This is a case of seemingly isolated absent septum pellucidum. MRI is required to ensure other more subtle abnormalities are not present.

The patient presented with one episode of seizure-like activity and underwent cross-sectional imaging in the emergency department to evaluate for underlying etiology. The imaging was negative for stroke, hemorrhage, or mass, but the septum pellucidum was incidentally found to be absent. This finding can be isolated, or part of a wider spectrum of disease affecting the neuroaxis. The patient was discharged and has been seizure free.