- Email: [email protected]
Central sulcus localization: Reappraisal of cortical median SSEP
Japanese Society of Clinical Neurophysiology / Clinical Neurophysiology 118 (2007) e189–e202
zure propagation to the LCx was weaker and motor manifestation was less severe in the transection group. Conclusions: It is likely that APWM is an important area for the secondary generalization of KA-induced limbic seizures in rats. doi:10.1016/j.clinph.2007.05.024
Results: Frequency rate of IEA during sleep and awake was Ave. 95.1 times/h [range 5.4–443.8] and 38.1 [0.1–252.2] (P < 0.01), respectively. Frequency rate of clinical seizure during sleep and awake was Ave. 0.16 times/h [0–0.71] and 0.16 [0–0.58 ]. Conclusion: Although an increase of IEA occurred during sleep in patients with MTLE, the influence of sleep on the occurrence of clinical seizures is not apparent.
14. Epilepsy
doi:10.1016/j.clinph.2007.05.026
EEG dipole in Panayiotopoulos syndrome—H. Yoshinaga, K. Kobayashi, T. Ogino, M. Ito, T. Nakahori, Y. Ohtsuka (Okayama, Japan)
16. Evoked potentials
Purpose: In a previous study, we observed high intraindividual dipole stability in Panayiotopoulos syndrome (PS) that is similar to that seen in rolandic epilepsy. In this study, we investigated whether the excellent intraindividual dipole stability in PS occurs also interindividually, and how such a dipole stability compares with that of other types of epilepsy. Methods: We performed dipole analysis of the interictal occipital spike discharges seen in 10 children with PS (Group A) and in 10 children with other types of symptomatic localization-related epilepsy (Group B). We analyzed the dipoles of the averaged spike in each patient. Results: (1) Dipole locations in Group A show a tighter clustering in the mesial occipital area alongside major cortical sulci, but in Group B they were scattered more superficially. (2) In Group A, the geometric centers of the dipoles at each time point (such as at the main negative peak and preceding or following a positive peak) were estimated in the neighbouring locations. In contrast, they tended to be scattered in Group B. Conclusions: Our study reveals that PS has high dipole stability, similar to that of rolandic epilepsy. From the electroencephalographic view, this seems to indicate a close link between these two syndromes. doi:10.1016/j.clinph.2007.05.025
15. Epilepsy Influence of sleep on the occurrence of interictal epileptiform activities and clinical seizures in patients with medial temporal lobe epilepsy—M. Ohshio, A. Sakata, H. Shigeto, H. Izumi, M. Inoue, T. Morioka (Kyushu University, Fukuoka, Japan) Purpose: Interictal epileptiform activities (IEA) in patients with medial temporal epilepsy (MTLE) are thought to increase during sleep. However, the influence of sleep on seizure is not fully investigated. Therefore, we analyzed the occurrence of IEA and clinical seizures during sleep and awake separately in patients. Methods: Fourteen patients (five males and nine females, 14–65 ages) who underwent continuous video-EEG monitoring for presurgical evaluation of anterior temporal lobectomy were participated in this study. Hippocampal sclerosis is confirmed histologically in all patients. The number of IEA and clinical seizure during sleep and awake were counted retrospectively. Mann– Whitney test was used for comparing.
e193
Central sulcus localization: Reappraisal of cortical median SSEP—R. Matsumoto 1,2, D. Nair 1, I. Najm 1, A. Ikeda 2, R. Takahashi 2, H. Shibasaki 2, H.O. Lu¨ders 1 (1 Cleveland, USA, 2 Kyoto, Japan) Objective: To propose and validate the criteria for identifying the phase reversal of cortical median nerve SSEPs for the central sulcus (CS) localization. Methods: Cortical median nerve SSEPs were recorded from subdural electrodes placed in the perirolandic area in 30 patients as a part of the presurgical evaluation of intractable partial epilepsy. First and second negative and positive peaks (N1, P1, N2, P2) were identified in responses recorded from each electrode. The accuracy of the following three criteria for CS localization was studied; (1) N1 and P1 with the earliest peak latency, (2) Largest N1 and P1, (3) N1 and P1 that are followed by the largest later components (N2, P2, N3, P3). CS as correlated with electrode location was identified in 3D-MRI co-registered with subdural electrodes. Results: Criteria 1, 2 and 3 located P1 and N1 accurately within the pre- and post-central gyri in 17, 27 and 27 patients, respectively. The distance between the electrodes with N1 and P1 was shorter in Criterion 3 (mean 1.4 cm) than Criterion 1 (2.5 cm) (p < 0.01) and Criterion 2 (1.7 cm) (p < 0.05). Conclusion: The identification of a phase reversal of N1 and P1 with following large amplitude potentials is highly predictive of CS location. doi:10.1016/j.clinph.2007.05.027
17. Evoked potentials Involvement of sensory system in generalized dystonia – Evaluation of premovement gating in somatosensory evoked potentials (SEPs)—K. Kimura, Y. Nomura, Y. Nagao, K. Hachimori, Masami Segawa, Masaya Segawa (Segawa Neurological Clinic for Children, Tokyo, Japan) To evaluate the involvement of the sensory system in generalized dystonia, the attenuation (gating) of SEPs before and during finger movements was examined in seven patients with Segawa disease (12–63 y), 4 DYT1 (15–19 y) and with 10 normal controls (15– 51 y). For midmovement gating, SEPs over the frontal and hand sensory area leads were elicited by the median nerve stimulation at rest and during active thumb dorsiflexion movements. The frontal N30 (FrN30) was equally attenuated during movement compared with SEPs at rest, both in patients and normal controls.
zure propagation to the LCx was weaker and motor manifestation was less severe in the transection group. Conclusions: It is likely that APWM is an important area for the secondary generalization of KA-induced limbic seizures in rats. doi:10.1016/j.clinph.2007.05.024
Results: Frequency rate of IEA during sleep and awake was Ave. 95.1 times/h [range 5.4–443.8] and 38.1 [0.1–252.2] (P < 0.01), respectively. Frequency rate of clinical seizure during sleep and awake was Ave. 0.16 times/h [0–0.71] and 0.16 [0–0.58 ]. Conclusion: Although an increase of IEA occurred during sleep in patients with MTLE, the influence of sleep on the occurrence of clinical seizures is not apparent.
14. Epilepsy
doi:10.1016/j.clinph.2007.05.026
EEG dipole in Panayiotopoulos syndrome—H. Yoshinaga, K. Kobayashi, T. Ogino, M. Ito, T. Nakahori, Y. Ohtsuka (Okayama, Japan)
16. Evoked potentials
Purpose: In a previous study, we observed high intraindividual dipole stability in Panayiotopoulos syndrome (PS) that is similar to that seen in rolandic epilepsy. In this study, we investigated whether the excellent intraindividual dipole stability in PS occurs also interindividually, and how such a dipole stability compares with that of other types of epilepsy. Methods: We performed dipole analysis of the interictal occipital spike discharges seen in 10 children with PS (Group A) and in 10 children with other types of symptomatic localization-related epilepsy (Group B). We analyzed the dipoles of the averaged spike in each patient. Results: (1) Dipole locations in Group A show a tighter clustering in the mesial occipital area alongside major cortical sulci, but in Group B they were scattered more superficially. (2) In Group A, the geometric centers of the dipoles at each time point (such as at the main negative peak and preceding or following a positive peak) were estimated in the neighbouring locations. In contrast, they tended to be scattered in Group B. Conclusions: Our study reveals that PS has high dipole stability, similar to that of rolandic epilepsy. From the electroencephalographic view, this seems to indicate a close link between these two syndromes. doi:10.1016/j.clinph.2007.05.025
15. Epilepsy Influence of sleep on the occurrence of interictal epileptiform activities and clinical seizures in patients with medial temporal lobe epilepsy—M. Ohshio, A. Sakata, H. Shigeto, H. Izumi, M. Inoue, T. Morioka (Kyushu University, Fukuoka, Japan) Purpose: Interictal epileptiform activities (IEA) in patients with medial temporal epilepsy (MTLE) are thought to increase during sleep. However, the influence of sleep on seizure is not fully investigated. Therefore, we analyzed the occurrence of IEA and clinical seizures during sleep and awake separately in patients. Methods: Fourteen patients (five males and nine females, 14–65 ages) who underwent continuous video-EEG monitoring for presurgical evaluation of anterior temporal lobectomy were participated in this study. Hippocampal sclerosis is confirmed histologically in all patients. The number of IEA and clinical seizure during sleep and awake were counted retrospectively. Mann– Whitney test was used for comparing.
e193
Central sulcus localization: Reappraisal of cortical median SSEP—R. Matsumoto 1,2, D. Nair 1, I. Najm 1, A. Ikeda 2, R. Takahashi 2, H. Shibasaki 2, H.O. Lu¨ders 1 (1 Cleveland, USA, 2 Kyoto, Japan) Objective: To propose and validate the criteria for identifying the phase reversal of cortical median nerve SSEPs for the central sulcus (CS) localization. Methods: Cortical median nerve SSEPs were recorded from subdural electrodes placed in the perirolandic area in 30 patients as a part of the presurgical evaluation of intractable partial epilepsy. First and second negative and positive peaks (N1, P1, N2, P2) were identified in responses recorded from each electrode. The accuracy of the following three criteria for CS localization was studied; (1) N1 and P1 with the earliest peak latency, (2) Largest N1 and P1, (3) N1 and P1 that are followed by the largest later components (N2, P2, N3, P3). CS as correlated with electrode location was identified in 3D-MRI co-registered with subdural electrodes. Results: Criteria 1, 2 and 3 located P1 and N1 accurately within the pre- and post-central gyri in 17, 27 and 27 patients, respectively. The distance between the electrodes with N1 and P1 was shorter in Criterion 3 (mean 1.4 cm) than Criterion 1 (2.5 cm) (p < 0.01) and Criterion 2 (1.7 cm) (p < 0.05). Conclusion: The identification of a phase reversal of N1 and P1 with following large amplitude potentials is highly predictive of CS location. doi:10.1016/j.clinph.2007.05.027
17. Evoked potentials Involvement of sensory system in generalized dystonia – Evaluation of premovement gating in somatosensory evoked potentials (SEPs)—K. Kimura, Y. Nomura, Y. Nagao, K. Hachimori, Masami Segawa, Masaya Segawa (Segawa Neurological Clinic for Children, Tokyo, Japan) To evaluate the involvement of the sensory system in generalized dystonia, the attenuation (gating) of SEPs before and during finger movements was examined in seven patients with Segawa disease (12–63 y), 4 DYT1 (15–19 y) and with 10 normal controls (15– 51 y). For midmovement gating, SEPs over the frontal and hand sensory area leads were elicited by the median nerve stimulation at rest and during active thumb dorsiflexion movements. The frontal N30 (FrN30) was equally attenuated during movement compared with SEPs at rest, both in patients and normal controls.