• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.13.1-13.7
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• 2015

Background: This study evaluated Somatosensory evoked potentials (SEP), Quantitative sensory testing (QST), and thermography as diagnostic methods for nerve injury. Methods: From 2006 through 2011, 17 patients (mean age: 50.1 years) from ${\bigcirc}{\bigcirc}{\bigcirc}{\bigcirc}$ Hospital who sought care for altered sensation after dental implant treatment were identified. The mean time of objective assessment was 15.2 months after onset. Results: SEP of Inferior alveolar nerve(IAN) was $15.87{\pm}0.87ms$ on the normal side and $16.18{\pm}0.73ms$ on the abnormal side. There was delayed N20 latency on the abnormal side, but the difference was not statistically significant. In QST, the abnormal side showed significantly higher scores of the current perception threshold at 2 KHz, 250 Hz, and 5 Hz. The absolute temperature difference was $0.55^{\circ}C$ without statistically significance. Conclusion: These results indicate that QST is valuable as an objective method for assessment of nerve injury.

• Annals of Clinical Neurophysiology
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• 제8권2호
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• pp.158-162
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• 2006

Background: It has been proposed that proprioceptive input can modulate neural excitability in both primary motor cortices (M1) simultaneously, although direct evidence for this is still lacking. Previous studies showed that proprioceptive accuracy of one hand is reduced after the application of one-Hz repetitive transcranial magnetic stimulation (rTMS) for 15 minutes over the contralateral somatosensory cortex. The aim of this study was to investigate the effect of rTMS-induced central proprioceptive deafferentation to excitability of both M1 as reflected in ipsilateral and contralateral motor evoked potentials (MEP). Methods: MEPs of both abductor pollicis bravis (APB) muscles were recorded using single-pulse TMS over right M1 in seven healthy subjects. Immediately after one-Hz rTMS was applied for 15 minutes over the right somatosensory cortex, the MEP measurement was repeated. The proprioceptive function of the left thumb was assessed, before and after rTMS, using a position-matching task. Results: There was an increase in ipsilateral MEP after the rTMS: whereas no MEPs were recorded on the ipsilateral hand before the rTMS, MEPs were recorded in both ipsilateral and contralateral hand in three of seven subjects. At the same time, the mean log amplitude was reduced and the mean latency was prolonged in the contralateral MEP. Conclusions: rTMS-induced central proprioceptive deafferentation reduces the MEP generation in the contralateral hand, and fascilitates that in the ipsilateral hand. A further study with a larger sample seems warranted to confirm this finding and to elucidate the neurophysiology underlying it.

• 대한임상검사과학회지
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• 제48권3호
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• pp.262-268
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• 2016

편측성 안면경련(hemifacial spasm)은 불수의적으로 안면의 근육에서 발작적인 경련이 일측성으로 반복해서 발생하는 질환이다. 한 근육의 수축으로 인해 동시적으로 여러 근육이 동시에 수축되는 동시 수축성(synkinesia)이 특징이다. 발병원인은 제 7뇌신경인 안면신경이 혈관에 의해 압박을 받아서 나타나게 된다. 본 연구는 편측성 안면경련 환자의 미세혈관 감압 수술을 받은 환자를 대상으로 수술 중 진행되는 신경계 감시검사 방법들에 대해 다루었다. 청각유발전위 검사에서는 수술용 뇌 견인기의 사용시 주의 사항과 검사시기에 대해 언급하였다. 안면신경의 근전도검사에서는 잡파의 혼입과 신경손상 시 근전도 파형의 감별에 대해, 측면전파 반응 검사에서는 마취의 유지의 중요성에 대해 그리고 체성감각 유발전위검사에서는 환자를 좀더 자세하게 검사할 수 있도록 새로운 방법을 제안하였다. 위에 언급한 내용들을 토대로 검사한다면 수술 중 신경계 감시 검사를 원활하게 할 수 있으리라 생각된다.

• 대한임상검사과학회지
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• 제51권4호
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• pp.453-461
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• 2019

수술 중 발생하는 신경계 손상 여부를 감별하는 검사인 수술 중 신경계 모니터링(intraoperative neurophysiological monitoring, INM) 검사는 다양한 수술에서 안정적으로 수술이 잘 진행되고 있음을 확신하며 수술을 진행할 수 있도록 도움을 주는 매우 중요한 검사다. 수술실이라는 특수한 환경에서 검사의 최적화를 위하여 침 전극을 사용하여 검사를 진행하며, 수술실검사에 대하여 정확한 자극부위와 측정부위에 대한 교재나 안내책자가 없는 것이 실정이다. 그래서 이번 논문에서 운동유발전위검사, 체성감각유발전위검사, 청각유발전위검사, 시각유발전위검사에서 올바른 자극부위와 측정부위에 대하여 자세하게 설명을 하였다. 그리고 자유진행 및 유발근전도검사(free-running and triggered EMG)는 근육에서 발생하는 근전도의 관찰로 대부분의 뇌신경(cranial nerve)과 척수신경근(spinal nerve root)의 기능상태 파악을 한다. 검사의 이해를 돕기 위해 각각의 해당 근육에 전극을 삽입하는 사진을 첨부하였고, 척수신경근에 따른 해당근육도 표로 제시하였다. 검사 후 전극제거를 할 때에도 환자와 검사자 모두 안전한 방법을 제시하여 보다 완벽한 검사가 되었으면 한다.

• Journal of Korean Neurosurgical Society
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• 제51권5호
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• pp.286-291
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• 2012

Objective : To investigate the change of latency of cervical dermatomal somatosensory evoked potential (DSEP) according to stimulation intensity (SI) and severity of carpal tunnel syndrome (CTS). Methods : Stimulation sites were the C6, C7, and C8 dermatomal areas. Two stimulation intensities $1.5{\times}$sensory threshold (ST) and $2.5{\times}ST$ were used on both normal and CTS patients. Results : In moderate CTS, the latencies of C6 and C7 DSEP during $1.5{\times}ST$ SI and those of C7 DSEP during $2.5{\times}ST$ SI were significantly delayed compared with the values of normal subjects. Significant correlation between the latency of C7 DSEP of $2.5{\times}ST$ stimulation and the median sensory nerve conduction velocity was observed. Conclusion : We suggest that these data can aid in the diagnosis of cervical sensory radiculopathy using low stimulation intensity and of those who have cervical sensory radiculopathy combined with CTS patients.

• Annals of Clinical Neurophysiology
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• 제5권2호
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• pp.181-186
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• 2003

Background: Somatosensory evoked potential (SSEP) is valuable for the evaluation of the central pathway. However, peripheral neuropathy sometimes renders the test useless by preventing the conduction from reaching the CNS. We postulated that the peripheral conduction problems could be overcome by proximal stimulation in SSEP and wanted to verify this in the study. Methods: Twenty patients with diabetic sensorimotor polyneuropathy were included. SSEP was elicited by stimulating the median and posterior tibial nerves. We compared the effect of distal and proximal stimulations in each SSEP in the aspect of presence/absence and various latencies of resultant waves. Results: Among the 40 cases, proximal stimulation caused reappearance of subsided waves in 10 cases (25%). In the median nerve SSEP, proximal stimulation made EN1 and CN2 visible which were not evident when distally stimulated. In the posterior tibial nerve SSEP, there was also improvement of forming waves when proximally stimulated. Conclusions: In the diabetic polyneuropathy, proximal stimulation of SSEP is more effective than the conventional distal stimulation in evaluating central pathway.

• 대한두개안면성형외과학회지
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• 제20권4호
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• pp.223-227
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• 2019

Background: Neurosensory changes are frequently observed in the patients with mid-face fractures, and these symptoms are often caused by infraorbital nerve (ION) damage. Although ION damage is a relatively common phenomenon, there are no established and objective methods to evaluate it. The aim of this study was to test whether trigeminal somatosensory evoked potential (TSEP) could be used as a prognostic predictor of ION damage and TSEP testing was an objective method to evaluate ION injury. Methods: In this prospective TSEP study, 48 patients with unilateral mid-face fracture (only unilateral blow out fracture and unilateral zygomaticomaxillary fracture were included) and potential ION damages were enrolled. Both sides of the face were examined with TSEP and the non-traumatized side of the face was used as control. We calculated the latency difference between the affected and the unaffected sides. Results: Twenty-four patients recovered within 3 months, and 21 patients took more than 3 months to recover. The average latency difference between the affected side and unaffected side was 1.4 and 4.1 ms for the group that recovered within 3 months and the group that recovered after 3 months, respectively. Conclusion: Patients who suffered ION damage showed prolonged latency when examined using the TSEP test. TSEP is an effective tool for evaluation of nerve injury and predicting the recovery of patients with ION damage.

• Annals of Clinical Neurophysiology
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• 제1권2호
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• pp.112-117
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• 1999

부중심소엽 주변의 경막하 전극들에서 기록한 PTSEP는 전극의 위치에 따라 다양한 파형을 나타내며, 파형의 최대치는 주로 부중심소엽의 후 상부에 위치한다. 특히 최대값이 주변보다 확연히 차이 나며 10uV이상의 파형으로 기록될 경우는 40 msec에서 양극성을 나타낸다. 또한 주변의 전극과 상역전을 형성할 수 있는데 최대 전극의 뒤에서 형성될 경우는 더욱 분명한 상역전을 관찰할 수 있다. 따라서 경막하전극을 통한 PTSEP는 내측 반구의 부중심소엽 주변의 위치를 파악하는데 도움을 줄 수 있다고 생각된다.

• Journal of Korean Neurosurgical Society
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• 제63권2호
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• pp.202-209
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• 2020

Objective : The purpose of this study was to evaluate the efficacy of the anterior approach following intraoperative reduction under general anesthesia in patients with cervical facet fracture and dislocation. Methods : Twenty-three patients with single level cervical facet fracture and dislocation who were subjected to the anterior approach alone following immediate intraoperative reduction under general anesthesia from March 2013 to December 2017 were enrolled in this study. Neurological status, clinical outcome, and radiological studies were evaluated preoperatively, postoperatively, and during the follow-up period. Results : The cohort comprised 15 men and eight women with a mean age of 57 years (from 24 to 81). All patients were operated on within the first 8 hours following the injury. After gentle manual reduction or closed reduction with Gardner-Wells traction, under general anesthesia monitored by somatosensory-evoked potentials, all operations were successfully completed using the anterior approach alone except in two patients, who had a risk of over-distraction. In them, a satisfactory gentle manual reduction or closed reduction was not possible, and required open posterior reduction of the locked facets followed by anterior cervical discectomy and fusion. In one patient, screw retropulsion was observed in 1 month after surgery. There were no reduction-related complications or neurological aggravations after surgery. All patients showed evidence of stability at the instrumented level at the final follow-up (mean follow-up, 12 months). Conclusion : Anterior approach following intraoperative reduction monitored by somatosensory-evoked potentials under general anesthesia for cervical dislocation and locked facets is a relatively safe and effective alternative when cervical alignment is achieved by intraoperative reduction.

• 대한두개안면성형외과학회지
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• 제23권2호
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• pp.59-63
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• 2022

Background: Deformational plagiocephaly is usually managed conservatively, as it tends to improve over time and with the use of conservative measures. However, before the year 2017 we operated on patients with severe plagiocephaly and neurological symptoms at the Helsinki Cleft Palate and Craniofacial Center. Methods: Of the 20 infants with severe deformational plagiocephaly and neurological symptoms referred to us between 2014 and 2016, 10 underwent cranioplasty open reshaping of the posterior cranial vault. The parents of the last 10 patients were given information on the natural history of the condition and the patients were followed up with an outpatient protocol. The aim of this study was to gain information on the brain electrophysiology and recovery of patients after total cranial vault reconstruction by measuring the electroencephalogram (EEG) somatosensory evoked potentials (SEP; median nerve). Results: Of the 10 participants in the operation arm, six had abnormal SEP at least on the affected cerebral hemisphere and all SEPs were recorded as normal when controlled postoperatively. In the follow-up arm, eight out of 10 participants had abnormal SEP at the age of approximately 24 months, and all had normalized SEPs at control visits. Conclusion: Our data suggest that cranioplasty open reshaping of the posterior cranial vault did not affect abnormal SEP-EEG recordings. We have abandoned the operations in deformational plagiocephaly patients due to findings suggesting that expanding cranioplasty is not beneficial for brain function in this patient group.