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1.  Predictive Factors for a Kyphosis Recurrence Following Short-Segment Pedicle Screw Fixation Including Fractured Vertebral Body in Unstable Thoracolumbar Burst Fractures 
The technique of short segment pedicle screw fixation (SSPSF) has been widely used for stabilization in thoracolumbar burst fractures (TLBFs), but some studies reported high rate of kyphosis recurrence or hardware failure. This study was to evaluate the results of SSPSF including fractured level and to find the risk factors concerned with the kyphosis recurrence in TLBFs.
This study included 42 patients, including 25 males and 17 females, who underwent SSPSF for stabilization of TLBFs between January 2003 and December 2010. For radiologic assessments, Cobb angle (CA), vertebral wedge angle (VWA), vertebral body compression ratio (VBCR), and difference between VWA and Cobb angle (DbVC) were measured. The relationships between kyphosis recurrence and radiologic parameters or demographic features were investigated. Frankel classification and low back outcome score (LBOS) were used for assessment of clinical outcomes.
The mean follow-up period was 38.6 months. CA, VWA, and VBCR were improved after SSPSF, and these parameters were well maintained at the final follow-up with minimal degree of correction loss. Kyphosis recurrence showed a significant increase in patients with Denis burst type A, load-sharing classification (LSC) score >6 or DbVC >6 (p<0.05). There were no patients who worsened to clinical outcome, and there was no significant correlation between kyphosis recurrence and clinical outcome in this series.
SSPSF including the fractured vertebra is an effective surgical method for restoration and maintenance of vertebral column stability in TLBFs. However, kyphosis recurrence was significantly associated with Denis burst type A fracture, LSC score >6, or DbVC >6.
PMCID: PMC4217060  PMID: 25368766
Kyphosis; Short-segment pedicel screw fixation; Thoracolumbar burst fractures; Instability
2.  Surgical Results after Unilateral Laminectomy for the Removal of Spinal Cord Tumors 
Korean Journal of Spine  2012;9(3):232-238.
To reduce the risk of postoperative spinal instability or deformity, unilateral laminectomy (UL) has been recommended to remove spinal space-occupying lesions. The purpose of this study was to determine whether there were any advantages of UL for removal of spinal cord tumors.
From May 1995 to May 2010, 94 patients with spinal cord tumors, who underwent tumor removal via UL in our institute, were enrolled in this study. Intramedullary spinal cord tumors were excluded. Simple radiographs were obtained for accessing the restoration of the spinal column. Spinal magnetic resonance imaging (MRI) was also obtained during the follow-up period to evaluate tumor recurrence.
There were 51 women and 43 men; their mean age was 47.8 years (range, 9-83 years). The mean follow-up period was 52.6 months (range, 24 month-16 years). The sites of the tumors were cervical in 21 cases, thoracic in 37, lumbar in 33, and sacral in 3. These cases included 85 intradural extramedullary (IDEM) and 9 extradural (ED) lesions. IDEM tumors consisted mainly of neurilemmomas (56.3%) and meningiomas (22.3%).Tumors were totally removed in 80 cases and subtotally removed in 14 cases. Postoperative neurological status was improved in 53 cases, unchanged in 31 cases, and worsened in 10 cases. During follow-up, MRI showed tumor recurrence in 4 patients. Histopathologically, three cases were meningiomas and one case was neurilemmoma. None of the patients showed spinal instability or kyphotic deformity at last follow-up.
UL is an optimal approach for providing sufficient exposure of spinal cord tumors without development of postoperative spinal instability and regional sagittal imbalance in any location of spinal column. In cases of meningioma, careful long-term follow up is needed due to it's relatively high recurrence rate after removal via UL.
PMCID: PMC4431008  PMID: 25983821
Unilateral laminectomy; Spinal cord tumors; Surgical result
4.  Symptomatic aggravation after corticosteroid pulse therapy in definite sporadic Creutzfeldt-Jakob disease with the feature of Hashimoto’s encephalopathy 
BMC Neurology  2014;14:179.
Creutzfeldt-Jakob disease and Hashimoto’s encephalopathy often show similar clinical presentation. Among Creutzfeldt-Jakob disease mimics, Hashimoto’s encephalopathy is particularly important as it is treatable with corticosteroids. Thus, in cases of middle-aged woman diagnosed with probable Creutzfeldt-Jakob disease and who exhibit high titers of antithyroid antibodies, corticosteroid pulse therapy is typically performed with expectations of near complete recovery from Hashimoto’s encephalopathy. Herein, we provide the first case report that exhibited a negative effect of corticosteroid pulse therapy for a patient with Creutzfeldt-Jakob disease with features of Hashimoto’s encephalopathy.
Case presentation
We report a case of 59-year-old Asian woman with blurred vision, dysarthria, myoclonus, and rapidly progressive dementia. Cerebrospinal fluid showed 14-3-3 protein positive. Electroencephalogram showed periodic sharp waves (1.5 Hz) at the bilateral frontal or occipital areas. Magnetic resonance imaging showed high signal intensities at the bilateral cerebral cortex, caudate nucleus, and putamen. The patient was diagnosed with probable Creutzfeldt-Jakob disease. However, serum analysis showed a high titer of antithyroid antibodies. We started corticosteroid pulse therapy with subsequent aggravation of seizure activity including generalized myoclonus, epilepsia parialis continua, and ballistic dyskinesia, which was effectively treated with clonazepam.
We provide evidence of a case of Creutzfeldt-Jakob disease that exhibited clinical deterioration after corticosteroid therapy. Although histopathological confirmation with brain biopsy is not easily available in Creutzfeldt-Jakob disease patients, selective initiation of corticosteroid pulse therapy should be considered in cases of uncertain diagnosis for differentiation with Hashimoto’s encephalopathy.
PMCID: PMC4172833  PMID: 25196053
Creutzfeldt-Jakob disease; Hashimoto’s encephalopathy; Corticosteroid; Seizure
5.  Arachnoid Membrane Suturing for Prevention of Subdural Fluid Collection in Extracranial-intracranial Bypass Surgery 
Water-tight closure of the dura in extracranial-intracranial (EC-IC) bypass is impossible because the superficial temporal artery (STA) must run through the dural defect. Consequently, subdural hygroma and subcutaneous cerebrospinal fluid (CSF) collection frequently occur postoperatively. To reduce these complications, we prospectively performed suturing of the arachnoid membrane after STA-middle cerebral artery (STA-MCA) and evaluated the clinical usefulness.
Materials and Methods
Between Mar. 2005 and Oct. 2010, extracranial-intracranial arterial bypass (EIAB) with/without encephalo-myo-synangiosis was performed in 88 cases (male : female = 53 : 35). As a control group, 51 patients (57 sides) underwent conventional bypass surgery without closure of the arachnoid membrane. Postoperative computed tomography (CT) scan was performed twice in three days and seven days later, respectively, for evaluation of the presence of subdural fluid collection and other mass lesions.
The surgical result was excellent, with no newly developing ischemic event until recent follow-up. The additional time needed for arachnoid suture was five to ten minutes, when three to eight sutures were required. Post-operative subdural fluid collection was not seen on follow-up computed tomography scans in all patients.
Arachnoid suturing is simple, safe, and effective for prevention of subdural fluid collection in EC-IC bypass surgery, especially the vulnerable ischemic hemisphere.
PMCID: PMC4102753  PMID: 25045645
Arachnoid suture; Extracranial-intracranial bypass surgery; Subdural hygroma; Mass effect
6.  Differential White Matter Connectivity in Early Mild Cognitive Impairment According to CSF Biomarkers 
PLoS ONE  2014;9(3):e91400.
Mild cognitive impairment (MCI) is a heterogeneous group and certain MCI subsets eventually convert to dementia. Cerebrospinal fluid (CSF) biomarkers are known to predict this conversion. We sought evidence for the differences in white matter connectivity between early amnestic MCI (EMCI) subgroups according to a CSF phosphorylated tau181p/amyloid beta1–42 ratio of 0.10. From the Alzheimer's Disease Neuroimaging Initiative database, 16 high-ratio, 25 low-ratio EMCI patients, and 20 normal controls with diffusion tensor images and CSF profiles were included. Compared to the high-ratio group, radial diffusivity significantly increased in both sides of the corpus callosum and the superior and inferior longitudinal fasciculus in the low-ratio group. In widespread white matter skeleton regions, the low-ratio group showed significantly increased mean, axial, and radial diffusivity compared to normal controls. However, the high-ratio group showed no differences when compared to the normal group. In conclusion, our study revealed that there were significant differences in white matter connectivity between EMCI subgroups according to CSF phosphorylated tau181p/amyloid beta1–42ratios.
PMCID: PMC3948821  PMID: 24614676
7.  Comparison of Clinical and Radiologic Results between Expandable Cages and Titanium Mesh Cages for Thoracolumbar Burst Fracture 
A thoracolumbar burst fracture is usually unstable and can cause neurological deficits and angular deformity. Patients with unstable thoracolumbar burst fracture usually need surgery for decompression of the spinal canal, correction of the angular deformity, and stabilization of the spinal column. We compared two struts, titanium mesh cages (TMCs) and expandable cages.
33 patients, who underwent anterior thoracolumbar reconstruction using either TMCs (n=16) or expandable cages (n=17) between June 2000 and September 2011 were included in this study. Clinical outcome was measured by visual analogue scale (VAS), American Spinal Injury Association (ASIA) scale and Low Back Outcome Score (LBOS) for functional neurological evaluation. The Cobb angle, body height of the fractured vertebra, the operation time and amount of intra-operative bleeding were measured in both groups.
In the expandable cage group, operation time and amount of intraoperative blood loss were lower than that in the TMC group. The mean VAS scores and LBOS in both groups were improved, but no significant difference. Cobb angle was corrected higher than that in expandable cage group from postoperative to the last follow-up. The change in Cobb angles between preoperative, postoperative, and the last follow-up did not show any significant difference. There was no difference in the subsidence of anterior body height between both groups.
There was no significant difference in the change in Cobb angles with an inter-group comparison, the expandable cage group showed better results in loss of kyphosis correction, operation time, and amount of intraoperative blood loss.
PMCID: PMC4024813  PMID: 24851149
Thoracolumbar; Lumbar; Fracture; Corpectomy; Cage; Kyphosis
8.  Core–Shell Triangular Bifrustums 
Nano letters  2009;9(8):3038-3041.
Aucore–Agshell triangular bifrustum nanocrystals were synthesized in aqueous solution using a seed-mediated approach. The formation of the Ag layer on the Au nanoprism seeds leads to structures with highly tunable dipole and quadrupole surface plasmon resonances. Discrete dipole approximation calculations show that it is the geometry of these novel structures rather than the addition of a new element that leads to the plasmon tunability. The structure and composition of these novel nanocrystals have been investigated by transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and energy-dispersive spectrometry.
PMCID: PMC3930336  PMID: 19603815
9.  In-Wire Conversion of a Metal Nanorod Segment into an Organic Semiconductor** 
PMCID: PMC3930343  PMID: 19387988
chemical vapor deposition; multisegmented nanowires; nanojunctions; organic semiconductors
10.  Reflections of Two Parallel Pathways between the Hippocampus and Neocortex in Transient Global Amnesia: A Cross-Sectional Study Using DWI and SPECT 
PLoS ONE  2013;8(7):e67447.
Two parallel pathways have been proposed between the hippocampus and neocortex. Recently, the anterior and posterior hippocampus showed distinct connectivity with different cortical areas in an fMRI study. We investigated whether the two parallel pathways could be confirmed in patients with transient global amnesia (TGA) which is a natural lesion model of a perturbation of the hippocampus. In addition, we evaluated the relationship between the location of the hippocampal lesion and various clinical variables.
A consecutive series of 37 patients were identified from the TGA registry database of Seoul National University Bundang Hospital. Based on the location of the diffusion-weighted imaging (DWI) lesion along the anterior-posterior axis of the hippocampus, they were divided into the following three groups: head (n = 15), body (n = 15) or tail (n = 7). To evaluate which cortical regions showed hypoperfusion according to the location of the DWI lesion, their SPECT images were compared between two groups using statistical parametric mapping. We performed hierarchical cluster analysis to group demographic and clinical variables, including the location of the DWI lesion, into clusters.
Statistical parametric mapping analyses revealed that more anterior DWI lesions were associated with hypoperfusion of the anterior temporal and frontal areas, whereas more posterior lesions were associated with hypoperfusion of the posterior temporal, parietal, occipital and cerebellar areas. The difference was most prominent between the group of hippocampal lesions on the head and tail. Hierarchical cluster analysis demonstrated that vomiting was related to female gender and hippocampal head lesions, whereas vascular risk factors were related to male gender and hippocampal body lesions.
We confirmed the parallel pathways between the hippocampus and neocortex with DWI and SPECT images of patients with TGA. Patients with hippocampal head lesions and body lesions were clustered within different groups of clinical variables.
PMCID: PMC3702497  PMID: 23861765
11.  Femoral Graft-Tunnel Angles in Posterior Cruciate Ligament Reconstruction: Analysis with 3-Dimensional Models and Cadaveric Experiments 
Yonsei Medical Journal  2013;54(4):1006-1014.
The purpose of this study was to compare four graft-tunnel angles (GTA), the femoral GTA formed by three different femoral tunneling techniques (the outside-in, a modified inside-out technique in the posterior sag position with knee hyperflexion, and the conventional inside-out technique) and the tibia GTA in 3-dimensional (3D) knee flexion models, as well as to examine the influence of femoral tunneling techniques on the contact pressure between the intra-articular aperture of the femoral tunnel and the graft.
Materials and Methods
Twelve cadaveric knees were tested. Computed tomography scans were performed at different knee flexion angles (0°, 45°, 90°, and 120°). Femoral and tibial GTAs were measured at different knee flexion angles on the 3D knee models. Using pressure sensitive films, stress on the graft of the angulation of the femoral tunnel aperture was measured in posterior cruciate ligament reconstructed cadaveric knees.
Between 45° and 120° of knee flexion, there were no significant differences between the outside-in and modified inside-out techniques. However, the femoral GTA for the conventional inside-out technique was significantly less than that for the other two techniques (p<0.001). In cadaveric experiments using pressure-sensitive film, the maximum contact pressure for the modified inside-out and outside-in technique was significantly lower than that for the conventional inside-out technique (p=0.024 and p=0.017).
The conventional inside-out technique results in a significantly lesser GTA and higher stress at the intra-articular aperture of the femoral tunnel than the outside-in technique. However, the results for the modified inside-out technique are similar to those for the outside-in technique.
PMCID: PMC3663220  PMID: 23709438
Posterior cruciate ligament; reconstruction; graft-tunnel angle; 3-dimensional
12.  Evaluation of Probability of Survival Using Trauma and Injury Severity Score Method in Severe Neurotrauma Patients 
Despite several limitations, the Trauma Injury Severity Score (TRISS) is normally used to evaluate trauma systems. The aim of this study was to evaluate the preventable trauma death rate using the TRISS method in severe trauma patients with traumatic brain injury using our emergency department data.
The use of the TRISS formula has been suggested to consider definitively preventable death (DP); the deaths occurred with a probability of survival (Ps) higher than 0.50 and possible preventable death (PP); the deaths occurred with a Ps between 0.50 and 0.25. Deaths in patients with a calculated Ps of less than 0.25 is considered as no-preventable death (NP). A retrospective case review of deaths attributed to mechanical trauma occurring between January 1, 2011 and December 31, 2011 was conducted.
A total of 565 consecutive severe trauma patients with ISS>15 or Revised Trauma Score<7 were admitted in our institute. We excluded a total of 24 patients from our analysis : 22 patients younger than 15 years, and 2 patients with burned injury. Of these, 221 patients with head injury were analyzed in the final study. One hundred eighty-two patients were in DP, 13 in PP and 24 in NP. The calculated predicted mortality rates were 11.13%, 59.04%, and 90.09%. The actual mortality rates were 12.64%, 61.547%, and 91.67%, respectively.
Although it needs to make some improvements, the present study showed that TRISS performed well in predicting survival of traumatic brain injured patients. Also, TRISS is relatively exact and acceptable compared with actual data, as a simple and time-saving method.
PMCID: PMC3772286  PMID: 24044080
Traumatic brain injury; TRISS; Survival
13.  Value of Indocyanine Green Videoangiography in Deciding the Completeness of Cerebrovascular Surgery 
Recently, microscope-integrated near infrared indocyanine green videoangiography (ICG-VA) has been widely used in cerebrovascular surgery because it provides real-time high resolution images. In our study, we evaluate the efficacy of intraoperative ICG-VA during cerebrovascular surgery.
Between August 2011 and April 2012, 188 patients with cerebrovascular disease were surgically treated in our institution. We used ICG-VA in that operations with half of recommended dose (0.2 to 0.3 mg/kg). Postoperative digital subtraction angiography and computed tomography angiography was used to confirm anatomical results.
Intraoperative ICG-VA demonstrated fully occluded aneurysm sack, no neck remnant, and without vessel compromise in 119 cases (93.7%) of 127 aneurysms. Eight clipping (6.3%) of 127 operations were identified as an incomplete aneurysm occlusion or compromising vessel after ICG-VA. In 41 (97.6%) of 42 patients after carotid endarterectomy, the results were the same as that of postoperative angiography with good patency. One case (5.9%) of 17 bypass surgeries was identified as a nonfunctioning anastomosis after ICG-VA, which could be revised successfully. In the two patients of arteriovenous malformation, ICG-VA was useful for find the superficial nature of the feeding arteries and draining veins.
ICG-VA is simple and provides real-time information of the patency of vessels including very small perforators within the field of the microscope and has a lower rate of adverse reactions. However, ICG-VA is not a perfect method, and so a combination of monitoring tools assures the quality of cerebrovascular surgery.
PMCID: PMC3756127  PMID: 24003369
Cerebrovascular surgery; Indocyanine green videoangiography; Intraoperative angiography; Patency of graft; Complete obliteration of aneurysm
14.  Matrix-Assisted Dip-Pen Nanolithography (MA-DPN) and Polymer Pen Lithography (MA-PPL)** 
The controlled patterning of nanomaterials presents a major challenge to the field of nanolithography because of differences in size, shape and solubility of these materials. Matrix-assisted dip-pen nanolithography and polymer pen lithography provide a solution to this problem by utilizing a polymeric matrix that encapsulates the nanomaterials and delivers them to surfaces with precise control of feature size.
PMCID: PMC3517014  PMID: 19885890
Dip-Pen Nanolithography; Polymer Pen Lithography; Nanomaterials; Poly(ethylene glycol)
15.  Activation of Matrix Metalloproteinases-9 after Photothrombotic Spinal Cord Injury Model in Rats 
Matrix metalloproteinases (MMPs), especially MMP-2 and MMP-9 have been known to play an important role in secondary inflammatory reaction after spinal cord injury (SCI). The aim of this study was to investigate the expression and activity of MMP-2 and MMP-9 and to determine their relationship with disruption of endothelial blood-barrier after photochemically induced SCI in rats.
Female Sprague-Dawley rats, weighing between 250 and 300 g (aged 8 weeks) received focal spinal cord ischemia by photothrombosis using Rose Bengal. Expressions and activities of MMP-2 and MMP-9 were assessed by Western blot and gelatin zymography at various times from 6 h to 7 days. Endothelial blood-barrier integrity was assessed indirectly using spinal cord water content.
Zymography and Western blot analysis demonstrated rapid up-regulation of MMP-9 protein levels in spinal cord after ischemic onset. Expressions and activities of MMP-9 showed a significant increased at 6 h after the photothrombotic ischemic event, and reached a maximum level at 24 h after the insult. By contrast, activated MMP-2 was not detected at any time point in either the experimental or the control groups. When compared with the control group, a significant increase in spinal cord water content was detected in rats at 24 h after photothrombotic SCI.
Early up-regulation of MMP-9 might be correlated with increased water content in the spinal cord at 24 h after SCI in rats. Results of this study suggest that MMP-9 is the key factor involved in disruption of the endothelial blood-barrier of the spinal cord and subsequent secondary damage after photothrombotic SCI in rats.
PMCID: PMC3243829  PMID: 22200008
Endothelial blood-barrier; Matrix metalloproteinases-9; Photothrombosis; Rat; Spinal cord injury
16.  Laminotomy with Continuous Irrigation in Patients with Pyogenic Spondylitis in Thoracic and Lumbar Spine 
Pyogenic spondylitis often results in acute neurological deterioration requiring adequate surgical intervention and appropriate antibiotic treatment. The purpose of this study was to conduct an analysis of the clinical effect of continuous irrigation via laminotomy in a series of patients with pyogenic spondylitis in thoracic and lumbar spine.
The authors conducted a retrospective investigation of 31 consecutive patients with pyogenic thoracic and lumbar spondylitis who underwent continuous irrigation through laminotomy from 2004 to 2008. The study included 22 men and 9 women, ranging in age from 38 to 78 years (mean 58.1 years). The average follow-up duration was 13.4 months (range, 8-34 months). We performed debridement and abscess removal after simple laminotomy, and then washed out epidural and disc space using a continuous irrigation system. Broad spectrum antibiotics were administered empirically and changed according to the subsequent culture result. Clinical outcomes were based on the low back outcome scale (LBOS), visual analogue scale (VAS) score, and Frankel grade at the last follow-up. Radiological assessment involved plain radiographs, including functional views.
Common predisposing factors included local injection for pain therapy, diabetes mellitus, chronic renal failure, and liver cirrhosis. Causative microorganisms were identified in 22 cases (70.9%) : Staphylococcus aureus and Streptococcus spp. were the main organisms. After surgery, LBOS, VAS score, and Frankel grade showed significant improvement in most patients. Spinal stability was maintained during the follow-up period, making secondary reconstructive surgery unnecessary for all patients, except one.
Simple laminotomy with continuous irrigation by insertion of a catheter into intervertebral disc space or epidural space was minimally invasive and effective in the treatment of pyogenic spondylitis. This procedure could be a beneficial treatment option in patients with thoracolumbar spondylitis combined with minimal or moderate destructive change of vertebrae.
PMCID: PMC3243837  PMID: 22200016
Irrigation; Laminotomy; Pyogenic; Spondylitis; Thoracolumbar
17.  Post-Traumatic Cerebral Infarction : Outcome after Decompressive Hemicraniectomy for the Treatment of Traumatic Brain Injury 
Posttraumatic cerebral infarction (PTCI), an infarction in well-defined arterial distributions after head trauma, is a known complication in patients with severe head trauma. The primary aims of this study were to evaluate the clinical and radiographic characteristics of PTCI, and to assess the effect on outcome of decompressive hemicraniectomy (DHC) in patients with PTCI.
We present a retrospective analysis of 20 patients with PTCI who were treated between January 2003 and August 2005. Twelve patients among them showed malignant PTCI, which is defined as PTCI including the territory of Middle Cerebral Artery (MCA). Medical records and radiologic imaging studies of patients were reviewed.
Infarction of posterior cerebral artery distribution was the most common site of PTCI. Fourteen patients underwent DHC an average of 16 hours after trauma. The overall mortality rate was 75%. Glasgow outcome scale (GOS) of survivors showed that one patient was remained in a persistent vegetative state, two patients were severely disabled and only two patients were moderately disabled at the time of discharge. Despite aggressive treatments, all patients with malignant PTCI had died. Malignant PTCI was the indicator of poor clinical outcome. Furthermore, Glasgow coma scale (GCS) at the admission was the most valuable prognostic factor. Significant correlation was observed between a GCS less than 5 on admission and high mortality (p<0.05).
In patients who developed non-malignant PTCI and GCS higher than 5 after head injury, early DHC and duroplasty should be considered, before occurrence of irreversible ischemic brain damage. High mortality rate was observed in patients with malignant PTCI or PTCI with a GCS of 3-5 at the admission. A large prospective randomized controlled study will be required to justify for aggressive treatments including DHC and medical treatment in these patients.
PMCID: PMC3243842  PMID: 22200021
Brain trauma; Cerebral infarction; Decompressive craniectomy
18.  The transdural approach for thoracic disc herniations: a technical note 
European Spine Journal  2010;19(7):1206-1211.
Surgery for thoracic disc herniations is still challenging, and the disc excision via a posterior laminectomy is considered risky. A variety of dorsolateral and ventral approaches have been developed. However, the lateral extracavitary and transthoracic approach require extensive surgical exposure. Therefore, we adopted a posterior transdural approach for direct visualization without entry into the thoracic cavity. Three cases that illustrate this procedure are reported here with the preoperative findings, radiological findings and surgical techniques used. After the laminectomy, at the involved level, the dorsal dura was opened with a longitudinal paramedian incision. The cerebrospinal fluid was drained to gain more operating space. After sectioning of the dentate ligaments, gentle retraction was applied to the spinal cord. Between the rootlets above and below, the ventral dural bulging was clearly observed. A small paramedian dural incision was made over the disc space and the protruded disc fragment was removed. Neurological symptoms were improved, and no surgery-related complication was encountered. The posterior transdural approach may offer an alternative surgical option for selected patients with thoracic paracentral soft discs, while limiting the morbidity associated with the exposure.
PMCID: PMC2900008  PMID: 20143105
Disc herniation; Transdural approach; Thoracic
20.  Vertebral artery injury after cervical spine trauma: A prospective study using computed tomographic angiography 
Although the vertebral artery injuries (VAI) associated with cervical spine trauma are usually clinically occult, they may cause fatal ischemic damage to the brain stem and cerebellum.
We performed a prospective study using computed tomographic angiography (CTA) to determine the frequency of VAI associated with cervical spine injuries and investigate the clinical and radiological characteristics. Between January 2005 and August 2007, 99 consecutive patients with cervical spine fractures and/or dislocations were prospectively evaluated for patency of the VA, using the CTA, at the time of injury.
Complete disruption of blood flow through the VA was demonstrated in seven patients with unilateral occlusion (7.1%). There were four men and three women with a mean age of 43 (range, 33-55 years). Unilateral occlusion of the right vertebral artery occurred in four patients and of the left in three. Regarding the cervical injury type, two cases were cervical burst fractures (C6 and C7), two had C4-5 fracture/dislocations, two had a unilateral transverse foraminal fracture, and one had dens type III fracture. All patients presented with good patency of the contralateral VA. None of the patients developed secondary neurological deterioration due to vertebrobasilar ischemia during the follow-up period with a mean duration of 23 months.
VAI should be suspected in patients with cervical trauma that have cervical spine fractures and/or dislocations or transverse foramen fractures. CTA was useful as a rapid diagnostic method for ruling out VAI after cervical spine trauma.
PMCID: PMC3086173  PMID: 21541205
Cervical spine; computed tomographic angiography; injury; vertebral artery
21.  Clinical Features and Treatments of Upper Lumbar Disc Herniations 
Disc herniations at the L1-L2 and L2-L3 levels are different from those at lower levels of the lumbar spine with regard to clinical characteristics and surgical outcome. Spinal canals are narrower than those of lower levels, which may compromise multiple spinal nerve roots or conus medullaris. The aim of this study was to evaluate the clinical features and surgical outcomes of upper lumbar disc herniations.
We retrospectively reviewed the clinical features of 41 patients who had undergone surgery for single disc herniations at the L1-L2 and L2-3 levels from 1998 to 2007. The affected levels were L1-L2 in 14 patients and L2-L3 in 27 patients. Presenting symptoms and signs, patient characteristics, radiologic findings, operative methods, and surgical outcomes were investigated.
The mean age of patients with upper lumbar disc was 55.5 years (ranged 31 to 78). The mean follow-up period was 16.6 months. Most patients complained of back and buttock pain (38 patients, 92%), and radiating pain in areas such as the anterior or anterolateral aspect of the thigh (32 patients, 78%). Weakness of lower extremities was observed in 16 patients (39%) and sensory disturbance was presented in 19 patients (46%). Only 6 patients (14%) had undergone previous lumbar disc surgery. Discectomy was performed using three methods : unilateral laminectomy in 27 cases, bilateral laminectomy in 3 cases, and the transdural approach in 11 cases, which were performed through total laminectomy in 10 cases and unilateral laminectomy in 1 case. With regard to surgical outcomes, preoperative symptoms improved significantly in 33 patients (80.5%), partially in 7 patients (17%), and were aggravated in 1 patient (2.5%).
Clinical features of disc herniations at the L1-L2 and L2-L3 levels were variable, and localized sensory change or pain was rarely demonstrated. In most cases, the discectomy was performed successfully by conventional posterior laminectomy. On the other hand, in large central broad based disc herniation, when the neural elements are severely compromised, the posterior transdural approach could be an alternative.
PMCID: PMC2941853  PMID: 20856659
Clinical feature; Disc herniation; Transdural; Upper lumbar
22.  Synovial Sarcoma of the Posterior Neck : A Case Report and Review of Literature 
We recently experienced a case of synovial sarcoma in the posterior neck, which involved adjacent bony structures. Synovial sarcoma is rare, malignant soft tissue tumor that occur predominantly in the lower extremities. Wide surgical excision with involved tissue is the treatment of first choice, because most synovial sarcomas reveal aggressive features. We removed the tumor with involved bony structures and patient was given postoperative radiation therapy. Despite these treatment options, the patient died 1 year after surgery. We report this case with a review of the literature.
PMCID: PMC2864827  PMID: 20461175
Synovial sarcoma; Posterior neck; Bony involvement
23.  A Mouse Model of Photochemically Induced Spinal Cord Injury 
A mouse model of spinal cord injury (SCI) could further increase our basic understanding of the mechanisms involved in injury and repair of the nervous system. The purpose of this study was to investigate whether methods used to produce and evaluate photochemical graded ischemic SCI in rats, could be successfully adapted to mice, in a reliable and reproducible manner.
Thirty female imprinting control region mice (weighting 25-30 g, 8 weeks of age) were used in this study. Following intraperitoneal injection of Rose bengal, the translucent dorsal surface of the T8-T9 vertebral laminae of the mice were illuminated with a fiber optic bundle of a cold light source. The mice were divided into three groups; Group 1 (20 mg/kg Rose bengal, 5 minutes illumination), Group 2 (20 mg/kg Rose bengal, 10 minutes illumination), and Group 3 (40 mg/kg Rose bengal, 10 minutes illumination). The locomotor function, according to the Basso-Beattie-Bresnahan scale, was assessed at three days after the injury and then once per week for four weeks. The animals were sacrificed at 28 days after the injury, and the histopathology of the lesions was assessed.
The mice in group 1 had no hindlimb movement until seven days after the injury. Most mice had later recovery with movement in more than two joints at 28 days after injury. There was limited recovery of one joint, with only slight movement, for the mice in groups 2 and 3. The histopathology showed that the mice in group 1 had a cystic cavity involving the dorsal and partial involvement of the dorsolateral funiculi. A larger cavity, involving the dorsal, dorsolateral funiculi and the gray matter of the dorsal and ventral horns was found in group 2. In group 3, most of the spinal cord was destroyed and only a thin rim of tissue remained.
The results of this study show that the photochemical graded ischemic SCI model, described in rats, can be successfully adapted to mice, in a reliable and reproducible manner. The functional deficits are correlated an increase in the irradiation time and, therefore, to the severity of the injury. The photothrombotic model of SCI, in mice with 20 mg/kg Rose bengal for 5 minutes illumination, provides an effective model that could be used in future research. This photochemical model can be used for investigating secondary responses associated with traumatic SCI.
PMCID: PMC2796355  PMID: 20041059
Photochemical; Spinal cord Injury; Mouse

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