Identifying subtle cortical gyral abnormalities as a predictor of focal cortical dysplasia and a cure for epilepsy.

OBJECTIVES To highlight a case series of 3 cases of focal cortical dysplasia that were unrecognized for many years though the patients were seen by various neurologists and received the appropriate neuroimaging studies, and to retrospectively characterize the clinical elements, neuroimaging, electroencephalography, and pathologic findings in these cases. DESIGN Retrospective descriptive study. SETTING Tertiary urban and suburban neurology and epilepsy outpatient and inpatient clinic settings and hospitals. PATIENTS We analyze retrospectively 3 patients in whom magnetic resonance images were previously deemed as normal, who, in fact, exhibited subtle gyral abnormalities and who underwent focal surgical resections of these regions after invasive electroencephalography monitoring or electrocorticography and were cured of their epilepsy. MAIN OUTCOME MEASURES Clinical semiology and neuroimaging findings. RESULTS Focal cortical dysplasias may present with subtle gyral abnormalities. These gyral abnormalities may guide invasive electroencephalography or electrocorticography and may delineate seizure onsets with precision. Resection of these areas in 3 such patients resulted in excellent surgical outcomes. CONCLUSIONS Subtle gyral abnormalities may be associated with intractable epilepsy and seizure onsets. Focal resection after appropriate evaluations in selected patients may be curative. The magnetic resonance imaging features of focal cortical dysplasia can be subtle and require a high index of suspicion based on ictal semiology and clinical presentation.