Showing papers in "Journal of Korean Neurosurgical Society in 2011"

Peritumoral Brain Edema in Meningiomas : Correlation of Radiologic and Pathologic Features

Abstract: Objective : The primary objective of this study was to perform a retrospective evaluation of the radiological and pathological features influencing the formation of peritumoral brain edema (PTBE) in meningiomas. Methods : The magnetic resonance imaging (MRI) and pathology data for 86 patients with meningiomas, who underwent surgery at our institution between September 2003 and March 2009, were examined. We evaluated predictive factors related to peritumoral edema including gender, tumor volume, shape of tumor margin, presence of arachnoid plane, the signal intensity (SI) of the tumor in T2-weighted image (T2WI), the WHO histological classification (GI, GII/GIII) and the Ki-67 antigen labeling index (LI). The edema-tumor volume ratio was calculated as the edema index (EI) and was used to evaluate peritumoral edema. Results : Gender (p=0.809) and pathological finding ( p=0.084) were not statistically significantly associated with peritumoral edema by univariate analysis. Tumor volume was not correlated with the volume of peritumoral edema. By univariate analysis, three radiological features, and one pathological finding, were associated with PTBE of statistical significance: shape of tumor margin ( p=0.001), presence of arachnoid plane (p=0.001), high SI of tumor in T2WI (p=0.001), and Ki-67 antigen LI (p=0.049). These results suggest that irregular tumor margins, hyperintensity in T2WI, absence of arachnoid plane on the MRI, and high Ki-67 LI can be important predictive factors that influence the formation of peritumoral edema in meningiomas. By multivariate analysis, only SI of the tumor in T2WI was statistically significantly associated with peritumoral edema. Conclusion : Results of this study indicate that irregular tumor margin, hyperintensity in T2WI, absence of arachnoid plane on the MRI, and high Ki67 LI may be important predictive factors influencing the formation of peritumoral edema in meningiomas.

Strategies of spinal fusion on osteoporotic spine.

Abstract: The prevalence of osteoporosis has been increasing globally Recently surgical indications for elderly patients with osteoporosis have been increasing However, only few strategies are available for osteoporotic patients who need spinal fusion Osteoporosis is a result of negative bone remodeling from enhanced function of the osteoclasts Because bone formation is the result of coupling between osteoblasts and osteoclasts, anti-resorptive agents that induce osteoclast apoptosis may not be effective in spinal fusion surgery, necessitating new bone formation Therefore, anabolic agents may be more suitable for osteoporotic patients who undergo spinal fusion surgery The instrumentations and techniques with increased pullout strength may increase fusion rate through rigid fixation Studies on new osteoinductive materials, methods to increase osteogenic cells, strengthened and biocompatible osteoconductive scaffolds are necessary to enable osteoporotic patients to undergo spinal fusion When osteoporotic patients undergo spinal fusion, surgeons should consider appropriate osteoporosis medication, instrumentation and technique

Changes in the cross-sectional area of multifidus and psoas in unilateral sciatica caused by lumbar disc herniation.

Abstract: Objective To quantitatively evaluate the asymmetry of the multifidus and psoas muscles in unilateral sciatica caused by lumbar disc herniation using magnetic resonance imaging (MRI).

Chronic Subdural Hematoma Treated by Small or Large Craniotomy with Membranectomy as the Initial Treatment

Abstract: Objective There are few studies comparing small and large craniotomies for the initial treatment of chronic subdural hematoma (CSDH) which had non-liquefied hematoma, multilayer intrahematomal loculations, or organization/calcification on computed tomography and magnetic resonance imaging. These procedures were compared to determine which would produce superior postoperative results.

Percutaneous radiofrequency thermocoagulation under fluoroscopic image-guidance for idiopathic trigeminal neuralgia.

Abstract: Objective : We retrospectively investigated the long-term results of percutaneous radiofrequency thermocoagulation (RFT) using fluoroscopic im age-guidance for treatment of trigeminal neuralgia. Methods : A total of 38 patients diagnosed and treated with RFT as an idiopathic trigeminal neuralgia were investigated. To minimize the risks related to conventional technique based on cutaneous landmarks, and to eliminate the need to frequent reposition of cannula, we adopted a technique of image-guided fluoroscopic cannulation of the foramen ovale. To minimize sensory complication following thermal lesion, our target re sponse was a generation of a lesion with mild to moderate hypalgesia rather than dense hypalgesia. Results : The immediate pain-relief was achieved in all patients underwent RFT. With mean duration of follow-up of 38.2 months (range,12-72), 11 (28.9%) experienced recurrence of pain. The mean timing of recurrence was 26.1 months (range,12-46). A 42.7% recurrence rate was estimated by Kaplan-Meier analysis for the 38 patients at 46 months; 20.2% within 2 years, 29.1% within 3 years. In the long-term, 27 patients (71%) and 6 patients (15.8%) showed Barrow Neurological Institute (BNI) score I and BNI score II responses. 3 (7.9%) patients was assessed as BNI score III, 2 patients (5.3%) showed BNI score IV response. As a complication, troublesome dysesthesia occurred in 3 of 38 patients (7.9%), however, there was no permanent cranial nerve palsy or morbidity. Conclusion : These results indicates that RFT under fluoroscopic image-guided cannulation of foramen ovale is a safe, effective, and reliable means of treating trigeminal neuralgia.

Postoperative survival and ambulatory outcome in metastatic spinal tumors : prognostic factor analysis.

Abstract: Objective : The purposes of this study are to estimate postoperative survival and ambulatory outcome and to identify prognostic factors thereafter of metastatic spinal tumors in a single institute. Methods : We reviewed the medical records of 182 patients who underwent surgery for a metastatic spinal tumor from January 1987 to January 2009 retrospectively. Twelve potential prognostic factors (age, gender, primary tumor, extent and location of spinal metastases, interval between primary tumor diagnosis and metastatic spinal cord compression, preoperative treatment, surgical approach and extent, preoperative Eastern Cooperative Oncology Group (ECOG) performance status, Nurick score, Tokuhashi and Tomita score) were investigated. Results : The median survival of the entire patients was 8 months. Of the 182 patients, 80 (44%) died within 6 months after surgery, 113 (62%) died within 1 year after surgery, 138 (76%) died within 2 years after surgery. Postoperatively 47 (26%) patients had improvement in ambulatory function, 126 (69%) had no change, and 9 (5%) had deterioration. On multivariate analysis, better ambulatory outcome was associated with being ambulatory before surgery (p=0.026) and lower preoperative ECOG score (p=0.016). Survival rate was affected by preoperative ECOG performance status (p<0.001) and Tomita score (p<0.001). Conclusion : Survival after metastatic spinal tumor surgery was dependent on preoperative ECOG performance status and Tomita score. The ambulatory functional outcomes after surgery were dependent on preoperative ambulatory status and preoperative ECOG performance status. Thus, prompt decompressive surgery may be warranted to improve patient’s survival and gait, before general condition and ambulatory function of patient become worse.

Accuracy and Safety of Bedside External Ventricular Drain Placement at Two Different Cranial Sites : Kocher's Point versus Forehead.

Abstract: OBJECTIVE: External ventricular drain (EVD) is commonly performed with a freehand technique using surface anatomical landmarks at two different cranial sites, Kocher's point and the forehead. The aim of this study was to evaluate and compare the accuracy and safety of these percutaneous ventriculostomies. METHODS: A retrospectively review of medical records and head computed tomography scans were examined in 227 patients who underwent 250 freehand pass ventriculostomy catheter placements using two different methods at two institutions, between 2003 and 2009. Eighty-one patients underwent 101 ventriculostomies using Kocher's point (group 1), whereas 146 patients underwent 149 forehead ventriculostomies (group 2). RESULTS: In group 1, the catheter tip was optimally placed in either the ipsilateral frontal horn or the third ventricle, through the foramen of Monro (grade 1) in 82 (81.1%) procedures, in the contralateral lateral ventricle (grade 2) in 4 (3.9%), and into eloquent structures or non-target cerebrospinal space (grade 3) in 15 (14.8%). Intracerebral hemorrhage (ICH) >1 mL developed in 5 (5.0%) procedures. Significantly higher incidences of optimal catheter placements were observed in group 2. ICH>1 mL developed in 11 (7.4%) procedures in group 2, showing no significant difference between groups. In addition, the mean interval from the EVD to ventriculoperitoneal shunt was shorter in group 2 than in group 1, and the incidence of EVD-related infection was decreased in group 2. CONCLUSION: Accurate and safe ventriculostomies were achieved using both cranial sites, Kocher's point and the forehead. However, the forehead ventriculostomies provided more accurate ventricular punctures.

The Effect of Minocycline on Motor Neuron Recovery and Neuropathic Pain in a Rat Model of Spinal Cord Injury

Abstract: Objective Minocycline, a second-generation tetracycline-class antibiotic, has been well established to exert a neuroprotective effect in animal models and neurodegenerative disease through the inhibition of microglia. Here, we investigated the effects of minocycline on motor recovery and neuropathic pain in a rat model of spinal cord injury.

Effect of amniotic membrane to reduce postlaminectomy epidural adhesion on a rat model.

Abstract: Objective Epidural fibrosis and adhesion are the main reasons for post-laminectomy sustained pain and functional disability. In this study, the authors investigate the effect of irradiated freeze-dried human amniotic membrane on reducing epidural adhesion after laminectomy on a rat model.

Correlation between Serum D-Dimer Level and Volume in Acute Ischemic Stroke.

Abstract: Objective D-dimer is a breakdown product of fibrin mesh after factor XIII stabilization. Previously, many authors have demonstrated a relationship between D-dimer level and stroke progression or type. This study aimed to investigate the relationship between D-dimer level and stroke volume. Methods Between January 2008 and December 2009, we analyzed the D-dimer levels of 59 acute ischemic stroke patients in our neurosurgical department both upon admission and after seven days of initial treatment. Each patient's National Institute of Health Stroke Scale score, modified Rankin Scales score, Glasgow outcome score, and infarction volume were also evaluated. Results Mean D-dimer level at admission was 626.6 µg/L (range, 77-4,752 µg/L) and the mean level measured after seven days of treatment was 238.3 µg/L (range, 50-924 µg/L). Mean D-dimer level at admission was 215.3 µg/L in patients with focal infarctions, 385.7 µg/L in patients with multiple embolic infarctions, 566.2 µg/L in those with 1-19 cc infarctions, 668.8 µg/L in 20-49 cc infarctions, 702.5 µg/L in 50-199 cc infarctions, and 844.0 µg/L in >200 cc infarctions (p=0.044). On the 7th day of treatment, the D-dimer levels had fallen to 201.0 µg/L, 293.2 µg/L, 272.0 µg/L, 232.8 µg/L, 336.6 µg/L, and 180.0 µg/L, respectively (p=0.530). Conclusion Our study shows that D-dimer level has the positive correlation with infarction volume and can be use to predict infarction-volume.

Efficacy of decompression and fixation for metastatic spinal cord compression: analysis of factors prognostic for survival and postoperative ambulation.

Abstract: Objective : The goals of surgical intervention for metastatic spinal cord compression (MSCC) are prolonging survival and improving quality of life. Non-ambulatory paraplegic patients, either at presentation or after treatment, have a much shorter life expectancy than ambulatory patients. We therefore analyzed prognostic factors for survival and postoperative ambulation in patients surgically treated for MSCC. Methods : We assessed 103 patients with surgically treated MSCC who presented with lower extremity weakness between January 2001 and December 2008. Factors prognostic for overall survival (OS) and postoperative ambulation, including surgical method, age, sex, primary tumor site, metastatic spinal site, surgical levels, Tokuhashi score, and treatment with chemo- or radiation therapy, were analyzed retrospectively. Results : Median OS was significantly longer in the postoperatively ambulatory group [11.0 months; 95% confidence interval (CI), 9.29-12.71 months] than in the non-ambulatory group (5.0 months; 95% CI, 1.80-8.20 months) (p=0.035). When we compared median OS in patients with high (9-11) and low (0-8) Tokuhashi scores, they were significantly longer in the former (15.0 months; 95% CI, 9.29-20.71 months vs. 9.0 months; 95% CI, 7.48-10.52 months; p=0.003). Multivariate logistic regression analysis showed that preoperative ambulation with or without aid [odds ratio (OR) 5.35; 95% CI 1.5718.17; p=0.007] and hip flexion power greater than grade III (OR 6.23; 95% CI, 1.29-7.35; p=0.038) were prognostic of postoperative ambulation. Conclusion : We found that postoperative ambulation and preoperative high Tokuhashi score were significantly associated with longer patient sur vival. In addition, preoperative hip flexion power greater than grade III was critical for postoperative ambulation.

Posterior cervical inclinatory foraminotomy for spondylotic radiculopathy preliminary.

Abstract: Posterior cervical foraminotomy is an attractive therapeutic option in selected cases of cervical radiculopathy that maintains cervical range of motion and minimize adjacent-segment degeneration. The focus of this procedure is to preserve as much of the facet as possible with decompression. Posterior cervical inclinatory foraminotomy (PCIF) is a new technique developed to offer excellent results by inclinatory decompression with minimal facet resection. The highlight of our PCIF technique is the use of inclinatory drilling out for preserving more of facet joint. The operative indications are radiculopathy from cervical foraminal stenosis (single or multilevel) with persistent or recurrent root symptoms. The PCIFs were performed between April 2007 and December 2009 on 26 male and 8 female patients with a total of 55 spinal levels. Complete and partial improvement in radiculopathic pain were seen in 26 patients (76%), and 8 patients (24%), respectively, with preserving more of facet joint. We believe that PCIF allows for preserving more of the facet joint and capsule when decompressing cervical foraminal stenosis due to spondylosis. We suggest that our PCIF technique can be an effective alternative surgical approach in the management of cervical spondylotic radiculopathy.

Acute-on-Chronic Subdural Hematoma: Not Uncommon Events.

Abstract: Objective : Patients with asymptomatic chronic subdural hematoma (SDH) are prone to fall or slip. Acute trauma on these patients may develop acute subdural bleeding over the chronic SDH. We recently experienced 9 patients with acute-on-chronic SDH. We report the clinical and radiological features of this lesion. Methods : We retrospectively examined the computed tomographic (CT) scans of 107 consecutive patients who diagnosed as chronic SDH from January 2008 to December 2010. All cases of CSDH were diagnosed on CT with or without MRI scan. Results : Acute-on-chronic SDH is not rare, being 8% of chronic SDH. The most common cause of trauma was a slip in drunken state. Alcoholism with multiple episodes of trauma was one of the prominent histories. Acute-on-chronic SDH appeared as a hyperdense layer of clot with irregular blurred margin or lumps in liquefied hematoma. Single or two burr holes was usually effective to remove the hematoma. Conclusion : Repeated trauma may cause acute bleeding over the chronic SDH. It will be helpful to understand the role of repeated trauma as a mechanism of hematoma enlargement.

Gamma knife radiosurgery for brainstem metastasis.

Abstract: Objective Brainstem metastases are rarely operable and generally unresponsive to conventional radiation therapy or chemotherapy. Recently, Gamma Knife Radiosurgery (GKRS) was used as feasible treatment option for brainstem metastasis. The present study evaluated our experience of brainstem metastasis which was treated with GKRS. Methods Between November 1992 and June 2010, 32 patients (23 men and 9 women, mean age 56.1 years, range 39-73) were treated with GKRS for brainstem metastases. There were metastatic lesions in pons in 23, the midbrain in 6, and the medulla oblongata in 3 patients, respectively. The primary tumor site was lung in 21, breast in 3, kidney in 2 and other locations in 6 patients. The mean tumor volume was 1,517 mm(3) (range, 9-6,000), and the mean marginal dose was 15.9 Gy (range, 6-23). Magnetic Resonance Imaging (MRI) was obtained every 2-3 months following GKRS. Follow-up MRI was possible in 24 patients at a mean follow-up duration of 12.0 months (range, 1-45). Kaplan-Meier survival analysis was used to evaluate the prognostic factors. Results Follow-up MRI showed tumor disappearance in 6, tumor shrinkage in 14, no change in tumor size in 1, and tumor growth in 3 patients, which translated into a local tumor control rate of 87.5% (21 of 24 tumors). The mean progression free survival was 12.2 months (range, 2-45) after GKRS. Nine patients were alive at the completion of the study, and the overall mean survival time after GKRS was 7.7 months (range, 1-22). One patient with metastatic melanoma experienced intratumoral hemorrhage during the follow-up period. Survival was found to be associated with score of more than 70 on Karnofsky performance status and low recursive partitioning analysis class (class 1 or 2), in terms of favorable prognostic factors. Conclusion GKRS was found to be safe and effective for management of brainstem metastasis. The integral clinical status of patient seems to be important in determining the overall survival time.

Comparison of Serum CRP and Procalcitonin in Patients after Spine Surgery.

Abstract: Objective Classical markers of infection cannot differentiate reliably between inflammation and infection after neurosurgery. This study investigated the dynamics of serum procalcitonin (PCT) in patients who had elective spine surgeries without complications.

Visual outcome after transsphenoidal surgery in patients with pituitary apoplexy.

Abstract: OBJECTIVE: Pituitary apoplexy is one of the most serious life-threatening complications of pituitary adenoma. The purpose of this study is to investigate the visual outcome after early transsphenoidal surgery for the patients with pituitary apoplexy. METHODS: We retrospectively reviewed the 31 patients with pituitary apoplexy who were admitted due to acute visual acuity or field impairment and treated by transsphenoidal surgery. Five patients were excluded because of the decreased conscious level. The visual acuity of each individual eye was evaluated by Snellen's chart. Visual fields were also checked using automated perimetry. To compare the visual outcome according to the surgical timing, we divided the patients into 2 groups. The first group, 21 of the patients have been undertaken transsphenoidal approach (TSA) within at least 48 hours after admission. The second group included 8 patients who have been undertaken TSA beyond 48 hours. All patients were monitored at least 12 months after surgery. RESULTS: Patients were 21 males and 8 females (M : F=2.6 : 1) with the mean age of 42.4 years. Among the enrolled 29 patients, 26 patients presented with decreased visual acuity and 23 patients revealed the defective visual field respectively. Postoperatively, improvement in the visual acuity was seen in 15 patients (83.3%) who underwent surgery within the first 48 hours of presentation, as compared to those in whom surgery was delayed beyond 48 hours (n=5; 62.5%) (p=0.014). Improvement in the visual field deficits was observed in 15 (88.2%) of patients who had been operated on within the first 48 hours of presentation, as compared to those in whom surgery was delayed beyond 48 hours (n=3; 50.0%) (p=0.037). CONCLUSION: This study suggests that rapid transsphenoidal surgery is effective to recover the visual impairment in patients with pituitary apoplexy. If there are associated abnormalities of visual acuity or visual fields in patients with hemorrhagic pituitary apoplexy, early neurosurgical intervention within 48 hours should be also required to recover visual impairment.

Radiological apoplexy and its correlation with acute clinical presentation, angiogenesis and tumor microvascular density in pituitary adenomas.

Abstract: Objective : Pituitary apoplexy is life-threatening clinical syndrome caused by the rapid enlargement of a pituitary tumor due to hemorrhage and/or infarction. The pathogenesis of pituitary apoplexy is not completely understood. We analyzed the magnetic resonance imaging (MRI) of pituitary tumors and subsequently correlated the radiological findings with the clinical presentation. Additionally, immunohistochemistry was also performed to determine whether certain biomarkers are related to radiological apoplexy. Methods : Thirty-four cases of pituitary adenoma were enrolled for retrospective analysis. In this study, the radiological apoplexy was defined as cases where hemorrhage, infarction or cysts were identified on MRI. Acute clinical presentation was defined as the presence of any of the following symptoms: severe sudden onset headache, decreased visual acuity and/or visual field deficit, and acute mental status changes. Angiogenesis was quantified by immunohistochemical expression of fetal liver kinase 1 (Flk-1), neuropilin (NRP) and vascular endothelial growth factor (VEGF) expres sion, while microvascular density (MVD) was assessed using Endoglin and CD31. Results : Clinically, fourteen patients presented with acute symptoms and 20 for mild or none clinical symptoms. Radiologically, fifteen patients met the criteria for radiological apoplexy. Of the fifteen patients with radiologic apoplexy, 9 patients presented acute symptoms whereas of the 19 pa tient without radiologic apoplexy, 5 patients presented acute symptoms. Of the five biomarkers tracked, only VEGF was found to be positively corre lated with both radiological and nonradiological apoplexy. Conclusion : While pituitary apoplexy is currently defined in cases where clinical symptoms can be histologically confirmed, we contend that cases of radiologically identified pituitary hemorrhages that present with mild or no symptoms should be designated subacute or subclinical apoplexy. VEGF is believed to have a positive correlation with pituitary hemorrhage. Considering the high rate of symptomatic or asymptomatic pituitary tumor hemorrhage, additional studies are needed to detect predictors of the pituitary hemorrhage.

Ischemic complications occurring in the contralateral hemisphere after surgical treatment of adults with moyamoya disease.

Abstract: Objective Direct revascularization surgery is regarded as the most effective method of treatment of adults with moyamoya disease. These patients, however, have a higher risk of perioperative ischemic complications than do patients with atherosclerotic stroke, and are at risk for ischemic complications in the hemisphere contralateral to the one operated on. We investigated the incidence and risk factors for ischemic stroke in the contralateral hemisphere after surgical treatment of adults with moyamoya disease.

The clinical features of spinal leptomeningeal dissemination from malignant gliomas.

Abstract: Objective The incidence of leptomeningeal dissemination from malignant glioma is rare, so the clinical features of this are not well documented yet. We attempted to determine the clinical features of leptomeningeal dissemination from malignant gliomas. Methods We retrospectively analyzed 11 cases of leptomeningeal dissemination of malignant glioma, who were treated at our institution between 2006 and 2009. We investigated the clinical features of these patients by considering the following factors : tumor locations, the events of ventricular opening during surgery and the cerebrospinal fluid (CSF) profiles, including the cytology. Results The group was composed of 9 males and 2 females. The histological diagnosis of their initial intracranial tumors were 4 primary glioblastoma, 3 anaplastic astrocytoma, 1 anaplastic oligoastrocytoma, 2 ganglioglioma and 1 pleomorphic xanthoastrocyotma with anaplastic features. The mean age of the patients at the time of the initial presentation was 42.8±10.3 years. The mean time between surgery and the diagnosis of spinal dissemination was 12.3±7.9 (3-28) months. The mean overall survival after dissemination was 2.7±1.3 months. All our patients revealed a history of surgical opening of the ventricles. Elevated protein in the CSF was reported for eight patients who had their CSF profiles checked. Conclusion We propose that in the malignant gliomas, the surgical opening of ventricles can cause the spinal leptomeningeal dissemination and the elevated protein content of CSF may be a candidate marker of leptomeningeal dissemination.

Characterization of invading glioma cells using molecular analysis of leading-edge tissue.

Abstract: Objective We have introduced a method of characterization of invading glioma cells by using molecular analysis of marginal invading tumor cells and molecular profiles of glioma tumor margin. Methods Each of tumor core and marginal tissues was obtained in 22 glioma patients. Tumor core cells and marginal cells from each glial tumor were collected by laser capture microdissection or intraoperative microdissection under the operating microscope. Expression of MMP-2, MMP-9, CD44 and RHAMM mRNA by invading glioma cells compared with tumor core was confirmed by realtime-PCR of twenty-four glioma specimens. Clinical data also were reviewed for invasion and recurrence pattern of the gliomas radiologically and invasive rim pattern microscopically. Results Overall results of the molecular analysis showed that relative overexpression of MMP-2, MMP-9 and RHAMM were noted at the invasive edge of human glioma specimens comparing to the tumor core but CD44 was highly expressed in the tumor core comparing to the margin. High marginal expression of MMP-2 and MMP-9 were noted in poorly ill-defined margin on the pathological finding. High marginal expression of CD44 and MMP-2 were demonstrated in the midline cross group on the radiological review, and that of RHAMM and MMP-2 were showed in the aggressive recurrence group. High expression of MMP-2 seems to be involved in the various invasion-related phenomenons. Conclusion Up-regulation of MMP-2, MMP-9, CD44 and RHAMM was noted in invasive edge of gliomas according to the various clinical situations.

Endoscopic third ventriculostomy in patients with shunt malfunction.

Abstract: Objective This paper presents data from a retrospective study of endoscopic third ventriculostomy (ETV) in patients with shunt malfunction and proposes a simple and reasonable post-operative protocol that can detect ETV failure.

Symptomatic post-discectomy pseudocyst after endoscopic lumbar discectomy.

Abstract: Objective The objectives of this study were to determine the frequency of symptomatic postdiscectomy pseudocyst (PP) after endoscopic discectomy and to compare the results of surgical and conservative management of them. Methods Initial study participants were 1,503 cases (1,406 patients) receiving endoscopic lumbar discectomy by 23-member board of neurosurgeons from March 2003 to October 2008. All patients' postoperative magnetic resonance imaging (MRI) scans were evaluated. On the postoperative MRI, cystic lesion of T2W high and T1W low at discectomy site was regarded as PP. Reviews of medical records and radiological findings were done. The PP patients were divided into two groups, surgical and conservative management by treatment modality after PP detection. We compared the results of the two groups using the visual analogue scale (VAS) for low back pain (LBP), VAS for leg pain (LP) and the Oswestry disability index (ODI). Results Among 1,503 cases of all male soldiers, the MRIs showed that pseudocysts formed in 15 patients, about 1.0% of the initial cases. The mean postoperative interval from surgery to PP detection was 53.7 days. Interlaminar approach was correlated with PP formation compared with transforaminal approach (p=0.001). The mean VAS for LBP and LP in the surgical group improved from 6.5 and 4.8 to 2.0 and 2.3, respectively. The mean VAS for LBP and LP in the conservative group improved from 4.4 and 4.4 to 3.9 and 2.3, respectively. There was no difference in treatment outcome between surgical and conservative management of symptomatic PP. Conclusion Although this study was done in limited environment, symptomatic PP was detected at two months' postoperative period in about 1% of cases. Interlaminar approach seems to be more related with PP compared with transforaminal approach.

Profiles of Spinal Cord Tumors Removed through a Unilateral Hemilaminectomy

Abstract: Objective : To present the profiles of spinal cord tumors that can be removed through a unilateral hemilaminectomy and to demonstrate its useful ness 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 crosssectional 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 sur gery of the benign spinal cord tumors in various sizes.

Leukoencephalopathy and Disseminated Necrotizing Leukoencephalopathy Following Intrathecal Methotrexate Chemotherapy and Radiation Therapy for Central Nerve System Lymphoma or Leukemia

Abstract: Objective Intrathecal methotrexate (MTX) therapy combined with whole brain radiotherapy (WBRT) is one of the major treatment modalities for leukemia and lymphoma involving the central nervous system (CNS). The purpose of this study was to retrospectively determine the incidences of leukoencephalopathy and disseminated necrotizing leukoencephalopathy (DNL) following intrathecal MTX therapy for CNS lymphoma or leukemia and to assess the potential risk factors.

Spontaneous resolution of nontraumatic acute spinal subdural hematoma.

Abstract: Spinal subdural hematoma (SSDH) is an extremely uncommon condition. Causative factors include trauma, anticoagulant drug administration, hemostatic disorders, and vascular disorders such as arteriovenous malformations and lumbar punctures. Of SSDH cases, those that do not have any traumatic event can be considered cases of nontraumatic acute spinal subdural hematoma, which is known to have diverse clinical progress. Treatment typically consists of surgical decompression and cases in which the condition is relieved with conservative treatment are rarely reported. We report two nontraumatic acute spinal subdural hematoma patients who were successfully treated without surgery.

Unilateral extrapedicular vertebroplasty and kyphoplasty in lumbar compression fractures : technique, anatomy and preliminary results.

Abstract: Objective : A single balloon extrapedicular kyphoplasty has been introduced as one of the unilateral approaches for thoracic compression fractures; however, the unilateral extrapedicular technique in the lumbar area needs a further understanding of structures in the lumbar area. The purpose of the present study is to describe methods and pitfalls of this procedure based on the anatomy of the lumbar area and to analyze clinical outcome and complications. Methods : Anatomical evaluation was performed with 2 human cadavers. A retrospective review of unilateral extrapedicular approaches yielded 74 vertebral levels in 55 patients that were treated with unilateral extrapedicular vertebroplasty and kyphoplasty. Radiographic assessment included the restoration rate of vertebral height and correction of kyphosis. Results : Anatomical evaluation indicates that the safe needle entry zone of bone for the extrapedicular approach was located in the supero-lateral aspect of the junction between the pedicle and vertebral body. The unilateral extrapedicular procedure achieved adequate pain relief with a mean decreases in pain severity of 7.25±1.5 and 2.0±1.4, respectively. Complications were 1 retroperitoneal hematoma, 6 unilateral fillings and 3 epi dural leak of the polymethylmethacrylate. Conclusion : The method of a unilateral extrapedicular approach in kyphoplasty and vertebroplasty in the lumbar area might be similar to that in thoracic approach using a route via the extrapedicular space. However, different anatomical characteristics of the lumbar area should be considered.

Risk factors associated with subdural hygroma after decompressive craniectomy in patients with traumatic brain injury : a comparative study.

Abstract: Objective Subdural hygroma (SDG) is a complication occurring after head trauma that may occur secondary to decompressive craniectomy (DC). However, the mechanism underlying SDG formation is not fully understood. Also, the relationship between the operative technique of DC or the decompressive effect and the occurrence and pathophysiology of SDG has not been clarified. Purpose of this study was to investigate the risk factors of SDG after DC in our series.

Vertical Reduction Using Atlantoaxial Facet Spacer in Basilar Invagination with Atlantoaxial Instability

Abstract: Although posterior segmental fixation technique is becoming increasingly popular, surgical treatment of craniovertebral junctional disorders is still challenging because of its complex anatomy and surrounding critical neurovascular structures. Basilar invagination is major pathology of craniovertebral junction that has been a subject of clinical interest because of its various clinical presentations and difficulty of treatment. Most authors recommend a posterior occipitocervical fixation following transoral decompression or posterior decompression and occipitocervical fixation. However, both surgical modalities inadvertently sacrifice C0-1 and C1-2 joint motion. We report two cases of basilar invagination reduced by the vertical distraction between C1-2 facet joint. We reduced the C1-2 joint in an anatomical position and fused the joint with iliac bone graft and C1-2 segmental fixation using the polyaxial screws and rods C-1 lateral mass and the C-2 pedicle.

Segmental artery injury following percutaneous vertebroplasty using extrapedicular approach.

Abstract: We performed a percutaneous vertebroplasty at the compressed L2 vertebral body of a 73-year-old female using a left-sided unilateral extrapedicular approach. She complained severe radiating pain and a tingling sensation in her left leg two hours after the vertebroplasty. Spinal computed tomographic scan showed a large retroperitoneal hematoma, and a subsequent spinal angiography revealed a left L2 segmental artery injury. Bleeding was successfully controlled by endovascular embolization. Recently, extrapedicular approaches have been attempted, allowing for the avoidance of facet and pedicle injury with only a unilateral approach. With this approach, however, the needle punctures the vertebral body directly. Therefore, this procedure carries the potential risk of a spinal segmental artery.

Fluoroscopic Radiation Exposure during Percutaneous Kyphoplasty

Abstract: Objective : The author measured levels of fluoroscopic radiation exposure to the surgeon’s body based on the different beam directions during ky phoplasty. Methods : This is an observational study. A series of 84 patients (96 vertebral bodies) were treated with kyphoplasty over one year. The patients were divided into four groups based on the horizontal and vertical directions of the X-Ray beams. We measured radiation exposure with the seven dosimetry badges which were worn by the surgeon in each group (total of 28 badges). Twenty-four procedures were measured in each group. Cumulative dose and dose rates were compared between groups. Results : Fluoroscopic radiation is received by the operator in real-time for approximately 50% (half) of the operation time. Thyroid protectors and lead aprons can block radiation almost completely. The largest dose was received in the chest irrespective of beam directions. The lowest level of radiation were received when X-ray tube was away from the surgeon and beneath the bed (dose rate of head, neck, chest, abdomen and knee : 0.2986, 0.2828, 0.9711, 0.8977, 0.8168 mSv, respectively). The radiation differences between each group were approximately 2.7-10 folds. Conclusion : When fluoroscopic guided-KP is performed, the X-Ray tube should be positioned on the opposite side of the operator and below the table, otherwise the received radiation to the surgeon’s body would be 2.7-10 times higher than such condition.