• 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.

• Journal of Yeungnam Medical Science
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• v.19 no.1
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• pp.49-54
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• 2002

The central pain in patient with spinal cord injury is a common and disabling sequela. The microsurgical DREZ(Dorsal Root Entry Zone)otomy is a surgical procedure effective in the treatment of intractable pain and spasticity in spinal cord injured patients. It consists of a microsurgical lesions performed in the ventrolateral region of the dorsal root entry zone at the selected levels. This report presents one case with incomplete paraplegia patient, who had chronic central neuropathic pain ineffective to many conservative treatments in bilateral T10 and right T11 segments and both lower extremities, is relieved from the pain after microsurgical DREZotomy. In conclusion, microsurgical DREZotomy is one method of effective treatments for spinal cord injured patients with intractable central neuropathic pain.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1228-1232
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• 2000

Objective : This study was undertaken to analysis gamma knife radiosurgery(GKR) effect for trigeminal neuralgia after long term follow-up. Methods : There were 11 trigeminal neuralgia patients. The authors irradiated 67-85 Gy maximally to the nerve root entry zone(NREZ) using single 4mm collimator, just 1-6mm lateral side from the junction of the trigeminal nerve and pons. For the first 3 cases, we targeted the junction between the nerve and the pons. In theses cases, the pons was irradiated 56 or 60 gray in the surface. In the later 8 cases, the isocenter is positioned more distal side so that the brain stem surface would receive less than the 20% isodose. Results : The average follow-up duration was 25 months(13-50 months). Pain relief was noticed within a week to 5 months. In 3 patients, pain was relieved completely and in other 3 patients, mark improvement was achieved(80-90%). Remaining 4 patients showed significant improvement(30-50%). There was recurrence in only one case and she complained with similar intensity of pain at the last follow-up. There was no significant complication related to GKR. Conclusion : GKR is considered effective for trigeminal neuralgia based on the long term follow-up evaluation, but more clinical experience is needed to evaluate the efficacy of GKR for trigeminal neuralgia as a primary treatment modality.

• Journal of Korean Neurosurgical Society
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• v.55 no.5
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• pp.244-247
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• 2014

Objective : The aim of this study was to evaluate the microanatomy and histological features of the central myelin in the root exit zone of facial nerve. Methods : Forty facial nerves with brain stem were obtained from 20 formalin fixed cadavers. Among them 17 facial nerves were ruined during preparation and 23 root entry zone (REZ) of facial nerves could be examined. The length of medial REZ, from detach point of facial nerve at the brain stem to transitional area, and the thickness of glial membrane of central myelin was measured. We cut brain stem along the facial nerve and made a tissue block of facial nerve REZ. Each tissue block was embedded with paraffin and serially sectioned. Slices were stained with hematoxylin and eosin (H&E), periodic acid-Schiff, and glial fibrillary acid protein. Microscopy was used to measure the extent of central myelin and thickness of outer glial membrane of central myelin. Thickness of glial membrane was examined at two different points, the thickest area of proximal and distal REZ. Results : Special stain with PAS and GFAP could be differentiated the central and peripheral myelin of facial nerve. The length of medial REZ was mean 2.6 mm (1.6-3.5 mm). The glial limiting membrane of brain stem is continued to the end of central myelin. We called it glial sheath of REZ. The thickness of glial sheath was mean $66.5{\mu}m(40-110{\mu}m$) at proximal REZ and $7.4{\mu}m(5-10{\mu}m$) at distal REZ. Conclusion : Medial REZ of facial nerve is mean 2.6 mm in length and covered by glial sheath continued from glial limiting membrane of brain stem. Glial sheath of central myelin tends to become thin toward transitional zone.

• Annals of Clinical Neurophysiology
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• v.7 no.1
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• pp.43-45
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• 2005

Trigeminal sensory neuropathy is a clinical diagnosis in which the main feature is facial numbness limited to territory of one or more sensory branches of the trigeminal nerve. We describe a 46-year-old woman who presented with left facial numbness in the territories of maxillary nerve and mandibular nerve. MRI disclosed a lesion in left trigeminal nerve root entry zone. In Blink test stimulating infraorbital foramen, ipsilateral R1 was delayed compared with contralateral R1. Lesion in pons or medulla can present as trigeminal sensory neuropathy.

• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.12-23
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• 2023

Glossopharyngeal neuralgia (GPN) is a rare disease that must be differentiated from trigeminal neuralgia. The purpose of this article is to provide a comprehensive review of anatomy, pathophysiology, diagnostic criteria, and several options of treatment for GPN. Lessons learned through our experience of treating GPN are presented in detail, as well as cases of misdiagnosis and diagnostic pitfalls. Microvascular decompression (MVD) should be primarily considered for medically intractable GPN. Techniques employed in MVD for GPN are categorized and described. Especially, we underscore the advantages of the 'transposition' technique where insulating material is positioned 'off' the root entry zone (REZ), instead of 'on' it. We believe this 'off-the-REZ' technique can fundamentally prevent recurrence, if applicable. In addition, Gamma Knife radiosurgery can be an alternative option when a patient is ineligible for MVD, though it is categorized as a destructive procedure.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.42-47
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• 2012

Objective : The aim of this prospective study was to demonstrate the influence of some factors on the prognosis of microvascular decompression in 37 patients with trigeminal neuralgia. Methods : The results of microvascular decompression (MVD) in 37 patients with trigeminal neuralgia were evaluated at 6 months after surgery and were compared with clinical and operative findings. Results : The sex of the patient, the patient's age at surgery, the side of the pain, and the duration of symptoms before surgery did not play any significant roles in prognosis. Also, the visual analogue scale (VAS) of the patient, the duration of each pain attack, and the frequency of pain over 24 hours did not play any significant roles in prognosis. In addition, intraoperative detection of the type of conflicting vessel, the degree of severity of conflict, and the location of the conflict around the circumference of the root did not play any roles in prognosis. The only factors affecting the prognosis in MVD surgery were intraoperative detection of the site of the conflict along the root and neuroradiological compression signs on preoperative magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA). Conclusion : These findings demonstrated that if neurovascular compression is seen on preoperative MRI/MRA and/or compression is found intraoperative at the root entry zone, then the patient will most likely benefit from MVD surgery.

• Journal of Korean Neurosurgical Society
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• v.47 no.4
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• pp.271-277
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• 2010

Objective : The purpose of this study is to evaluate the clinical characteristics and surgical outcome of cerebellopontine angle (CPA) epidermoids presenting with trigeminal neuralgia. Methods : Between 1996 and 2004, 10 patients with typical symptoms of trigeminal neuralgia were found to have cerebellopontine angle epidermoids and treated surgically at our hospital. We retrospectively analyzed the clinico-radiological records of the patients. Results : Total resection was done in 6 patients (60%). Surgical removal of tumor and microvascular decompression of the trigeminal nerve were performed simultaneously in one case. One patient died due to postoperative aseptic meningitis. The others showed total relief from pain. During follow-up, no patients experienced recurrence of their trigeminal neuralgia (TN). Conclusion : The clinical features of TN from CPA epidermoids are characterized by symptom onset at a younger age compared to TN from vascular causes. In addition to removal of the tumor, the possibility of vascular compression at the root entry zone of the trigeminal nerve should be kept in mind. If it exists, a microvascular decompression (MVD) should be performed. Recurrence of tumor is rare in both total and subtotal removal cases, but long-term follow-up is required.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.85-90
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• 2001

Objective : DREZotomy is effective for the treatment of deafferentation pain as a consequence of root avulsion, postparaplegic pain, posttraumatic syrinx, postherpetic neuralgia, spinal cord injury, and peripheral nerve injury. We performed microsurgical DREZotomy to the patients with deafferentation pain and relieved pain without any serious complication. The purpose of this study is to evaluate the usefulness of the microsurgical DREZotomy for deafferentation pain. Methods : We evaluated 4 patients with deafferntation pain who were intractable to medical therapy. Two of them were brachial plexus injury with root avulsion owing to trauma, one was axillary metastasis of the squamous cell carcinoma of the left forearm, and the last was anesthesia dolorosa after surgical treatment(MVD and rhizotomy) of trigeminal neuralgia. Preoperative evaluation was based on the neurologic examination, radiologic imaging, and electrophysiological study. In the case of anesthesia dolorosa, we produced two parallel lesions in cephalocaudal direction, 2mm in distance, from the C2 dorsal rootlet to the 5mm superior to the obex including nucleus caudalis, after suboccipital craniectomy and C1-2 laminectomy, with use of microelectrode. In the others, we confirmed lesion site with identification of the nerve root after hemilaminectomy. We performed arachnoid dissection along the posterolateral sulcus and made lesion with microsurgical knife and microelectrocoagulation, 2mm in depth, 2mm in distance, to the direction of 30-45 degrees in the medial portion of the Lissauer's tract and the most dorsal layers of the posterior horn at the one root level above and below the lesion. Results : Compared with preoperative state, microsurgical DREZotomy significantly diminished dosage of the drugs and relieved pain meaningfully. One patient showed tansient ipsilateral ataxia, but recovered soon. There was not any serious complication. Conclusion : It may be concluded that microsurgical DREZotomy is very useful and safe therapeutic modality for deafferentation pain, especially segmentally distributed intermittent or evoke pain. Complete preoperative evaluation and proper selection of the patients and lesion making device are needed to improve the result.

• Journal of Korean Neurosurgical Society
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• v.51 no.5
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• pp.276-280
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• 2012

Objective : Gamma knife radiosurgery (GKRS) is the least invasive surgical option for patients with trigeminal neuralgia (TN). However, the indications and long term outcomes of GKRS are still controversial. Additionally, a series with uniform long-term follow-up data for all patients has been lacking. In the present study, the authors analyzed long-term outcomes in a series of patients with TN who underwent a single GKRS treatment followed by a minimum follow-up of 60 months. Methods : From 1994 to 2009, 40 consecutive patients with typical, intractable TN received GKRS. Among these, 22 patients were followed for >60 months. The mean maximum radiation dose was 77.1 Gy (65.2-83.6 Gy), and the 4 mm collimator was used to target the radiation to the root entry zone. Results : The mean age was 61.5 years (25-84 years). The mean follow-up period was 92.2 months (60-144 months). According to the pain intensity scale in the last follow-up, 6 cases were grades I-II (pain-free with or without medication; 27.3%) and 7 cases were grade IV-V (<50% pain relief with medication or no pain relief; 31.8%). There was 1 case (facial dysesthesia) with post-operative complications (4.54%). Conclusion : The long-term results of GKRS for TN are not as satisfactory as those of microvascular decompression and other conventional modalities, but GKRS is a safe, effective and minimally invasive technique which might be considered a first-line therapy for a limited group of patients for whom a more invasive kind of treatment is unsuitable.