• Title/Summary/Keyword: Somatosensory Evoked Potentials

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The Impact of Optical Illusions on the Vestibular System

  • Ozturk, Seyma Tugba;Serbetcioglu, Mustafa Bulent;Ersin, Kerem;Yilmaz, Oguz
    • Korean Journal of Audiology
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    • v.25 no.3
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    • pp.152-158
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    • 2021
  • Background and Objectives: Balance control is maintained in stationary and dynamic conditions, with coordinated muscle responses generated by somatosensory, vestibular, and visual inputs. This study aimed to investigate how the vestibular system is affected in the presence of an optical illusion to better understand the interconnected pathways of the visual and vestibular systems. Subjects and Methods: The study involved 54 young adults (27 males and 27 females) aged 18-25 years. The recruited participants were subjected to the cervical vestibular evoked myogenic potentials (cVEMP) test and video head impulse test (vHIT). The cVEMP and vHIT tests were performed once each in the absence and presence of an optical illusion. In addition, after each test, whether the individuals felt balanced was determined using a questionnaire. Results: cVEMP results in the presence of the optical illusion showed shortened latencies and increased amplitudes for the left side in comparison to the results in the absence of the optical illusion (p≤0.05). When vHIT results were compared, it was seen that the right lateral and bilateral anterior canal gains were increased, almost to 1.0 (p<0.05). Conclusions: It is thought that when the visual-vestibular inputs are incompatible with each other, the sensory reweighting mechanism is activated, and this mechanism strengthens the more reliable (vestibular) inputs, while suppressing the less reliable (visual) inputs. As long as the incompatible condition persists, the sensory reweighting mechanism will continue to operate, thanks to the feedback loop from the efferent vestibular system.

Effects of Robot-assisted Therapy on Lower Limb in Patients with Subacute Stroke (아급성기 뇌졸중 환자에서의 로봇 보조 보행훈련 효과)

  • Kim, Ji Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.7
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    • pp.459-466
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    • 2016
  • This study examined the effects of robot-assisted therapy on the motor and functional recovery of the lower limbs in 53 subacute stroke patients. Robot-assisted therapy was performed using Lokomat? (Hocoma AG, Zurich, Switzerland) for thirty minutes per day, five times a week for four weeks. The outcome measures used were the Fugl-Meyer assessment, Motricity index(MI), Functional ambulation category(FAC), Berg balance scale(BBS) for gait function and balance ability, 10m walking test, K-Modified Barthel Index(K-MBI) for the activities of daily living and Mini mental state examination (MMSE), and Beck's depression inventory(BDI) for depression. All patients recruited underwent these evaluations before and after the four week robot-assisted therapy. For the evaluation, the somatosensory evoked potentials were used to assess the functional recovery. Robot-assisted therapy on the lower limb after subacute stroke showed improvement in motor strength, gait function, and the activities of daily living. All changes in terms of MI, FAC, BBS, and K-MBI exhibited a statistically significant difference after the four weeks robot-assisted therapy. The somatosensory evoked potential result showed a correlation with the MI and K-MBI. Robot-assisted therapy is believed to facilitate the motor and functional recovery of the lower limb in subacute stroke patients.

Association of Sexual Disorders with Peripheral Neuropathy in Alcohol Dependence (주정의존에서 성기능장애와 말초신경염의 연관성)

  • Cheon, Jin-Sook;Han, Ho-Sung;Kim, Kee-Chan;Jung, Ho-Joong
    • Korean Journal of Biological Psychiatry
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    • v.4 no.1
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    • pp.108-115
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    • 1997
  • The alcoholic neuropathies developed in approximately 34% of chronic alcoholics and the sexual dysfunction had been experienced in 8-54% of male alcoholics(Schiavi 1990). The aims of this study were to identify the prevalence of subclinical polyneuropathies and sexual disorders in alcohol dependence, and to evaluate the association between them. The nerve conduction velocity(NCV), electromyography(EMG), and pudendal somatosensory evoked potentials(SEPs) were tested for the male alcoholics(N=34) and controls(N=17 for NCV & EMG, N=25 for pudendal SEPs). The pudendal SEPs were measured by the following procedures, in which we stimulated the dorsal nerve of penis attached by the ring electrode(stimulus intensity, three times of threshold : stimulus rate, 1-4.7Hz : stimulus duration, 0.1 or 0.2msec), and recorded at the scalp(active electrode, 2cm behind Cz : reference electrode, Fz). The NCV and EMG detected signs of peripheral neuropathies in 79.4% of alcoholics. Among the alcoholics, 64.7% were abnormal on the pudendal SEPs. Among the alcoholics who revealed abnormality on EMG and NCV, 81.4% were abnormal on the pudendal SEPs, in which 51.9% were not responded. The P1 latencies of pudendal SEPs on neuropathic alcoholics were significantly delayed(p<0.05) than non-neuropathic alcoholics. There was a relative correlation between peripheral neuropathies and sexual disorders in the alcoholics. The prevalence of subclinical neuropathies and sexual disorders seemed to be much higher in alcohol dependence than expectation, and these two problems were relatively correlated, and our results suggested that the peripheral polyneuropathies were one of the prerequisites of sexual disorders.

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EFFECTS OF LIDOCAINE ON SOMATOSENSORY EVOKED POTENTIALS IN RAT VIBRISSA/BARREL CORTEX (리도카인이 흰쥐 피질의 체성감각 유발전위에 미치는 영향)

  • Choi, Byung-Ju;Lee, Hye-Sook;Kim, Young-Jin;Nam, Soon-Heoun;Kim, Hyun-Jung;Lee, Maan-Gee G
    • Journal of the korean academy of Pediatric Dentistry
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    • v.23 no.3
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    • pp.582-592
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    • 1996
  • 본 실험은 삼차신경 자극으로 발생되는 체성 감각 유발 전위에 대한 국소마취제의 효과를 관찰하였다. 나트륨 통로차단을 통하여 약리작용을 나타내는 것으로 알려져 있는 리도카인를 뇌 피질에 국소 투여한 후 삼차신경의 체성 감각유발 전위의 강도및 지연시간을 측정하였다. 케타민으로 마취된 흰쥐의 대측성 구레나룻 자극후 뇌의 체성 감각영역으로부터 기록되는 유발전위를 분석한 결과, 리도카인을 뇌 피질에 국소 투여시 유발전위의 강도 및 지연시간의 감소가 나타났으며, 필드 전위의 형태는 이상성 (양극성 및 음극성) 혹은 삼상성 (양극성, 음극성 및 양극성) 의 파형으로 나타났다. 필드 전위의 발생 부위는 뇌 피질의 중대뇌동맥의 상행지 상방영역이었다. 본 실험에서 나타난 초기 전위변동은 피질판 상층에 존재하는 신경세포의 탈분극 과청에 의하여 생성되고 후기의 전위 변동은 동일 영역의 하층 신경세포에서 과분극 혹은 재분극이 발생한 결과라고 유추된다. 따라서 삼차신경계의 체성 감각 영역에서는 피질 상층및 하층의 과립성 피라미드 세포의 순차적인 활성화에 의하여 기본적인 신경 회로망이 형성되어 있으며 생리적 자극으로 유발되는 필드 전위는 이러한 신경망를 통하여 발생될 것으로 사료된다.

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The Analysis of Research Trend about Management of Low Back Pain (요통관리에 관한 연구동향 분석)

  • Hyun, Kyung-Sun
    • The Korean Journal of Rehabilitation Nursing
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    • v.1 no.1
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    • pp.51-60
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    • 1998
  • The result of studying papers about management of lower back pain published in domestic and foreign nursing and medical magazines in these 10 years is as follows ; 1. General characteristic of lower back pain ; 1) In sex distribution, there were more men than women in 5 papers and more women than men in 4 papers among 9 papers surveryed. 2) In age distribution, thirties to forties of patients had more lower back pain as surveyed by general hospitals and fifties to sixties of patients had more lower back pain as surveyed by oriental medical hospitals. 3) In cause factor, there were 50 to 65% of sprain, 32 to 44% of herniated intervertebral disc and 13 to 29% of degenerative changes. 4) In symtom distribution, there were 26 to 57% of lower back pain, 42 to 65% of lower back pain with radiating pain and 34 to 99% of paravertevral muscle spasm. 5) In period of pain management distribution, 18 to 40% of patients experienced pain for less than 6 months and 59 to 82% of them experienced pain for more than 6 months in 3 papers among 4 papers. 6) In surveying the treatment, 66 to 88% of patients had conservative treatment and there were treatments of general hospital, oriental medicine, self remedy and traditional practice in conservative treatment. 7) In job distribution, 12 to 50% of them were housekeepers, 23 to 31% office workers, 4.6 to 36% blue color workers and 11 to 15% students. 2. As psychological character lower back pain paients had anxiety, depression, anger-hostility, phobic anxiety, neurasthenia, hypochondriasis, and interpersonal sensitivity. 3. To distinguish the cause of lower back pain, plain lumbar roentgenogram, straight leg rasing test, eletromyelogic findings, somatosensory evoked potentials CT and MRI were performed. 4. To relieve lower back pain. epidural adhesiolysis, epidulal injection of local anesthetic in mixture with steroid, lumbar spinal root block, low level laser therapy, acupuncture like transcutaneous nerve stimulation(AL TENS), topical capsaicin and lumbar orthotics were used in medical field, and relaxation technique was used in nursing field. 5. Mckenzie's extension exercise and William's flexsion exercise for lower back pain were used in medical field and Yoga exercise was applied in nursing field. 6. The more school education and self efficacy were high, the better they had active coping lower back pain positively and the less self efficacy was the more they had serious pain. As a result of studying the paper there have been very little research for lower back pain in nursing fields of Korea and foreign countries. Because 60 to 80% of population expeience lower back pain at least more than once, it is necessary to develop the study and clinical practice for management of lower back pain.

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Effects of Human Mesenchymal Stem Cell Transplantation Combined with Polymer on Functional Recovery Following Spinal Cord Hemisection in Rats

  • Choi, Ji Soo;Leem, Joong Woo;Lee, Kyung Hee;Kim, Sung-Soo;SuhKim, Haeyoung;Jung, Se Jung;Kim, Un Jeng;Lee, Bae Hwan
    • 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.

Radiographic, MRI and Histopathologic Assessment to Standardize Canine Spinal Cord Injury Model (척수손상 모델 견 표준화를 위한 방사선, 자기공명영상 및 조직 병리 평가)

  • Seong, Yun-Sang;Yun, Sung-Ho;Park, Jai-Soon;Kim, Hee-Kyung;Chang, Yong-Min;Ku, Sae-Kwang;Park, Hyun-Jeong;Jang, Kwang-Ho
    • Journal of Veterinary Clinics
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    • v.27 no.5
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    • pp.546-552
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    • 2010
  • Previous studies could not offer available guideline to decide size of balloon and grade of injury before induction of spinal cord injury (SCI) because grade of SCI was assessed after inserting a catheter and each experimental animal were different in body size and weight as well as in species. This study was performed to provide guideline for standardized SCI model. Eight healthy adult beagle dogs that had 8 mm of spinal canal height were assigned to four groups according to the diameter of balloon and compression time: 4 mm/3hrs, 4 mm/6hrs, 4 mm/12hrs and 6 mm/3hrs group. Radiography was performed to standardize between experimental animal and balloon before selecting balloon diameter to induce SCI. Behaviors outcomes, somatosensory evoked potentials (SEPs), magnetic resonance imaging (MRI) and histopathological examination were evaluated. Behaviors outcomes and SEPs were not available to assess grade of SCI and those only indicate SCI. The damaged area was revealed clear hyperintensity on STIR image and T2WI after induction of SCI. The hyperintense area on MRI was cranially and caudally expanded with increasing of the diameter of balloon or the compression time. Well corresponded to expanding of hyperintense area on MRI, the damaged region and the numbers of caspase-3 and PARP immunoreactive cells were increased on histopathological findings. Therefore, these results will be considered fundamental data to induce standardized SCI model in experimental animal that has various weight and size.