• Title/Summary/Keyword: Visual evoked potential

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Eyeblinks, EP Augmenting / Reducing and Personality (눈깜작임, 증감뇌유발전위와 성격의 상호관계)

  • Lee, Sung-Hoon;Haier, Richard J.
    • Sleep Medicine and Psychophysiology
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    • v.1 no.2
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    • pp.156-162
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    • 1994
  • Objectives: Eyeblinking varied depending on individual cognitive abilities or personality traits thought to related to brain mechanisms of sensory modulation. This study explored whether personality traits are related to the rate of eye blinks and how eyeblink and evoked potential augumenting-reducing(EPAR) interact Methods: Forty four students were studied with EPAR topography to explore how eyeblinks, personality and EPAR interact The Zuckerman Sensation Seeking Scale(SSS) and Eysenck Personality Questionnaire(EPQ) were used as personality measured by a stimulus response program during EP study. Results: Rate of blink increased as intensity of light increased. The General(GEN), Thrill and Adventure Seeking(TAS), Experience Seeking(ES) and Disinhibition(DS) subscales in SSS and Extraversion-Introversion(E) subscale in EPQ showed significant negative correlations with number of eyeblinks in the hightest intensity of light, whereas Neuroticism(N) subscales in EPQ showed a positive correlation. Correlation between number of eyeblinks with the brightest light and EPAR slope varied topographically. The strongest positive correlation was noted in right posterior temporal area. Conclusion: High sensation seekers blinked significantly fewer times than lower sensation seeker did. Higher personality correlations with eyeblink than with EP may imply that the eyeblink works as a primary filter since it is more directly related to central mechanisms of sensory modulation than EP. The right posterior temporal area may play an important role in modulation of visual stimuli.

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Development of Retinal Prosthesis Module for Fully Implantable Retinal Prosthesis (완전삽입형 인공망막 구현을 위한 인공망막모듈 개발)

  • Lee, Kang-Wook;Kaiho, Yoshiyuki;Fukushima, Takafumi;Tanaka, Tetsu;Koyanagi, Mitsumasa
    • Journal of Biomedical Engineering Research
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    • v.31 no.4
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    • pp.292-301
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    • 2010
  • To restore visual sensation of blind patients, we have proposed a fully implantable retinal prosthesis comprising an three dimensionally (3D) stacked retinal chip for transforming optical signal to electrical signal, a flexible cable with stimulus electrode array for stimulating retina cells, and coupling coils for power transmission. The 3D stacked retinal chip is consisted of several LSI chips such as photodetector, signal processing circuit, and stimulus current generator. They are vertically stacked and electrically connected using 3D integration technology. Our retinal prosthesis has a small size and lightweight with high resolution, therefore it could increase the patients` quality of life (QOL). For realizing the fully implantable retinal prosthesis, we developed a retinal prosthesis module comprising a retinal prosthesis chip and a flexible cable with stimulus electrode array for generating optimal stimulus current. In this study, we used a 2D retinal chip as a prototype retinal prosthesis chip. We fabricated the polymide-based flexible cable of $20{\mu}m$ thickness where 16 channels Pt stimulus electrode array was formed in the cable. Pt electrode has an impedance of $9.9k{\Omega}$ at 400Hz frequency. The retinal prosthesis chip was mounted on the flexible cable by an epoxy and electrically connected by Au wire. The retinal prosthesis chip was cappted by a silicone to pretect from corrosive environments in an eyeball. Then, the fabricated retinal prosthesis module was implanted into an eyeball of a rabbit. We successfully recorded electrically evoked potential (EEP) elicited from the rabbit brain by the current stimulation supplied from the implanted retinal prosthesis module. EEP amplitude was increased linearly with illumination intensity and irradiation time of incident light. The retinal prosthesis chip was well functioned after implanting into the eyeball of the rabbit.

A Case of Neuroblastoma Presenting with Sudden Blindness (실명을 주소로 한 신경아세포종 1예)

  • Ma, In-Youl;Hah, Jeong-Ok;Kim, Chun-Dong;Lee, Tae-Sook
    • Journal of Yeungnam Medical Science
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    • v.2 no.1
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    • pp.259-264
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    • 1985
  • Neuroblastoma is the most common extracranial solid tumor of childhood which presents various clinical symptoms depending on the primary and metastatic sites. However, it has been rarely reported that sudden onset of blindness was the chief complaint of neuroblastoma. A four years old boy was admitted to the Yeungnam University Hospital with the chief complaint of a sudden onset of blindness due to a distant metastasis of abdominal neuroblastoma to the sphenoid sinus. On admission, both side pupils were dilated without light reflex, fundoscopy showed pale optic disk, electroretinogram was subnormal and visual evoked potential showed no response. The liver was palpable in $3{\frac{1}{2}}$ finger breadth from the right costal margin and adult fist sized mass was palpable in the right flank. Skull X-ray showed destructed sphenoid bone and clinoid process and brain CT scan showed tumor mass in the sphenoid sinus and left orbit. Ultrasonogram and CT scan of the abdomen showed large tumor masses around the right kidney and para-aortic and retropancreatic lymph node. IVP showed displaced right calyceal system with preserved contour. Left supraclavicular lymph node which appeared after admission was biopsied and it showed poorly differentiated neuroblasts. He was treated according to the multiagent chemotherapy schedule for stage IV neuroblastoma patient of children's cancer study group. Abdominal tumor masses and sphenoid sinus mass were markedly reduced after 2 courses of the combination chemotherapy of cyclophosphamide, vincristine, DTIC, adriamycin and VM-26. Eventhough the blindness was not improved, the patient has been in good clinical condition.

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Proposal on the Diagnostic Criteria of Definite Isolated Otolith Dysfunction

  • Park, Han Gyeol;Lee, Jun Ho;Oh, Seung Ha;Park, Moo Kyun;Suh, Myung-Whan
    • Journal of Audiology & Otology
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    • v.23 no.2
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    • pp.103-111
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    • 2019
  • Background and Objectives: Dizzy patients with abnormal otolith function tests, despite a normal caloric response, are defined as having specific (isolated) otolith organ dysfunction. This study was performed to compare the differences in clinical presentation between isolated otolith dysfunction (iOD) patients with lab- and Sx-based iOD group and lab-based iOD symptoms. Subjects and Methods: The medical records of 23 iOD patients with normal caloric response but abnormal cervical vestibular evoked myogenic potential (VEMP), ocular VEMP, or subjective visual vertical were reviewed. Non-spinning vertigo was considered as otolith-related symptoms. The patients' age, onset of dizziness, Numeric Rating Scale on the severity of dizziness, and concomitant vestibular disorders were analyzed. Results: Patients in the lab-based iOD group were significantly older than those in the lab- and Sx-based iOD group. Known vestibular disorders were significantly more common in the lab-based iOD group (83.3%) compared to the lab- and Sx-based iOD group (18.2%). Despite the normal caloric response, catch-up saccade was found in the video head impulse test in more than half (54.5%) of the lab-based iOD group patients. There was no catch-up saccade in the lab- and Sx-based iOD group. There were no significant differences in gender ratio, frequency of dizziness attacks, and duration of illness. Conclusions: We propose new definitions of definite iOD (lab- and Sx-based iOD) and probable iOD (lab- or Sx-based iOD). These new definitions may help researchers to identify patients who are more likely to have true iOD, and facilitate comparisons of results between different studies.

Proposal on the Diagnostic Criteria of Definite Isolated Otolith Dysfunction

  • Park, Han Gyeol;Lee, Jun Ho;Oh, Seung Ha;Park, Moo Kyun;Suh, Myung-Whan
    • Korean Journal of Audiology
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    • v.23 no.2
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    • pp.103-111
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    • 2019
  • Background and Objectives: Dizzy patients with abnormal otolith function tests, despite a normal caloric response, are defined as having specific (isolated) otolith organ dysfunction. This study was performed to compare the differences in clinical presentation between isolated otolith dysfunction (iOD) patients with lab- and Sx-based iOD group and lab-based iOD symptoms. Subjects and Methods: The medical records of 23 iOD patients with normal caloric response but abnormal cervical vestibular evoked myogenic potential (VEMP), ocular VEMP, or subjective visual vertical were reviewed. Non-spinning vertigo was considered as otolith-related symptoms. The patients' age, onset of dizziness, Numeric Rating Scale on the severity of dizziness, and concomitant vestibular disorders were analyzed. Results: Patients in the lab-based iOD group were significantly older than those in the lab- and Sx-based iOD group. Known vestibular disorders were significantly more common in the lab-based iOD group (83.3%) compared to the lab- and Sx-based iOD group (18.2%). Despite the normal caloric response, catch-up saccade was found in the video head impulse test in more than half (54.5%) of the lab-based iOD group patients. There was no catch-up saccade in the lab- and Sx-based iOD group. There were no significant differences in gender ratio, frequency of dizziness attacks, and duration of illness. Conclusions: We propose new definitions of definite iOD (lab- and Sx-based iOD) and probable iOD (lab- or Sx-based iOD). These new definitions may help researchers to identify patients who are more likely to have true iOD, and facilitate comparisons of results between different studies.

Nerve Injuries after the Operations of Orbital Blow-out Fracture (안와골절 수술 후 발생한 신경손상)

  • Choi, Jae Il;Lee, Seong Pyo;Ji, So Young;Yang, Wan Suk
    • Archives of Craniofacial Surgery
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    • v.11 no.1
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    • pp.28-32
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    • 2010
  • Purpose: In accordance with the increasing number of accidents caused by various reasons and recently developed fine diagnostic skills, the incidence of orbital blow-out fracture cases is increasing. As it causes complications, such as diplopia and enophthalmos, surgical reduction is commonly required. This article reports a retrospective series of 5 blow-out fracture cases that had unusual nerve injuries after reduction operations. We represents the clinical experiences about treatment process and follow-up. Methods: From January 2000 to August 2009, we treated total 705 blow-out fracture patients. Among them, there were 5 patients (0.71%) who suffered from postoperative neurologic complications. In all patients, the surgery was performed with open reduction with insertion of $Medpor^{(R)}$. Clinical symptoms and signs were a little different from each other. Results: In case 1, the diagnosis was oculomotor nerve palsy. The diagnosis of the case 2 was superior orbital fissure syndrome, case 3 was abducens nerve palsy, and case 4 was idiopathic supraorbital nerve injury. The last case 5 was diagnosed as optic neuropathy. Most of the causes were extended fracture, especially accompanied with medial and inferomedial orbital blow-out fracture. Extensive dissection and eyeball swelling, and over-retraction by assistants were also one of the causes. Immediately, we performed reexploration procedure to remove hematomas, decompress and check the incarceration. After that, we checked VEP (visual evoked potential), visual field test, electromyogram. With ophthalmologic test and followup CT, we can rule out the orbital apex syndrome. We gave $Salon^{(R)}$ (methylprednisolone, Hanlim pharmaceuticals) 500 mg twice a day for 3 days and let them bed rest. After that, we were tapering the high dose steroid with $Methylon^{(R)}$ (methylprednisolon 4 mg, Kunwha pharmaceuticals) 20 mg three times a day. Usually, it takes 1.2 months to recover from the nerve injury. Conclusion: According to the extent of nerve injury after the surgery of orbital blow-out fracture, the clinical symptoms were different. The most important point is to decide quickly whether the optic nerve injury occurred or not. Therefore, it is necess is to diagnose the nerve injury immediately, perform reexploration for decompression and use corticosteroid adequately. In other words, the early diagnosis and treatment is most important.

Effects of Repetitive High Frequency Motor Cortex Transcranial Magnetic Stimulation and Cortical Disinhibition in Diabetic Patients with Neuropathic Pain: A Case Control Study (신경병성 통증이 있는 당뇨 환자에서 반복 경두개 자기자극치료의 효과 및 피질 탈억제 현상: 환자 대조군 연구)

  • Han, Yong;Lee, Chan Ho;Min, Kyung Wan;Han, Kyung Ah;Choi, Hyo Seon;Kang, Youn Joo
    • Clinical Pain
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    • v.18 no.1
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    • pp.1-7
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    • 2019
  • Objective: To investigate the cortical disinhibition in diabetic patients with neuropathic pain and without pain. In addition, we assessed the cortical disinhibition and pain relief after repetitive transcranial magnetic stimulation (rTMS). Method: We recruited diabetic patients with neuropathic pain (n = 15) and without pain (n = 15). We compared the TMS parameters such as motor evoked potential (MEP) amplitude, cortical silent period (CSP), intracortical inhibition (ICI %) and intracortical facilitation (ICF %) between two groups. Moreover, we evaluated the changes of pain and TMS parameters after five consecutive high frequency (10 Hz) rTMS sessions in diabetic patients with neuropathic pain. The neuropathic pain intensity (visual analog scale) and TMS parameters were assessed on pre-rTMS, post-rTMS 1day, and post-rTMS 5 day. Results: The comparison of the CSP, ICI % revealed significant differences between two groups (p<0.01). After rTMS sessions, the decrease in pain intensity across the three time points revealed a pattern of significant differences (p<0.01). The change of CSP and ICI % across the three test points revealed a pattern of significant differences (p<0.01). The ICI % revealed immediate increase after first rTMS application and significant increase after five rTMS application (p<0.01) in diabetic patients with neuropathic pain. The MEP amplitude and ICF % did not reveal any significant changes. Conclusion: Our findings demonstrate that cortical inhibition was decreased in diabetic patients with neuropathic pain compared with patients without pain. Furthermore, we also identified that five daily rTMS sessions restored the defective intracortical inhibition which related to improvement of neuropathic pain in diabetic patients.