changes seen by NIRS appear to reflect hemodynamic compromisein the human brain.

doi:10.1016/j.clinph.2009.02.137

132. SREDA-like discharges in a patient with Parkinson’s dis-ease—Yuji Kanamori, Hiroshi Shigeto, Ayumi Sakata, Jun-ichiKira, Shozo Tobimatsu (Kyushu University, Fukuoka, Japan)

Subclinical rhythmic electrographic discharges of adults (SREDA)is a rare pattern reported in fewer than 0.05% of patients. We docu-mented SREDA-like discharges in a patient with Parkinson’s disease(PD). A 59-year-old woman was admitted to our hospital due toslowly progressive motor disturbance of her left arm. On examina-tion, she had left-dominant rigidity without autonomic and cogni-tive dysfunctions. Brain MRI showed a mild diffuse cerebralatrophy and SPECT revealed the hypoperfusion in the right thalamusand bifrontal areas. Her symptoms improved by L-DOPA, and thuswe diagnosed her with PD. She underwent EEGs twice. In both tests,we found the repetitive discharges characterized by an abrupt onsetduring hyperventilation: occipital dominant theta waves precededby delta waves appeared and evolved repeatedly, lasting 4–5 min.While these discharges were observed, her consciousness was alertand she had no symptoms. These discharges seemed to be SREDA,however, they lasted for long time and showed slower frequencies.

doi:10.1016/j.clinph.2009.02.138

133. Transcranial magnetic stimulation and neural networks—Takenori Uozumi, Kouichiro Yoshinaga (University of Occupa-tional Environmental Health, Kitakyushu, Japan)

Background: A effect on brain activity by transcranial magneticstimulation (TMS) can now be studied by new approaches thatsimultaneously combine TMS with neuroimaging methods, such asfunctional MRI and near-infrared spectroscopy (NIRS). We showacute BOLD MRI changes or remote effect after 5 Hz rTMS.

Method: Twelve healthy subjects were studied in 3 T MR scannerafter suprathreshold 5 Hz rTMS over M1. We used cluster volumeacquisition method.

Results: TMS activated motor association areas, including BA 40,BA 44 and BA5/7, but TMS elicited on detectable activity in M1 andS1 area.

Conclusion: The present finding support that BOLD MRI changeselicited by rTMS remains for a few seconds and high-frequency rTMSseems to have a greater impact on non-primary motor areas thanprimary motor area. This combining TMS with neuroimaging tech-niques may lead to developing research attempting to ascertainfunctional neural networks and more efficient therapeuticapplications.

doi:10.1016/j.clinph.2009.02.139

134. Advocacy of a new variable for assessment of sleep apneasyndrome—Mitsuo Sato (Tokyo Medical and Dental University,Tokyo, Japan)

We investigated differences in the depth of hypoxia produced byapneic events of the same duration (30 s) amongst patients with dif-ferent degrees of OSAS according to their AIs (apnea indices). The

relationship between apnea duration (seconds) and fall in oxygensaturation (%) was evaluated by means of a linear regression analy-sis. The fall induced by a 30-s apnea event was designated as the‘‘oxygen desaturation value 30’’ (ODV30). We analyzed the polysom-nographic recordings of 122 OSAS patients who showed significantcorrelations (p < 0.01) between apnea duration and subsequent fallin oxygen saturation and calculated their respective ODV30. TheODV30 of mild, moderate and severe OSAS patients was8.84 ± 2.62% (mean ± SD), 8.25 ± 2.45% and 10.59 ± 3.32%, respec-tively. As AI and BMI increased, ODV30 increased. ODV30 was largerin supine than in non-supine. However, there was no statistical sig-nificance of ODV30 between REM and non-REM sleep, and betweenmales and females. There was no significant correlation betweenODV30 and age, either. Our study shows that fall in oxygen satura-tion is particularly extensive in severe OSAS patients and that fallin oxygen saturation is deepened as obesity increases. We thinkODV30 is a useful variable for evaluating OSAS.

doi:10.1016/j.clinph.2009.02.140

135. Bilateral independent ictal EEG activity in a patient withAicardi syndrome—Kiyoko Watanabe, Katsuhiro Kobayashi,Yoko Ohtsuka (Okayama University Hospital, Okayama, Japan)

A patient with Aicardi syndrome began to have spasms in clustersat age 2 months. Her brain MRI displayed agenesis of the corpus cal-losum, bilateral frontal cortical dysplasia, and periventricular het-erotopias. She had two types of spasms in clusters, each of whichwas associated with its own ictal EEG pattern and symptoms. Onetype was characterized by asymmetrical movement of the extremi-ties, with left-sided high-voltage slow waves in EEG (A). The otherwas characterized by different asymmetrical movement of theextremities, with right-sided high-voltage slow waves in EEG (B).Besides independent clusters of a mixed occurrence of the two typeswere also observed. Time-interval from the beginning of one spasmto the next was regular in each (A) and (B) cluster. n the combinedclusters, (A)- and (B)-type spasms each appeared at a regular inter-val, but the occurrence of one type did not at all influence the occur-rence of the other type. Thus, total agenesis of the corpus callosumand extensive bilateral brain dysplasia might be related to such char-acteristic combined clusters of two types of spasms.

doi:10.1016/j.clinph.2009.02.141

136. Long-term effect of repetitive transcranial magnetic stimu-lation (rTMS) over the premotor cortex for upper limb dystonia—Nagako Murase, Ryo Urushihara, Mari Matsumoto, HidekiShimadu, Kotaro Asanuma, Kenta Satou, Ryuji Kaji (TokushimaUniversity Faculty of Medicine, Tokushima, Japan)

We previously reported the acute effect of repetitive TranscranialMagnetic Stimulation (rTMS) over the premotor cortex for upperlimb dystonia. rTMS was applied for more than 6 months andlong-term effect was examined in 16 patients. Ten patients (63%)showed improvement of more than one point in BFM scale.Increased sensitivity of premotor cortex to subthreshold rTMS indystonia has a therapeutic effect of inducing LTD.

Method: Subthreshold (85% of resting motor threshold) 0.2 HzrTMS was applied and 250 stimuli were delivered to the premotorcortex. Among 93 patients with idiopathic upper limb dystonia, 23(25%) were chosen because they were resistant to the therapies ofbotulinum toxin, lidocaine injection and/or medication.

Society Proceedings / Clinical Neurophysiology 120 (2009) e147–e180 e177