• The Journal of Korean Medicine
• /
• v.28 no.3 s.71
• /
• pp.289-298
• /
• 2007

Objectives : Electrical acupoint stimulation (EAS) has been used to treat motor dysfunction of stroke patients with reportedly effective results. The purpose of this study was to evaluate the efficacy of EAS with different frequencies in treating motor dysfunction of ischemic stroke patients. Methods : The subjects of this study were sixty-two ischemic stroke patients with motor dysfunction at Kyunghee Oriental Medicine Hospital who were hospitalized for one week to one month from onset. They were treated with 2Hz or 120Hz EAS for two weeks, and motor evoked potentials (MEP) were measured before and after EAS treatment. To compare the effect of 2Hz EAS with 120Hz, we measured latency, central motor conduction time (CMCT) and amplitude of MEP before and after EAS treatment. Results : After two weeks of treatment, we compared MEP data of the affected side between the 2Hz group and the 120Hz group. The 2Hz group showed more significant improvement than the 120Hz group in latency, CMCT and amplitude (P=0.008, 0.002, 0.002). In case of the affected side MEP data divided by normal side MEP data, the 2Hz group also showed improvement on latency, CMCT and amplitude with significant differences (P=0.003, 0.000, 0.008). Conclusions : These results suggest that low frequency EAS activates the central motor conduction system better than high frequency EAS, and it means that EAS with low frequency is more helpful for motor recovery after ischemic stroke than that with high frequency.

• Journal of Korean Neurosurgical Society
• /
• v.64 no.1
• /
• pp.78-87
• /
• 2021

Objective : Intraoperative neurophysiological monitoring (IONM) has been widely used during spine surgery to reduce or prevent neurologic deficits, however, its application to the surgical management for cervical myelopathy remains controversial. This study aimed to assess the success rate of IONM in patients with cervical myelopathy and to investigate the factors associated with successful baseline monitoring and the effect of increasing the stimulation intensity by focusing on motor evoked potentials (MEPs). Methods : The data of 88 patients who underwent surgery for cervical myelopathy with IONM between January 2016 and June 2018 were retrospectively reviewed. The success rate of baseline MEP monitoring at the initial stimulation of 400 V was investigated. In unmonitorable cases, the stimulation intensity was increased to 999 V, and the success rate final MEP monitoring was reinvestigated. In addition, factors related to the success rate of baseline MEP monitoring were investigated using independent t-test, Wilcoxon rank-sum test, chi-squared test, and Fisher's exact probability test for statistical analysis. The factors included age, sex, body mass index, diabetes mellitus, smoking history, symptom duration, Torg-Pavlov ratio, space available for the cord (SAC), cord compression ratio (CCR), intramedullary increased signal intensity (SI) on magnetic resonance imaging, SI length, SI ratio, the Medical Research Council (MRC) grade, the preoperative modified Nurick grade and Japanese Orthopedic Association (JOA) score. Results : The overall success rate for reliable MEP response was 52.3% after increasing the stimulation intensity. No complications were observed to be associated with increased intensity. The factors related to the success rate of final MEP monitoring were found to be SAC (p<0.001), CCR (p<0.001), MRC grade (p<0.001), preoperative modified Nurick grade (p<0.001), and JOA score (p<0.001). The cut-off score for successful MEP monitoring was 5.67 mm for SAC, 47.33% for the CCR, 3 points for MRC grade, 2 points for the modified Nurick grade, and 12 points for the JOA score. Conclusion : Increasing the stimulation intensity could significantly improve the success rate of baseline MEP monitoring for unmonitorable cases at the initial stimulation in cervical myelopathy. In particular, the SAC, CCR, MRC grade, preoperative Nurick grade and JOA score may be considered as the more important related factors associated with the success rate of MEP monitoring. Therefore, the degree of preoperative neurological functional deficits and the presence of spinal cord compression on imaging could be used as new detailed criteria for the application of IONM in patients with cervical myelopathy.

• Annals of Clinical Neurophysiology
• /
• v.1 no.2
• /
• pp.126-146
• /
• 1999

In clinical neurology various different electrophysiological tests are widely used to demonstrate the unsuspected malfunctioning in the nervous system and to monitor over time the clinical status of patients. In addition clinical neurologists and neurosurgeons take advantage of the intraoperative monitorings to increase the quality of neurosurgical operations in the posterior fossa, in the spinal cord, or in visual pathways. In the field of movement disorders, elecrophysiolgical tests provide neurologists with making accurate differential diagnoses with useful therapeutic stratergies as well as with investigating the pathophysiological machanisms. By using the electromyographic tests it could be possible for us to evaluate the types of blephalospasm, the extent of hemifacial spasm, the level of myoclonus, and the prime muscles of torticollis etc. Sometimes the myographic guidance may be critical for choosing the exact injecting site of botulinum toxin. These several decades various electroencephalographic and evoked potential tests has been utilized in the electrophysiological laboratories to understand the basic pathophysiology of myoclonus, spasticity and other central motor dysfunctions. It could be one of the breakthroughs in the area of behavorial neurology that the brain function can be mapped by the spontaneous or evoked electrical activities of nervous system since the movement related potentials (MRPs) had been studies for several decades. Various reflex tests such as masseter reflex, blink reflex, click evoked vestibulocollic reflex, facial reflex, stretch reflex, flexor reflex, H-reflex, H-reflex recovery curve, vestibular inhibition of H-reflex, reciprocal inhibition, recurrent or Renshaw reflex, Ib inhibition, cutaneous reflex have been also used to understand normal or abnormal physiology in movement disorders. Polysomnography, posturography and gait studies are also applied in clinical neurology in association with with movement disorders which are useful in deciding the treatment regimen.

• Annals of Clinical Neurophysiology
• /
• v.6 no.2
• /
• pp.85-91
• /
• 2004

Background: Needle electromyography (EMG) and motor evoked potential (MEP) of the genioglossus (tongue) are difficult to perform in evaluations of the craniobulbar region in amyotrophic lateral sclerosis (ALS). Therefore, we investigated the yields of needle EMG and MEP recorded from the upper trapezius, since it receives innervation from the lower medulla and upper cervical cord. Methods: Needle EMG and MEP of the upper trapezius were obtained in 17 consecutive ALS patients. The needle EMG parameters recorded included abnormal spontaneous activity and motor unit action potential (MUAP) morphology. An upper motor neuron (UMN) lesion was presumed when either response to cortical stimulation was absent, or the central conduction time was delayed (>mean+2SD). Results: Of the five patients with bulbar-onset ALS, four had abnormalities in the upper trapezius and four in the tongue by needle EMG. In contrast, of the 12 patients with limb-onset ALS, 11 had abnormalities in the upper trapezius, and only five in the tongue. When MEP was performed, it was found that three of the five patients with bulbar symptoms and three of the six patients with isolated limb involvement had abnormal MEP findings. Conclusions: Electrophysiological studies of the upper trapezius are more sensitive those of the tongue in patients without bulbar symptoms. Thus, needle EMG and MEP of the upper trapezius are alternative tools for assessing bulbar and rostral neuraxial involvement in the diagnosis of ALS.

• Korean Journal of Psychosomatic Medicine
• /
• v.18 no.1
• /
• pp.3-10
• /
• 2010

Gilles de la Tourette syndrome is a chronic motor and vocal tic disorder of childhood onset. Abnornmalities in basal ganglia-thalamo-cortical circuits may play an important role in the pathophysiology underlying the involuntary tics. It is often complicated by comorbid attention-deficit/hyperactivity disorder or obsessive-compulsive disorder. Transcranial magnetic stimulation(TMS) is a neurophysiologic technique with research ap-plication. As there is good evidence that this technique can modify cortical activity, repetitive TMS is also used for treatment to change the cortical excitability and therefore affect underlying interconnected cortical-sub-cortical loop. We reviewed the neurophysiologic parameters and the clinical applicability of TMS and rTMS.

• Annals of Clinical Neurophysiology
• /
• v.3 no.2
• /
• pp.156-159
• /
• 2001

Miller Fisher syndrome(MFS) has been the focus of conflicting opinions regarding the peripheral versus the central nature of the site of major neural injury. We present our electrophysiological findings in one case of MFS to help clarify the pattern of peripheral nerve injury in this syndrome. A 45-year-old man visited our hospital due to sudden diplopia. Initial examination revealed internuclear opthalmoplegia. The next day, his symptoms rapidly aggravated to complete external ophthalmoplegia, ataxia, and areflexia with hand and foot numbness. Serial electrophysiological studies were performed. The results of brainstem evoked potential(BAEP) and blink reflex were normal in the serial studies. Motor and sensory nerve conduction study(NCS) were normal findings in second hospital day, but ulnar sensory nerve shows no sensory nerve action potential(SNAP) and sural sensory conduction velocity was delayed in 7th hospital day. Our patient's clinical presentation began to improve on 15th hospital day, and his electrophysiologic study showed improvement on 29th hospital day. We believe that all the manifestations of MFS can be explained by the involvement of peripheral nerves without brainstem or cerebellar lesion with the serial electrophysiological studies.

• Journal of Yeungnam Medical Science
• /
• v.18 no.1
• /
• pp.67-74
• /
• 2001

Background: Meralgia paresthetica(MP) which is characterized by paresthesias and sensory impairment without motor weakness in the anterolateral aspects of the thigh is produced by compression of the lateral femoral cutaneous nerve(LFCN). Even though the diagnosis of MP is mostly based on the clinical symptoms, electrophysiologic study is mandatory to confirm the disease objectively. It has been known that Somatosensory evoked potential(SSEP) study of LFCN is a simple and very useful method to evaluate MP, so we studied SSEP of LFCN in normal adults and offer normal values. Materials and Methods: Thirty six normal adults(23 males and 13 females) ages from 21 to 73 years old($mean{\pm}SD$:$42.06{\pm}15.74$) were studied SSEP of LFCN bilaterally. The stimulation site was anterolateral aspect of thighs and the recording site was Cz'. Results: The mean values($mean{\pm}SD$) of $LP_0$, $SP_0$, $LN_1$ and $SN_1$ of all subjects were 35.10(${\pm}2.42$), 33.80(${\pm}2.4$), 43.68(${\pm}1.88$) and 42.16(${\pm}2.12$) and the mean values($mean{\pm}SD$ of $DP_0$, $DN_1$ and DA(${\mu}V{\pm}SD$ were 1.30(${\pm}1.14$), 1.52(${\pm}1.38$) and 0.32(${\pm}0.33$). Conclusion: For the diagnosis of MP. comparison of latency difference between both sides is more reliable than simple value of latency itself because of individual differences of body types. According to our results. the latency difference should be less than 2 msec and the amplitude difference was less than 1.6 times in normal adults.

• Journal of the Institute of Convergence Signal Processing
• /
• v.19 no.1
• /
• pp.7-13
• /
• 2018

In the current study, we proposed an optimized brain-computer interface (BCI) which employed blind source separation (BBS) approach to remove noises. Thus motor imagery (MI) signal and steady state visual evoked potential (SSVEP) signal were easily to be detected due to enhancement in signal-to-noise ratio (SNR). Moreover, a combination between MI and SSVEP which is typically can increase the number of commands being generated in the current BCI. To reduce the computational time as well as to bring the BCI closer to real-world applications, the current system utilizes a single-channel EEG signal. In addition, a convolutional neural network (CNN) was used as the multi-class classification model. We evaluated the performance in term of accuracy between a non-BBS+BCI and BBS+BCI. Results show that the accuracy of the BBS+BCI is achieved $16.15{\pm}5.12%$ higher than that in the non-BBS+BCI by using BBS than non-used on. Overall, the proposed BCI system demonstrate a feasibility to be applied for multi-dimensional control applications with a comparable accuracy.

• Journal of Ginseng Research
• /
• v.36 no.2
• /
• pp.190-197
• /
• 2012

Ginseng has a long history of use for health enhancement, and there is some evidence from animal studies that it has a beneficial effect on cognitive performance. The purpose of this study was to investigate the effect of Korean red ginseng on cognitive performance in humans. A total of 15 healthy young males with no psychiatric or cognitive problems were selected based on an interview with a board-certified psychiatrist. The subjects were randomly assigned to receive a daily dose of 4,500 mg red ginseng or placebo for a 2-week trial. There were 8 subjects in the red ginseng group and 7 subjects in the placebo group. All of the subjects were analyzed with the Vienna test system and a P300 event-related potential (ERP) test. There were no significant differences in the Vienna test system scores between the red ginseng group and the placebo group. In the event-related potential test, the C3 latency of the red ginseng group tended to decrease during the study period (p=0.005). After 2 wk, significant decreases were observed in the P300 latencies at Cz (p=0.008), C3 (p=0.005), C4 (p=0.002), and C mean (p=0.003) in the red ginseng group. Our results suggest that the decreased latency in ERP is associated with improved cognitive function. Further studies with a higher dosage of ginseng, a larger sample size, and a longer follow-up period are necessary to confirm the clinical efficacy of Korean red ginseng.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.9
• /
• pp.179-185
• /
• 2013

In this paper, the RTA-ERP(Response Time Aligned-Evoked Relative Potential) was modelled to analyze the effect of motor activation pattern in response to visual sensory stimuli. Simon effect was analysed using the amplitude response of RTA-ERP and measured response time. The 'odd number' experiments, which identify an odd number mixed with same numbers, was performed with 15 healthy adult participants(9 males and 6 females, whose mean age of 31) for 7 minutes for each participant. Throughout experimentation, we observed that the proposed RTA-ERP can compensate the timing variation due to different neural processing procedures in the brain, and shows enhanced LRP(Lateralized Readiness Potential) and Pe(Error Related Positivity). Regarding to 'congruence' and 'incongruence' testing patterns, the amplitude of RTA-ERP and the response time for the 'congruence' are $0.03{\mu}V$ larger, and 43 ms faster than those for the 'incongruence', respectively. The amplitude characteristics of RTA-ERP, obtained by synchronizing the onset times with respect to response time, corresponds more likely to that of P300 in the ERP pattern (the characteristics of the Simon effect).