| Kee Duk Park | 7 Articles |
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[English]
Orbital metastases are rare and predominantly unilateral occurrences. Bilateral metastases affecting the extraocular muscles are extremely rare. A few case reports of bilateral metastases to extraocular muscles described binocular diplopia with conspicuous bilateral external ophthalmoplegia as an initial symptom. We report a case in which unilateral ptosis was an initial symptom and bilateral incomplete ophthalmoplegia was found on initial neurologic examination in invasive ductal carcinoma of the breast. The patient had hormone receptor-positive breast cancer, and so was treated by hormonal therapies and closely monitored. The presence of a secondary orbital lesion presents many difficulties of differential diagnosis and treatment. A thorough neurologic examination to detect ocular manifestations is most important for localization and broad differential diagnosis including mechanical orbital metastatic lesion. Citations Citations to this article as recorded by
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Vertebral artery dissection (VAD) is one of important causes of posterior circulation strokes in young age patients. Typical presentations of VAD are occipital headache or posterior neck pain, with various signs arising from brainstem or cerebellar infarctions. Muscular weakness or sensory change of an ipsilateral arm owing to cervical nerve root involvement in association with the VAD has been reported very rarely. Herein we describe two unusual manifestations of extracranial VAD, which presented with monoplegia of single upper limb.
[English]
To develop a proper electrophysiologic techniques for examining the rat femoral nerve. 10 Sprague Dawley rats were use to perform the electrophysiologic study of the exposed femoral nerves by surgical incision. Needle electrodes were used to stimulate the nerves and to obtain the compound nerve action potentials of those nerves. The normal conduction velocity of femoral nerve in this method is 35.4±5.6m/sec and the mean amplitudes of compound nerve action potentials were 40.6±32.8µV. The data of conduction velocity was quite reliable with narrow ranges of standard deviations. But the compound nerve potentials amplitudes data showed wide ranges of variations among individual rats. The techniques and resultion data of femoral verve conduction of rats are described in this article. Even though this technique needs surgical incision exposing the noninvasiveness and rapid healing of the surgical wound in the rats. This verve conduction study method of examining femoral nerve in rats is relatively easy, accurate and repeatable techniques that permits visual and microscopic observation of the exposed nerves during the nerve conduction study.
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To observe the developmental maturation of brainstem auditory evoked potential(BAEP) for neonates by obtaining the normative data of each BAEP component in our own electrophysiological laboratory. We reviewed 129 BAEP recordings in neonates ranging in gestational age from 33 weeks to 44 weeks. The BAEP recording were analyzed into latency(wave I,III,V), interpeak latency(I-III,III-V,I-V) and amplitude ratio(I/V) at 75dB sensation level clicks according to gestational age. The latencies of each BAEP component decreased with maturation. Interpeak latency of waveI-V(central conduction time)also decreased with increasing age during 33-40 weeks of gestational age. These results provided the concept of abnormal in neonatal BAEPs and opportunity of functional evaluation about the auditory or brainstem maturation in pathologic conditions. Citations Citations to this article as recorded by
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To construct the neural network model in the striatum that can explain the clin-ical effect of Parkinson disease. We use an approach to studying the function of neural systems that is based on the use of a class of computer models known as parallel distributed processors(PDPs).And the focus of this study is the nigrostriatal dopaminergic effects on the corticostriatal fibers and the striatal medium spiny neurons. A model that explains hypokinesia in Parkinson disease is presented for the opation of the striatum. In order to study the brain funcion and mechanism of physiopathology, te-stable theories that consider brain as a whole system are needed. We think neural network model with PDPs would be an important field in neuroscience in near future.
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There has been a need for animal experimental models to study the peripheral nerves to evalute the peripheral neuropathy. However, electrophysiologic test methods to confirm peripheral neuropathy in small experimental animals has not been properly addressed due to technical difficulties and also the limitation of numbers of examinations due to the invasive natures of previous techniques of peripheral nerve conduction studies in experimental animals. The purpose of this experiment is to find out easy, reliable and noninvasive repeatable technical of nerve conduction study of peripheral nerves of rat. The electrophysiologic tests including motor and sensory nerve conduction studies were performed in both hind limbs of 64 rats. And the results were reported with detailed description of techniques. The mean value(±SD) of motor nerve conduction velocity was 41.8±3.0m/sec and that of the sendory nerve conduction velocity was 29.7±1.7m/sec and they showed stable results. In addition to its accuracy, this technique is a relatively simple and nonivasive repeatable methods of nerve conduction study of rat. But the amplitudes of compound muscle action potential(CMAP) and compound nerve action potential(CNAP) revealed wide ranges of variability.
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Somatosensory Evoked Potential(SEP) is a useful study in animal experiments as well as in evaluation of human diseases. But in animal experiments most methods of obtaining the potential are difficult and usually require surgical or complex procedures. In this article easy and accurate methods of obtaining cervical SEPs is presented in addition to its normal data of 55 female Spraque-Dally rats. Another advantage of this methods is that serial studies are possible because of its relative noninvasiveness.
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, Hyung Jun Park
