Epilepsy with dual pathology: surgical treatment of cortical dysplasia accompanied by hippocampal sclerosis

The presence of two or more epileptogenic pathologies in patients with epilepsy is often observed, and the coexistence of focal cortical dysplasia (FCD) with hippocampal sclerosis (HS) is one of the most frequent clinical presentations. Although surgical resection has been an important treatment for patients with refractory epilepsy associated with FCD, there are few studies on the surgical treatment of FCD accompanied by HS, and treatment by resection of both neocortical dysplastic tissue and hippocampus is still controversial.

We retrospectively recruited epilepsy patients who had undergone surgical treatment for refractory epilepsy with the pathologic diagnosis of FCD and the radiologic evidence of HS. We evaluated the prognostic roles of clinical factors, various diagnostic modalities, surgical procedures, and the severity of pathology.

A total of 40 patients were included, and only 35.0% of patients became seizure free. Complete resection of the epileptogenic area (p = 0.02), and the presence of dysmorphic neurons or balloon cells on histopathology (p = 0.01) were associated with favorable surgical outcomes. Patients who underwent hippocampal resection were more likely to have a favorable surgical outcome (p = 0.02).

We show that patients with complete resection of epileptogenic area, the presence of dysmorphic neurons or balloon cells on histopathology, or resection of hippocampus have a higher chance of a favorable surgical outcome. We believe that this observation is useful in planning of surgical procedures and predicting the prognoses of individual patients with FCD patients accompanied by HS.