The Localizing Value Of Focal Delta Slowing In Temporal Lobe Epilepsy

Background Clinical and structural correlates of lateralized interictal delta activity in patients with temporal lobe epilepsy (TLE) have been well documented in the literature. Nevertheless, its occurrence has not been considered a significant clinical feature. Objective To evaluate the significance of focal delta- range slowing for localizing the epileptogenic focus in patients with TLE, and predicting the outcome of temporal lobe surgery. Methods Sixteen consecutive patients with temporal lobe epilepsy who underwent anterior temporal lobe resections were selected for the study. Findings of MRI, SPECT, neuropyschology assessment, pathology and surgical outcome were analyzed and correlated with focal delta slow activity of background rhythm. Results Twelve of 16 patients (75%) had localized temporal delta slowing corresponding to the resection site and pathology. Temporal delta slowing was the most frequent interictal EEG finding (75%) compared to spike and sharp wave (44%). MRI showed concordant abnormalities in 75% of the patients, and neuropyschology testing was able to lateralize the involved hemisphere in 37.5%. SPECT was concordant in 56%. There was no false localization with temporal delta activity. Slow wave EEG had a higher marginal probability than neuropsychological assessment of predicting the focus, and was equally effective as other investigative methods. Conclusion These results suggest that focal temporal delta slowing is useful in the localization of epileptogenic foci. There was no discordance with the resection site and pathology.Introduction Les corrélations entre clinique, et topographie des ondes delta intercritiques au cours de l\'épilepsie temporal (TLE) ont été bien documentées dans la litterature. But Évaluer la relation entre ralentissement delta et la localisation d\'un foyer épileptogène dans le cadre d\'une TLE et après une lobectomie temporale. Méthodes Seize patients consécutifs atteints d\'une épilepsie temporale qui ont bénéficié d\'une lobectomie temporale ont été séletionnés. Les données IRM, SPECT, neuropsychologiques, neuropathologiques et l\'évolution post-chirurgicale ont été analysées et correlées au foyer d\'ondes delta. Résultats Douze des 16 patients (75%) avaient une correspondance entre les ondes delta, et la résection chirurgicale et l\'anatomopathologie. Les ondes lentes delta temporales sont les anomalies les plus fréquemment rencontrées durant les périodes intercriques comparées aux spikes et pointes ondes (44%). La concordance entre l\'IRM et les anomalies est notée chez 75% des patients ; les tests neuropsychologiques sont capables de déterminer la lateralisation de l\'hémisphère impliqué dans 37% des cas. La SPECT était concordante dans 56% des cas. Il n\'y avait pas de faux positif dans la localisation par l\'activité temporale delta. Les ondes EEG lentes ont une plus grande probabilité localisatrice que les tests neuropsychologiques et sont aussi effectives que les autres méthodes Conclusion Ces résultats suggèrent que les ondes lentes temporales sont utiles dans la localization d\'un foyer épileptique. Il n\'y a aucune discordance entre le site de la résection et l\'anatomo-pathologie. Keywords: EEG, Epilepsie, Crises épileptiques, Chirurgie. Lobe temporal, slowing, EEG, Epilepsy, Seizure, Surgery,Temporal lobe African Journal of Neurological Sciences Vol. 24 (1) 2005: pp. 37-4

Emotional Voice Processing: Investigating the Role of Genetic Variation in the Serotonin Transporter across Development

The ability to effectively respond to emotional information carried in the human voice plays a pivotal role for social interactions. We examined how genetic factors, especially the serotonin transporter genetic variation (5-HTTLPR), affect the neurodynamics of emotional voice processing in infants and adults by measuring event-related brain potentials (ERPs). The results revealed that infants distinguish between emotions during an early perceptual processing stage, whereas adults recognize and evaluate the meaning of emotions during later semantic processing stages. While infants do discriminate between emotions, only in adults was genetic variation associated with neurophysiological differences in how positive and negative emotions are processed in the brain. This suggests that genetic association with neurocognitive functions emerges during development, emphasizing the role that variation in serotonin plays in the maturation of brain systems involved in emotion recognition