Unenhanced CT should be the first imaging examination performed when patients present with new-onset seizure, according to a new analysis published in the American Journal of Roentgenology. It can help specialists exclude conditions that would require urgent or emergent intervention.
“An unprovoked first seizure can be a dramatic and life-changing event and immediately raises the specter of serious intracranial pathologic abnormality or a potential epilepsy diagnosis,” wrote lead author Eric Tranvinh, MD, Department of Radiology at Stanford University Medical Center, and colleagues. “The diagnoses of seizure and epilepsy are largely made on clinical grounds; however, neuroimaging plays an important role in the evaluation of patients with new seizure.”
The authors reviewed evidence supporting the choice of neuroimaging for new-onset seizure, noting that 10 percent of the population is expected to experience a seizure in their lifetime.
“The history and physical examination, including neurologic examination, are central to the evaluation of the patient presenting with first seizure,” the authors wrote. “If an epileptic seizure has occurred, the next step is to determine whether precipitating factors were present, or, alternatively, whether the seizure was unprovoked. The presence of a focal neurologic deficit on physical examination is the most consistently reported clinical finding associated with abnormalities at neuroimaging in adults presenting to the emergency department with first seizure. The clinical evaluation of patients with first seizure, however, can be challenging.”
Tranvinh and colleagues explained neuroimaging helps determine whether a seizure was caused by an intracranial lesion. “Robust” evidence indicates that CT it a smart first choice, the authors wrote, and recent research shows that the addition of IV contrast material “is of little benefit.” Also, depending on certain circumstances, MRI may also play a vital role in caring for these patients.
The authors reviewed what various medical societies have recommended for patients presenting with new-onset seizure. The American Association of Neurology issued guidelines in 2007 that said CT “is possibly useful for acute patient management in the emergency department,” and American College of Radiology (ACR) appropriateness criteria says CT “may be the imaging study of choice in the acute or emergency setting.” MRI, meanwhile, is the ACR’s study-of-choice in a non-acute setting.
Tranvinh et al. also detailed numerous findings related to MRI use for these patients, though research on MRI specifically as a way to evaluate new-onset seizure is limited.
“In the outpatient setting, MRI can guide drug therapy and aid in prognosis and, importantly, can detect significant epileptogenic lesions (e.g., tumors) missed at CT,” the authors wrote. “In the inpatient setting, one study showed that MRI detects subtle structural lesions missed at CT that could explain the first seizure presentation. Although MRI results did not acutely affect patient management in this study, it is our opinion that MRI can still potentially achieve the secondary goal of neuroimaging in new-onset seizure of determining prognosis and recurrence risk; more studies are needed to evaluate the value of MRI in this setting.”
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.