Dyspnoea and chest pain associated with pulmonary polymethylmethacrylate embolism after percutaneous vertebroplasty.
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Aged, 80 and over↗
Biomedical subjects
Han-Jung Chen
Publications and source records attributed to Han-Jung Chen.
Single versus separate registration for computer-assisted lumbar pedicle screw placement.
STUDY DESIGN: This is a retrospective study conducted to evaluate the efficacy of single versus separate registration in assessing the pedicle screw accuracy in the computer-assisted lumbar spinal instrumentation. OBJECTIVES: To see if separate registration reduced lumbar pedicle screw misplacement. SUMMARY OF BACKGROUND DATA: Computer-assisted spinal instrumentation has been shown to improve pedicle screw installation accuracy, but 2.7% to 8% of screws still perforate the pedicular cortex. Suspected causes include differences in lumbar lordosis between preoperative CT scans and surgery. METHODS: Postoperative radiographs and CT scans were used to assess the accuracy of pedicle screw placement in 47 adult patients following computer-assisted lumbar spinal instrumentation. Twenty-two patients underwent single registration at one level, while the other 25 underwent registration at each level. RESULTS: The time required for a registration procedure on one level was 6 to 8 minutes, while the time required for application of a pedicle screw using computer-assisted techniques was an additional 6 to 10 minutes. The total number of screw placements was 118 in the single registration group and 130 in the separate registration group. In the former group, 85 (72%) pedicle screw placements were categorized as good, 28 (24%) were fair, and 5 (4%) were poor. All five poorly placed screws were placed in the lower lumbar or upper sacral spine with high mobility, and at levels without registration, with one causing root injury. In the latter group, 117 (90%) pedicle screw placements were good and 13 (10%) were fair. The difference in placement was found to be statistically significant (chi2, P = 0.0003). CONCLUSION.: Before the intraoperative real-time CT imaging is widely used, separate registration at each instrumented level during traditional computer-assisted lumbar spinal instrumentation is necessary to enhance the accuracy of screw placement.
Adult↗
Injury severity and cell death mechanisms: effects of concomitant hypovolemic hypotension on spinal cord ischemia-reperfusion in rats.
A number of previous studies indicated that ischemia-reperfusion injury causes two distinct types of cell death--necrosis and apoptosis--in the central nervous system. It was also implicated that the intensity of injury can somehow affect the cell death mechanisms. By occluding the descending thoracic aorta with or without simultaneously induced hypovolemic hypotension in rats, we established a model of experimental spinal cord ischemia-reperfusion (I/R) in which the injury severity can be controlled. Recordings of carotid blood pressure (CBP) and spinal cord blood flow (SCBF) showed that aortic occlusion induced dramatic CBP elevation but SCBF drop in both the normotensive (NT) and hypotensive (HT) groups of rats. However, the HT group demonstrated significantly lower SCBF during aortic occlusion, and much slower elevation of SCBF after reperfusion, and extremely poor neurological performance. Spinal cord lesions were characterized by infarction associated with extensive necrotic cell death, but little apoptosis and caspase-3 activity. In contrast, in the NT group, I/R injury resulted in minor tissue destruction associated with persistent abundant apoptosis, augmented caspase-3 activity, and favorable functional outcome. The relative sparing of motoneurons in the ventral horns from apoptosis might have accounted for the minor functional impairment in the NT group. The severity of I/R injury was found to have substantial impact on the histopathological changes and cell death mechanisms, which correlate with neurological performance. Our results implicate that injury severity and duration after injury are two critical factors to be considered in therapeutic intervention.
Animals↗
Outer table craniotomy for frontal sinus mucocele.
Variants of the external osteoplastic flap procedure or endoscopy have been used to approach the frontal sinus mucocele. The authors introduce a modified external approach for radical resection of the mucocele. Using the bicoronal skin incision, the skin flap exposed the right upper orbital rim. The outer table craniotomy was then performed to expose the frontal sinus cavity while carefully preserving the inner table, with radical removal of the mucocele mucosa. The sinus cavity was irrigated with hyper-oxide solution to ensure adequate destruction of possible residual mucosa. The fascia of the frontalis muscle was split, with one part placed into the mucocele cavity to plug the nasofrontal duct. The advantages of the procedures for mucocele removal include clear visualization of the frontal sinus for radical resection of the mucosa, preservation of the inner table avoiding dura manipulation, prevention of central nervous system infection, possibly lower rates of recurrence, prevention of mucosal ingrowth by plugging of the nasofrontal ducts with fascia, and favorable cosmetic outcome. The disadvantages are more intensive surgery comparable to the endoscopic approaches and execution difficulties when the frontal mucocele is small. Additional clinical studies are needed to evaluate the efficiency and safety of this procedure.
Craniotomy↗
Multiple tuberculomas in the brain and spinal cord: a case report.
STUDY DESIGN: A case of disseminated tuberculoma in the spinal cord and brain is reported. OBJECTIVES: To present a case of disseminated tuberculoma in the spinal cord and brain and to describe the unusual pathologic features and clinical presentation. SUMMARY AND BACKGROUND: DATA Intramedullary tuberculoma concomitant with intracerebral disseminated tuberculoma is rare. Only one other case has been reported in the world literature. This represents the second reported case of this unusual lesion. MATERIALS AND METHODS: The authors report a 67-year-old man with miliary tuberculosis of the lung and started on antituberculous therapy. His pulmonary complaints were resolved, but he presented acute paraparesis caused by tuberculomas in the thoracolumbar spinal cord. MRI showed more tuberculomas in the brain stem, cerebellum, and cerebral hemispheres. RESULTS: After 6 months, the patient's muscle power gradually improved with a combination of medical and surgical management. CONCLUSIONS: Our experience indicates that antituberculous medication is effective in managing multiple central nervous system tuberculomas. The purpose of surgical intervention is to decompress the cord or brain when progressing neurologic defects occur and to examine the tissue pathologically.
Aged↗
Shunt surgery for hydrocephalus complicating cryptococcal meningitis in human immunodeficiency virus-negative patients.
From 1988 through 2001, 27 patients with cryptococcal meningitis who had hydrocephalus were identified and were treated by placement of ventriculoperitoneal (VP) shunts. To assess the predictive value of the response to VP shunts in terms of outcome in these patients, univariate analysis for variables was performed. Poor outcome was associated with a Glasgow Coma Scale score of 48 h (P=.02). Use of VP shunts did not result in a good response or outcome in comatose patients. Thus, any delay in the diagnosis or treatment of patients with hydrocephalus could cause a deterioration of consciousness and is associated with poor outcome.
Antifungal Agents↗
Neuroprotective synergy of N-methyl-D-aspartate receptor antagonist (MK801) and protein synthesis inhibitor (cycloheximide) on spinal cord ischemia-reperfusion injury in rats.
Thoraco-abdominal aortic surgery requiring temporal cross clamping of the aorta results in a high incidence of paraplegia due to temporary ischemia of the spinal cord. Both excitotoxicity and apoptosis are implicated in the pathogenesis of spinal cord ischemia-reperfusion injury. We propose that the N-methyl-D-aspartate receptor antagonist dizocilpine maleate (MK801) and the protein synthesis inhibitor cycloheximide produce a synergic effect in a rodent model of spinal cord ischemia-reperfusion injury. Injury was induced by 20 min of temporal thoracic aorta occlusion and distal blood volume reduction. After injury, the animals were treated with vehicle, MK801, cycloheximide or MK801 and cycloheximide. Hind limb motor function recovery was better in the MK801 and combined therapy groups than in the control and cycloheximide groups. The mean neuronal survival rate of the control group was 45.3 +/- 3.2% on the 7(th) day after injury. In the MK801 and cycloheximide treatment groups, neuronal survival increased to 62.4 +/- 3.6% and 54.1 +/- 2.4%, respectively. For the combined therapy group, neuronal survival increased to 75.6 +/- 2.5%. The number of apoptotic cells in the control group was 211.4 +/- 8.8 per section on the 7th day after ischemic insult, while apoptosis was significantly reduced in the cycloheximide (96.8 +/- 6.7 cells) and combined (84.8 +/- 8.5 cells) groups. It was unchanged in the MK801 group (209.8 +/- 5.4 cells). These results suggest that combined treatments directed at blocking both N-methyl-D-aspartate receptor-mediated excitotoxic necrosis and caspase-mediated apoptosis might have synergic therapeutic potential in reducing spinal cord ischemia-reperfusion injury.
Animals↗
Rapidly growing internal carotid artery aneurysm after amphetamine abuse: case report.
Amphetamine is one of the most common illicitly abused drugs in certain countries. It is a potent sympathomimetic that may lead to vascular events, including stroke and myocardial infarction. Most reports of stroke after amphetamine abuse are of intracerebral hemorrhage. In this report, the authors describe a ruptured aneurysm of the right internal carotid artery in a young man with amphetamine abuse. It grew rapidly within 2 weeks. Surgery revealed fibrosis and fibrinoid necrosis around the aneurysm. The aneurysm was successfully embolized with Guglielmi detachable coil. A rapidly growing aneurysm in the major intracranial vessels resulting from amphetamine abuse is very rare.
Adult↗
Nuclear factor-kappaB-regulated cyclooxygenase-2 expression in surgery-associated paraspinal muscle injury in rats.
OBJECT: Paraspinal muscle injury is a common but neglected complication of posterior spinal surgery. Evidence suggests that surgical retraction places mechanical and oxidative stress on the paraspinal muscles and that inflammation is a major postoperative pathological finding in the muscles. The roles of cyclooxygenase (COX)-2 and nuclear factor (NF)-kappaB in the inflammatory processes after retraction remain to be clarified. METHODS: In the control group, paraspinal muscles were dissected from the spine via a posterior incision and then laterally retracted. Paraspinal muscle specimens were harvested before as well as at designated time points during and after persistent retraction. The time course of NF-kappaB activation was determined by gel shift assay. Expression of COX-2 was examined using Western blot analysis and immunohistochemistry. The severity of inflammation was evaluated based on histopathology and myeloperoxidase (MPO) activity. The NF-kappaB activation was inhibited by the administration of pyrrolidine dithiolcarbamate (PDTC) in the PDTC-treated group. Retraction induced early activation of NF-kappaB in paraspinal muscle cells. The expression of COX-2 could not be detected until 1 day postoperativley, reaching a peak at 3 days. The time course of COX-2 expression correlated with that of inflammatory responses and MPO activity. Pretreatment with PDTC inhibited intraoperative NF-kappaB activation and greatly downregulated postoperative COX-2 expression and inflammation in the muscles. Postinflammation fibrosis was also abolished by PDTC administration. CONCLUSIONS: Both NF-kappaB-regulated COX-2 expression and inflammation play an important role in the pathogenesis of surgery-associated paraspinal muscle injury. The therapeutic strategy of NF-kappaB inhibition may be applicable to the prevention of such injury.
Animals↗
Treatment outcomes and prognostic factors of patients with supratentorial low-grade oligodendroglioma.
PURPOSE: Oligodendroglioma is a relatively rare central nervous system tumor. Currently, surgical intervention is the mainstay of treatment, and the role of postoperative radiotherapy (RT) remains a subject of controversy. The objective of this study was to investigate the prognostic factors, evaluate the treatment outcomes, and assess whether postoperative RT has a benefit on local control and overall survival rates. METHODS AND MATERIALS: This was a retrospective review of 52 consecutive adult patients with supratentorial low-grade oligodendrogliomas diagnosed at our institution between September 1980 and September 1998. Thirty-two received postoperative RT. Data were analyzed retrospectively to survey the significant prognostic factors for local control and overall survival. RESULTS: The 5-year overall and progression-free survival rate was 80% and 67%, respectively. Twenty-five patients experienced local disease progression during the follow-up period. In multivariate analysis, postoperative RT and age at diagnosis showed independent prognostic significance for overall survival. For progression-free survival, postoperative RT was the only independent prognostic factor. CONCLUSION: On the basis of the results of this study, we recommend considering postoperative RT as one of the standard adjuvant treatment modalities for patients with supratentorial low-grade oligodendroglioma, regardless of the extent of surgical resection. The optimal treatment strategy to maximize the treatment outcome should still be explored.
Adult↗
Implication of telomere length as a proliferation-associated marker in schwannomas.
BACKGROUND AND OBJECTIVES: Some schwannomas in the central nervous system may demonstrate relatively aggressive behavior in pathological findings and clinical course. We evaluate the diagnostic values of telomerase activity and telomere length in the clinicopathological behavior of schwannomas. METHODS: Thirty surgical specimens from intracranial and intraspinal schwannomas were analyzed by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) for telomerase activity and terminal restriction fragments (TRFs) using Southern blot for telomere length. Proliferative indices were also studied. RESULTS: Telomerase activity could not be detected in all schwannomas. Elongated telomere length (mean 17,101 +/- 259 bp) was found in four specimens (13.3%). Three of these four were found to have mitotic figures, high vascularity, cellularity, and pleomorphism in the pathological findings. The proliferative indices (35) showed correlative high values. One patient died of this disease, and one was found to have recurrence at follow-up evaluation. Those that displayed benign histopathological pictures showed relatively short telomere length (8,866 +/- 271 base pairs) and low proliferative indices (21). These is a significant difference between these two groups (P = 0.001). CONCLUSIONS: Elongation of telomere length in schwannomas appears to predict aggressive clinicopathological behavior.
Adolescent↗
Chronic subdural haematoma in young and extremely aged adults: a comparative study of two age groups.
To compare the clinical presentation, etiological factors and the outcome of chronic subdural haematoma (CSDH) in young and old adults, a retrospective analysis was performed by differentiating young adults, age<40 years (n=24) versus extremely aged adults, age>75 years (n=51). The clinical data, computed tomography (CT) findings and surgical outcome were recorded for analysis. We observed certain characteristics particular to young CSDH patients, higher incidence of headache (P<0.001) and vomiting (P=0.009), the shorter duration from trauma to operation (P=0.018) and more severe traumatic episodes (P=0.001). The older patients had a higher frequency of mental change (P=0.006), motor deficits (P=0.014) and larger haematomas (P<0.001). The surgical complication rate was not statistically different between the two age groups. An understanding of the varied clinical presentation of CSDH is essential to stimulate clinical suspicion and prompt evaluation, particularly for the differences between young and extremely aged patients.
Adolescent↗
The neurological abnormalities and operative findings in the transcallosal approach for large juxtasellar-ventricular craniopharyngiomas.
From February 1994 to June 1999, there were 36 patients who underwent microsurgical resection for craniopharyngiomas. Of6 adult patients, large tumours (>4 cm) with extension from intrasellar or parasellar space to the foramen of Monro were found. There were 4 male and 2 female patients with ages from 18 to 44 years (mean 32.4 years). All of them underwent one-stage interhemispheric transcallosal total exc ision of tumours. This approach affords good overhead view of tumours and surrounding structures.Preoperatively, decreased visual acuity and restriction in the visual field was found in 5 patients. Studies of anterior pituitary function revealed far below the normal range in all patients. Polyuria was noted in 4 patients. All of 6 patients showed abnormally high levels of blood cholesterol and triglyceride and 4 patients were obese. Tumours with extension into the pituitary fossa were found in 2 cases. A relatively caudal location in the third Ventricle was found in case 6, who showed better preoperative visual function and no polyuria. There were no major surgical complications encountered. One patient with high cholesterol (731 mg%) died of acute pancreatitis 6 months after surgery. For large craniopharyngiomas without pre-chiasmatic extension, proper treatment could be achieved under substitution therapy and one stage transcallosal total excision of tumours with preservation of important neural structures.
Adolescent↗
Dissociation of atlantoaxial junction in ankylosing spondylitis: case report.
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Accidents, Traffic↗
Oxidative stress and heat shock protein response in human paraspinal muscles during retraction.
OBJECT: The need for wide dissection and forceful retraction of paraspinal muscles often required for posterolateral lumbar fusion and fixation may severely jeopardize the muscles, structurally and functionally. The underlying pathophysiology of muscle damage may involve both mechanical and ischemic mechanisms. On the other hand, the surgery-related stress may trigger certain protective responses within the insulted paraspinal muscles. This study was conducted to assess the relationship between the oxidative stress and the stress response mediated by heat shock protein 70 (HSP70) induction within paraspinal muscles being retracted. METHODS: Multifidus muscle specimens were surgically obtained before, during, and after retraction in patients with lumbar spondylolisthesis undergoing posterolateral lumbar fusion, pedicle fixation, and laminectomy. Muscle samples were analyzed to determine HSP70 and malondialdehyde (MDA) levels. Both HSP70 expression and MDA production within multifidus muscle cells were increased significantly by retraction. Expression of HSP70 then decreased after a peak at 1.5 hours of retraction, whereas MDA levels remained elevated even after release of retractors for reperfusion of the muscles. Analysis of histopathological and immunohistochemical evidence indicated that the decline of HSP70 synthesis within muscle cells after prolonged retraction was the result of severe muscle damage. CONCLUSIONS: Results of this study highlight the deleterious effect of intraoperative retraction on human paraspinal muscles at the cellular and molecular levels. The authors also found that intraoperative maneuvers aimed at reducing the oxidative stress within the paraspinal muscles may help to attenuate surgery-related paraspinal muscle damage.
Aged↗
Percutaneous vertebroplasty improves pain and physical functioning in elderly osteoporotic vertebral compression fracture patients.
BACKGROUND: Osteoporotic vertebral compression fractures are being recognized increasingly often in the elderly. They frequently cause severe and prolonged back pain and physical decline. Bed rest, narcotic analgesia, and external bracing were the only therapeutic modalities available in the past and had limited success. OBJECTIVE: The purpose of our study was to determine the efficacy of percutaneous vertebroplasty in treating osteoporotic vertebral compression fractures in the elderly. METHODS: Twenty-two vertebroplasties were performed in 16 elderly patients. Pain relief, medication requirements, and physical functioning were evaluated before and 24 h and 6 months after vertebroplasty. RESULTS: There was 81% improvement in pain intensity 24 h after operation, and 94% improvement was noted at the 6-month follow-up checkup. Physical functioning improved 69% 24 h after vertebroplasty and 63% 6 months later. Medication requirements also decreased in 75% of the patients. CONCLUSION: Percutaneous vertebroplasty for osteoporotic vertebral compression fractures is safe and effective and should not be withheld from the elderly.
Administration, Cutaneous↗