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P5-19 Value of subthalamic nucleus local field potentials recording in predicting stimulation parameters for deep brain stimulation in Parkinson's disease
29th International Congress of Clinical Neurophysiology hand tip position. All the parameters were then evaluated by comparing the UPDRS scores related to characteristics of akinesia and bradykinesia. Results: Parameter of reaction time became larger value according to the UPDRS score increased. Concerning the parameters on correctness, some patterns were observed for each subject. Correlations to UPDRS scores were recognized for some parameters on reaction time and correctness. Conclusions: Some of movement characteristics on PD patients were extracted from the measurement data of visual tracking test. The test adopted in this study was easy to utilize in daily life and hospital. The proposed method will be effective for simple evaluation of movement disorders such as PD. P5-16 Pain related SEP and cortical SEP in Parkinson’s disease T. Hama1 , M. Hirayama1 , T. Hara1 , T. Nakamura1 , G. Sobue1 1 Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan Objective: It is known that various somatic sensory symptoms including pain are observed in patients with Parkinson’s disease (PD). However, it is often difficult to detect these sensory symptoms objectively, and even examination such as nerve conduction velocity does not show abnormality. In this study, we analyzed pain and tactile recognition using electrophysiological technique in patients with PD. Methods: To examine sensory processing in PD, we put an intra-epidermal needle electrode on the face, which specifically stimulates A-delta fibers. Pain related somatosensory evoked potentials (PSEP) were derived from 30 PD patients and 10 normal controls. In addition, we stimulated distal site of median nerve and cortical SEP (CSEP), the ingredient of the latter period of SEP, was derived. In both exams, we assumed Cz as an exploring electrode and linked earlobes as a referenced electrode. We evaluated the amplitudes of N1, P1 potentials derived from both exams. Results: In both studies, PD group demonstrated a significant low amplitude compared to control group. (P < 0.01). Conclusions: The brain regions participating in pain and tactile recognition are reported to be similar. N1, P1 potentials in both PSEP and CSEP represent the brain potential in the medial temporal lobe including amygdala and hippocampus, which is considered to contribute to the emotional processing of sense. In addition, Lewy bodies are observed in this region. It is suggested that our result may reflect pathological abnormality of the medial temporal lobe and may be linked to sensory symptoms in PD. P5-17 Autonomic function and quantitative sensory testing (QST) in PD and PD plus syndromes R. Borgohain1 , A.K. Meena1 , A. Jabeen1 , R.M. Kandadai1 , C.H.V. Muralikrishna1 1 Department of Neurology, Nizam’s Inst. of Medical Sciences, Punjagutta, Hyderabad, India Aim: To evaluate autonomic and quantitative sensory abnormalities in idiopathic PD (IPD) and PD plus patients and correlate them with disease duration and severity. Methods: Thirty-nine patients attending movement disorders clinic with diagnosis of IPD, PSP and MSA-P were included in the study. Other diseases or drugs causing autonomic dysfunction were exclusionary. Detailed history, neurological examination, ENMG, autonomic function testing (AFT) and computer assisted sensory examination (CASE IV) studies were evaluated in all. Results: Among 39 patients, males were 33 (84.6%); IPD were 15 (38.4%), PSP 12 (30.7%), MSA 12 (30.7%). Mean age for patients with PSP, IPD and MSA were 62±5.2, 59.8±9.5 and 56.6±5.3 yrs respectively. Mean duration of disease was 3.2±2.2 years with significantly longer duration in IPD (p = 0.003). AFT abnormalities were seen in 75% of MSA, 46% of IPD and 33.3% of PSP patients. Most common abnormality was heart rate variation to deep breathing (51.2%). Significantly more MSA patients had abnormalities in sympathetic skin response (p = 0.0119) and BP fall on standing (p = 0.003) when compared to IPD and PSP groups. 30:15 ratio was significantly lower in IPD compared to PSP patients (p = 0.024). No patient had peripheral nerve disease either clinically or electrophysiologically. IPD (53.3%) and MSA-P (41.6%) had significantly higher abnormalities on CASE-IV compared to PSP patients (8.1%). There was significant correlation between disease duration and E/I ratios, DBP rise with hand grip, heat and cold perception in IPD; E/I ratios HR on
S131 standing, heat perception in MSA and vibration perception in PSP patients. Disease severity in PD correlated significantly with E/I, Valsalva & 30/15 ratios, DBP rise on handgrip and cold perception. Conclusions: Autonomic dysfunction and QST abnormalities were more common in MSA and IPD compared to PSP. Disease duration and severity correlated with some autonomic and CASE IV parameters. P5-18 Quantitative EMG abnormalities of the external anal sphincter were found in patients with parkinsonism within three months after the first visit R.H. Libelius1 , J.O. Linder2 , L.S. Forsgren2 1 Department of Pharmacology and Clinical Neurosciences, Division of Clinical Neurophysiology, University Hospital, Umea, Sweden, 2 Department of Pharmacology and Clinical Neurosciences, Division of Neurology, University Hospital, Umea, Sweden Objectives: The differential diagnosis in parkinsonian disorders is difficult, especially early in the course of the disease. Current clinical diagnostic criteria are mainly based on clinical features but ancillary tests, e.g. neuroimaging and neurophysiological tests have previously been undertaken in order to try to distinguish the different diagnostic entities form each other. These studies have mainly been conducted in patients with advanced diseases. Therefore it is largely unknown if, and to what extent, anal sphincter EMG abnormalities are present already early in the course of the disease. Methods: During the years 2004 through 2008 we included all new patients presenting with parkinsonism (n = 177) in our catchment area of northern Sweden (142,000 inhabitants), in a population-based prospective cohort study of incident cases. Quantitative external anal sphincter EMG was performed in 43 healthy controls and in 123 patients (definite Parkinson disease (PD) n = 83, probable PD n = 22, progressive supranuclear palsy (PSP) n = 6 and multiple system atrophy (MSA) n = 12) within three months after the first visit and before the initiation of any treatment. The clinical diagnosis used was the diagnosis set at the 12month follow-up visit. Results: Motor unit potential (MUP) duration was significantly increased in PD, probable PD and MSA compared to controls. MUP polyphasia was also increased in patients compared to controls. There were no significant differences of these parameters between patient groups. Conclusions: There were significant anal sphincter EMG abnormalities, in all patient groups as compared to healthy controls investigated within three months of their first visit. There were no statistically significant differences between the findings in patients with definite PD, probable PD, MSA or PSP, possibly due to the few cases in the MSA and PSP groups. Future follow-up may disclose whether the different diagnostic entities will develop EMG abnormalities in varying degree during the course of the disease. P5-19 Value of subthalamic nucleus local field potentials recording in predicting stimulation parameters for deep brain stimulation in Parkinson’s disease F. Yoshida1,2 , I. Martinez-Torres2 , A. Pogosyan2 , E. Holl2 , E. Petersen2 , C.C. Chen2 , T. Tom Foltynie2 , P. Limousin2 , L.U. Zrinzo2 , M.I. Hariz2 , P. Brown2 1 Department of Neurosurgery, Kyushu University, Fukuoka, Japan, 2 Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, UK Objectives: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) can be a highly effective treatment for Parkinson’s disease. However, therapeutic efficacy can be limited by inconsistent targeting of this nucleus. It has been previously shown that an increase in local field potential (LFP) power over the beta frequency band may provide intra-operative confirmation of STN targeting. Here we test whether the depth of this focal increase also helps predict the depth and voltage chosen for chronic stimulation. Methods: We recorded LFPs from the contacts of 57 DBS electrodes as the latter were advanced in 2 mm steps from above to below the intended surgical target point in STN. Results: A spectral peak in the bipolar LFP was recorded in the 11 35 Hz band at the lowest contact pair that underwent a steep but focal change during electrode descent in all but 3 sides. The depth of the initial intraoperative step increase in beta correlated with the depth of the contact
S132 independently chosen for chronic DBS (Spearman’s rho = 0.35, p = 0.01). In addition, the absolute difference between the depths of the initial increase in beta and the contact chosen for chronic DBS correlated with the voltage used for chronic stimulation (rho = 0.322, p = 0.017). Thus more voltage had to be employed if a depth was selected for chronic stimulation that differed from that of the beta generator. Conclusions: On-line spectral analysis of LFPs recorded from the DBS electrode may help identify the optimal therapeutic target in the STN region for DBS. P5-20 Deep brain stimulation of the subthalamic nucleus retrieves the normal REM stage with atonia in Parkinson‘s disease N. Nishida1 , H. Saiki2 , R. Nagata2 , M. Yamanegi2 , T. Murakami3 , K. Kadoh3 , K. Ueda4 , S. Matsumoto2 , J.A. Takahashi1 , M. Ishikawa1 , H. Toda1 1 Department of Neurosurgery, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan, 2 Department of Neurology, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan, 3 Department of Laboratory Medicine, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan, 4 Department of Psychiatry, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan Sleep disturbances are common in Parkinson’s disease (PD). PD-related neuronal degeneration, which contributes to the nocturnal disabilities, progresses caudo-rostrally through brainstem involving the several sleepwake modulators. The aim of this study was to evaluate the effect of deep brain stimulation of the subthalamic nucleus on the PD-related sleep symptoms. We assessed the sleep symptoms of 10 patients (4M/6F, age 57.5±9.8 years, disease duration 12.3±2.7 years) subjectively with PD sleep scale (PDSS) and objectively with polysomnography (PSG) before surgery and after DBS-tuning. The medication and motor symptoms were assessed by levodopa equivalent daily dose (LEDD) and by Unified PD Rating Scale (UPDRS), individually. The locations of the active contacts were evaluated on postoperative MRI, and relative distances from electrophysiologically confirmed STN border were estimated. PDSS total score and item 15 (somnolence) improved significantly. PSG showed improved sleep architecture with decreased wakefulness after sleep onset (WASO) and increased REM sleep, especially REM phase with atonia. Improved PDSS total score correlated with UPDRS motor score and decreased WASO, and PDSS item 15 correlated with atonic REM, respectively. The normal atonic REM-sleep increase was positively correlated with active contacts within the STN border, and was negatively correlated with age, PD duration. This study indicates that not only the alleviated motor symptoms and reduced antiparkinsonian drug burden but also the activated viable REM-modulating neurons could have contributed to the modification of sleep architecture. P5-21 Effects of chronic subthalamic stimulation on electroencephalography in Parkinson’s disease Y. Higuchi1,2 , O. Nagano3 , K. Aoyagi1 , T. Uchiyama4 , I. Shimoyama2 , S. Kuwabara4 , N. Saeki1 1 Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba, Japan, 2 Section for Human Neurophysiology, Research center for Frontier Medical Engineering, Chiba university, Chiba, Japan, 3 Department of Neurosurgery, Chiba Cardiovascular Center, Ichihara, Chiba, Japan, 4 Department of Neurology, Chiba University Graduate School of Medicine, Chiba, Japan Objective: Deep brain stimulation provides improvement of motor fluctuation and severe dyskinesia in advanced Parkinson’s disease. Stimulation of deep brain structure may influence oscillation of in the cortical electroencephalography (EEG). However, electrical artifacts from implantable pulse generator (IPG) make it difficult to performed EEG. We evaluated the effects of beep brain stimulation to EEG with reducing artifact from IPG. Method: We evaluated consecutive 10 patients (4 men and 6 women) with Parkinson’s disease who underwent bilateral subthalamic deep brain stimulation. The disease duration was 5 20 years (mean 12.1 years). The disease status was followings: UPDRS Part I 3.1; Part II (on/off) 9.5/24.1; Part III (on/off) 21.3/51.5; Part IV 8.1. L-dopa equivalent dose (LED) was 974.1 (525 1250) mg. Scalp EEG was recorded at 3 6 weeks after implantation of the intracranial electrodes. After artifact rejection, the
Posters total length of EEG records was 30 s for each setting. Spectral analysis was performed and we detected the artifact from implantable pulse generator (IPG) in preliminary study and deleted band power generated from IPG. Each band power was defined as the ratio to total band power. Following factors effecting to EEG were analyzed: Channel (1 16); stimulation; age; gender; disease duration; preoperative LED; dopa-response (UPDRS part III OFF/ON >2). Statistical analysis was performed using least square method and the significance was defined as P < 0.005. Results: Stimulation-on reduced alpha activity and increased theta activity. Aged patients (>65 years old) and patients with long disease duration (>10 years) had reduced beta and alpha activity and increased theta activity. High pre-surgical LED reduced theta activity and increased beta and alpha activity. Significance: Subthalamic stimulation affects EEG band power in relatively early postoperative state of Parkinson’s disease who underwent surgery for subthalamic deep brain stimulation. Age, disease duration, preoperative LED also affected EEG band power. P5-22 The 20 Hz oscillatory brain activity evoked by high-frequency stimulation of subthalamic nucleus in the patients with Parkinson’s disease N. Nakano1,6 , R. Okada1,6 , K. Nakanishi1 , T. Uchiyama1 , A. Kato1,6 , K. Ikeda2,6 , T. Shibata2,6 , J. Ohta3,6 , T. Tokuda3,6 , S. Shiosaka4,6 , Y. Hara4,6 , N. Tsuyuguchi5,6 1 Department of Neurosurgery, Kinki University, School of Medicine. Osakasayama, Osaka, Japan, 2 Graduate school of Imformation Science Theoretical Life-Science Laboratory, Nara Institute of Science and Technology, Japan, 3 Graduate School of Materials Science, Nara Institute of Science and Technology, Japan, 4 Graduate School of Biological Sciences, Nara Institute of Science and Technology, Japan, 5 Department of Neurosurgery, Osaka City University, Japan, 6 Japan Science and Techonology Agency, Core Research for Evolutional Science and Technology, Japan Objective: Subthalamic nucleus (STN) deep brain stimulation (DBS) has been reported highly effective treatment for the selected patients with advanced Parkinson’s disease. The stimulation parameters, such as amplitude, frequency and rate, are empirically adjusted at times for maximum improvement, because the mechanism of STN DBS is not well understood. Recent reports revealed that the generation of abnormal and involuntary movements of Parkinson’s disease closely correlated to various frequency oscillatory brain activities analyzed with electroencephalogram. Therefore, the change in oscillatory brain activities might be used as an indicator for optimization of deep brain stimulation parameters. Methods: We investigated the changes of electrocorticograms (ECoG) stimulating subthalamic nucleus that might reflect the functional interaction between the cortex and subthalamic nucleus. Five patients with Parkinson’s disease underwent subthalamic nucleus deep brain stimulation. During the operation, ECoG were recorded from the subdural grid electrode place on the ipsilateral motor cortex with low frequency (5 10 Hz) and high frequency (100 160 Hz) stimulation of STN under general anesthesia. The time frequency alteration in ECoG by STN stimulation was analyzed using brain electrical source analysis. Results: It disclosed significant increase in the power of 20 Hz frequency band in the primary motor cortex with high frequency (over 100 Hz) of STN stimulation. This power increase became more prominent as the stimulation point moved from ventral portion to dorsal portion of subthalamic nucleus, which also correlated with improvement of motor symptom of the patients. Conclusions: Our study suggested that 20 Hz oscillatory brain activity in primary motor cortex evoked by stimulation of STN might become a objective index for optimization of stimulation parameter in STN DBS therapy. P5-23 Deep brain stimulation of the subthalamic nucleus improves temperature sensation in Parkinson’s disease T. Maruo1 , Y. Saitoh1 , K. Hosomi1 , H. Kishima1 , M. Hirata1 , T. Goto1 , M. Ali1 , T. Yanagisawa1 , S. Morris1 , T. Yoshimine1 1 Department of Neurosurgery, Osaka University Graduate school of Medicine, Japan Objective: Deep brain stimulation of subthalamic nucleus (STN-DBS) has been shown to be clinically effective for motor symptom of Parkinson’s
S131 standing, heat perception in MSA and vibration perception in PSP patients. Disease severity in PD correlated significantly with E/I, Valsalva & 30/15 ratios, DBP rise on handgrip and cold perception. Conclusions: Autonomic dysfunction and QST abnormalities were more common in MSA and IPD compared to PSP. Disease duration and severity correlated with some autonomic and CASE IV parameters. P5-18 Quantitative EMG abnormalities of the external anal sphincter were found in patients with parkinsonism within three months after the first visit R.H. Libelius1 , J.O. Linder2 , L.S. Forsgren2 1 Department of Pharmacology and Clinical Neurosciences, Division of Clinical Neurophysiology, University Hospital, Umea, Sweden, 2 Department of Pharmacology and Clinical Neurosciences, Division of Neurology, University Hospital, Umea, Sweden Objectives: The differential diagnosis in parkinsonian disorders is difficult, especially early in the course of the disease. Current clinical diagnostic criteria are mainly based on clinical features but ancillary tests, e.g. neuroimaging and neurophysiological tests have previously been undertaken in order to try to distinguish the different diagnostic entities form each other. These studies have mainly been conducted in patients with advanced diseases. Therefore it is largely unknown if, and to what extent, anal sphincter EMG abnormalities are present already early in the course of the disease. Methods: During the years 2004 through 2008 we included all new patients presenting with parkinsonism (n = 177) in our catchment area of northern Sweden (142,000 inhabitants), in a population-based prospective cohort study of incident cases. Quantitative external anal sphincter EMG was performed in 43 healthy controls and in 123 patients (definite Parkinson disease (PD) n = 83, probable PD n = 22, progressive supranuclear palsy (PSP) n = 6 and multiple system atrophy (MSA) n = 12) within three months after the first visit and before the initiation of any treatment. The clinical diagnosis used was the diagnosis set at the 12month follow-up visit. Results: Motor unit potential (MUP) duration was significantly increased in PD, probable PD and MSA compared to controls. MUP polyphasia was also increased in patients compared to controls. There were no significant differences of these parameters between patient groups. Conclusions: There were significant anal sphincter EMG abnormalities, in all patient groups as compared to healthy controls investigated within three months of their first visit. There were no statistically significant differences between the findings in patients with definite PD, probable PD, MSA or PSP, possibly due to the few cases in the MSA and PSP groups. Future follow-up may disclose whether the different diagnostic entities will develop EMG abnormalities in varying degree during the course of the disease. P5-19 Value of subthalamic nucleus local field potentials recording in predicting stimulation parameters for deep brain stimulation in Parkinson’s disease F. Yoshida1,2 , I. Martinez-Torres2 , A. Pogosyan2 , E. Holl2 , E. Petersen2 , C.C. Chen2 , T. Tom Foltynie2 , P. Limousin2 , L.U. Zrinzo2 , M.I. Hariz2 , P. Brown2 1 Department of Neurosurgery, Kyushu University, Fukuoka, Japan, 2 Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, UK Objectives: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) can be a highly effective treatment for Parkinson’s disease. However, therapeutic efficacy can be limited by inconsistent targeting of this nucleus. It has been previously shown that an increase in local field potential (LFP) power over the beta frequency band may provide intra-operative confirmation of STN targeting. Here we test whether the depth of this focal increase also helps predict the depth and voltage chosen for chronic stimulation. Methods: We recorded LFPs from the contacts of 57 DBS electrodes as the latter were advanced in 2 mm steps from above to below the intended surgical target point in STN. Results: A spectral peak in the bipolar LFP was recorded in the 11 35 Hz band at the lowest contact pair that underwent a steep but focal change during electrode descent in all but 3 sides. The depth of the initial intraoperative step increase in beta correlated with the depth of the contact
S132 independently chosen for chronic DBS (Spearman’s rho = 0.35, p = 0.01). In addition, the absolute difference between the depths of the initial increase in beta and the contact chosen for chronic DBS correlated with the voltage used for chronic stimulation (rho = 0.322, p = 0.017). Thus more voltage had to be employed if a depth was selected for chronic stimulation that differed from that of the beta generator. Conclusions: On-line spectral analysis of LFPs recorded from the DBS electrode may help identify the optimal therapeutic target in the STN region for DBS. P5-20 Deep brain stimulation of the subthalamic nucleus retrieves the normal REM stage with atonia in Parkinson‘s disease N. Nishida1 , H. Saiki2 , R. Nagata2 , M. Yamanegi2 , T. Murakami3 , K. Kadoh3 , K. Ueda4 , S. Matsumoto2 , J.A. Takahashi1 , M. Ishikawa1 , H. Toda1 1 Department of Neurosurgery, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan, 2 Department of Neurology, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan, 3 Department of Laboratory Medicine, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan, 4 Department of Psychiatry, Kitano Hospital Tazuke Kofukai Medical Research Institute, Osaka, Japan Sleep disturbances are common in Parkinson’s disease (PD). PD-related neuronal degeneration, which contributes to the nocturnal disabilities, progresses caudo-rostrally through brainstem involving the several sleepwake modulators. The aim of this study was to evaluate the effect of deep brain stimulation of the subthalamic nucleus on the PD-related sleep symptoms. We assessed the sleep symptoms of 10 patients (4M/6F, age 57.5±9.8 years, disease duration 12.3±2.7 years) subjectively with PD sleep scale (PDSS) and objectively with polysomnography (PSG) before surgery and after DBS-tuning. The medication and motor symptoms were assessed by levodopa equivalent daily dose (LEDD) and by Unified PD Rating Scale (UPDRS), individually. The locations of the active contacts were evaluated on postoperative MRI, and relative distances from electrophysiologically confirmed STN border were estimated. PDSS total score and item 15 (somnolence) improved significantly. PSG showed improved sleep architecture with decreased wakefulness after sleep onset (WASO) and increased REM sleep, especially REM phase with atonia. Improved PDSS total score correlated with UPDRS motor score and decreased WASO, and PDSS item 15 correlated with atonic REM, respectively. The normal atonic REM-sleep increase was positively correlated with active contacts within the STN border, and was negatively correlated with age, PD duration. This study indicates that not only the alleviated motor symptoms and reduced antiparkinsonian drug burden but also the activated viable REM-modulating neurons could have contributed to the modification of sleep architecture. P5-21 Effects of chronic subthalamic stimulation on electroencephalography in Parkinson’s disease Y. Higuchi1,2 , O. Nagano3 , K. Aoyagi1 , T. Uchiyama4 , I. Shimoyama2 , S. Kuwabara4 , N. Saeki1 1 Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba, Japan, 2 Section for Human Neurophysiology, Research center for Frontier Medical Engineering, Chiba university, Chiba, Japan, 3 Department of Neurosurgery, Chiba Cardiovascular Center, Ichihara, Chiba, Japan, 4 Department of Neurology, Chiba University Graduate School of Medicine, Chiba, Japan Objective: Deep brain stimulation provides improvement of motor fluctuation and severe dyskinesia in advanced Parkinson’s disease. Stimulation of deep brain structure may influence oscillation of in the cortical electroencephalography (EEG). However, electrical artifacts from implantable pulse generator (IPG) make it difficult to performed EEG. We evaluated the effects of beep brain stimulation to EEG with reducing artifact from IPG. Method: We evaluated consecutive 10 patients (4 men and 6 women) with Parkinson’s disease who underwent bilateral subthalamic deep brain stimulation. The disease duration was 5 20 years (mean 12.1 years). The disease status was followings: UPDRS Part I 3.1; Part II (on/off) 9.5/24.1; Part III (on/off) 21.3/51.5; Part IV 8.1. L-dopa equivalent dose (LED) was 974.1 (525 1250) mg. Scalp EEG was recorded at 3 6 weeks after implantation of the intracranial electrodes. After artifact rejection, the
Posters total length of EEG records was 30 s for each setting. Spectral analysis was performed and we detected the artifact from implantable pulse generator (IPG) in preliminary study and deleted band power generated from IPG. Each band power was defined as the ratio to total band power. Following factors effecting to EEG were analyzed: Channel (1 16); stimulation; age; gender; disease duration; preoperative LED; dopa-response (UPDRS part III OFF/ON >2). Statistical analysis was performed using least square method and the significance was defined as P < 0.005. Results: Stimulation-on reduced alpha activity and increased theta activity. Aged patients (>65 years old) and patients with long disease duration (>10 years) had reduced beta and alpha activity and increased theta activity. High pre-surgical LED reduced theta activity and increased beta and alpha activity. Significance: Subthalamic stimulation affects EEG band power in relatively early postoperative state of Parkinson’s disease who underwent surgery for subthalamic deep brain stimulation. Age, disease duration, preoperative LED also affected EEG band power. P5-22 The 20 Hz oscillatory brain activity evoked by high-frequency stimulation of subthalamic nucleus in the patients with Parkinson’s disease N. Nakano1,6 , R. Okada1,6 , K. Nakanishi1 , T. Uchiyama1 , A. Kato1,6 , K. Ikeda2,6 , T. Shibata2,6 , J. Ohta3,6 , T. Tokuda3,6 , S. Shiosaka4,6 , Y. Hara4,6 , N. Tsuyuguchi5,6 1 Department of Neurosurgery, Kinki University, School of Medicine. Osakasayama, Osaka, Japan, 2 Graduate school of Imformation Science Theoretical Life-Science Laboratory, Nara Institute of Science and Technology, Japan, 3 Graduate School of Materials Science, Nara Institute of Science and Technology, Japan, 4 Graduate School of Biological Sciences, Nara Institute of Science and Technology, Japan, 5 Department of Neurosurgery, Osaka City University, Japan, 6 Japan Science and Techonology Agency, Core Research for Evolutional Science and Technology, Japan Objective: Subthalamic nucleus (STN) deep brain stimulation (DBS) has been reported highly effective treatment for the selected patients with advanced Parkinson’s disease. The stimulation parameters, such as amplitude, frequency and rate, are empirically adjusted at times for maximum improvement, because the mechanism of STN DBS is not well understood. Recent reports revealed that the generation of abnormal and involuntary movements of Parkinson’s disease closely correlated to various frequency oscillatory brain activities analyzed with electroencephalogram. Therefore, the change in oscillatory brain activities might be used as an indicator for optimization of deep brain stimulation parameters. Methods: We investigated the changes of electrocorticograms (ECoG) stimulating subthalamic nucleus that might reflect the functional interaction between the cortex and subthalamic nucleus. Five patients with Parkinson’s disease underwent subthalamic nucleus deep brain stimulation. During the operation, ECoG were recorded from the subdural grid electrode place on the ipsilateral motor cortex with low frequency (5 10 Hz) and high frequency (100 160 Hz) stimulation of STN under general anesthesia. The time frequency alteration in ECoG by STN stimulation was analyzed using brain electrical source analysis. Results: It disclosed significant increase in the power of 20 Hz frequency band in the primary motor cortex with high frequency (over 100 Hz) of STN stimulation. This power increase became more prominent as the stimulation point moved from ventral portion to dorsal portion of subthalamic nucleus, which also correlated with improvement of motor symptom of the patients. Conclusions: Our study suggested that 20 Hz oscillatory brain activity in primary motor cortex evoked by stimulation of STN might become a objective index for optimization of stimulation parameter in STN DBS therapy. P5-23 Deep brain stimulation of the subthalamic nucleus improves temperature sensation in Parkinson’s disease T. Maruo1 , Y. Saitoh1 , K. Hosomi1 , H. Kishima1 , M. Hirata1 , T. Goto1 , M. Ali1 , T. Yanagisawa1 , S. Morris1 , T. Yoshimine1 1 Department of Neurosurgery, Osaka University Graduate school of Medicine, Japan Objective: Deep brain stimulation of subthalamic nucleus (STN-DBS) has been shown to be clinically effective for motor symptom of Parkinson’s