Diagnosis of Acute Ischemic Stoke

Evaluation of Advanced Artificial Intelligence Algorithms' Diagnostic Efficacy in Acute Ischemic Stroke: A Comparative Analysis of ChatGPT-4o and Claude 3.5 Sonnet Models

Background/Objectives: Acute ischemic stroke (AIS) is a leading cause of mortality and disability worldwide, with early and accurate diagnosis being critical for timely intervention and improved patient outcomes. This retrospective study aimed to assess the diagnostic performance of two advanced artificial intelligence (AI) models, Chat Generative Pre-trained Transformer (ChatGPT-4o) and Claude 3.5 Sonnet, in identifying AIS from diffusion-weighted imaging (DWI). Methods: The DWI images of a total of 110 cases (AIS group: n = 55, healthy controls: n = 55) were provided to the AI models via standardized prompts. The models' responses were compared to radiologists' gold-standard evaluations, and performance metrics such as sensitivity, specificity, and diagnostic accuracy were calculated. Results: Both models exhibited a high sensitivity for AIS detection (ChatGPT-4o: 100%, Claude 3.5 Sonnet: 94.5%). However, ChatGPT-4o demonstrated a significantly lower specificity (3.6%) compared to Claude 3.5 Sonnet (74.5%). The agreement with radiologists was poor for ChatGPT-4o (κ = 0.036; %95 CI: -0.013, 0.085) but good for Claude 3.5 Sonnet (κ = 0.691; %95 CI: 0.558, 0.824). In terms of the AIS hemispheric localization accuracy, Claude 3.5 Sonnet (67.2%) outperformed ChatGPT-4o (32.7%). Similarly, for specific AIS localization, Claude 3.5 Sonnet (30.9%) showed greater accuracy than ChatGPT-4o (7.3%), with these differences being statistically significant (p < 0.05). Conclusions: This study highlights the superior diagnostic performance of Claude 3.5 Sonnet compared to ChatGPT-4o in identifying AIS from DWI. Despite its advantages, both models demonstrated notable limitations in accuracy, emphasizing the need for further development before achieving full clinical applicability. These findings underline the potential of AI tools in radiological diagnostics while acknowledging their current limitations.

Spinal cord infarction: A systematic review and meta-analysis of patient's characteristics, diagnosis accuracy, management, and outcome

Background

Acute spinal cord infarction (SCI) is a rare ischemic vascular lesion. It is difficult to diagnose during the acute phase because the clinical features can vary widely, and the diffusion-weighted imaging of spinal cord magnetic resonance imaging (MRI) often fails to detect any obvious abnormality. The first aim of this study was to describe the SCI patients' characteristics, evaluate the accuracy of its diagnosis tools and management, and then find the strength of the effect of spinal surgical decompression on the patient's outcome.

Methods

A PubMed keyword and Boolean search using ("spinal cord infarction" OR "spinal cord ischemia" AND diagnosis OR management OR outcome) returned 221,571 results by applying filters. We added 17,400 results from Google Scholar. Fourteen studies were included in the quantitative meta-analysis of mean differences.

Results

The Time to Nadir was <6 h (56.1%), 6-12 h (30.7%), 12-72 h (5.4%), and more than 72 h (7.8%). The higher proportion of Owl's eye findings in the MRI was reported at the cervical level (39.6%) and thoracic level (22.9%) P = 0.031. The T2DWI has a moderate accuracy (area under the curve = 0.835) in detecting the T2 hypersignal intensity (T2HSI) at the hyperacute time to NADIR (<6 h). The median modified Rankin Scale (mRS) at admission was 3 (2-3), and after a follow-up duration of 12 months (6-15.5), the median mRS was reported to be 1 (1-2). About 68.9% benefited from medical treatment and physiotherapy, whereas spinal surgical decompression was done in 22.8%. Seventy percent of the overall studies favor spinal surgical decompression, with the estimated average standardized mean difference between medical and surgical treatment being = 1.2083 (95% confidence interval: 1.0250-1.3917).

Conclusion

The T2DWI has moderate accuracy in detecting the T2HSI at the hyperacute time (NADIR <6 h). Even though surgical decompression favored good outcomes, medical treatment with physiotherapy was mostly used for the management of SCI.

Mitochondrial dysfunctions induce PANoptosis and ferroptosis in cerebral ischemia/reperfusion injury: from pathology to therapeutic potential

Ischemic stroke (IS) accounts for more than 80% of the total stroke, which represents the leading cause of mortality and disability worldwide. Cerebral ischemia/reperfusion injury (CI/RI) is a cascade of pathophysiological events following the restoration of blood flow and reoxygenation, which not only directly damages brain tissue, but also enhances a series of pathological signaling cascades, contributing to inflammation, further aggravate the damage of brain tissue. Paradoxically, there are still no effective methods to prevent CI/RI, since the detailed underlying mechanisms remain vague. Mitochondrial dysfunctions, which are characterized by mitochondrial oxidative stress, Ca²⁺ overload, iron dyshomeostasis, mitochondrial DNA (mtDNA) defects and mitochondrial quality control (MQC) disruption, are closely relevant to the pathological process of CI/RI. There is increasing evidence that mitochondrial dysfunctions play vital roles in the regulation of programmed cell deaths (PCDs) such as ferroptosis and PANoptosis, a newly proposed conception of cell deaths characterized by a unique form of innate immune inflammatory cell death that regulated by multifaceted PANoptosome complexes. In the present review, we highlight the mechanisms underlying mitochondrial dysfunctions and how this key event contributes to inflammatory response as well as cell death modes during CI/RI. Neuroprotective agents targeting mitochondrial dysfunctions may serve as a promising treatment strategy to alleviate serious secondary brain injuries. A comprehensive insight into mitochondrial dysfunctions-mediated PCDs can help provide more effective strategies to guide therapies of CI/RI in IS.

Stroke and stroke prevention in sickle cell anemia in developed and selected developing countries

This comprehensive review provides an insight into the pathophysiology, epidemiology, evaluation, and treatment of sickle cell anemia (SCA)-related stroke in developed and developing countries. Vascular injury, hypercoagulability and vaso-occlusion play a role in the pathophysiology of stroke in SCA. Transcranial Doppler ultrasound (TCD) has lowered the incidence of ischemic stroke from 11% to 1% as TCD identifies children who are at risk for stroke, providing opportunities for interventions to reduce this risk. Whereas blood exchange is indicated in acute stroke, chronic transfusions (either simple or exchange on a monthly basis) are used for primary as well as secondary stroke prevention in developed countries. Children with abnormally high TCD velocities (≥ 200 cm/s) are at high risk of stroke and might benefit from hydroxyurea or hydroxycarbamide (HU) after a period of a successful transition from chronic transfusions. Hematopoietic stem cell transplant presents a cure for SCA. Gene therapy is currently investigated and may be offered to patients with SCA who had a stroke or who are at high risk of stroke if proven efficacious and safe. However, gene therapy is not likely to be implemented in low-income countries due to cost. Alternatively, HU is utilized for primary and secondary stroke prevention in developing countries. Further expansion of TCD implementation should be a priority in those settings.

Novel Treatments for Transient Ischemic Attack and Acute Ischemic Stroke

The treatment of acute ischemic stroke is one of the most rapidly evolving areas in medicine. Like all ischemic vascular emergencies, the priority is reperfusion before irreversible infarction. The central nervous system is sensitive to brief periods of hypoperfusion, making stroke a golden hour diagnosis. Although the phrase "time is brain" is relevant today, emerging treatment strategies use more specific markers for consideration of reperfusion than time alone. Innovations in early stroke detection and individualized patient selection for reperfusion therapies have equipped the emergency medicine clinician with more opportunities to help stroke patients and minimize the impact of this disease.

Cutting Edge Acute Ischemic Stroke Management

Acute ischemic stroke (AIS) is a medical emergency that requires prompt recognition and streamlined work-up to ensure that time-dependent therapies are initiated to achieve the best outcomes. This article discusses frequently missed AIS in the emergency department, the role of various imagining modalities in the work-up of AIS, updates on the use of intravenous thrombolytics and endovascular therapy for AIS, pearls on supportive care management of AIS, and prehospital and hospital process improvements to shorten door-to-needle time.