[Incidental finding of a focal cortical heterotopy in long-term epilepsy]

A 72-year-old woman was admitted for the work-up of an abdominal pseudomyxoma. A brain CT was performed and revealed the presence of a tumorlike lesion in the left temporal lobe. The diagnosis of focal heterotopy was suggested and confirmed by MRI. Careful clinical history revealed Grand Mal epilepsy during infancy that was well controlled by antiepileptic drugs. No imaging studies had ever been performed. This case illustrates that the diagnosis of idiopathic epilepsy should be established only after having ruled out brain disorders including heterotopy, which can be demonstrated by MRI.