Introduction
Focal cortical dysplasia (FCD) type II, or Taylor-type FCD, is considered a common cause of drug-resistant epilepsy, with specific characteristics. In many cases, these patients respond well to surgery.
Patients and methods
The study included patients with FCD type II who had undergone an epilepsy protocol brain MRI scan, evaluated by an expert neuroradiologist, since 2012. We performed a retrospective observational analysis of diagnostic variables, clinical correlations with presurgical evaluation studies, indications for surgery, and response.
Results
The sample included 50 patients (50% women, with a mean [SD] age at seizure onset of 13 [9.7] years). All patients were diagnosed with focal-onset seizures. Some 12.5% of patients also presented functional non-epileptic seizures. Seizure frequency was daily or weekly in 70% of cases, and drug-resistant epilepsy was diagnosed in 72%. FCD was most frequently located in the frontal lobes (68%). In 87% of cases, a correlation was observed between the FCD region and hypometabolism on FDG-PET. Twenty-six patients underwent surgical treatment, and two other patients are currently awaiting surgery. In the surgery group, 79% of patients were seizure-free at 2 years after the procedure.
Conclusions
FCD type II is not always associated with drug-resistant epilepsy. Diagnosis does not rule out the presence of functional seizures. Because of the need for neurophysiological and protocolised neuroimaging tests, these patients should be managed at expert units within referral centres. Surgery achieves clinical improvement in most cases, with complete seizure freedom in approximately 80% of our series.