• Journal of Korean Neurosurgical Society
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• 제29권6호
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• pp.778-785
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• 2000

Objectives : Intraoperative neurophysiologic monitoring(INM) is a well known useful method to reduce intraoperative neurological complications during neurosurgical procedures. Furthermore, INM is required in most cerebellopontine angle(CPA) surgery because cranial nerves or brain stem injuries can result in serious complications. Object of this study is to the correlation between the changes of intraoperative monitoring modalities during cerebellopontine angle tumor surgery and post-operative functional outcomes in auditory and facial functions. Material and Methods : Fifty-seven patients who underwent intraoperative neurophysiologic monitoring during CPA tumor surgery were retrospectively reviewed. Their lesions were as follows ; vestibular schwannomas in 42, other cranial nerve schwannomas in seven, meningiomas in five and cysts in three cases. Pre- and postoperative audiologic examinations and facial nerve function tests were performed in all patients. Intraoperative neurophysiologic monitoring modalities includes brainstem auditory evoked potentials(BAEP) and facial electromyographies(EMG). We compared the events of INM during CPA tumor surgeries with the outcomes of auditory and facial nerve functions. Results : The subjects who had abnormal changes during CPA tumor surgery were twenty cases with BAEP changes and facial EMG changes in twenty one cases. The changes of intraoperative neurophysiologic monitoring did not always result in poor functional outcomes. However, most predictable intraoperative monitoring changes were wave III-V complex losses in BAEP and continuous neurotonic activities in facial EMG. Conclusion : These results indicate that intraoperative neurophysiologic monitoring in CPA tumor surgery usually provide predictive value for postoperative functional outcomes.

• 재활복지공학회논문지
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• 제8권2호
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• pp.95-99
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• 2014

양이간섭은 청신경망에서 청각정보를 처리하는 과정의 하나로, 같은 크기의 소리를 두 귀로 번갈아 자극하여 기록한 청성뇌간유발반응(auditory brainstem responses; ABR)으로 확인할 수 있다. 그러나 소리는 두 귀가 동시에 청취하므로, 양이간섭도 서로 다른 강도의 자극을 두 귀에 동시 자극하여 연구할 필요가 있다. 이 연구 목적은 서로 다른 크기의 소리를 두 귀로 동시에 자극하여 기록한 ABR을 통해 양이간섭치(binaural interaction component; BIC)를 획득하는데 있다. 과거 병력이 없고 청력이 정상인 17.8-22.7세 사이 17명의 여자 대학생이 참여하였다. 소리는 한 귀를 90 dB nHL로 고정하고 반대 쪽 귀를 0부터 80 dB nHL까지 10 dB 단위로 변경시킨 click을 동시에 자극하였다. BI 파형은 양이 동일 강도를 자극한 파형에서 비대칭 자극한 파형을 빼어 구하였다(BI = B - (L + R)). BIC는 BI 파형에서 IV-V 복합파 잠복시간과 진폭으로 하였다. BIC 역치(threshold of BIC; t-BIC)는 자극 강도에 따른 BIC 진폭 변화를 통해 구하였다(대응표본 t-검정). BIC는 자극 음강도 0부터 90 dB nHL까지 10 dB마다 정점 잠복시간 4.65, 4.63, 4.57, 4.58, 4.62, 4.6, 4.48, 4.36, 4.23 ms, 골 잠복시간 5.57, 5.51, 5.51, 5.59, 5.61, 5.55, 5.44, 5.28, 5.19 ms, 진폭 .0.32, -0.3, -0.34, -0.32, -0.42, -0.53, -0.54, -0.61, $-0.67{\mu}V$로, t-BIC는 40 dB nHL(p=.001)로 각각 관찰되었다.

• Journal of Audiology & Otology
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• 제25권4호
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• pp.199-208
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• 2021

Background and Objectives: No known studies have investigated the influence of stimulus polarity on the Auditory Brainstem Response (ABR) elicited from level-specific (LS) chirp. This study is important as it provides a better understanding of the stimulus polarity selection for ABR elicited from LS chirp stimulus. We explored the influence of stimulus polarity on the ABR from LS chirp compared to the ABR from click at 80 dBnHL in normal-hearing adults. Subjects and Methods: Nineteen adults with normal hearing participated. The ABRs were acquired using click and LS chirp stimuli using three stimulus polarities (rarefaction, condensation, and alternating) at 80 dBnHL. The ABRs were tested only on the right ear at a stimulus rate of 33.33 Hz. The ABR test was stopped when the recording reached the residual noise level of 0.04 μV. The ABRs amplitudes, absolute latencies, inter-peak latencies (IPLs), and the recorded number of averages were statistically compared among ABRs at different stimulus polarities and stimuli combinations. Results: Rarefaction polarity had the largest ABR amplitudes and SNRs compared with other stimulus polarities in both stimuli. There were marginal differences in the absolute latencies and IPLs among stimulus polarities. No significant difference in the number of averages required to reach the stopping criteria was found. Conclusions: Stimulus polarities have a significant influence on the ABR to LS chirp. Rarefaction polarity is recommended for clinical use because of its larger ABR peak I, III, and V amplitudes than those of the other stimulus polarities.

• 대한청각학회지
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• 제25권4호
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• pp.199-208
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• 2021

Background and Objectives: No known studies have investigated the influence of stimulus polarity on the Auditory Brainstem Response (ABR) elicited from level-specific (LS) chirp. This study is important as it provides a better understanding of the stimulus polarity selection for ABR elicited from LS chirp stimulus. We explored the influence of stimulus polarity on the ABR from LS chirp compared to the ABR from click at 80 dBnHL in normal-hearing adults. Subjects and Methods: Nineteen adults with normal hearing participated. The ABRs were acquired using click and LS chirp stimuli using three stimulus polarities (rarefaction, condensation, and alternating) at 80 dBnHL. The ABRs were tested only on the right ear at a stimulus rate of 33.33 Hz. The ABR test was stopped when the recording reached the residual noise level of 0.04 μV. The ABRs amplitudes, absolute latencies, inter-peak latencies (IPLs), and the recorded number of averages were statistically compared among ABRs at different stimulus polarities and stimuli combinations. Results: Rarefaction polarity had the largest ABR amplitudes and SNRs compared with other stimulus polarities in both stimuli. There were marginal differences in the absolute latencies and IPLs among stimulus polarities. No significant difference in the number of averages required to reach the stopping criteria was found. Conclusions: Stimulus polarities have a significant influence on the ABR to LS chirp. Rarefaction polarity is recommended for clinical use because of its larger ABR peak I, III, and V amplitudes than those of the other stimulus polarities.

• 말소리와 음성과학
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• 제1권4호
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• pp.203-207
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• 2009

Electrically evoked compound action potentials (ECAP) have originated from the distal end of the auditory nerve. ECAP are characterized as the difference between the clearly large trough (N) and the following positive peak (P). N-wave occurs around $200-400\;{\mu}s$ after stimulus onset and P-wave at around $400-800\;{\mu}s$. Contrary to expectations, positive peaked ECAP (pp-ECAP) was dominated by a relatively large-amplitude positive following negative peak. pp-ECAP can be recorded from the sites on or near the surgically exposed nerve trunk in animal models and/or in cases of monophasic stimulation. This study will provide the causes of the appearance of pp-ECAP in cases of cochlear implant recipients using imaging studies and medical records and statistically analysis between N-P and P-N on the amplitude input-output function (amp-I/O) for the prediction of the possibilities of clinical tools. Thirteen children participated in the study and received a Cochlear CI-24RE (CA). ECAP was recorded using auto-NRT (Cochlear Ltd., Australia) at four to five weeks post surgery. pp-ECAP was measured from 36 electrodes and typical ECAP from 220 electrodes. There was no abnormality in the imaging study and operation finding in patients with typical ECAP. pp-ECAP was found at the inner ear anormaly and ossification in imaging study and gel-state inner ear fluid was observed in the operation finding. The amplitude of pp-ECAP increased depending on current intensities, but amp-I/O increase more gradually than in the case of typical ECAP (p=0.003). pp-ECAP is antidromic potential which can record from the inner ear anormaly and ossified cochlear. Amp-I/O also depends on current intensity as well typical ECAP. These results provide a useful tool for audiological evaluation for the spiral ganglion cell status to the value of pp-ECAP.

• Clinical and Experimental Pediatrics
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• 제53권4호
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• pp.607-611
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• 2010

Bickerstaff 뇌간 뇌염은(BBE) 4주 이내의 진행성이며, 비교적 대칭성으로 오는 안근 마비와 실조증, 의식 장애 또는 심부건 반사 항진 등의 임상적 특징을 가지며, 뇌간을 침범하는 타 질환을 배제하였을 때 진단할 수 있는 드문 질환이다. 혈청 또는 뇌척수액의 항 Ganglioside 항체(GM, GD and GQ) 는 때로 BBE의 진단에 도움이 되기도 하며, 뇌 자기 공명 영상, 뇌 척수액 검사, 신경 전도 검사 및 근 전도 검사 등은 진단에 크게 도움이 되지 않는다. 저자들은 안근 마비, 실조증, 언어 운동 장애, 연하 장애, 점진적 사지 마비, 의식 저하 등의 증상을 보이며 혈청과 뇌척수액에서 anti-GM1 항체의 증가를 보여 BBE로 진단하고 면역 글로불린과 스테로이드 치료 후 완치되었던 9세의 여아의 증례를 경험하였기에 문헌 고찰과 함께 이를 보고하는 바이다.

• Journal of Audiology & Otology
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• 제25권1호
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• pp.14-21
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• 2021

Background and Objectives: There is growing interest in the use of the Level-specific (LS) CE-Chirp^® stimulus in auditory brainstem response (ABR) due to its ability to produce prominent ABR waves with robust amplitudes. There are no known studies that investigate the test-retest reliability of the ABR to the LS CE-Chirp^® stimulus. The present study aims to investigate the test-retest reliability of the ABR to the LS CE-Chirp^® stimulus and compare its reliability with the ABR to standard click stimulus at multiple intensity levels in normal-hearing adults. Subjects and Methods: Eleven normal-hearing adults participated. The ABR test was repeated twice in the same clinical session and conducted again in another session. The ABR was acquired using both the click and LS CE-Chirp^® stimuli at 4 presentation levels (80, 60, 40, and 20 dBnHL). Only the right ear was tested using the ipsilateral electrode montage. The reliability of the ABR findings (amplitudes and latencies) to the click and LS CE-Chirp^® stimuli within the same clinical session and between the two clinical sessions was calculated using an intra-class correlation coefficient analysis (ICC). Results: The results showed a significant correlation of the ABR findings (amplitude and latencies) to both stimuli within the same session and between the clinical sessions. The ICC values ranged from moderate to excellent. Conclusions: The ABR results from both the LS CE-Chirp^® and click stimuli were consistent and reliable over the two clinical sessions suggesting that both stimuli can be used for neurological diagnoses with the same reliability.

• 대한청각학회지
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• 제25권1호
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• pp.14-21
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• 2021

Background and Objectives: There is growing interest in the use of the Level-specific (LS) CE-Chirp^® stimulus in auditory brainstem response (ABR) due to its ability to produce prominent ABR waves with robust amplitudes. There are no known studies that investigate the test-retest reliability of the ABR to the LS CE-Chirp^® stimulus. The present study aims to investigate the test-retest reliability of the ABR to the LS CE-Chirp^® stimulus and compare its reliability with the ABR to standard click stimulus at multiple intensity levels in normal-hearing adults. Subjects and Methods: Eleven normal-hearing adults participated. The ABR test was repeated twice in the same clinical session and conducted again in another session. The ABR was acquired using both the click and LS CE-Chirp^® stimuli at 4 presentation levels (80, 60, 40, and 20 dBnHL). Only the right ear was tested using the ipsilateral electrode montage. The reliability of the ABR findings (amplitudes and latencies) to the click and LS CE-Chirp^® stimuli within the same clinical session and between the two clinical sessions was calculated using an intra-class correlation coefficient analysis (ICC). Results: The results showed a significant correlation of the ABR findings (amplitude and latencies) to both stimuli within the same session and between the clinical sessions. The ICC values ranged from moderate to excellent. Conclusions: The ABR results from both the LS CE-Chirp^® and click stimuli were consistent and reliable over the two clinical sessions suggesting that both stimuli can be used for neurological diagnoses with the same reliability.

• 생물정신의학
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• 제19권3호
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• pp.115-120
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• 2012

Objectives : Event-related potentials have been suggested as an objective marker for brain functions in psychiatric disorders. This study was aimed to investigate the relationships between P300, the mismatch negativity (MMN), the loudness dependence of the auditory evoked potential (LDAEP), demographic and clinical variables including neurocognitive abilities in patients with schizophrenia. Methods : P300, the MMN, and the LDAEP were measured and the Korean Stroop color-word test (K-stroop test) and the Wisconsin Card Sorting Test (WCST) were performed in 43 patients with schizophrenia. The relationship of the latency and amplitude of P300 and the MMN as well as regression slope of the LDAEP with demographic and clinical variables were analyzed by t-test and correlation analyses for categorical and continuous variables, respectively. Results : After controlling for age, the latency of central (Cz) and parietal (Pz) P300 posivitively correlated with GAF at admission (Cz ; ${\gamma}$ = 0.385, p = 0.047, Pz ; ${\gamma}$ = 0.421, p = 0.029). The amplitude of parietal P300 correlated with the correction rate of the K-stroop test (${\gamma}$ = 0.575, p = 0.002). In addition, the frontal (Fz) P300 latency tended to negatively correlated with the correction rate of the WCST (${\gamma}$ = -0.371, p = 0.057). Conclusions : Our findings suggest that the values of P300 latency and amplitude might be correlated with GAF at admission and working memory measured by the K-Stroop test and the WCST. Meanwhile, the MMN and the LDAEP did not correlate with demographic and clinical variables. These results support the results of previous studies showing associations with P300 and impaired cognitive ability.

• Journal of Korean Neurosurgical Society
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• 제42권5호
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• pp.355-362
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• 2007

Hemifacial spasm (HFS) is characterized by tonic clonic contractions of the muscles innervated by the ipsilateral facial nerve. Compression of the facial nerve by an ectatic vessel is widely recognized as the most common underlying etiology. HFS needs to be differentiated from other causes of facial spasms, such as facial tic, ocular myokymia, and blepharospasm. To understand the overall craniofacial abnormalities and to perform the optimal surgical procedures for HFS, we are to review the prevalence, pathophysiology, differential diagnosis, details of each treatment modality, usefulness of brainstem auditory evoked potentials monitoring, debates on the facial EMG, clinical course, and complications from the literature published from 1995 to the present time.