Novel Treatments for Transient Ischemic Attack and Acute Ischemic Stroke

Hemiplegia in acute ischemic stroke: A comprehensive review of case studies and the role of intravenous thrombolysis and mechanical thrombectomy

Acute ischemic stroke is a significant health concern worldwide, often leading to long-term disability and decreased quality of life. Rapid and appropriate treatment is crucial for achieving optimal outcomes in these patients. Intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) are two commonly used interventions for acute ischemic stroke, but their effectiveness in improving neurological symptoms and functional outcomes in patients with hemiplegia remains uncertain. The aim of this work was to evaluate the impact of IVT and MT within a 4.5-h time frame on patients with acute ischemic stroke and hemiplegia. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies that assessed the impact of IVT and MT within 4.5-h on hemiplegia in patients with an acute ischemic stroke were included. Data were extracted and analyzed to determine the overall effects of these interventions. Most included case reports indicate positive outcomes in terms of neurological symptom improvement and functional recovery in patients with hemiplegia after receiving IVT and MT within the specified time frame. However, the heterogeneity among the patients and the limited use of IVT due to contraindications posed challenges in determining the most effective treatment option. The findings from the included studies demonstrate that both interventions led to a decrease in National Institutes of Health Stroke Scale scores, indicating an improvement in neurological symptoms. The results highlight the beneficial effects of early thrombolytic interventions and MT on the neurological status and functional outcomes of patients with an acute ischemic stroke.

Targeting the interaction of GABAB receptors with CaMKII with an interfering peptide restores receptor expression after cerebral ischemia and inhibits progressive neuronal death in mouse brain cells and slices

Cerebral ischemia is the leading cause for long-term disability and mortality in adults due to massive neuronal death. Currently, there is no pharmacological treatment available to limit progressive neuronal death after stroke. A major mechanism causing ischemia-induced neuronal death is the excessive release of glutamate and the associated overexcitation of neurons (excitotoxicity). Normally, GABA_B receptors control neuronal excitability in the brain via prolonged inhibition. However, excitotoxic conditions rapidly downregulate GABA_B receptors via a CaMKII-mediated mechanism and thereby diminish adequate inhibition that could counteract neuronal overexcitation and neuronal death. To prevent the deleterious downregulation of GABA_B receptors, we developed a cell-penetrating synthetic peptide (R1-Pep) that inhibits the interaction of GABA_B receptors with CaMKII. Administration of this peptide to cultured cortical neurons exposed to excitotoxic conditions restored cell surface expression and function of GABA_B receptors. R1-Pep did not affect CaMKII expression or activity but prevented its T286 autophosphorylation that renders it autonomously and persistently active. Moreover, R1-Pep counteracted the aberrant downregulation of G protein-coupled inwardly rectifying K⁺ channels and the upregulation of N-type voltage-gated Ca²⁺ channels, the main effectors of GABA_B receptors. The restoration of GABA_B receptors activated the Akt survival pathway and inhibited excitotoxic neuronal death with a wide time window in cultured neurons. Restoration of GABA_B receptors and neuroprotective activity of R1-Pep was verified by using brain slices prepared from mice after middle cerebral artery occlusion (MCAO). Treatment with R1-Pep restored normal GABA_B receptor expression and GABA receptor-mediated K⁺ channel currents. This reduced MCAO-induced neuronal excitability and inhibited neuronal death. These results support the hypothesis that restoration of GABA_B receptor expression under excitatory conditions provides neuroprotection and might be the basis for the development of a selective intervention to inhibit progressive neuronal death after ischemic stroke.

Comparing Treatment Outcomes Between In-Hospital and Emergency Department Management of Patients With Transient Ischemic Attacks

Introduction

A transient ischemic attack (TIA) is a medical emergency, as it is a sudden neurological episode caused by ischemia in a vascular territory in the brain, which lasts less than one hour. TIA definition has shifted from time-based to tissue-based according to modern literature. It is considered a warning sign for an impending stroke. Symptoms could range from weakness on one side of the body, diaphoresis, to slurred speech. In this study, we examined the differences in health outcomes, when patients diagnosed with TIA are treated and discharged home from the ED, versus when admitted to the hospital for additional care.

Methods

This is a descriptive and retrospective study. We examined all patients’ encounters from January 1, 2018 to December 31, 2019 at four emergency department locations. The cohort compared patients diagnosed with a TIA who takes medications (anti-lipid, antiplatelet drugs) versus patients diagnosed with a TIA who are not on any preventive medication. We compared the hospital readmission rate between these two group of patients and the need for additional medical treatments. Our study also considered hospital length of stay (LOS), admission rate, and its impact on patients with comorbidities.

Results

There were 983 patients included in the study. The patients on TIA prophylactic medications prior to coming to the ED made up (60.7%), and (51.2%) in this group required additional medications during hospital admission. The remaining 162 (39.3%), p=0.001 patients, were not on TIA prophylactic medications prior to presenting in the ED. The patients who required additional medications while in the ED were significantly older (mean +/-SD, 68.6 +/-14.0 years versus 62.18 +/- 17.4 years, p=0.001). Following a multivariate analysis, age greater than 60 (CI: 3.52-3.91, p=0.001) and results of the head CT/MRI investigations for any signs of neurological damage, were all found to be independent predictors of longer hospital stay and treatment outcomes. There were no significant differences in the treatment outcome for patients with TIA based on longer hospital stay and extra medication administration in the ED.

Conclusion

In our study, we observed that approximately, 75% of the patients who were on TIA prophylactic medications prior to presenting in the ED with symptoms of TIA were admitted to the hospital for further monitoring, compared to other group of patients who were not on TIA medications. We did also noted that there were no differences in mortality outcome between patients treated and discharged from the ED, versus patients admitted to the hospital for additional treatment. Lastly, patients who are 68 years and older, made up two-thirds of patient population admitted in the hospital and required additional medications, compared to younger patients.