• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.281-288
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• 2001

Objectives : The purpose of this study is to evaluate the usefulness of SSEP monitoring during intracranial aneurysm surgery and compare the characteristics of wave change in relation to neurologic changes between ACA aneurysms and MCA aneurysms. Methods : During recent three years(between January 1997 and November 1999), intraoperative SSEP monitoring had been done in 63 operations for intracranial aneurysms. We had monitored the median nerve SSEP during surgery for aneurysms of MCA and the posterior tibial nerve SSEP for aneurysms of ACoA or ACA. A more than 50% reduction of any cortical SEP response was considered to be a significant SEP change, compared to its baseline value before the start of surgery. Changes in the SEPs were categorized as follows : Type IA, no significant amplitude changes without temporary clipping ; Type IB, no significant amplitude changes with temporary clipping ; Type II, significant changes with temporary clipping and complete return to control amplitude ; Type III, significant changes with temporary clipping and incomplete return to control amplitude ; Type IV, significant changes with temporary clipping and more decreased amplitude changes. Results : Among the 63 intraoperative monitoring, there were 37 cases of ACA aneurysms(An), and 26 of MCA An. The temporary proximal arterial occlusion during surgery were performed in 31(83.8%)cases of ACA An, 22(84.6%) of MCA An. Seven of the 31 ACA An(22.6%) and ten of the 22 MCA An(45.5%) had significant changes. The type were as follows : 4 patients with type II and 3 with type III in the ACA An ; 3 patients with type II and 3 with type III and 4 with type IV in the MCA An. In both group type II changes had no new postoperative neurological deficit. All 6 patients with type III had new neurological deficits ; However, One case in the ACA An and two cases in the MCA An. had transient neurologic deficit and improved markedly over the next two months. All 4 type IV changes in the MCA An. had permanant neurologic deficits. Two out of 30 cases(6.7%) in the ACA An. and one out of 16 cases(6.3%) in the MCA An. without significant amplitude change had new neurologic deficit postoperatively. Conclusion : Based on this study, Intraoperative SSEP monitoring during aneurysm surgery would provide useful information for detecting cerebral ischemia. SSEP response during surgery for MCA An. is more sensitive than ACA An. Otherwise, there were no meaningful difference in rate of false negativity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2170-2178
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• 2014

In this paper, electroencephalographic (EEG) signal of one among subjects measured biosignal with visual evoked stimuli inducing the concentration was analyzed to detect the changes in the attention status during attention task fulfillment from January to February, 2011. The independent component analysis (ICA) was applied to EEG signals to isolate the attention related innate source signal within the brain and Electroculogram (EOG) artifact from measured EEG signals at the scalp. The consecutive accumulation of short time Fourier transformed (STFT) attention source signal with excluded EOG artifact can enhance the regular depiction of EPOCH graph and spectral color map representing time-varying pattern. The extracted attention indices associated with somatosensory rhythm (SMR: 12-15 Hz), and theta wave (4-7 Hz) increase marginally over time. Throughout experimental observation, the ICA with STFT can be used for the assessment of participants' status of attention.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.5 no.1
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• pp.45-58
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• 2007

This study aims to examine the effects on nociceptive neuron excitability by application of electroacupuncture and Meloxicam gel in rat with inflammation. It used 24 rats for experiment, divided them into control group, electroacupuncture group(EA group), Meloxicam group(ME group), combination of electroacupuncture with Meloxicam group(EA+ME group), caused hyperalgesia by injecting ${\lambda}$-carrageenan into hindpaw and conducted treatment three times for experimental period. Noxious flexion withdrawal reflex(NFR) and somatosensory evoked potential(SEP) were measured immediately after induction, at 24 hours, 48 hours and 72 hours after induction. Change of NFR(reaction time, RMS) showed no significant differences among EA group, Meloxicam group, and EA+Meloxicam group, but all treatment groups showed significant differences compared to control group from 48 hours. In NFR threshold, there were significant differences between EA+Meloxicam and other groups. In SEP amplitude, there were significant differences between EA+Meloxicam and control group from 48 hours. This study showed that EA+Meloxicam gel had an effect on nociceptive neurone excitability. Therefore, it is considered that appropriate combination of anti-inflammatory drug with electroacupuncture for pain control will be very desirable.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.954-958
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• 2000

In the removal of small subcortical lesion in the eloquent area like sensory-motor cortex, the prevention of neurologic deficit is important. We present our technique of identification of M-1, S-1 cortex in a case of subcortical granuloma located in sensorymotor cortex. To accurately localize mass, stereotactic craniotomy was planned. At the beginning of procedure, functional MRI of motor cortex was done with stereotactic headframe in place. Next, the stereotactic craniotomy about 4 cm was done under propofol anesthesia for cortical mapping. After reflection of dura, central sulcus was identified with phase-reversal response of intraoperative SEP(somatosensory evoked potential) of contralateral median nerve. Then the patient was awakened, and direct cortical stimulation was done. We observed the muscle contractions of elbow, hand and fingers and the paresthesia over forearm, hand, fingers on the M-1 and S-1 cortex. Through cortical mapping and stereotactic guidance, we concluded that the mass lie immediately posterior to central sulcus, then the mass was carefully removed through small transsulcal approach, opening about 1 cm of rolandic sulcus.

• The Journal of Korean Physical Therapy
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• v.19 no.1
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• pp.67-78
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• 2007

Purpose: The purpose of this study were to examine the anti-hyperalgesic effects of combination of electroacupuncture and microcurrent on anti-hyperalgesia in local hyperalgesia zone. Methods: It used 24 rats for experiment, divided them into control group, electroacupuncture group (EA group), microcurrent group (MC group), combination of electroacupuncture with microcurrent (EA+MC group), caused hyperalgesia by injecting ${\lambda}-carrageenan$ into hindpaw. Thickness of hindpaw, mechanical pain threshold (MPT), thermal pain threshold (TPT), noxious flexion withdrawal reflex (NFR) and somatosensory evoked potential (SEP) were measured immediately after induction, at 24 hours, 48 hours and 72 hours after induction. The electrical stimulation was given once a day for three days, 20min per session. Results: Change of thickness, MPT, and TPT showed significant difference in all groups compared to control group. In particular, there were remarkable difference in EA+ME group. In particular there were remarkable differences in EA group and EA+MC group. Change of NFR(% threshold, % reaction time, % RMS) and SEP showed mainly significant differences in EA group and EA+ME group compared to control group. In particular, there were remarkable difference in EA+ME group. Conclusion: The above results suggest that appropriate combination of microcurrent with electroacupuncture for pain control will be very desirable.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.6
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• pp.405-411
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• 2012

The spontaneous axon regeneration of damaged neurons is limited after spinal cord injury (SCI). Recently, mesenchymal stem cell (MSC) transplantation was proposed as a potential approach for enhancing nerve regeneration that avoids the ethical issues associated with embryonic stem cell transplantation. As SCI is a complex pathological entity, the treatment of SCI requires a multipronged approach. The purpose of the present study was to investigate the functional recovery and therapeutic potential of human MSCs (hMSCs) and polymer in a spinal cord hemisection injury model. Rats were subjected to hemisection injuries and then divided into three groups. Two groups of rats underwent partial thoracic hemisection injury followed by implantation of either polymer only or polymer with hMSCs. Another hemisection-only group was used as a control. Behavioral, electrophysiological and immunohistochemical studies were performed on all rats. The functional recovery was significantly improved in the polymer with hMSC-transplanted group as compared with control at five weeks after transplantation. The results of electrophysiologic study demonstrated that the latency of somatosensory-evoked potentials (SSEPs) in the polymer with hMSC-transplanted group was significantly shorter than in the hemisection-only control group. In the results of immunohistochemical study, ${\beta}$-gal-positive cells were observed in the injured and adjacent sites after hMSC transplantation. Surviving hMSCs differentiated into various cell types such as neurons, astrocytes and oligodendrocytes. These data suggest that hMSC transplantation with polymer may play an important role in functional recovery and axonal regeneration after SCI, and may be a potential therapeutic strategy for SCI.