Oligodendroglioma is an uncommon diffuse glial tumor, accounting for ~4.2% of all primary brain t... more Oligodendroglioma is an uncommon diffuse glial tumor, accounting for ~4.2% of all primary brain tumors (1). Liwnicz and Rubinstein (2) reviewed 116 cases of extracranial metastases and found that the most common primary tumor was glioblastoma (41.4%), followed by medulloblastoma (26.7%), ependymoma (16.4%), astrocytoma (10.3%), and oligodendroglioma (5.25%). Oligodendroglioma is the least common type to metastasize and only ~30 cases have been reported (3). Davis, in 1928, first described an extracranial metastasis of glioblastoma following craniotomy (4), whereas Rubinstin, in 1967, reported a case of glioblastoma with extracranial metastasis without craniotomy (3). We report a case of anaplastic oligodendroglioma with multiple extracranial metastases including scalp, neck lymph node, parotid gland, and bone after craniotomy. A 49-year-old man was admitted to the hospital with the chief complaint of right side facial palsy and multiple parotid and neck progressive tumors. He presented with frontal lobe tumor and received surgery at the age of 42. The tumor was diagnosed anaplastic oligodendroglioma. Four years later, the brain tumor recurred and a course of palliative
The role of radiosurgery has become increasingly important in the treatment of intracranial lesio... more The role of radiosurgery has become increasingly important in the treatment of intracranial lesions. In this study the authors evaluated the efficacy of the Novalis shaped beam radiosurgery system (dedicated linear accelerator) for various brain and spinal lesions. Between November 2000 and October 2003 the authors treated 356 cases of various intracranial and extracranial lesions with Novalis shaped beam radiosurgery. Of these 356 cases, 109 cases were followed for more than a 2-year period. Fifty patients underwent fractionated stereotactic radiosurgery. Twenty patients (40%) harbored benign tumors (two acoustic neuromas, seven meningiomas, five pituitary adenomas, four optic gliomas, and two craniopharyngiomas), 18 patients (36%) harbored malignant tumors (16 glioblastoma multiforme [GBM], and two metastases), and the others included five with brainstem gliomas, one chordoma, five gliomas, and one with an arteriovenous malformation (AVM). Eighteen of 20 patients with benign tumor...
The purpose of this study was to investigate follow-up MR findings of spinal foraminal nerve shea... more The purpose of this study was to investigate follow-up MR findings of spinal foraminal nerve sheath tumors after stereotactic irradiation. Thirty-five foraminal nerve sheath tumors in 28 patients who underwent stereotactic radiosurgery (SRS) (n = 28) or stereotactic radiotherapy (SRT) (n = 7) were included. The MR images were reviewed to identify serial changes in tumor volume and intratumoral necrosis. Growth and shrinkage were defined as volume changes of ±19.7 % or more; stability was within ±19.7 %. Transient swelling was defined as shrinkage preceded by significant growth. A tumor with shrinkage or stability was regarded as tumor control. Of 35 tumors, 16 (46 %) were stable, 14 (40 %) shrunk, and 5 (14 %) grew. Transient swelling was seen for 13 (37 %) lesions. Newly developed intratumoral necrosis was observed for 19 (54 %) of 35 tumors and was significantly associated with transient swelling (p = 0.039) and with tumor control (p = 0.017). SRS was not significantly associated ...
In symptomatic patients with subdural hygroma, variety of treatment strategies, such as observati... more In symptomatic patients with subdural hygroma, variety of treatment strategies, such as observation, repeated subdural tapping, external subdural drainage, and subduroperitoneal shunt (SPS) have been advocated. Until now, the ideal management for subdural hygromas in adults seems controversial, because of their differences between the effectiveness and the risk of complications. Thus, we evaluated the role of unvalved SPS for subdural hygromas in adults. Methods: From January 2001 to December 2007, fifteen patients who had undergone unvalved SPS for symptomatic subdural hygromas in adults at our hospital were retrospectively reviewed. We analyzed the age, gender, initial diagnosis, causes, symptoms, neurological signs, and radiological findings such as thickness of subdural hygroma. Outcome was evaluated according to the post operative Glasgow Outcome Scale (GOS), radiologic findings and complications. Results: The mean age of the patients is 61 years old (range from 29 to 86). We used the unvalved open-ended catheter to all patients. After SPS, all subdural hygromas disappeared on computed tomography scans within 14 days (mean 6.5 days) except 2 patients. Four patients had GOS 5. GOS 4 was present in three patients. GOS 3 was present in four patients. Three patients had GOS 2. One patient had GOS 1. Complications related to SPS occurred in 5 patients (33%). Conclusion: Our results suggest that unvalved SPS is one of the effective and safe treatment modality for symptomatic subdural hygromas in adults. The overall complication rate is relatively low, including infection and obstructions, compared to previous reports.
Objective: Cervical radicular pain is defined as pain arising in the arm caused by irritation of ... more Objective: Cervical radicular pain is defined as pain arising in the arm caused by irritation of a cervical spinal nerve or its roots. Although many treatment modalities are described in the literature, the available evidence for efficacy is not sufficient to allow definitive conclusions. The goal of this study was to establish the benefits and prognostic factors of pulsed radiofrequency (PRF) on the adjacent cervical dorsal root ganglia (DRG) of cervical radicular pain patients. Methods: A retrospective study of PRF treatment of patients with cervical radicular pain was carried out. Two times diagnostic block of cervical DRG were performed before PRF. PRF was applied for 2 minutes at a setting of 2 Hz and 45 V by two times on the same targets, with the end point being an electrode tip temperature 42℃. Numerical rating scale (NRS) score was evaluated post-treatment 2 week, 1 month, 3 months and 6 months, which were compared with pretreatment value. A successful outcome was defined that NRS change was improved more than 50% at 6 months. Results: The mean age was 54 years. The success rate was 68% (15/22) after six months of follow-up. PRF induced complications were not observed. Between success and failure group, we do not find any positive outcome prognostic factor. Interestingly, PRF treatment on foraminal stenosis is better outcome than herniated cervical disc. Conclusions: PRF on adjacent cervical DRG is effective and safe treatment option for cervical radicular pain patients. However, more long-term follow up and larger patients are needed to establish effectiveness PRF treatment on cervical radicular pain patients.
A 69-year-old woman presented with a 2-month history of progressive bilateral leg weakness and ga... more A 69-year-old woman presented with a 2-month history of progressive bilateral leg weakness and gait difficulty. On examination, the patient had diffuse lower extremity weakness and hypesthesia of the left leg. Magnetic resonance imaging revealed a 2.9-cm, extradural, soft tissue mass at the T5–6 level, with spinal cord compression; the mass was hypointense on a T1-weighted image (Figure 1a) and hyperintense on a T2-weighted image (Figure 1b). The tumor was a relatively well-demarcated epidural mass with focal invasions into both facet joints. Intraoperative examination showed a neoplasm with clear and granular cell morphologies displaying solid, papillocystic, and follicular patterns. Postoperative 18F-fluoro-2-deoxy-D-glucose positron emission tomographycomputed tomography (CT) and neck CT failed to identify a primary tumor or any other lesions.
Pseudomeningoceles are formed by extravasation of cerebrospinal fluid through a dural defect into... more Pseudomeningoceles are formed by extravasation of cerebrospinal fluid through a dural defect into soft tissue. Most pseudomeningoceles are iatrogenic and occur in the posterior lumbar region following surgery. But, post-traumatic pseudomeningocele rarely occurs in the head and neck. We present a case of post-traumatic an unusual cervical pseudomenigocele and review the related literatures.
Blunt injury to the carotid artery is rare but may produce a devastating outcome. Dissection of t... more Blunt injury to the carotid artery is rare but may produce a devastating outcome. Dissection of the internal carotid artery is the most frequent cause of trauma related cerebral infarction, whereas post-traumatic middle cerebral artery dissection (MCAD) has rarely been encountered clinically. We report a case of cerebral infarction who suggested post-traumatic MCAD. The patho-physiology, clinical presentation, and treatment options of trauma induced MCAD are discussed. (J
ObjectiveThoracoscopic spinal surgery provides minimally invasive approaches for effective verteb... more ObjectiveThoracoscopic spinal surgery provides minimally invasive approaches for effective vertebral decompression and reconstruction of the thoracic and thoracolumbar spine, while surgery related morbidity can be significantly lowered. This study analyzes clinical results of thoracoscopic spinal surgery performed at our institute.MethodsTwenty consecutive patients underwent video-assisted thoracosopic surgery (VATS) to treat various thoracic and thoracolumbar pathologies from April 2000 to July 2006. The lesions consisted of spinal trauma (13 cases), thoracic disc herniation (4 cases), tuberculous spondylitis (1 case), post-operative thoracolumbar kyphosis (1 case) and thoracic tumor (1 case). The level of operation included upper thoracic lesions (3 cases), midthoracic lesions (6 cases) and thoracolumbar lesions (11 cases). We classified the procedure into three groups: stand-alone thoracoscopic discectomy (3 cases), thoracoscopic fusion (11 cases) and video assisted mini-thoracotomy (6 cases).ResultsAnalysis on the Frankel performance scale in spinal trauma patients (13 cases), showed a total of 7 patients who had neurological impairment preoperatively : Grade D (2 cases), Grade C (2 cases), Grade B (1 case), and Grade A (2 cases). Four patients were neurologically improved postoperatively, two patients were improved from C to E, one improved from grade D to E and one improved from grade B to grade D. The preoperative Cobb's and kyphotic angle were measured in spinal trauma patients and were 18.9±4.4° and 18.8±4.6°, respectively. Postoperatively, the angles showed statistically significant improvement, 15.1±3.7° and 11.3±2.4°, respectively (P<0.001).ConclusionAlthough VATS requires a steep learning curve, it is an effective and minimally invasive procedure which provides biomechanical stability in terms of anterior column decompression and reconstruction for anterior load bearing, and preservation of intercostal muscles and diaphragm.
Polymer gel 3D dosimetry was used to confirm the accuracy of treatment plans produced by the trea... more Polymer gel 3D dosimetry was used to confirm the accuracy of treatment plans produced by the treatment planning software and assess the dosimetric uncertainties of the radiosurgery procedures. The aim of this study is to investigate the 3D dose distribution of intensity-modulated radiosurgery(IMRS) treatment using polymer gel dosimeter for a selected radiosurgery case. A spherical glass flask(160mm-radius) filled with the polymer gel dosimeter was fixed with in the stereotactic head frame. And the intensity modulated radiosurgery(IMRS) treatment procedure was simulated to a selected preclinical concave shaped pituitary tumor closed to the optic pathway. Images of the gel dosimeter were acquired using a Simens 1.5T MR imager. The images transferred to a planning computer for which a data analysis and compare to dose distribution produced by planning software. Reasonable agreement was observed at medium and high doses (50%-80% isodose lines) although differences of up to 10% were obse...
BACKGROUND CONTEXT: Axial back pain affects a large percentage of the population. Often aggravate... more BACKGROUND CONTEXT: Axial back pain affects a large percentage of the population. Often aggravated by weight-bearing activity, these patients frequently have associated degenerative or post-traumatic lumbar disc disease. Aquatherapy is frequently used to transition patients from less activity limited by pain to greater activity by reducing weight-bearing load of the lumbar spine. Development of a means to permit patients similar spinal unloading while active during normal daily living would have the potential to promote similar effects. PURPOSE: The purpose of this study is to measure internal disc pressure at L4/L5 in response to forces exerted by an external vest. The study hypothesis anticipated an unloading of the lumbar spine during upright posture, as measured by intradicsal pressure at the L4/5 disc, correlating with external forces provided to the trunk by the device. STUDY DESIGN: A controlled experimental study of spine biomechanical loading was undertaken using isolated cadaver torsos obtained from an approved tissue source. Ages ranged at death with a mean of 65Ϯ6 years. METHODS: The distractive force created by inflating a set of pneumatic lifters within vests for treatment of low back pain were calibrated in a materials testing machine. Effects of inflation on the disc pressures within the lumbar spine then were tested. A microscopic pressure sensor (Samba, Gothenburg, Sweden) was placed into the nucleus of the L4/L5 disc of six isolated cadaver torsos (1 female, 5 male) using a 15-gauge spinal needle under direct fluoroscopic visualization. The pressure sensor was 0.42 mm in diameter, and had a calibrated response range of 0-7500 mm Hg. A pneumatically actuated lumbar vest was fit snugly to the torso. Each torso was supported in an upright, weight-bearing position for testing. The vest was inflated while the internal disc pressure was monitored and recorded. The data were analyzed to test for correlation between the amount of external unloading force provided by the vest and the intradiscal pressure measured in vitro. RESULTS: Application of external loads between the pelvis and ribcage by the vest demonstrated a maximum mean reduction of internal disc pressure at L4/L5 of 25% when the vest was inflated to a level producing approximately 400 N of effective load. The reduction in disc pressure was significantly different compared with baseline (upright, weight-bearing disc pressure without the vest) for all distraction settings (pϽ.01) except for the very lowest setting which was significant only at pϭ.025. CONCLUSIONS: Spinal unloading with an externally applied vest with adequate surface interface is effective in reducing intradiscal pressures. Ambulatory reduction of pressure would permit beneficial reduction of loads and permit patients with weight-bearing intolerance a better quality of life.
BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy ... more BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy to prevent or treat osteoporosis is increasing. Drugs of the bisphosphonate family prevent bone resorption, as does calcitonin, though by different mechanisms. Bisphosphonates are deposited in bone, preventing resorption by osteoclasts. Calcitonin is a direct inhibitor of osteoclasts, but is not itself incorporated in bone. The same late middle-aged and elderly patients who are being treated for osteoporosis frequently come to spine fusion. Bone remodelling is a vital part of graft incorporation. Intereventions that interfere with remodelling may have a detrimental effect on the rate, time course, and strength of the fusion mass. PURPOSE: To delineate the effects of these anti-osteoporosis medications on the fusion process. STUDY DESIGN: Randomized, prospective, double-blind, animal model. METHODS: Posterolateral arthrodesis was performed at L5/6 in 60 skeletally mature 4.0-4.5 kg New Zealand white rabbits, using 3 cc of autologous iliac crest graft per side. Rabbits were randomized to one of three groups: PAM-pamidronate 1.2 mg subcutaneously 3 times/week for 4 weeks preoperatively, then 0.6 mg/day via miniosmotic pump for 4 weeks postoperatively; CALcalcitonin 14 IU/day via pump for 4 weeks postoperatively only; CON-no drug intervention. All animals were killed 5 weeks after surgery. Fusion, defined by absolute lack of intersegmental motion, was assessed by manual palpation by two spine surgeons. Where there was disagreement, a third surgeon made the final determination. Stiffness and peak load to failure were determined by mechanical testing of each operated motion segment, and normalized to the adjacent, unoperated level. RESULTS: Four rabbits excluded (1 each: death; euthanasia for hind-limb palsy; infection; incorrect level). Number fused at 5 weeks: CON 10/18 (56%), PAM 7/19 (37%), CAL 13/19 (68%). Fisher exact test showed no significant differences between groups. Analysis of variance (ANOVA) showed no significant differences in mechanical testing between CAL and CON, but PAM specimens had significantly less peak load than CON or CAL animals (pϽ.01) and were less stiff than CON (pϽ.01) or CAL (pϽ.05) animals. CONCLUSIONS: Though one must be careful in extrapolating animal data to humans, this study suggests that calcitonin is not detrimental to spine fusion. Pamidronate, however, does lead to a mechanically less robust fusion. Based on this study, there is no evidence to support a recommendation to stop antiresorptive therapy for osteoporosis in the spine fusion patient.
Object The purpose of this study was to measure and compare the ventral and lateral surface strai... more Object The purpose of this study was to measure and compare the ventral and lateral surface strain distributions and stiffness for two types of interbody cage placement: 1) central placement for anterior lumbar interbody fusion (ALIF); and 2) dorsolateral placement for extraforaminal lumbar interbody fusion (ELIF). Methods Two functional spine units were obtained for testing in each of 13 cadaveric spines, yielding 26 segments (three of which were not used because of bone abnormalities). Bilateral strain gauges were mounted adjacent to the endplate on the lateral and ventral walls of each vertebral body in the 23 motion segments. Each segment was cyclically tested in compression, flexion, and extension in the following conditions: while intact, postdiscectomy, and instrumented with interbody fusion cages placed using both insertion techniques. No significant differences were observed between ALIF and ELIF in compressive stiffness, bending stiffness in flexion and extension (p ≥ 0.1)...
We aimed to demonstrate the effect of angle and laminectomy on paired pedicle screws to determine... more We aimed to demonstrate the effect of angle and laminectomy on paired pedicle screws to determine whether a 90°screw angle is optimal as has been previously suggested. According to the angle between right and left screws, 28 calf vertebrae were divided into three groups and instrumented as follows: Group I: 60°screw angle; Group II: 90°angle; Group III: 60°angle with laminectomy. The screws were connected using rods and cross-fixators and tested to peak pullout force. Triangulated pedicle screws provided 76.5% more pullout strength than single screws. Most of the specimens failed through loss of convergence angle (toggling of screws on the rods) and subsequent uni-or bilateral screw pullout. Mean ± SD peak loads were: Group I: 2071 ± 622 N; Group II: 1753 ± 497 N; Group III: 2186 ± 587 N. The differences were not significant (p > 0.05). 90°triangulation was not associated with a superior pullout performance versus conventional 60°triangulation, suggesting that achieving additional triangulation angle is not necessary to obtain increased pullout strength. Laminectomy did not alter the effect of triangulation on fixation strength.
Primary spinal malignant melanoma is an extremely rare condition. We here describe a case of a 71... more Primary spinal malignant melanoma is an extremely rare condition. We here describe a case of a 71-year-old Asian female presenting with left upper extremity tingling sensation. Computed tomography (CT) showed a homogeneously enhanced mass occupying the left neural foramen at the C6-7 level. Magnetic resonance imaging revealed enhanced mass in intra-and extradural space compressing the spinal cord at this level. It also widened the neural foramen mimicking neurofibroma or schwannoma. Partial resection of the mass was performed. Pathologic diagnosis of the mass was malignant melanoma. Postoperative whole body positron emission tomography/ CT scan demonstrated an intense 18 F-FDG uptake at the residual mass site without abnormal uptake at other sites in the body.
BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy ... more BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy to prevent or treat osteoporosis is increasing. Drugs of the bisphosphonate family prevent bone resorption, as does calcitonin, though by different ...
Clear cell meningioma, about 20 cases of which have been reported in the literature, is a morphol... more Clear cell meningioma, about 20 cases of which have been reported in the literature, is a morphological variant of meningioma. The authors report a case of spinal clear cell meningioma that occurred in a child. A 14-month-old girl showed gradually progressive paraparesis 1 month after she started to walk. Magnetic resonance image showed an intradural extramedullary mass compressing the conus medullaris and cauda equina. Complete excision of the tumor was done, and the patient gradually recovered from motor weakness and neurogenic bladder. Histological examinations along with immunohistochemical and ultrastructural investigations allowed a diagnosis of clear cell meningioma. During the follow-up period, a recurrent mass lesion was detected on the 8-month follow-up MR image in the same region. Because clear cell meningioma might be biologically aggressive, postoperative adjuvant therapy and close follow-up investigation should be considered.
OBJECTIVE: The vertebral body is the major load bearing part of the vertebra and consists of a ce... more OBJECTIVE: The vertebral body is the major load bearing part of the vertebra and consists of a central trabecular core surrounded by a thin cortical shell. The aim of this in vitro biomechanical study is to determine the debated issue of load sharing in a vertebral body. METHODS: A series of non-destructive compressive testing on excised human thoracic vertebral bodies were performed. The testing process consisted of a stepwise removal of the vertebrae's trabecular centrum and measurement of surface strains. RESULTS: Load sharing of cortical shell of osteopenic vertebrae (48.1±7.6) was significantly higher than that of normal vertebrae (44.3±10.6). Load sharing of middle thoracic vertebrae (49.4 ±10.0) was significantly higher than that of lower thoracic vertebrae (42.4±8.5). According to general linear model analysis, test speed and load were not found to be effectual on load sharing with the exception that osteopenic vertebrae showed lower cortical load sharing under higher loads. CONCLUSIONS: The cortical shell takes nearly 45% of physiological loads acting upon an isolated thoracic vertebra. Load sharing between cortical shell and trabecular centrum is significantly affected by spinal level and bone mineral density. The load borne by trabecular bone increases towards the lower spinal levels, and decreases by osteoporosis.
Axial back pain affects a large percentage of the population. Often aggravated by weight-bearing ... more Axial back pain affects a large percentage of the population. Often aggravated by weight-bearing activity, these patients frequently have associated degenerative or post-traumatic lumbar disc disease. Aquatherapy is frequently used to transition patients from less activity limited by ...
Oligodendroglioma is an uncommon diffuse glial tumor, accounting for ~4.2% of all primary brain t... more Oligodendroglioma is an uncommon diffuse glial tumor, accounting for ~4.2% of all primary brain tumors (1). Liwnicz and Rubinstein (2) reviewed 116 cases of extracranial metastases and found that the most common primary tumor was glioblastoma (41.4%), followed by medulloblastoma (26.7%), ependymoma (16.4%), astrocytoma (10.3%), and oligodendroglioma (5.25%). Oligodendroglioma is the least common type to metastasize and only ~30 cases have been reported (3). Davis, in 1928, first described an extracranial metastasis of glioblastoma following craniotomy (4), whereas Rubinstin, in 1967, reported a case of glioblastoma with extracranial metastasis without craniotomy (3). We report a case of anaplastic oligodendroglioma with multiple extracranial metastases including scalp, neck lymph node, parotid gland, and bone after craniotomy. A 49-year-old man was admitted to the hospital with the chief complaint of right side facial palsy and multiple parotid and neck progressive tumors. He presented with frontal lobe tumor and received surgery at the age of 42. The tumor was diagnosed anaplastic oligodendroglioma. Four years later, the brain tumor recurred and a course of palliative
The role of radiosurgery has become increasingly important in the treatment of intracranial lesio... more The role of radiosurgery has become increasingly important in the treatment of intracranial lesions. In this study the authors evaluated the efficacy of the Novalis shaped beam radiosurgery system (dedicated linear accelerator) for various brain and spinal lesions. Between November 2000 and October 2003 the authors treated 356 cases of various intracranial and extracranial lesions with Novalis shaped beam radiosurgery. Of these 356 cases, 109 cases were followed for more than a 2-year period. Fifty patients underwent fractionated stereotactic radiosurgery. Twenty patients (40%) harbored benign tumors (two acoustic neuromas, seven meningiomas, five pituitary adenomas, four optic gliomas, and two craniopharyngiomas), 18 patients (36%) harbored malignant tumors (16 glioblastoma multiforme [GBM], and two metastases), and the others included five with brainstem gliomas, one chordoma, five gliomas, and one with an arteriovenous malformation (AVM). Eighteen of 20 patients with benign tumor...
The purpose of this study was to investigate follow-up MR findings of spinal foraminal nerve shea... more The purpose of this study was to investigate follow-up MR findings of spinal foraminal nerve sheath tumors after stereotactic irradiation. Thirty-five foraminal nerve sheath tumors in 28 patients who underwent stereotactic radiosurgery (SRS) (n = 28) or stereotactic radiotherapy (SRT) (n = 7) were included. The MR images were reviewed to identify serial changes in tumor volume and intratumoral necrosis. Growth and shrinkage were defined as volume changes of ±19.7 % or more; stability was within ±19.7 %. Transient swelling was defined as shrinkage preceded by significant growth. A tumor with shrinkage or stability was regarded as tumor control. Of 35 tumors, 16 (46 %) were stable, 14 (40 %) shrunk, and 5 (14 %) grew. Transient swelling was seen for 13 (37 %) lesions. Newly developed intratumoral necrosis was observed for 19 (54 %) of 35 tumors and was significantly associated with transient swelling (p = 0.039) and with tumor control (p = 0.017). SRS was not significantly associated ...
In symptomatic patients with subdural hygroma, variety of treatment strategies, such as observati... more In symptomatic patients with subdural hygroma, variety of treatment strategies, such as observation, repeated subdural tapping, external subdural drainage, and subduroperitoneal shunt (SPS) have been advocated. Until now, the ideal management for subdural hygromas in adults seems controversial, because of their differences between the effectiveness and the risk of complications. Thus, we evaluated the role of unvalved SPS for subdural hygromas in adults. Methods: From January 2001 to December 2007, fifteen patients who had undergone unvalved SPS for symptomatic subdural hygromas in adults at our hospital were retrospectively reviewed. We analyzed the age, gender, initial diagnosis, causes, symptoms, neurological signs, and radiological findings such as thickness of subdural hygroma. Outcome was evaluated according to the post operative Glasgow Outcome Scale (GOS), radiologic findings and complications. Results: The mean age of the patients is 61 years old (range from 29 to 86). We used the unvalved open-ended catheter to all patients. After SPS, all subdural hygromas disappeared on computed tomography scans within 14 days (mean 6.5 days) except 2 patients. Four patients had GOS 5. GOS 4 was present in three patients. GOS 3 was present in four patients. Three patients had GOS 2. One patient had GOS 1. Complications related to SPS occurred in 5 patients (33%). Conclusion: Our results suggest that unvalved SPS is one of the effective and safe treatment modality for symptomatic subdural hygromas in adults. The overall complication rate is relatively low, including infection and obstructions, compared to previous reports.
Objective: Cervical radicular pain is defined as pain arising in the arm caused by irritation of ... more Objective: Cervical radicular pain is defined as pain arising in the arm caused by irritation of a cervical spinal nerve or its roots. Although many treatment modalities are described in the literature, the available evidence for efficacy is not sufficient to allow definitive conclusions. The goal of this study was to establish the benefits and prognostic factors of pulsed radiofrequency (PRF) on the adjacent cervical dorsal root ganglia (DRG) of cervical radicular pain patients. Methods: A retrospective study of PRF treatment of patients with cervical radicular pain was carried out. Two times diagnostic block of cervical DRG were performed before PRF. PRF was applied for 2 minutes at a setting of 2 Hz and 45 V by two times on the same targets, with the end point being an electrode tip temperature 42℃. Numerical rating scale (NRS) score was evaluated post-treatment 2 week, 1 month, 3 months and 6 months, which were compared with pretreatment value. A successful outcome was defined that NRS change was improved more than 50% at 6 months. Results: The mean age was 54 years. The success rate was 68% (15/22) after six months of follow-up. PRF induced complications were not observed. Between success and failure group, we do not find any positive outcome prognostic factor. Interestingly, PRF treatment on foraminal stenosis is better outcome than herniated cervical disc. Conclusions: PRF on adjacent cervical DRG is effective and safe treatment option for cervical radicular pain patients. However, more long-term follow up and larger patients are needed to establish effectiveness PRF treatment on cervical radicular pain patients.
A 69-year-old woman presented with a 2-month history of progressive bilateral leg weakness and ga... more A 69-year-old woman presented with a 2-month history of progressive bilateral leg weakness and gait difficulty. On examination, the patient had diffuse lower extremity weakness and hypesthesia of the left leg. Magnetic resonance imaging revealed a 2.9-cm, extradural, soft tissue mass at the T5–6 level, with spinal cord compression; the mass was hypointense on a T1-weighted image (Figure 1a) and hyperintense on a T2-weighted image (Figure 1b). The tumor was a relatively well-demarcated epidural mass with focal invasions into both facet joints. Intraoperative examination showed a neoplasm with clear and granular cell morphologies displaying solid, papillocystic, and follicular patterns. Postoperative 18F-fluoro-2-deoxy-D-glucose positron emission tomographycomputed tomography (CT) and neck CT failed to identify a primary tumor or any other lesions.
Pseudomeningoceles are formed by extravasation of cerebrospinal fluid through a dural defect into... more Pseudomeningoceles are formed by extravasation of cerebrospinal fluid through a dural defect into soft tissue. Most pseudomeningoceles are iatrogenic and occur in the posterior lumbar region following surgery. But, post-traumatic pseudomeningocele rarely occurs in the head and neck. We present a case of post-traumatic an unusual cervical pseudomenigocele and review the related literatures.
Blunt injury to the carotid artery is rare but may produce a devastating outcome. Dissection of t... more Blunt injury to the carotid artery is rare but may produce a devastating outcome. Dissection of the internal carotid artery is the most frequent cause of trauma related cerebral infarction, whereas post-traumatic middle cerebral artery dissection (MCAD) has rarely been encountered clinically. We report a case of cerebral infarction who suggested post-traumatic MCAD. The patho-physiology, clinical presentation, and treatment options of trauma induced MCAD are discussed. (J
ObjectiveThoracoscopic spinal surgery provides minimally invasive approaches for effective verteb... more ObjectiveThoracoscopic spinal surgery provides minimally invasive approaches for effective vertebral decompression and reconstruction of the thoracic and thoracolumbar spine, while surgery related morbidity can be significantly lowered. This study analyzes clinical results of thoracoscopic spinal surgery performed at our institute.MethodsTwenty consecutive patients underwent video-assisted thoracosopic surgery (VATS) to treat various thoracic and thoracolumbar pathologies from April 2000 to July 2006. The lesions consisted of spinal trauma (13 cases), thoracic disc herniation (4 cases), tuberculous spondylitis (1 case), post-operative thoracolumbar kyphosis (1 case) and thoracic tumor (1 case). The level of operation included upper thoracic lesions (3 cases), midthoracic lesions (6 cases) and thoracolumbar lesions (11 cases). We classified the procedure into three groups: stand-alone thoracoscopic discectomy (3 cases), thoracoscopic fusion (11 cases) and video assisted mini-thoracotomy (6 cases).ResultsAnalysis on the Frankel performance scale in spinal trauma patients (13 cases), showed a total of 7 patients who had neurological impairment preoperatively : Grade D (2 cases), Grade C (2 cases), Grade B (1 case), and Grade A (2 cases). Four patients were neurologically improved postoperatively, two patients were improved from C to E, one improved from grade D to E and one improved from grade B to grade D. The preoperative Cobb's and kyphotic angle were measured in spinal trauma patients and were 18.9±4.4° and 18.8±4.6°, respectively. Postoperatively, the angles showed statistically significant improvement, 15.1±3.7° and 11.3±2.4°, respectively (P<0.001).ConclusionAlthough VATS requires a steep learning curve, it is an effective and minimally invasive procedure which provides biomechanical stability in terms of anterior column decompression and reconstruction for anterior load bearing, and preservation of intercostal muscles and diaphragm.
Polymer gel 3D dosimetry was used to confirm the accuracy of treatment plans produced by the trea... more Polymer gel 3D dosimetry was used to confirm the accuracy of treatment plans produced by the treatment planning software and assess the dosimetric uncertainties of the radiosurgery procedures. The aim of this study is to investigate the 3D dose distribution of intensity-modulated radiosurgery(IMRS) treatment using polymer gel dosimeter for a selected radiosurgery case. A spherical glass flask(160mm-radius) filled with the polymer gel dosimeter was fixed with in the stereotactic head frame. And the intensity modulated radiosurgery(IMRS) treatment procedure was simulated to a selected preclinical concave shaped pituitary tumor closed to the optic pathway. Images of the gel dosimeter were acquired using a Simens 1.5T MR imager. The images transferred to a planning computer for which a data analysis and compare to dose distribution produced by planning software. Reasonable agreement was observed at medium and high doses (50%-80% isodose lines) although differences of up to 10% were obse...
BACKGROUND CONTEXT: Axial back pain affects a large percentage of the population. Often aggravate... more BACKGROUND CONTEXT: Axial back pain affects a large percentage of the population. Often aggravated by weight-bearing activity, these patients frequently have associated degenerative or post-traumatic lumbar disc disease. Aquatherapy is frequently used to transition patients from less activity limited by pain to greater activity by reducing weight-bearing load of the lumbar spine. Development of a means to permit patients similar spinal unloading while active during normal daily living would have the potential to promote similar effects. PURPOSE: The purpose of this study is to measure internal disc pressure at L4/L5 in response to forces exerted by an external vest. The study hypothesis anticipated an unloading of the lumbar spine during upright posture, as measured by intradicsal pressure at the L4/5 disc, correlating with external forces provided to the trunk by the device. STUDY DESIGN: A controlled experimental study of spine biomechanical loading was undertaken using isolated cadaver torsos obtained from an approved tissue source. Ages ranged at death with a mean of 65Ϯ6 years. METHODS: The distractive force created by inflating a set of pneumatic lifters within vests for treatment of low back pain were calibrated in a materials testing machine. Effects of inflation on the disc pressures within the lumbar spine then were tested. A microscopic pressure sensor (Samba, Gothenburg, Sweden) was placed into the nucleus of the L4/L5 disc of six isolated cadaver torsos (1 female, 5 male) using a 15-gauge spinal needle under direct fluoroscopic visualization. The pressure sensor was 0.42 mm in diameter, and had a calibrated response range of 0-7500 mm Hg. A pneumatically actuated lumbar vest was fit snugly to the torso. Each torso was supported in an upright, weight-bearing position for testing. The vest was inflated while the internal disc pressure was monitored and recorded. The data were analyzed to test for correlation between the amount of external unloading force provided by the vest and the intradiscal pressure measured in vitro. RESULTS: Application of external loads between the pelvis and ribcage by the vest demonstrated a maximum mean reduction of internal disc pressure at L4/L5 of 25% when the vest was inflated to a level producing approximately 400 N of effective load. The reduction in disc pressure was significantly different compared with baseline (upright, weight-bearing disc pressure without the vest) for all distraction settings (pϽ.01) except for the very lowest setting which was significant only at pϭ.025. CONCLUSIONS: Spinal unloading with an externally applied vest with adequate surface interface is effective in reducing intradiscal pressures. Ambulatory reduction of pressure would permit beneficial reduction of loads and permit patients with weight-bearing intolerance a better quality of life.
BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy ... more BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy to prevent or treat osteoporosis is increasing. Drugs of the bisphosphonate family prevent bone resorption, as does calcitonin, though by different mechanisms. Bisphosphonates are deposited in bone, preventing resorption by osteoclasts. Calcitonin is a direct inhibitor of osteoclasts, but is not itself incorporated in bone. The same late middle-aged and elderly patients who are being treated for osteoporosis frequently come to spine fusion. Bone remodelling is a vital part of graft incorporation. Intereventions that interfere with remodelling may have a detrimental effect on the rate, time course, and strength of the fusion mass. PURPOSE: To delineate the effects of these anti-osteoporosis medications on the fusion process. STUDY DESIGN: Randomized, prospective, double-blind, animal model. METHODS: Posterolateral arthrodesis was performed at L5/6 in 60 skeletally mature 4.0-4.5 kg New Zealand white rabbits, using 3 cc of autologous iliac crest graft per side. Rabbits were randomized to one of three groups: PAM-pamidronate 1.2 mg subcutaneously 3 times/week for 4 weeks preoperatively, then 0.6 mg/day via miniosmotic pump for 4 weeks postoperatively; CALcalcitonin 14 IU/day via pump for 4 weeks postoperatively only; CON-no drug intervention. All animals were killed 5 weeks after surgery. Fusion, defined by absolute lack of intersegmental motion, was assessed by manual palpation by two spine surgeons. Where there was disagreement, a third surgeon made the final determination. Stiffness and peak load to failure were determined by mechanical testing of each operated motion segment, and normalized to the adjacent, unoperated level. RESULTS: Four rabbits excluded (1 each: death; euthanasia for hind-limb palsy; infection; incorrect level). Number fused at 5 weeks: CON 10/18 (56%), PAM 7/19 (37%), CAL 13/19 (68%). Fisher exact test showed no significant differences between groups. Analysis of variance (ANOVA) showed no significant differences in mechanical testing between CAL and CON, but PAM specimens had significantly less peak load than CON or CAL animals (pϽ.01) and were less stiff than CON (pϽ.01) or CAL (pϽ.05) animals. CONCLUSIONS: Though one must be careful in extrapolating animal data to humans, this study suggests that calcitonin is not detrimental to spine fusion. Pamidronate, however, does lead to a mechanically less robust fusion. Based on this study, there is no evidence to support a recommendation to stop antiresorptive therapy for osteoporosis in the spine fusion patient.
Object The purpose of this study was to measure and compare the ventral and lateral surface strai... more Object The purpose of this study was to measure and compare the ventral and lateral surface strain distributions and stiffness for two types of interbody cage placement: 1) central placement for anterior lumbar interbody fusion (ALIF); and 2) dorsolateral placement for extraforaminal lumbar interbody fusion (ELIF). Methods Two functional spine units were obtained for testing in each of 13 cadaveric spines, yielding 26 segments (three of which were not used because of bone abnormalities). Bilateral strain gauges were mounted adjacent to the endplate on the lateral and ventral walls of each vertebral body in the 23 motion segments. Each segment was cyclically tested in compression, flexion, and extension in the following conditions: while intact, postdiscectomy, and instrumented with interbody fusion cages placed using both insertion techniques. No significant differences were observed between ALIF and ELIF in compressive stiffness, bending stiffness in flexion and extension (p ≥ 0.1)...
We aimed to demonstrate the effect of angle and laminectomy on paired pedicle screws to determine... more We aimed to demonstrate the effect of angle and laminectomy on paired pedicle screws to determine whether a 90°screw angle is optimal as has been previously suggested. According to the angle between right and left screws, 28 calf vertebrae were divided into three groups and instrumented as follows: Group I: 60°screw angle; Group II: 90°angle; Group III: 60°angle with laminectomy. The screws were connected using rods and cross-fixators and tested to peak pullout force. Triangulated pedicle screws provided 76.5% more pullout strength than single screws. Most of the specimens failed through loss of convergence angle (toggling of screws on the rods) and subsequent uni-or bilateral screw pullout. Mean ± SD peak loads were: Group I: 2071 ± 622 N; Group II: 1753 ± 497 N; Group III: 2186 ± 587 N. The differences were not significant (p > 0.05). 90°triangulation was not associated with a superior pullout performance versus conventional 60°triangulation, suggesting that achieving additional triangulation angle is not necessary to obtain increased pullout strength. Laminectomy did not alter the effect of triangulation on fixation strength.
Primary spinal malignant melanoma is an extremely rare condition. We here describe a case of a 71... more Primary spinal malignant melanoma is an extremely rare condition. We here describe a case of a 71-year-old Asian female presenting with left upper extremity tingling sensation. Computed tomography (CT) showed a homogeneously enhanced mass occupying the left neural foramen at the C6-7 level. Magnetic resonance imaging revealed enhanced mass in intra-and extradural space compressing the spinal cord at this level. It also widened the neural foramen mimicking neurofibroma or schwannoma. Partial resection of the mass was performed. Pathologic diagnosis of the mass was malignant melanoma. Postoperative whole body positron emission tomography/ CT scan demonstrated an intense 18 F-FDG uptake at the residual mass site without abnormal uptake at other sites in the body.
BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy ... more BACKGROUND CONTEXT: As the population ages, the number of individuals undergoing pharmacotherapy to prevent or treat osteoporosis is increasing. Drugs of the bisphosphonate family prevent bone resorption, as does calcitonin, though by different ...
Clear cell meningioma, about 20 cases of which have been reported in the literature, is a morphol... more Clear cell meningioma, about 20 cases of which have been reported in the literature, is a morphological variant of meningioma. The authors report a case of spinal clear cell meningioma that occurred in a child. A 14-month-old girl showed gradually progressive paraparesis 1 month after she started to walk. Magnetic resonance image showed an intradural extramedullary mass compressing the conus medullaris and cauda equina. Complete excision of the tumor was done, and the patient gradually recovered from motor weakness and neurogenic bladder. Histological examinations along with immunohistochemical and ultrastructural investigations allowed a diagnosis of clear cell meningioma. During the follow-up period, a recurrent mass lesion was detected on the 8-month follow-up MR image in the same region. Because clear cell meningioma might be biologically aggressive, postoperative adjuvant therapy and close follow-up investigation should be considered.
OBJECTIVE: The vertebral body is the major load bearing part of the vertebra and consists of a ce... more OBJECTIVE: The vertebral body is the major load bearing part of the vertebra and consists of a central trabecular core surrounded by a thin cortical shell. The aim of this in vitro biomechanical study is to determine the debated issue of load sharing in a vertebral body. METHODS: A series of non-destructive compressive testing on excised human thoracic vertebral bodies were performed. The testing process consisted of a stepwise removal of the vertebrae's trabecular centrum and measurement of surface strains. RESULTS: Load sharing of cortical shell of osteopenic vertebrae (48.1±7.6) was significantly higher than that of normal vertebrae (44.3±10.6). Load sharing of middle thoracic vertebrae (49.4 ±10.0) was significantly higher than that of lower thoracic vertebrae (42.4±8.5). According to general linear model analysis, test speed and load were not found to be effectual on load sharing with the exception that osteopenic vertebrae showed lower cortical load sharing under higher loads. CONCLUSIONS: The cortical shell takes nearly 45% of physiological loads acting upon an isolated thoracic vertebra. Load sharing between cortical shell and trabecular centrum is significantly affected by spinal level and bone mineral density. The load borne by trabecular bone increases towards the lower spinal levels, and decreases by osteoporosis.
Axial back pain affects a large percentage of the population. Often aggravated by weight-bearing ... more Axial back pain affects a large percentage of the population. Often aggravated by weight-bearing activity, these patients frequently have associated degenerative or post-traumatic lumbar disc disease. Aquatherapy is frequently used to transition patients from less activity limited by ...
Uploads
Papers by Moon-Jun Sohn