The “spot sign” is a specific finding observed on medical imaging scans in individuals experiencing a type of brain bleed known as an intracerebral hemorrhage. This sign indicates ongoing, active bleeding within the brain tissue. Its identification provides healthcare professionals with immediate insight into the dynamic nature of the hemorrhage.
Identifying the Spot Sign
The detection of a spot sign relies on a specialized medical imaging technique called a Computed Tomography Angiogram (CTA). A CTA differs from a standard non-contrast CT scan because it involves injecting a contrast dye into the patient’s bloodstream. This dye travels through the blood vessels, making them visible on the scan.
The spot sign appears as a small, distinct area of bright enhancement within the pool of blood, known as a hematoma, on the CTA images. This enhancement signifies that the contrast dye has leaked out of a damaged blood vessel and into the surrounding hematoma, indicating active extravasation of blood. The spot sign typically measures at least 1.5 millimeters in diameter and shows an attenuation, or density, that is at least double that of the surrounding hematoma, often exceeding 120 Hounsfield Units (HU). It is also discontinuous with any visible normal or abnormal blood vessels around the hematoma and does not correspond to any pre-existing dense areas on a non-contrast CT scan.
Clinical Significance of a Positive Spot Sign
Identifying a positive spot sign carries significant meaning for a patient’s prognosis. The presence of this sign is a strong predictor of hematoma expansion. Hematoma expansion occurs in approximately 10% to 30% of patients with acute intracerebral hemorrhage within the first few hours of symptom onset.
A growing hematoma increases pressure within the confined space of the skull, which can compress brain tissue. This elevated pressure leads to worse neurological outcomes for the patient. The risk of mortality also increases significantly when hematoma expansion occurs. To help quantify this risk, physicians sometimes use a “Spot Sign Score,” which incorporates characteristics such as the number of spot signs (e.g., three or more), their maximum axial dimension (e.g., 5 millimeters or larger), and their maximum attenuation (e.g., 180 HU or greater).
Medical Management and Treatment Approaches
Once a spot sign is identified, this guides immediate medical care. The primary treatment goal for a patient with a positive spot sign is aggressive control of blood pressure. Rapidly reducing the systolic blood pressure to below 140 mmHg is a common strategy, aiming to lessen the stress on the damaged blood vessel and potentially halt further bleeding.
Other medical therapies may help stop the bleeding. Hemostatic agents, such as tranexamic acid, are sometimes used to promote blood clotting and stabilize the hemorrhage. While some studies suggest that tranexamic acid might modestly reduce hematoma growth, especially if given within 4.5 hours of symptom onset, overall clinical trials have not consistently shown a clear benefit in terms of patient outcomes, and further validation is often needed. These proactive medical interventions are designed to mitigate the risks associated with ongoing bleeding and hematoma expansion, striving to improve patient outcomes.