Rapid Activation of Neuroinflammation in Stroke: Plasma and Extracellular Vesicles Obtained on a Mobile Stroke Unit.

BACKGROUND: Neuroinflammation is ubiquitous in acute stroke and worsens outcome. However, the precise timing of the inflammatory response is unknown, hindering the design of acute anti-inflammatory therapeutic interventions. We sought to identify the onset of the neuroinflammatory cascade using a mobile stroke unit. METHODS: The study is a proof-of-concept, cohort investigation of ultra-early blood- and extracellular vesicle-derived markers of neuroinflammation and outcome in acute stroke. Blood was obtained, prehospital, on an mobile stroke unit. Outcomes were biomarker concentrations, modified Rankin Scale score, and National Institutes of Health Stroke Scale score. RESULTS: Forty-one adults were analyzed, including 15 patients treated on the mobile stroke unit between August 2021 and April 2022, and 26 healthy controls to establish biomarker reference levels. Median patient age was 74 (range, 36-97) years, 60% were female, and 80% White. Ten (67%) were diagnosed as stroke, with 8 (53%) confirmed and 2 likely transient ischemic attack or stroke averted by thrombolysis; 5 were stroke mimics. For strokes, median initial National Institutes of Health Stroke Scale score was 11 (range, 4-19) and 6 (75%) received tPA (tissue-type plasminogen activator). Blood was obtained a median of 58 (range, 36-133) minutes after symptom onset. Within 36 minutes after stroke, plasma IL-6 (interleukin-6), neurofilament light chain, UCH-L1 (ubiquitin C-terminal hydrolase L1), and GFAP (glial fibrillary acidic protein) were elevated by as much as 10 times normal. In EVs, MMP-9 (matrix metalloproteinase-9), CXCL4 (chemokine (C-X-C motif) ligand 4), CRP (C-reactive protein), IL-6, OPN (osteopontin), and PECAM1 (platelet and endothelial cell adhesion molecule 1) were elevated. Inflammatory markers increased rapidly in the first 2 hours and continued rising for 24 hours. CONCLUSIONS: The neuroinflammatory cascade was found to be activated within 36 to 133 minutes after stroke and progresses rapidly. This is earlier than observed previously in humans and suggests injury from neuroinflammation occurs faster than had been surmised. These findings could inform development of acute immunomodulatory stroke therapies and lead to new diagnostic tools and improved outcomes.

Effects of olfactory stimulus on group performance and individual stress responses in university students.

Group work is essential in professional settings to encourage effective communication and optimize outcomes. Stress can reduce teamwork effectiveness and aromatherapy might be able to reduce feelings of stress/anxiety in individuals. However, it is unclear if aromatherapy impacts stress levels or performance during group activities. Therefore, we examined if essential oil exposure impacted stress responses and performance of individuals and groups during a team-based task involving a challenging medical decision. Subjects (n = 36) were part of a 3-person group (12 groups total) that completed a timed moral reasoning dilemma wearing a mask that contained a purported stimulatory essential oil (peppermint), a purported relaxing essential oil (lavender) or masks that contained neither odor (3 groups/mask type). Heart rate (HR) responses were recorded continuously before, during and after the task. The time to complete the task, decision making during the task, and subject's perceptions of the task were also recorded. Control subjects and subjects exposed to peppermint demonstrated a significant stress-induced increase in HR during the group task. However, subjects exposed to lavender demonstrated a significantly attenuated HR. Subjects in the control group who perceived high stress levels during the task demonstrated further elevations in HR than those not reporting stress, however, this pattern was not observed in subjects exposed to either essential oil. Groups did not differ in the time required to complete the task although only the groups exposed to lavender used decision making consistent with medical practice. Therefore, exposure to lavender was associated with differential physiological responses during a stressful group task, potentially due to olfactory system stimulation of anxiolytic and/or trust promoting central nervous system pathways. Aromatherapy might be a useful tool in group settings to mitigate the impact of stress and improve group performance.