• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.483-486
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• 2004

The expression of nestin and vimentin in the spinal nerve roots of rats with experimental autoimmune encephalomyelitis (EAE) was studied to ascertain whether Schwann cells in the peripheral nerves respond to acute central nervous system autoimmune injury. Immunohistochemistry demonstrated that nestin was constitutively expressed in the dorsal roots of spinal nerves in control rats; its expression was enhanced in the spinal nerve roots of rats with EAE. Vimentin expression was weak in control rat spinal nerve roots, and it was increased in the dorsal roots of rats with EAE. It is postulated that normal animals have multipotent progenitor cells that constitutively express nestin and vimentin in the spinal nerve roots. In response to an injury of the central nervous system, these multipotent Schwann cells are activated in the spinal nerve roots through the expression of the intermediate filament proteins vimentin and nestin.

• The Korean Journal of Physiology
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• v.21 no.1
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• pp.59-66
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• 1987

This study was aimed to investigate whether the conduction velocity of nerve impulses through the ventral afferent fibers is constant along their entire courses in dorsal as well as in ventral roots. Cats were anesthetized with ${\alpha}-chloralose$ (60 mg/kg, i.p.) and artificially ventilated. Laminectomies were done on L4-S1 spinal vertebrae to expose the lumbosacral spiral cord. Both ventral and dorsal roots of L7 or S1 spinal segments were isolated and cut near the spinal cord. Ventral roots were placed on 6-lead stimulating electrodes and stimulated with supra C-threshold intensity. Divided dorsal root fascicles were placed on bipolar recording electrodes and single fiber units activated by the stimulation of the ventral roots were identified. Followings are the results obtained: 1) A total of 27 VRA units were identified. 10 units of them conducted impulses slower than 2 m/sec. Conduction velocities of the remaining units were in the range of 3.11-20.91 m/sec. 2) In 12 Units conduction velocities Of the VRA units through dorsal$(CV_{DR})$ and venral root$(CV_{DR})$ were determined respectively. There was a tendency to conduct impulses faster through dorsal roots$(CV_{DR}=8.19{\pm}3.26\;m/sec)$ than ventral roots$(CV_{DR}=3.46{\pm}1.02\;m/sec)$. From the above results we confirmed that there exist nerve fibers in continuity between the spinal ventral and dorsal roots but we could not ascertain whether there is a change in conduction velocity through the entire course of ventral afferent unit.

• Journal of Korean Neurosurgical Society
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• v.52 no.4
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• pp.384-390
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• 2012

Objective : The objective of this study was to investigate the morphologic characteristics between the vertebral body and the regions of the cervical and thoracic spinal cords where each rootlets branch out. Methods : Sixteen adult cadavers (12 males and 4 females) with a mean age of 57.9 (range of 33 to 70 years old) were used in this study. The anatomical relationship between the exit points of the nerve roots from the posterior root entry zone at each spinal cord segment and their corresponding relevant vertebral bodies were also analyzed. Results : Vertical span of the posterior root entry zone between the upper and lower rootlet originating from each spinal segment ranged from 10-12 mm. The lengths of the rootlets from their point of origin at the spinal cord to their entrance into the intervertebral foramen were 5.9 mm at the third cervical nerve root and increased to 14.5 mm at the eighth cervical nerve root. At the lower segments of the nerve roots (T3 to T12), the posterior root entry zone of the relevant nerve roots had a corresponding anatomical relationship with the vertebral body that is two segments above. The posterior root entry zones of the sixth (94%) and seventh (81%) cervical nerve roots were located at a vertebral body a segment above from relevant segment. Conclusion : Through these investigations, a more accurate diagnosis, the establishment of a better therapeutic plan, and a decrease in surgical complications can be expected when pathologic lesions occur in the spinal cord or vertebral body.

• The Korean Journal of Pain
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• v.18 no.1
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• pp.69-73
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• 2005

This report describes a case of spinal nerve root compression due to an acute inflammatory granuloma after lumbar surgery. A 39 year-old man with a history of increasing back pain with a 3-week duration was diagnosed with a herniated intervertebral disc (HIVD). The diagnosis of a HIVD was confirmed by magnetic resonance imaging (MRI) with indications for surgery. A discectomy and a partial laminectomy was performed and the symptoms were alleviated immediately after surgery for a five-day period. However, a slowly progressing pain was subsequently noted along a different dermatome. There was no pain relief despite the patient being given pharmacological treatments, combined with an epidural steroid injection. The follow up MRI images showed severe compression of the nerve roots by a epidural lesion. Another procedure was performed 17 days after the initial operation. The lesion responsible for the compression of the nerve roots was found to be an acute inflammatory granuloma. The pain was relieved after the second procedure and there were no other symptoms or neurological problems. This case is remarkable in that a granuloma formed relatively quickly and grew to such a size that it was able to severely compress the surrounding nerve roots.

• Journal of Korean Neurosurgical Society
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• v.64 no.2
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• pp.143-150
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• 2021

Spinal dysraphism often causes neurological impairment from direct involvement of lesions or from cord tethering. The conus medullaris and lumbosacral roots are most vulnerable. Surgical intervention such as untethering surgery is indicated to minimize or prevent further neurological deficits. Because untethering surgery itself imposes risk of neural injury, intraoperative neurophysiological monitoring (IONM) is indicated to help surgeons to be guided during surgery and to improve functional outcome. Monitoring of electromyography (EMG), motor evoked potential, and bulbocavernosus reflex (BCR) is essential modalities in IONM for untethering. Sensory evoked potential can be also employed to further interpretation. In specific, free-running EMG and triggered EMG is of most utility to identify lumbosacral roots within the field of surgery and filum terminale or non-functioning cord can be also confirmed by absence of responses at higher intensity of stimulation. The sacral nervous system should be vigilantly monitored as pathophysiology of tethered cord syndrome affects the sacral function most and earliest. BCR monitoring can be readily applicable for sacral monitoring and has been shown to be useful for prediction of postoperative sacral dysfunction. Further research is guaranteed because current IONM methodology in spinal dysraphism is still deficient of quantitative and objective evaluation and fails to directly measure the sacral autonomic nervous system.

• Journal of the Korean Society of Radiology
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• v.85 no.3
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• pp.607-617
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• 2024

Purpose Recent studies have demonstrated the usefulness of diffusion-weighted MR neurography (DW MRN) for assessing nerve roots. This study aimed to evaluate the utility of DW MRN with a unidirectional motion-probing gradient (MPG) for the lumbar nerve roots at 1.5T MR. Materials and Methods Sixty-four lumbar spine MRI scans with DW MRN using anteroposterior unidirectional MPG were retrospectively analyzed. Any changes in the 512 lumbar spinal nerve roots from L3 to S1 were evaluated using T2-weighted imaging (T2WI), contrast-enhanced T1-weighted imaging (CE T1WI), and DW MRN, with agreement and correlation analysis. Results T2WI revealed compression of 78 nerve roots, and CE T1WI revealed 52 instances of nerve root enhancement. Sixty-seven nerve roots showed swelling and hyperintensity on DW MRN. A total of 42 nerve roots showed changes in the CE T1WI and DW MRN sequences. Moderate to substantial agreement and moderate positive correlation were observed between DW MRN and CE T1WI, as well as DW MRN and T2WI (κ = 0.59-0.65, ρ = 0.600-0.653). Conclusion DW MRN with unidirectional anteroposterior MPG can help evaluate neuritisrelated changes in spinal nerve roots and could serve as a sequence capable of complementing or substituting gadolinium CE imaging.

• Journal of Korean Neurosurgical Society
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• v.52 no.3
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• pp.215-220
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• 2012

Objective : There were previous reports of redundant nerve roots (RNRs) focused on their clinical significance and pathogenesis. In this study, we investigated the significant radiologic findings that correlate with RNRs occurrence. These relations would provide an advanced clue for clinical significance and pathogenesis of RNRs. Methods : Retrospective research was performed with data from 126 patients who underwent surgery for central lumbar spinal stenosis (LSS). Finally, 106 patients with common denominators (inter-observer accuracy : 84%) were included on this study. We divided the patients into two groups by MRI, patients with RNRs and those with no RNRs (NRNRs). Comparative analyses were performed with clinical and radiologic parameters. Results : RNRs were found in 45 patients (42%) with central LSS. There were no statistically significant differences between the two groups in severity of symptoms. On the other hand, we found statistically significant differences in duration of symptom and number of level included (p<0.05). In the maximal stenotic level, ligamentum flavum (LF) thickness, LF cross-sectional area (CSA), dural sac CSA, and segmental angulation are significantly different in RNRs group compared to NRNRs group (p<0.05). Conclusion : RNRs patients showed clinically longer duration of symptoms and multiple levels included. We also confirmed that wide segmental angulation and LF hypertrophy play a major role of the development of RNRs in central LSS. Together, our results suggest that wide motion in long period contribute to LF hypertrophy, and it might be the key factor of RNRs formation in central LSS.

• Journal of Korean Neurosurgical Society
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• v.50 no.3
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• pp.195-200
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• 2011

Objective : To present the profiles of spinal cord tumors that can be removed through a unilateral hemilaminectomy and to demonstrate its usefulness for benign spinal cord tumors that significantly occupy the spinal canal. Methods : From June 2004 to October 2010, 25 spinal cord tumors were approached with unilateral hemilaminectomy. We calculated the cross-sectional occupying ratio (CSOR) of tumor to spinal canal before and after the operations. Results : The locations of the tumors were intradural extramedullary in 20 cases, extradural in 2, and intramedullary in 3. The levels of the tumors were lumbar in 12, thoracic 9, and cervical 4. In all cases, the tumor was removed grossly and totally without damaging spinal cord or roots. The mean height and width of the lesions we195re 17.64 mm (3-47.5) and 12.62 mm (4-32.7), respectively. The mean CSOR was 69.40% (range, 27.8-96.9%). Postoperative neurological status showed improvement in all patients except one whose neurologic deficit remained unchanged. Postoperative spinal stability was preserved during the follow-up period (mean, 21.5 months) in all cases. Tumor recurrence did not develop during the follow-up period. Conclusion : Unilateral hemilaminectomy combined with microsurgical technique provides sufficient space for the removal of diverse spinal cord tumors. The basic profiles of the spinal cord tumors which can be removed through the unilateral hemilaminectomy demonstrate its role for the surgery of the benign spinal cord tumors in various sizes.

• The Korean Journal of Pain
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• v.32 no.3
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• pp.147-159
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• 2019

Lumbar foraminal pathology causing entrapment of neurovascular contents and radicular symptoms are commonly associated with foraminal stenosis. Foraminal neuropathy can also be derived from inflammation of the neighboring lateral recess or extraforaminal spaces. Conservative and interventional therapies have been used for the treatment of foraminal inflammation, fibrotic adhesion, and pain. This update reviews the anatomy, pathophysiology, clinical presentation, diagnosis, and current treatment options of foraminal neuropathy.

• Journal of Korean Neurosurgical Society
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• v.56 no.3
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• pp.206-210
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• 2014

Objective : Lumbar spinal stenosis is a common degenerative spine disease that requires surgical intervention. Currently, there is interest in minimally invasive surgery and various technical modifications of decompressive lumbar laminectomy without fusion. The purpose of this study was to present the author's surgical technique and results for decompression of spinal stenosis. Methods : The author performed surgery in 57 patients with lumbar spinal stenosis between 2006 and 2010. Data were gathered retrospectively via outpatient interviews and telephone questionnaires. The operation used in this study was named central decompressive laminoplasty (CDL), which allows thorough decompression of the lumbar spinal canal and proximal two foraminal nerve roots by undercutting the lamina and facet joint. Kyphotic prone positioning on elevated curvature of the frame or occasional use of an interlaminar spreader enables sufficient interlaminar working space. Pain was measured with a visual analogue scale (VAS). Surgical outcome was analyzed with the Oswestry Disability Index (ODI). Data were analyzed preoperatively and six months postoperatively. Results : The interlaminar window provided by this technique allowed for unhindered access to the central canal, lateral recess, and upper/lower foraminal zone, with near-total sparing of the facet joint. The VAS scores and ODI were significantly improved at six-month follow-up compared to preoperative levels (p<0.001, respectively). Excellent pain relief (>75% of initial VAS score) of back/buttock and leg was observed in 75.0% and 76.2% of patients, respectively. Conclusion : CDL is easily applied, allows good field visualization and decompression, maintains stability by sparing ligament and bony structures, and shows excellent early surgical results.