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Summary:Purpose: The International League Against Epilepsy (ILAE) classification distinguishes medial and neocortical temporal lobe epilepsies. Among other criteria, this classification relies on the identification of two different electroclinical patterns, those of medial (limbic) and lateral (neocortical) temporal lobe seizures, depending on the structure initially involved in the seizure activity. Recent electrophysiologic studies have now identified seizures in which medial and neocortical structures are both involved at seizure onset. The purpose of the study was therefore to study the correlations of ictal semiology with the spatiotemporal pattern of discharge in temporal lobe seizures.Methods: The 187 stereoelectroencephalography-recorded seizures from 55 patients were analyzed. Patients were classified into three groups according to electrophysiologic findings: medial (M; seizure onset limited to medial structures, n = 24), lateral (L; seizure onset limited to lateral structures, n = 13), and medial-lateral (ML; seizure onset involving both medial and lateral structures, n = 18). Clinical findings were compared between groups.Results: Initial epigastric sensation, initial fear, delayed oroalimentary and elementary upper limb automatisms, delayed loss of contact, long seizure duration, and absent or rare secondary generalizations were associated with M seizures. Initial auditory illusion or hallucination, initial loss of contact, shorter duration of seizures, and more frequent generalizations were associated with L seizures. Initial epigastric sensation, initial loss of contact, early oroalimentary and verbal automatisms, and long duration of seizures were associated with ML seizures.Conclusions: Although the syndrome of mesial temporal epilepsy is now relatively well defined, our findings support the idea that the organization of temporal lobe seizures may be complex and that different patterns exist. We demonstrate three distinct patterns, characterized by both semiologic and electrophysiologic features. This distinction may help to define better the epileptogenic zone and the subsequent surgical procedure.

Human neuroimaging studies have identified a network of distinct face-selective regions in the ventral occipito-temporal cortex (VOTC), with a right hemispheric dominance. To date, there is no evidence for this hemispheric and regional specialization with direct measures of brain activity. To address this gap in knowledge, we recorded local neurophysiological activity from 1,678 contact electrodes implanted in the VOTC of a large group of epileptic patients (n = 28). They were presented with natural images of objects at a rapid fixed rate (six images per second: 6 Hz), with faces interleaved as every fifth stimulus (i.e., 1.2 Hz). High signal-to-noise ratio face-selective responses were objectively (i.e., exactly at the face stimulation frequency) identified and quantified throughout the whole VOTC. Face-selective responses were widely distributed across the whole VOTC, but also spatially clustered in specific regions. Among these regions, the lateral section of the right middle fusiform gyrus showed the largest face-selective response by far, offering, to our knowledge, the first supporting evidence of two decades of neuroimaging observations with direct neural measures. In addition, three distinct regions with a high proportion of face-selective responses were disclosed in the right ventral anterior temporal lobe, a region that is undersampled in neuroimaging because of magnetic susceptibility artifacts. A high proportion of contacts responding only to faces (i.e., "face-exclusive" responses) were found in these regions, suggesting that they contain populations of neurons involved in dedicated face-processing functions. Overall, these observations provide a comprehensive mapping of visual category selectivity in the whole human VOTC with direct neural measures.face perception | intracerebral recordings | fast periodic visual stimulation | face selectivity | fusiform gyrus