Association of postoperative covert stroke and cognitive dysfunction among elderly patients undergoing non-cardiac surgery: protocol for a prospective cohort study (PRECISION study)

Neurofilament Light Chain: A Candidate Biomarker of Perioperative Stroke

Perioperative stroke is defined as a brain infarction of ischemic or hemorrhagic etiology that occurs during surgery or within 30 days after surgery. However, identifying perioperative stroke is challenging. Thus, the discovery and validation of neurological biomarkers for perioperative stroke are urgently needed. Neurofilament forms part of the neuronal cytoskeleton and is exclusively expressed in neurons. After disease-related neuroaxonal damage occurs, neurofilament light chain protein is released into the cerebrospinal fluid and blood. Blood neurofilament light chain has recently been shown to serve as a potential marker of interest during the perioperative period. Therefore, the aim of the present review was to give an overview of the current understanding and knowledge of neurofilament light chain as a potential biomarker of perioperative stroke.

Influence of Anemia on Postoperative Cognitive Function in Patients Undergo Hysteromyoma Surgery

Cognitive dysfunction is a common disease in aging population. This study aims to compare the influence of different degrees of anemia on the cognitive function of patients undergo hysteromyoma surgery. Sixty-one patients aged 18-60 years who underwent uterine fibroid surgery in the Second Affiliated Hospital of Shantou University Medical College from March 2019 to December 2020 were selected for this study. Patients were divided into three groups: group normal (Group N, patients have no anemia), group of mild anemia (Group Mi, patients have mild anemia) and group of moderate anemia (Group Mo, patients had moderate anemia). Combined spinal and epidural anesthesia were administered. Cognitive function tests were performed 1 day before the surgery and repeated at the 5th and 30th days after surgery. Peripheral venous blood samples from patients were collected before the surgery, right after surgery and at the 24th and 72nd hours after surgery. The contents of S-100β, IL-6, TNF-α and IL-1β in serum samples were determined by ELISA. It was found that there were no significant differences in general characteristics of patients among Group N, Group Mi and Group Mo (p > 0.05). Nine patients developed postoperative cognitive dysfunction after surgery, and the incidence was 14.75% (9/61). The incidence of postoperative cognitive dysfunction (POCD) was 40% in Group Mo, which was higher than that in Group N and Group Mi. The difference was statistically significant (p < 0.05). Inflammatory factors in patients with POCD were higher in post-surgery than before-surgery (p < 0.05), while there was no statistical significance in the difference of inflammatory factors of patients without POCD before and after surgery (p > 0.05). Taken together, this study suggested that moderate anemia could be a risk factor of POCD in patients undergoing hysteromyoma surgeries. This study will help surgeons developing measures for preventing the occurrence of POCD.

Cognitive declines after perioperative covert stroke: Recent advances and perspectives

PURPOSE OF REVIEW

With the aging of the population, there are increasing number of aged patients who require surgical interventions. Perioperative covert stroke is emerging as an important health threat and social burden that could affect patients' long-term neurological outcomes.

RECENT FINDINGS

Recent findings of the association between perioperative covert stroke with long-term cognitive declines of surgical patients highlighted the significance of the silent cognitive function killer-perioperative covert stroke. Considering the devastating long-term consequence of the asymptomatic covert stroke, early diagnosis and prevention are turning out as crucial problems to tackle. The evolving brain imaging techniques, such as multimodel MRI sequences are not only able to detect early, small and subtle injuries of the acute ischemic lesions, but also quite advantageous in capturing the preexisting brain vascular diseases that are considered as important risk factors of covert stroke. However, effective predictive markers are still lacking to identify high risk patients for perioperative covert stroke, rendering an unmet need of investigations in this regard.

SUMMARY

The present review will summarize recent findings in perioperative covert stroke and highlight future perspectives of its early diagnosis and the impact of postoperative cognitive impairments.