Traumatic subarachnoid hemorrhage classification
Traumatic subarachnoid hemorrhage (tSAH) classification is typically based on imaging findings, clinical severity, and associated factors such as prognosis or treatment needs. Here are the main systems and approaches to classify tSAH:
1. Classification by Imaging Features
This approach evaluates the extent and location of the subarachnoid hemorrhage, often using CT scans.
a. Greene Classification (1995): Proposed by Greene et al., this CT-based scale grades tSAH as follows:
Grade 0: No subarachnoid hemorrhage detected. Grade 1: Localized hemorrhage in one cistern or fissure. Grade 2: Hemorrhage involving multiple cisterns or fissures but not diffuse. Grade 3: Diffuse hemorrhage across multiple cisterns and fissures. Grade 4: Diffuse hemorrhage with associated intraventricular hemorrhage or intracerebral hematoma.
b. Basal Cistern Involvement: Localized: Limited to sulci or cortical areas. Diffuse: Spreads to basal cisterns (e.g., interpeduncular, prepontine), associated with severe brain injury. Focal with Associated Lesions: Combined with contusions or hematomas.
c. Rotterdam CT Score: Incorporates tSAH in assessing overall traumatic brain injury severity:
Presence of tSAH adds points to the score, reflecting a worse prognosis.
2. Clinical Severity Classification
Based on the patient's neurological status and Glasgow Coma Scale (GCS):
Mild tSAH:
GCS: 13–15. Minimal or localized bleeding, often incidental findings. Moderate tSAH:
GCS: 9–12. Often associated with moderate brain trauma and neurological deficits. Severe tSAH:
GCS: ≤8. Frequently occurs with diffuse brain injury, elevated intracranial pressure, and poor prognosis.
3. Prognostic Classification
Isolated vs. Complex tSAH: Isolated tSAH: Occurs without other significant traumatic brain injuries (TBIs). Better prognosis, often managed conservatively. Complex tSAH: Accompanied by other injuries like contusions, hematomas, or diffuse axonal injury (DAI). Associated with higher mortality and morbidity. Trauma and Hemodynamic Impact: Subarachnoid hemorrhage with secondary complications such as cerebral edema or vasospasm indicates a more severe prognosis.
4. Pathophysiological and Mechanistic Classification
Primary tSAH: Direct rupture of vessels due to trauma, often localized to the impact area. Secondary tSAH: Results from secondary effects like raised intracranial pressure, vascular injury, or systemic hypoperfusion.
5. Systems Used in Practice
Marshall computed tomography classification:
Grades diffuse injury and incorporates tSAH indirectly as part of the evaluation for brain swelling, midline shift, and other features.
Fisher Scale (Modified for Trauma): Although primarily used for aneurysmal SAH, some adaptations for tSAH have been suggested to describe the hemorrhage's extent and its risk for vasospasm. Clinical Relevance High-grade tSAH (diffuse or with associated injuries) is a marker for poor outcomes, including high mortality and long-term disability. Low-grade tSAH (localized or isolated) is generally associated with better recovery potential.
Greene classification for Traumatic subarachnoid hemorrhage