Temporal lobe epilepsy associated with ‘triple pathology’ of hippocampal sclerosis, focal cortical dysplasia and cavernoma in the ipsilateral frontal lobe

The coexistence of hippocampal sclerosis (HS) and extrahippocampal lesions such as focal cortical dysplasia (FCD) and cavernoma (CA) in temporal lobe epilepsies (TLE) is termed ‘dual pathology’. We report a case of TLE having ‘triple pathology’ of HS, FCD and CA in the ipsilateral frontal lobe. Using chronic subdural electrode recording, an interictal electrocorticogram (ECoG) demonstrated that the medial temporal lobe lesion and the FCD lesion exhibited independent paroxysmal discharges, while an ictal ECoG demonstrated that the medial temporal lobe was the ictal on-set zone. We postulated that the FCD lesion caused repeated seizures, which in turn, caused secondary hippocampal damage and HS, and eventually medically intractable epilepsy. The coexistence of CA was considered incidental. As treatments, the epileptogenic HS was resected through an anterior temporal lobectomy, and the FCD lesion was biopsied, while no surgical intervention was performed for the CA lesion. The patient achieved good seizure control during 12 months after surgery. Chronic subdural electrode recording is important for the assessment of multiple epileptogenic lesions before epilepsy surgery.