Neuroprotection in acute cerebral ischemia: can we improve clinical outcomes?

Comparison of anesthesia methods for intra-arterial therapy of patients with acute ischemic stroke: an updated meta-analysis and systematic review

OBJECTIVES

Currently, there remains debate regarding the optimal anesthesia approach for patients undergoing intra-arterial therapy for acute ischemic stroke. Therefore, we conducted a comparative analysis to assess the effects of general anesthesia versus non general anesthesia on patient outcomes.

METHODS

The research methodology entailed comprehensive searches of prominent databases such as the Cochrane Library, PubMed, Scopus, and Web of Science, covering the period from January 1, 2010, to March 1, 2024. Data synthesis employed techniques like risk ratio or standardized mean difference, along with 95% confidence intervals. The study protocol was prospectively registered with PROSPERO (CRD42024523079).

RESULTS

A total of 27 trials and 12,875 patients were included in this study. The findings indicated that opting for non-general anesthesia significantly decreased the risk of in-hospital mortality (RR, 1.98; 95% CI: 1.50 to 2.61; p<0.00001; I2 = 20%), as well as mortality within three months post-procedure (RR, 1.24; 95% CI: 1.15 to 1.34; p<0.00001; I2 = 26%), while also leading to a shorter hospitalization duration (SMD, 0.24; 95% CI: 0.15 to 0.33; p<0.00001; I2 = 44%).

CONCLUSION

Ischemic stroke patients who undergo intra-arterial treatment without general anesthesia have a lower risk of postoperative adverse events and less short-term neurological damage. In routine and non-emergency situations, non-general anesthetic options may be more suitable for intra-arterial treatment, offering greater benefits to patients. In addition to this, the neuroprotective effects of anesthetic drugs should be considered more preoperatively and postoperatively.

Tissue plasminogen activator followed by antioxidant-loaded nanoparticle delivery promotes activation/mobilization of progenitor cells in infarcted rat brain

Inherent neuronal and circulating progenitor cells play important roles in facilitating neuronal and functional recovery post stroke. However, this endogenous repair process is rather limited, primarily due to unfavorable conditions in the infarcted brain involving reactive oxygen species (ROS)-mediated oxidative stress and inflammation following ischemia/reperfusion injury. We hypothesized that during reperfusion, effective delivery of antioxidants to ischemic brain would create an environment without such oxidative stress and inflammation, thus promoting activation and mobilization of progenitor cells in the infarcted brain. We administered recombinant human tissue-type plasminogen activator (tPA) via carotid artery at 3 h post stroke in a thromboembolic rat model, followed by sequential administration of the antioxidants catalase (CAT) and superoxide dismutase (SOD), encapsulated in biodegradable nanoparticles (nano-CAT/SOD). Brains were harvested at 48 h post stroke for immunohistochemical analysis. Ipsilateral brain slices from animals that had received tPA + nano-CAT/SOD showed a widespread distribution of glial fibrillary acidic protein-positive cells (with morphology resembling radial glia-like neural precursor cells) and nestin-positive cells (indicating the presence of immature neurons); such cells were considerably fewer in untreated animals or those treated with tPA alone. Brain sections from animals receiving tPA + nano-CAT/SOD also showed much greater numbers of SOX2- and nestin-positive progenitor cells migrating from subventricular zone of the lateral ventricle and entering the rostral migratory stream than in t-PA alone treated group or untreated control. Further, animals treated with tPA + nano-CAT/SOD showed far fewer caspase-positive cells and fewer neutrophils than did other groups, as well as an inhibition of hippocampal swelling. These results suggest that the antioxidants mitigated the inflammatory response, protected neuronal cells from undergoing apoptosis, and inhibited edema formation by protecting the blood-brain barrier from ROS-mediated reperfusion injury. A longer-term study would enable us to determine if our approach would assist progenitor cells to undergo neurogenesis and to facilitate neurological and functional recovery following stroke and reperfusion injury.