New guideline recommends when to use CT scans in ER for seizures

A guideline developed by the American Academy of Neurology recommends immediate brain CT scans to screen certain emergency room patients with seizures.

Evidence shows such scans can help doctors select the right treatment option. The guideline is published in the October 30, 2007, issue of Neurology®, the medical journal of the American Academy of Neurology.

To develop the guideline, the authors analyzed all available scientific studies on the topic.

“Our analysis found immediate CT scans are a useful screening procedure because the results can help doctors decide how to care for the patient, especially after the first seizure, and for very young children and people with AIDS,” said the guideline's lead author Cynthia L. Harden, MD, with Weill Cornell Medical College in New York and member of the American Academy of Neurology.

The strongest evidence shows that imaging in the emergency room with a head CT scan is particularly useful for seizure patients with a predisposing history, focal seizure onset, an abnormal neurologic exam, a history of AIDS, or who are younger than six months old.

“Infants under six months old with seizure may have brain abnormalities on their CT scans 50 percent of the time,” said Harden. “In addition, evidence shows people with AIDS who are treated in the emergency room for their first seizure have high rates of brain abnormalities. Central nervous system toxoplasmosis, an infectious disease caused by a parasite, is also frequently found in AIDS patients.”

The guideline suggests physicians consider an emergency CT scan in adults and children with a first seizure because evidence shows the results will change how these people are treated in up to 17 percent of adult cases and up to eight percent of cases involving children.

Abnormalities found on CT scans that would lead to a change in treatment include: tumors, traumatic brain injury with skull fracture, and stroke including bleeding in the brain.

Harden says future research should address the use of brain MRI in the emergency room to screen people with seizures because there isn't sufficient data available to make recommendations regarding its use.