• The Korean Journal of Physiology
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• v.25 no.2
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• pp.211-221
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• 1991

Although the existence of nerve cells which determine the activity of sympathetic nervous system in ventrolateral medulla is advocated recently, there are wide varieties on the location and function of them according to authors. Present study aimed to identify and characterize the medullospinal tract cells in rostral and caudal medulla of cats .which branch to the lateral horn of the upper thoracic spinal cord. Cats were anesthetized with ${\alpha}-chloralose$. The upper thoracic spinal cord and floor of the IVth ventricle were exposed. Medullospinal tract cells in rostral and caudal medulla were identified by anti-dromic stimulation of the intermediolateral nucleus in the upper thoracic cord and then the location and physiological characteristics of these cells were studied. A total of seventy cells in medulla had constant latency and responded to high frequency stimulation to thoracic cord. Among them fifty-six cells were identified as medullospinal tract cells either by collision with spontaneous activities or activities evoked by sciatic nerve stimulation(27/56), or by determining the refractory period (29/56). Thirty-one of these cells branched to the contralateral thoracic spinal cord, twenty-one cells to the ipsilateral side and remaining four cells branched to both sides. The conduction velocity of cells branching to the contralateral side was $29{\pm}2.9\;m/sec$ and that of cells to the ipsilateral side was $39.1{\pm}6.0\;m/sec$. When medulla was devided into two by a horizontal plane at 3 mm rostral to the obex, fifty-one among seventy cells were in the rostral medulla and nineteen were in the caudal medulla. The conduction velocities of these two groups were $21.6{\pm}1.0\;and\;33.3{\pm}3.9\;m/sec$, respectively. In this study, we confirmed the existence of two groups of medullospinal tract cells in rostral and caudal ventrolateral medulla, which branch to the lateral horn of thoracic cord and these cells have relatively few spontaneous activities and rapid conduction velocity, so we concluded that these cells are different from the previously known sympatho-related cells in ventrolateral medulla.

• Journal of Korean Neurosurgical Society
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• v.45 no.2
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• pp.81-84
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• 2009

Objective : Many biomechanical and clinical studies on adjacent segment degeneration (ASD) have addressed cranial segment. No study has been conducted on caudal segment degeneration after upper segment multiple lumbar fusions. This is a retrospective investigation of the L5-S1 segment after spinal fusion at and above L4-5, which was undertaken to analyze the rate of caudal ASD at L5-S1 after spinal fusion on and above L4-5 and to determine that factors that might have influenced it. Methods : The authors included 67 patients with L4-5, L3-5, or L2-5 posterior fusions. Among these patients, 28 underwent L4-5 fusion, 23 L3-5, and 16 L2-5 fusions. Pre- and postoperative radiographs were analyzed to assess degenerative changes at L5-S1. Also, clinical results after fusion surgery were analyzed. Results : Among the 67 patients, 3 had pseudoarthrosis, and 35 had no evidence of ASD, cranially and caudally. Thirteen patients (19.4%) showed caudal ASD, 23 (34.3%) cranial ASD, and 4 (6.0%) both cranial and caudal ASD. Correlation analysis for caudal ASD at L5-S1 showed that pre-existing L5-S1 degeneration was most strongly correlated. In addition, numbers of fusion segments and age were also found to be correlated. Clinical outcome was not correlated with caudal ASD at L5-S1. Conclusion : If caudal and cranial ASD are considered, the overall occurrence rate of ASD increases to 50%. The incidence rate of caudal ASD at L5-S1 was significantly lower than that of cranial ASD. Furthermore, the occurrence of caudal ASD was found to be significantly correlated with pre-existing disc degeneration.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.380-385
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• 2021

Caudal agenesis refers to the congenital malformation with the essential feature of the agenesis of the sacrococcygeal bone. It is associated with various types of spinal cord anomaly as well as with complex anomalies of genitourinary or gastrointestinal system. The wide spectrum of the disease can be attributed to its pathoembryological origin, the secondary neurulation. This review presents the definition, etiology, classification, and clinical features of the disease.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.346-358
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• 2021

Secondary neurulation is a morphological process described since the second half of the 19th century; it accounts for the formation of the caudal spinal cord in mammals including humans. A similar process takes place in birds. This form of neurulation is caused by the growth of the tail bud region, the most caudal axial region of the embryo. Experimental work in different animal species leads to questioning dogmas widely disseminated in the medical literature. Thus, it is clearly established that the tail bud is not a mass of undifferentiated pluripotent cells but is made up of a juxtaposition of territories whose fate is different. The lumens of the two tubes generated by the two modes of neurulation are continuous. There seem to be multiple cavities in the human embryo, but discrepancies exist according to the authors. Finally, the tissues that generate the secondary neural tube are initially located in the most superficial layer of the embryo. These cells must undergo internalization to generate the secondary neurectoderm. A defect in internalization could lead to an open neural tube defect that contradicts the dogma that a secondary neurulation defect is closed by definition.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1569-1575
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• 2007

In oriental medicine, Sukjihwang (SJH, Rehmanniae radix preparat) has been used as one of the key ingredients for the prescription of several herbal decoctions and applied clinically for the treatment of several diseases including nervous system and cardiovascular disease. Here, possible growth-promoting effects of SJH on injured spinal cord axons were investigated in the rats. SJH administration increased levels of active form of ERK1/2 protein and Cdc2 proteins in the injured spinal cord tissue. Anterograde DiI-tracing of corticospinal tract axons showed that SJH-treatment enhanced axonal arborization in the injury area and extensive axonal extension into the caudal area. In SJH-treated group, glial scar formed after spinal cord injury was confined in a smaller area compared to the control group, and the trabecula structure was well observed within the injury cavity. Furthermore, increased proliferation and migration of astrocytes in the injury cavity were observed by SJH treatment. Thus, these present data provide a biological evidence on potential importance of SJH therapy for the treatment of injured spinal cord.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.237-240
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• 2006

This report describes a case of spinal cord infarction after acupuncture. The patient was treated with lumbar sympathetic block with using C-arm fluoroscopy. A 66-year-old patient with chronic low back pain and radiating pain in the lower limb was treated with acupuncture and he suddenly had a loss of motor and sensory of both lower extremities. His clinical presentaion and neuroimaging studies were consistent with spinal cord infarction. He was treated with steroid megatherapy and he showed improved in motor function, but there was no pain relief despite the phamacological treatments that were combined with caudal blockade. He visited to our hospital and had lumbar sympathetic blockade performed. The pain was relieved without any related complication after 1 month (VAS $9/10{\rightarrow}2/10$), and he has been content with the results of treatment.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.37-43
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• 1993

Electrical or chemical stimulation of many areas in the brainstem modulates activity of dorsal horn neurons (DHN). This is known to be mediated by a population of bulbospinal neurons. Yet, little is known about responses of DHNs to stimulation of the caudal ventrolateral medulla (CVLM). Thus, the purpose of the present study is to see if there is any change in activity of DHNs when CVLM is stimulated electrically. Thirty-one DHNs were recorded from dorsal horn of the spinal cord. Fourteen DHNs (45%) were classified as wide dynamic range neurons and 9 (19%) were high threshold cells, and 4 (13%) and 4 (13%) were deep and low threshold neurons, respectively. Among 31 neurons tested for responses to stimulation of CVLM, 21 DHNs (68%) were inhibited by the electrical stimulation of CVLM ($200{\mu}A,\;100{\mu}s$ duration, 100 Hz), and 9 cells (39%) did not show any change in neuronal activity. One neuron was excited by the stimulation. The electrical stimulation of CVLM not only inhibited spontaneous activity of DHNs but also inhibited evoked responses of DHNs to somatic stimulation in the receptive field. These data suggest that CVLM is one of the pain-modulatory areas that control transmission of ascending information of noxious input to the brain from the spinal cord.

• The Journal of Korean Medicine
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• v.29 no.5
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• pp.1-13
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• 2008

Objective : This study is investigate the effects of Sagunjatang-Ga-Nokyong(SGJ-NY) treatment on regenerative responses of corticospinal tract(CST) axons in the injured spinal cord. Methods :Using rats, we damaged their spinal cord, and then applied SGJ-NY extract to the lesion. Then we observed GAP-43 and NGF protein, astrcyte, axonal regeneration responses and axonal elongation. Result :Determination of GAP-43 and NGF protein levels were increased. And increased proliferation of astrocyte and enhanced processes in astrocytes were observed by SGJ-NY treatment. Higher number of astrocytes within the injury cavity in SGJ-NY treated group were showed, yet CSPG proteins were a weaker staining in the cavity in SGJ-NY. CST axons extended into the cavity and to the caudal area in SGJ-NY treated group were increased. Conclusion : SGJ-NY treatment might increase neural activity in the injured spinal cord tissue, and improved axonal regeneration responses. In this process, activation of astrocytes may play a role in promoting enhanced axonal elongation. the current study show that SGJ-NY exerts positive activity on inducing nerve regeneration responses by elevating neural tissue migration activities.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.386-405
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• 2021

Recent advancements in basic research on the process of secondary neurulation and increased clinical experience with caudal spinal anomalies with associated abnormalities in the surrounding and distal structures shed light on further understanding of the pathoembryogenesis of the lesions and led to the new classification of these dysraphic entities. We summarized the changing concepts of lesions developed from the disordered secondary neurulation shown during the last decade. In addition, we suggested our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase of development may cause corresponding lesions, such as failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neuro-cutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and regression failure spectrum of the medullary cord (thickened filum and filar cyst, low-lying conus, retained medullary cord, terminal myelocele and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association with the activity of caudal mesenchymal tissue in secondary neurulation involves a wider range of surrounding structures than in primary neurulation. Although the majority of the data are from animals, not from humans and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.

• Journal of Korean Neurosurgical Society
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• v.59 no.5
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• pp.471-477
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• 2016

Objectives : The correction of clinical and radiologic abnormalities in patients with symptomatic ossification of the posterior longitudinal ligament (OPLL) is the current mainstay of treatment. This study aimed to identify radiographic predictors of severity of myelopathy in patients with symptomatic OPLL. Methods : Fifty patients with symptomatic cervical OPLL were enrolled. Based on Japanese Orthopedic Association (JOA) scores, patients were divided into either the mild myelopathy (n=31) or severe myelopathy (n=19) group. All subjects underwent preoperative plain cervical roentgenogram, computed tomography (CT), and MR imaging (MRI). Radiological parameters (C2-7 sagittal vertical axis, SVA; C2-7 Cobb angle; C2-7 range of motion, ROM; OPLL occupying ratio; and compression angle) were compared. Compression angle of OPLL was defined as the angle between the cranial and caudal surfaces of OPLL at the maximum level of cord compression Results : The occupying ratio of the spinal canal, C2-7 Cobb angle, C2-7 SVA, types of OPLL, and C2-7 ROM of the cervical spine were not statistically different between the two groups. However, the OPLL compression angle was significantly greater (p=0.003) in the severe myelopathy group than in the mild myelopathy group and was inversely correlated with JOA score (r=-0.533, p<0.01). Furthermore, multivariate regression analysis demonstrated that the compression angle (B=-0.069, p<0.001) was significantly associated with JOA scores (R=0.647, p<0.005). Conclusion : Higher compression angles of OPLL have deleterious effects on the spinal cord and decrease preoperative JOA scores.