial susceptibility abnormalities have recently been described among patients with coronavirus disease 2019 (COVID-19), although prior studies have consisted of case reports and/or series. This brief literature review seeks to compile and catalogue the available data to elucidate characteristic features of such findings. MATERIALS AND METHODS: Scientific articles and studies on intracranial microhemorrhages in the setting of COVID-19 were searched on PubMed, Google Scholar, and the Cochrane Library. Included studies described intracranial microbleed(s) on magnetic resonance imaging in patients with COVID-19. If multiple patients were described, only patients with intracranial microhemorrhage on magnetic resonance imaging were included for analysis. Patient demographics, severity of illness (e.g. intensive care unit admission and/or intubation), time from diagnosis of COVID-19 to magnetic resonance imaging, and location(s) of any observed microhemorrhages were noted. RESULTS: A total of 39 patients with suspected intracranial microhemorrhages have been described in prior studies. The average age of patients was 64.7 years; 21.9% were women. The average time between COVID-19 diagnosis and magnetic resonance imaging was 31.7 days. All patients in the cohort were admitted to critical care and were either intubated or treated with extracorporeal membrane oxygenation during their clinical course. Microhemorrhages were most commonly located in the subcortical/juxtacortical white matter and corpus callosum. CONCLUSIONS: Intracranial microbleeds are a well-documented finding in patients with severe COVID-19, and are most commonly callosal and subcortical/juxtacortical in location.