What should be the diagnostic and therapeutic approach to a child who has had a first episode of seizure, in whom a single ring-enhancing lesion is identified on CT scan of the brain?
C.R. Sundaresan, MD
The first step would be to perform an MRI of the head, to further clarify the exact nature of the lesion. Possibilities include postviral demyelinating disease, cerebritis, tumor (for example, a pilocytic astrocytoma), subacute hemorrhage (with isodense, resolving blood), or cysticercosis (is the child from an endemic area?). Cavernous angioma might be more likely to manifest as an enhancing nodule with some calcification.
Once the nature of the lesion is further clarified, then the course of treatment should be more clear. Regardless of the lesion type, I would suggest checking an EEG and starting prophylactic treatment with an antiepileptic drug. In this setting, with a lesion identified on CT, the likelihood for seizure recurrence is substantial. My personal choice for initial antiepileptic treatment would be carbamazepine.