• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.211-215
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• 2018

The aim of this study was to preserve the corticospinal tract during surgery and assess more accurately the motor performance in brain tumor patients around the motor cortex. TceMEP is not entirely reliable, even though there has been no change in waveforms due to a mixture of false positive and false negative signals. For a more detailed examination, DCS was employed to selectively stimulate the motor cortex. In both cases, the indications could find the region to which the cortex was responsible, and constantly check and examine the changes in amplitude, thereby preserving the motor pathway and performing surgery. On the other hand, patients who did not implement the DCS but did implement the TceMEP experienced a decrease in their postoperative motor performance. DCS is a very useful examination and it is a method that can reduce the post-surgery disorder that may occur in patients with the TceMEP in brain tumor surgery.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.4
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• pp.468-474
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• 2019

Deep brain stimulation (DBS) is an effective surgical procedure for treating drug refractory movement disorders, and DBS involves delivering high frequency electrical stimulation to deep brain nuclei. Microelectrode recording (MER) is a complementary test that can precisely identify the location of deep brain nuclei, along with MRI correlation, during DBS surgery to improve the surgical outcome and minimize side effects. The purpose of this paper is to analyze the neuro-physiological waveforms and identify the usefulness of MER by analyzing the MER performed during DBS surgery for treating movement disorders. We retrospectively reviewed 28 patients who underwent MER during DBS surgery for movement disorders from January to December 2018. Of the 28 patients, 38 MERs for the subthalamic nucleus (STN), 10 MERs for the globuspallidusinternus (Gpi), and 4 MERs for the ventral intermediate thalamic nucleus (VIM) were performed. In all the cases, the target sites were found and micro-stimulations were used to check for side effects and to readjust the target sites. The clinical symptoms of all 28 patients improved after surgery. In conclusion, MER is a useful test that employs neuro-physiological waveforms to accurately identify the deep brain nuclei, along with MRI correlation, to improve the DBS surgical outcomes for movement disorders and to minimize side effects.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.723-730
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• 2018

Objective : The aim of the present study was to identify whether the deformity angular ratio (DAR) influences the occurrence of complications after posterior vertebral column resection (PVCR) and to establish the DAR cut-off value. Methods : Thirty-six consecutive patients undergoing PVCR from December 2010 to October 2016 were reviewed. The relationships between the total, sagittal, and coronal DAR and complications were assessed using receiver operator characteristics curves. The patients were divided into two groups according to a reference value based on the cut-off value of DAR. Demographic, surgical, radiological, and clinical outcomes were compared between the groups. Results : There were no significant differences in the patient demographic and surgical data between the groups. The cut-off values for the total DAR (T-DAR) and the sagittal DAR (S-DAR) were 20.2 and 16.4, respectively (p=0.018 and 0.010). Both values were significantly associated with complications (p=0.016 and 0.005). In the higher T-DAR group, total complications (12 vs. 21, p=0.042) and late-onset complications (3 vs. 9, p=0.036) were significantly correlated with the T-DAR. The number of patients experiencing complications (9 vs. 11, p=0.029) and the total number of complications (13 vs. 20, p=0.015) were significantly correlated with the S-DAR. Worsening intraoperative neurophysiologic monitoring was more frequent in the higher T-DAR group (2 vs. 4) than in the higher S-DAR group (3 vs. 3). There was no difference in neurological deterioration between the groups after surgery. Conclusion : Both the T-DAR and the S-DAR are risk factors for complications after PVCR. Those who had a T-DAR >20.2 or S-DAR >16.4 experienced a higher rate of complications after PVCR.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.470-476
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• 2018

Facial motor evoked potential (FMEP) by multi-pulse transcranial electrical stimulation (mpTES) can complement free-running electromyography (EMG) and direct facial nerve stimulation to predict the functional integrity of the facial nerve during cerebello-pontine angle (CPA) tumor surgery. The purpose of this paper is to examine the standardized test methods and the usefulness of FMEP as a predictor of facial nerve function and to minimize the incidence of facial paralysis as an aftereffect of surgery. TES was delivered through electrode Mz (cathode) - M3/M4 (anode), and extracranially direct distal facial muscle excitation was excluded by the absence of single pulse response (SPR) and by longer onset latency (more than 10 ms). FMEP from the orbicularis oris (o.oris) and the mentalis muscle simultaneously can improve the accuracy and success rate compared with FMEP from the o.oris alone. Using the methods described, we can effectively predict facial nerve outcomes immediately after surgery with a reduction of more than 50% of FMEP amplitude as a warning criterion. In conclusion, along with free-running EMG and direct facial nerve stimulation, FMEP is a useful method to reduce the incidence of facial paralysis as a sequela during CPA tumor surgery.