4. Sequential mapping of small positive spikes preceding focal epileptic discharge

4. Sequential mapping of small positive spikes preceding focal epileptic discharge

e148 Society Proceedings / Clinical Neurophysiology 120 (2009) e147–e180 SpO2 wave was delayed and/or lowered in ischemic areas. Principle component...

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e148

Society Proceedings / Clinical Neurophysiology 120 (2009) e147–e180

SpO2 wave was delayed and/or lowered in ischemic areas. Principle component analysis was used to analyze statistically. The weights of principal component in the ischemic regions were reduced, and these findings agreed with IMP-SPECT findings. Conclusions: The regional attenuation of the oxy-hemoglobin wave reflects the state of cerebral ischemia. This method uses oxyhemoglobin as a tracer of OT. It can be utilized as a noninvasive method to assess the cerebral ischemia. doi:10.1016/j.clinph.2009.02.009

4. Sequential mapping of small positive spikes preceding focal epileptic discharge—Harumi Yoshinaga, Katsuhiro Kobayashi, Tomoyuki Nakahori, Yoko Ohtsuka (Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan) Purpose: Small positive spikes preceding rolandic spikes have been paid attention. To clarify the significance of such preceding positive spikes (PPS), we investigated the focal spikes characteristic of two types of benign partial epilepsies in childhood and those observed in febrile seizures (FS). Subjects and methods: In 13 patients with rolandic epilepsy (RE), 16 patients with Panayiotopoulos syndrome (PS), and 10 patients with FS, we applied the sequential mapping method on the averaged focal spikes selected by automatic spike analysis system, and compared (the rate of) the existence of PPS in these three groups. Results: Rolandic spikes accompanied PPS in 7 of 13 patients (53.8%) with RE and 5 of 11 patients (45.5%) with PS, but none of 5 patients with FS. With occipital spikes, PPS was demonstrated in 4 of 5 patients (80.0%) with PS, but only one of 5 patients (20.0%) with FS. Conclusion: PPS is not specific to rolandic spikes in RS with sylvian seizures, and it is also detected in rolandic and occipital spikes observed in PS, but rare in those of FS. This finding suggests the strong correlation of PPS with epileptogenesis.

suggest the PSS is associated with the intense activation of bilateral SII and a weak activation of ipsilateral SI. doi:10.1016/j.clinph.2009.02.011

6. Effects of MuSK-antibodies on neuromuscular transmission— Takayasu Fukudome 1, Masakatsu Motomura 2 (1 Nagasaki Medical Center of Neurology, Nagasaki, Japan, 2 Graduate School of Biomedical Sciences, Nagasaki, Japan) Objective: To search for effects of IgG on neuromuscular transmission, using autoantibodies (Abs) against MuSK and soluble mouse MuSK-6His protein (SmMuSK). Background: Passive transfer of IgG from MuSK-MG induces neuromuscular defects similar to those observed in IgG from AChR-MG. Design/methods: (1) SmMuSK was purified from HEK293. (2) IgG purified from one MuSK-MG patient was mixed with SmMuSK (mixed-IgG) and anti-MuSK Abs was reassayed. (3) Purified IgGs from three AChR-MG patients, IgGs from three MuSK-MG patients, mixed-IgG and IgGs from three healthy controls were injected in BKTO mice. Twenty-four to forty-eight hours after injection, MEPPs and EPPs were recorded from the diaphragm. RESULTS: Anti-MuSK Abs was not detected in mixed-IgG. The control MEPP amplitude was 1:35  0:06 (mean  SE), decay time of MEPP (Þ was 1:63  0:05, and m was 35:5  2:9. In mice treated with AChR-MG and MuSK-MG IgG, the amplitude of MEPP was 0:73  0:04 and 0:88  0:06;  was 1:78  0:05 and 2:53  0:08, and m was 39:9  2:5 and 38:5  2:3, respectively. In mice treated with mixed-IgG, the amplitude of MEPP was 0:99  0:07;  was 2:35  0:12, and m was 47:2  3:5. Conclusion: (1) Either AChR-MG or MuSK-MG IgG significantly reduces MEPP amplitude in recipient mice but  was significantly prolonged with MuSK-MG IgG. (2) These physiological changes were not attenuated with mixed-IgG. doi:10.1016/j.clinph.2009.02.012

doi:10.1016/j.clinph.2009.02.010

5. Induced phantom somatic sensation with a mirror activates SI and SII regions: An fMRI study—Jun Takasugi, Kenji Numata, Daisuke Matsuzawa, Takashi Murayama, Masahiko Monma, Ken Nakazawa, Eiji Shimizu (Chiba University, Chiba, Japan)

7. Magnetic lumbosacral motor root stimulation with a flat large round coil—Hideyuki Matsumoto, Fitri Octaviana, Ritsuko Hanajima, Yasuo Terao, Masashi Hamada, Akihiro Yugeta, Satomi Inomata-Terada, Setsu Nakatani-Enomoto, Shoji Tsuji, Yoshikazu Ugawa (University of Tokyo, Tokyo, Japan)

It has been reported that somatic sensation of the limb behind a mirror is induced by the observation of the tactile stimulation on the other limb reflected in the mirror. However, the neurophysiological basis of this phenomenon (phantom somatic sensation, PSS) is not clear. Our study aims to identify the brain areas related to PSS. Fifteen right-handed healthy volunteers were enrolled and subjected to a blocked design fMRI study. A mirror was placed vertically on the subjects’ chests so as to see the mirror image of their right hands overlapped with their left hands. During the EPI scans, subjects’ right thumb was touched to induce PSS on the left thumb (mirror session, MS). Then, the mirror plane was hid by a white paper, and the right thumb was touched (non-mirror session, NMS). In subtractive fMRI images (MS > NMS), right primary somatosensory area (SI) (BA3, 2) was activated. While those who felt PSS clearly in the MS showed the bilateral intense activations in the secondary somatosensory area (SII), those who did not felt PSS showed weak activations in the SII. Our results

The aim of this study is to develop a reliable method for supramaximal magnetic spinal motor root stimulation (MRS) for lower limb muscles using a specially devised coil. Forty-two healthy subjects were recruited. We used a coil of diameter 20 cm named Magnetic Augmented Translumbosacral Stimulation coil (MATS coil). Compound muscle action potentials (CMAPs) were recorded from the abductor hallucis muscle. Their CMAPs were compared with those obtained by MRS using a conventional round or double coil and also those by high-voltage electrical stimulation. MATS coil evoked CMAPs to supramaximal stimulation in 80 out of 84 nerves. By contrast, round and double coils elicited supramaximal CMAPs in only 15 and 18 out of 84 nerves, respectively. The CMAP size to MRS with the MATS coil was the same as that to high-voltage electrical motor root stimulation. MATS coil enables us to achieve supramaximal stimulation of the lumbosacral spinal nerves. The CMAPs to supramaximal stimulation are requisite for the measurement of amplitude and area for detection of conduction blocks. MATS coil