Epileptiform abnormalities predict delayed cerebral ischemia in subarachnoid hemorrhage

Area of Science:

• Neuroscience
• Neurology
• Critical Care Medicine

Background:

• Subarachnoid hemorrhage (SAH) can lead to delayed cerebral ischemia (DCI), a major cause of secondary brain injury.
• Continuous electroencephalography (cEEG) monitoring is crucial for detecting abnormal neural activity.

Purpose of the Study:

• To investigate the association between ictal-interictal continuum abnormalities (IICAs) and the development of DCI in patients with SAH.
• To determine if IICAs can serve as an early marker for DCI risk.

Main Methods:

• Retrospective analysis of cEEG reports and medical records from 124 patients with moderate to severe SAH.
• Identification of daily seizures and IICAs.
• Survival analysis to estimate IICA onset time in relation to DCI.

Main Results:

• The presence of IICAs increases the risk of DCI, particularly when they emerge days after SAH onset.
• Most IICA types, excluding generalized rhythmic delta activity, were more common in patients who developed DCI.
• Later onset of IICAs correlated with a higher risk of DCI.

Conclusions:

• IICAs may serve as a novel, early marker for identifying patients at increased risk of DCI following SAH.
• IICAs could potentially contribute mechanistically to DCI, suggesting them as a therapeutic target to prevent secondary brain injury.