Neuroimaging of Dual/Double Pathology

So called dual pathology is not uncommon, up to %۲۰ of patients with drug resistant focal epilepsy, which may cause some difficulties in seizure focus localization and planning of epilepsy surgery. This has been reported in various form of epileptogenic lesions, but the most frequently hippocampal sclerosis (HS) is seen in association with focal cortical dysplasia (FCD), particularly in temporal lobe. It is not always clear if HS is an epiphenomenon caused by frequent seizures or the initial insult or abnormality leads to HS. The more crucial question is the role of identified lesions including HS in patient’s epilepsy. Intracranial video-EEG monitoring is usually required to answer this question. Based on the reported case series, having more than one epileptogenic lesion does not preclude a good surgical outcome. In fact, the outcomes are comparable with those patients who have single epileptogenic lesion. In general, a better surgical outcome could be achieved if both lesions are completely removed, but it should not be done or justified in every patient routinely as patients with preserved hippocampal function or lesion in eloquent area may experience a significant functional deficit after resection