New-onset afebrile seizures in infants: role of neuroimaging

Abstract

Objective: To investigate the presenting characteristics of new-onset afebrile seizures in infants (age 1-24 months) and the yield of neuroimaging.

Methods: Prospective data were obtained from a standardized evaluation and management plan mandated by a critical care pathway. A total of 317 infants presented with new-onset afebrile seizures between 2001 and 2007. EEG was performed on 90.3%, head CT was obtained on 94%, and MRI was obtained on 57.4%.

Results: We found half of the infants had partial features to their seizures, yet evidence for primary generalized seizures was rare. The majority had more than 1 seizure upon presentation. Seizures in this age group tended to be brief, with 44% lasting less than 1 minute. EEG abnormalities were found in half. One-third of CTs were abnormal, with 9% of all CTs requiring acute medical management. Over half of MRIs were abnormal, with cerebral dysgenesis being the most common abnormality (p < 0.05). One-third of normal CTs had a subsequent abnormal MRI-only 1 resulted in altered medical management.

Conclusions: Infantile seizures are usually brief, but commonly recurrent, and strong consideration should be made for inpatient observation. Acute imaging with CT can alter management in a small but important number of infants. Due to the superior yield, strong consideration for MRI should be given for all infants, as primary generalized seizures are rare, and there is a high rate of cerebral dysgenesis.