Cerebral Computed Tomography Scan Demonstrating Ischemic Stroke in a Filly After Intravenous Antibiotic Administration.

This research paper discusses the use of a Computed Tomography (CT) scan to diagnose an ischemic stroke in a young horse (filly) following the administration of intravenous antibiotics. The stroke was believed to be induced by a disruption in blood flow to the brain during a massive drop in blood pressure (cardiovascular collapse).

CT Scanning and Anesthesia

• The process of performing a CT scan on a foal requires specialized equipment and large animal anesthesia. Despite the clear challenges, the information gained from a CT scan can help identify the neurological deficits caused by various lesions.

Cerebral Ischemia Categories and Mechanism

• Ischemia of the brain has been categorized into three types: territorial infarctions, watershed infarctions, and lacunar infarctions. Understanding these distinctions can aid in understanding the mechanisms that lead to cerebral ischemia.

Risks of Sulfonamide Administration

• The administration of sulfonamide antibiotics carries a risk of severe hypersensitivity and Type I anaphylactic reactions. In approximate three percent of cases, these adverse effects can occur.
• In horses, an anaphylactic reaction often manifests as a significant drop in blood pressure leading to the animal collapsing. This cardiovascular collapse can subsequently result in a reduced flow to multiple organs, leading to an infarction – a tissue death due to lack of oxygen. This can further lead to multiple organ failure and death.

Case Report

• In this particular case, a filly suffered a suspected watershed cerebral infarction after being administered antibiotics via an injection, as indicated by a CT scan of the brain.
• The cause of the infarction is presumed to be a disruption in the flow of blood to the brain during an episode of cardiovascular collapse. A problem at the junction of posterior right cerebral arteries was identified.
• Originally, no abnormalities appeared on the CT scan. However, upon closer examination by a specialized radiologist, an ischemic scar in the watershed area (indicative of a hemodynamic infarction) was identified. This finding underscores the importance of having specialized knowledge and experience when interpreting CT scans, especially in cases of minor lesions.