Tapia's Syndrome after Posterior Cervical Spine Surgery under General Anesthesia

We present a case report to remind surgeons of this unusual complication that can occur in any surgery, even posterior cervical spine surgery under general anesthesia and discuss its causes, treatment methods, and the follow-up results in the literature. The peripheral Tapia's syndrome is a rare complication of anesthetic airway management. Main symptoms are hoarseness of voice and difficulty of tongue movement. Tapia's syndrome after endotracheal general anesthesia is believed to be due to pressure neuropathy of the vagus nerve and the hypoglossal nerve caused by the endotracheal tube. To our knowledge, no report has been published or given an explanation for Tapia's syndrome after posterior cervical spine surgery. Two patients who underwent posterior cervical surgery complained hoarseness and tongue palsy postoperatively. There is no direct anatomical relation between the operation, the vagus nerves and the hypoglossal nerves, and there is no record of displacement or malposition of the endotracheal tube. After several months, all symptoms are resolved. To avoid this problem in posterior cervical spine surgery, we suggest paying special attention to the position of the endotracheal tube to avoid excessive neck flexion before and during the positioning of the patient.

Barrier Techniques for Spinal Cord Protection from Thermal Injury in Polymethylmethacrylate Reconstruction of Vertebral Body:Experimental and Theoretical Analyses

OBJECTIVES: Polymethylmethacrylate(PMMA) is often used to reconstruct the spine after total corpectomy, but the exothermic curing of liquid PMMA poses a risk of thermal injury to the spinal cord. The purposes of this study are to analyze the heat blocking effect of pre-polymerized PMMA sheet in the corpectomy model and to establish the minimal thickness of PMMA sheet to protect the spinal cord from the thermal injury during PMMA cementation of vertebral body. MATERIALS AND METHODS: An experimental fixture was fabricated with dimensions similar to those of a T12 corpectomy defect. Sixty milliliters of liquid PMMA were poured into the fixture, and temperature recordings were obtained at the center of the curing PMMA mass and on the undersurface(representing the spinal cord surface) of a pre-polymerized PMMA sheet of variable thickness(group 1:0mm, group 2:5mm, or group 3:8mm). Six replicates were tested for each barrier thickness group. RESULTS: Consistent temperatures(106.8+/-3.9degreesC) at center of the curing PMMA mass in eighteen experiments confirmed the reproducibility of the experimental fixture. Peak temperatures on the spinal cord surface were 47.3degreesC in group 2, and 43.3degreesC in group 3, compared with 60.0degreesC in group 1(p<0.00005). So pre-polymerized PMMA provided statistically significant protection from heat transfer. The difference of peak temperature between theoretical and experimental value was less than 1%, while the predicted time was within 35% of experimental values. The data from the theoretical model indicate that a 10mm barrier of PMMA should protect the spinal cord from temperatures greater than 39degreesC(the threshold for thermal injury in the spinal cord). CONCLUSION: These results suggest that pre-polymerized PMMA sheet of 10mm thickness may protect the spinal cord from the thermal injury during PMMA reconstruction of vertebral body.

Comparisons of Unicortical and Bicortical Lateral Mass Screws in the Cervical Spine: Safety vs Strength

INTRODUCTION: The purpose of this study was to analyze the safety, pullout strength and radiographic characteristics of unicortical and bicortical screws of cervical facet within cadaveric specimens and evaluate the influence of level of training on the positioning of these screws. METHODS: Twenty-one cadavers, mean 78.9 years of age, underwent bilateral placement of 3.5mm AO lateral mass screw from C3-C6(n=168) using a slight variation of the Magerl technique. Intraoperative imaging was not used. The right side(unicortical) utilized only 14mm screws(effective length of 11mm) while on the left side to determine the length of the screw after the ventral cortex had been drilled. Three spine surgeons(attending, fellow, chief resident) with varying levels of spine training performed the procedure on seven cadavers each. All spines were harvested and lateral radiographs were taken. Individual cervical vertebrae were carefully dissected and then axial radiographs were taken. The screws were evaluated clinically and radiographically for their safety. Screws were graded clinically for their safety with respect to the spinal cord, facet joint, nerve root and vertebral artery. The grades consisted of the following categories: "satisfactory", "at risk" and "direct injury". Each screw was also graded according to its zone placement. Screw position was quantified by measuring a sagittal angle from the lateral radiograph and an axial angle from the axial radiograph. Pull-out force was determined for all screws using a material testing machine. RESULTS: Dissection revealed that fifteen screws on the left side actually had only unicortical and not bicortical purchase as intended. The majority of screws(92.8%) were satisfactory in terms of safety. There were no injuries to the spinal cord. On the right side(unicortical), 98.9% of the screws were "satisfactory" and on the left side(bicortical) 68.1% were "satisfactory". There was a 5.8% incidence of direct arterial injury and a 17.4% incidence of direct nerve root injury with the bicortical screws. There were no "direct injuries" with the unicortical screws for the nerve root or vertebral artery. The unicortical screws had a 21.4% incidence of direct injury of the facet joint, while the bicortical screws had a 21.7% incidence. The majority of "direct injury" of bicortical screws were placed by the surgeon with the least experience. The performance of the resident surgeon was significantly different from the attending or fellow(p<0.05) in terms of safety of the nerve root and vertebral artery. The attending's performance was significantly better than the resident or fellow(p<0.05) in terms of safety of the facet joint. There was no relationship between the safety of a screw and its zone placement. The axial deviation angle measured 23.5+/-6.6 degrees and 19.8+/-7.9 degrees for the unicortical and bicortical screws, respectively. The resident surgeon had a significantly lower angle than the attending or fellow(p<0.05). The sagittal angle measured 66.3+/-7.0 degrees and 62.3+/-7.9 degrees for the unicortical and bicortical screws, respectively. The attending had a significantly lower sagittal angle than the fellow or resident(p<0.05). Thirty-three screws that entered the facet joint were tested for pull-out strength but excluded from the data because they were not lateral mass screws per-se and had deviated substantially from the intended final trajectory. The mean pull-out force for all screws was 542.9+/-296.6N. There was no statistically significant difference between the pull-out force for unicortical(519.9+/-286.9N) and bicortical(565.2+/-306N) screws. There was no significant difference in pull-out strengths with respect to zone placement. CONCLUSION: It is our belief that the risk associated with bicortical purchase mandates formal spine training if it is to be done safely and accurately. Unicortical screws are safer regardless of level of training. It is apparent that 14mm lateral mass screws placed in a supero-lateral trajectory in the adult cervical spine provide an equivalent strength with a much lower risk of injury than the longer bicortical screws placed in a similar orientation.

Posterior Lumbar Interbody Fusion Using Posterolateral Placement of A Single Cylindrical Threaded Cage and Two Regular Cages: A Biomechanical Study

OBJECTIVES: An in vitro biomechanical study of posterior lumbar interbody fusion(PLIF) with threaded cage using two different approaches was performed on eighteen functional spinal units of bovine lumbar spines. The purpose of this study was to compare the segmental stiffnesses among PLIF with one long posterolateral cage, PLIF with one long posterolateral cage and simultaneous facet joint fixation, and PLIF with two posterior cages. METHODS: Eighteen bovine lumbar functional spinal units were divided into three groups. All specimens were tested intact and with cage insertion. Group 1(n=12) had a long threaded cage(15x36mm) inserted posterolaterally and oriented counter anterolaterally on the left side by posterior approach with left unilateral facetectomy. Group 2(n=6) had two regular length cages(15x24mm) inserted posteriorly with bilateral facetectomy. Six specimens from group 1 were then retested after unilateral facet joint screw fixation in neutral(group 3). Likewise, the other six specimens from group 1 were retested after fixation with a facet joint screw in an extended position(group 4). Nondestructive tests were performed in pure compression, flexion, extension, lateral bending, and torsion. RESULTS: PLIF with a single cage, group 1, had a significantly higher stiffnesses than PLIF with two cages, group 2, in left and right torsion(p<0.05). Group 1 showed higher stiffness values than group 2 in pure compression, flexion, left and right bending but were not significantly different. Group 3 showed a significant increase in stiffness in comparison to group 1 for pure compression, extension, left bending and right torsion(p<0.05). For group 4, the stiffness significantly increased in comparison to group 1 for extension, flexion and right torsion(p<0.05). Although there was no significant difference between groups 3 and 4, group 4 had increased stiffness in extension, flexion, right bending and torsion. CONCLUSION: Posterior lumbar interbody fusion with a single long threaded cage inserted posterolaterally with unilateral facetectomy enables sufficient decompression while maintaining a majority of the posterior elements. In combination with a facet joint screw fixation, adequate postoperative stability can be achieved. We suggest that posterolateral insertion of a long threaded cage is biomechanically an ideal alternative to PLIF.

The Effects of Plate Stabilization on Maintenance of Interspace Height in Patients with Lower Cervical Lesion Underwent Anterior Cervical Interbody Fusion

OBJECTIVEL: Anterior cervical discectomy and fusion has been successfully performed for many years using a variety of techniques. Recently, the concept of internal fixation has been applied to the lower cervical lesions. The need for postoperative immobilization, usually required to stabilize the patient while the fusion mass heals, is decreased or negated by internal fixation. In order to determine the effects of plate stabilization on maintenance of interspace height during postoperative period, we assessed the potential differences between anterior interbody fusion without plate and fusion with plate in patients with lower cervical lesions. PATIENTS AND METHODS: The authors analyzed the results of 76 patients with lower cervical lesions, who underwent anterior interbody fusion between May, 1991 and December, 1997. Of these, 36 underwent only anterior interbody bony fusion and 40 underwent bony fusion plus interbody fixation with plate system. RESULTS: In order to compare the difference of two groups, we investigated the pre- and postoperative interspace height, clinical outcomes, and radiographic fusion success rates. Anterior interbody fusion with plate was found to be superior to anterior interbody fusion without plate after anterior cervical decompression procedures with respect to maintenance of cervical interspace height(p<0.01), and radiographic and clinical fusion success rates. CONCLUSION: The authors concluded that the use of anterior plate fixation may provide added security to the nervous system before bony fusion occurs, may potentiate the maintenance of interspace height, may increase the probability of successful fusion, and may permit early ambulation.

Inflammatory Pseudotumor of the Thoracic Spinal Cord Meninges: A Case Report

Inflammatory pseudotumor arising in the meninges of spinal cord is extremely rare and most of the cases have occurred in the lung. A case of a thoracic inflammatory pseudotumor causing myelopathy and mimicking an extradural mass is presented. The lesion was demonstrated by magnetic resonance imaging, and total removal of the mass was performed. Its histology was characterized by infiltration of three kinds of cells; histiocytes with slight epithelioid appearance, plasma cells with numerous Russell bodies, and lymphocytes. Although extrapulmonary inflammatory pseudotumors have been reported, the authors believe this is the second case of this type tumor in the spinal cord meninges.

Falcine Mesenchmal Chondrosarcoma

We experienced a case of falcine mesenchymal chondrosarcoma in a 22-year-old pregnant woman. Cartilage cell tumors within the cranium are very rare, only less than 0.2% of all intracranial tumors. Because a few examples of mesenchymal chondrosarcoma in this locttion have been reported, we reviewed previous reports cases, to determine the natural history of intracranial chondrosarcomas. The distinguishing features of this rare tumor are compared with previous cases of itracranial tumors derived from cartilage.

Long-Term Follow-up Study after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis plus Encephalomyosynangiosis for Moyamoya Disease

During the period from March 1990, through September 1993, 11 patients with moyamoya disease underwent superficial temporal artery(STA)-to-middle cerebral artery(MCA) anastomosis and encephalomyosynangiosis(EMS) bilaterally. The mean follow-up period was 30.6 months(range 17 to 42 months). The most frequent computed tomographic findings were intraventricular hemorrhage in adult patients and cortical infarction in pediatric patients. In all of the patients, confirmatory diagnosis could be made by angiography, and all had typical angiographic finding of moyamoya disease. According to angiographic classification by Suzuki, the most frequent phase was stage three. A modified continuous suture technique was used during anastomosis. The advantages of this microvascular suture technique are saving time for the surgical procedure, lessening bleeding from the anastomotic site and the ease and safety with which anastomosis can be achieved in the deep cranial cavity. Postoperatively, follow-up angiography was taken between 1 year and 2 years after operation. The angiography revascularization rate was 100%, excellent in 6, and good in 5. The typical postoperative angiography findings are as follows : 1) reduction of moyamoya vessels, 2) normalization or improvement of abnormal posterior circulation, 3) visualization of MCA territory through MCA-STA bypass, and 4) dilatation of STA. There were no major complication in patients with surgery, and no poor outcomes. These results indicate that the STA-MCA anastomosis and EMS in moyamoya disease can normalize cerebral circulation and reduce repeat ischemic attack and repeated bleeding.

A Surgical Experience of a Odontoid Type II Fracture by Transoral Approach and Internal Fixation with Screws and Mini-plate

With changing mechanisms of injury, heightened clinical awareness, and better diagnostic technology, odontoid fractures constitute 9~18% of cervical fractures in recent reports. The odontoid type II fracture is the most common axis fracture and it is also the most difficult to treat. Type II fractures with greater than 6mm dens dislocation have a higher incidence of nonunion with nonoperative therapy and should be offered early operative reduction with fusion. Recently we have experienced a young male patient with odontoid type II fracture. The degree of dens dislocation was 8mm. The fractured odontoid process was removed through transoral-transpharyngeal approach and bone fusion was performed with iliac bone. And the inserted bone was fixed with screws and mini-plate for further stabilization. The operative result was good without any serious complications. The operation technique is detailed.

Effects of Nimodipine on Seizure Pattern and Electroencephalography of Penicillin-Induced Temporal Epileptic Rat

In order to investigate the antiepileptic effects of calcium antagonist, nimodipine, we studied the changes of seizure pattern and electroencephalographic finding of the epileptic rats before and after nimodipine administration which were induced by stereotaxic instillation of penicillin solution into the right amygadala. 40 Sprague-Dowley rats were divided into 2 groups:the control group(n=10) which underwent craniectomy on the biparietal area and was instilled penicillin solution into the right amygdala on the basis of stereotaxic coordinates, and the experimental group(n=30) which was subdivided into 3 subgraups:nimodipine pre-treatment group(n=10), nimodipine 0 minute post-treatment group(n=10) and nimodipine 20 minutes post-treatment group(n=10) depending on the intraperitoneal administration time of nimodipine. The results were as follows; 1) In control group typical epileptiform discharges were noted at 3.4+/-1.9 mm after penicillin instillation and the frequency and amplitude of discharges were 9.8+/-2.2/sec, 25.0+/-3.9mm/50+/-microV. The degree of behavioral seizure was between stage IV and VI. 2) In nimodipine pre-treatment group, there was inhibitory effects of seizure development. The frequency and amplitude were significantly decreased and the degree of behavioral seizure was attenuated in comparison to that of control group. 3) There was no statistical difference in effects of penicillin induced seizure between nimodipine 0 minute, 20 minutes post-treatment and control group. This experiment provided that calcium antagonist showed inhibitory effects on the penicillin-induced epileptic rats, but did not prevent seizure propagation. And calcium currents might play a role to evoke seizure. Therefore calcium antagonist "nimodipine" might be beneficial to the treatment of patients with seizure.

Sternum-Splitting Approach for Anterior Space-Taking Lesions in the Upper Thoracic Lesion

Recently we performed a modified sternum-splitting approach in surgery for anterior space-taking lesion in the upper thoracic region. In contrast to the original trans-sternal approach introduced by Cauchoix, we cut only the manubrium and split it using vertebral spreader. After reaching the anterior surface of the cervico-Thoracic vertebrae, the central portion of the vertebral body was removed with air-drill under an operating microscope. The longitudinal bone defect of the vertebral bodies was filled with a bone graft obtained from the iliac bone. Removal of the space-taking lesions in the cervico-thoracic junction and upper thoracic region can be performed safely by utilizing the modified sternum-splitting approach. This approach can be applied also to endarterectomies at the origins of the vertebral arteries and the subclavian artery.

The Experiences of Modified Bilateral Open Expansive Laminoplasty in Secondary Developmental Spinal Stenosis

The surgical intervention for secondary developmental cervical spinal stenosis that results in myelopathy and radiculopathy has been modified by technical improvement to obtain more reliable enlargement of the cervical spinal canal. The authours have experienced good results with the modified open door expansive laminoplasty, so we report this article. The patients were treated by surgical intervention during the period from October 1989 to February 1991. The results obtained were as follows : 1) The average age was 54.7 years, and the sex distribution ratio of female to male was 2 : 8. 2) In clinical symptoms and symptoms of both myelopathy and radiculopathy. 3) In morphological analysis of lesions, all patients except one case had lesions over 3 levels, The lesions were spondylosis, spondylosis combined with soft disc herniation, spondylosis combined with OPLL, spondylosis combined with OPLL and soft disc herniation, OPLL and OYL in the order of frequency. 4) The operation method was as follows : after the patient was positioned in modified Concorde position, open door lamina was anchored to faced joint capsule and surrounding tissue with nylon sutures. And then the raw epidural space was covered with Lyodura by the modified Hirabayashi method. By this method, reclosure of widened spinal canal was prevented. 5) The outcomes were evaluated by JOA score difference between preoperation and post operation times. The outcome of recovery rate was 100% in five cases. Therewere no aggravated or unimproved cases. The results were excellent 8 cases, good 1 case, unchanged 0 case, poor 0 case and expired 1 case.

Clinical Analysis of Surgical Results in Moyamoya Disease Associated with Intraventricular Hemorrhage

Moyamoya disease is an unusual vascular disorder highlighted by progressive bilateral internal carotid artery occlusion and collateralization of intracranial blood flow. The purposes of the bypass procedures : 1) reduce or arrest of the chance of repeated ischemic attack by making the additional collateral blood flow, 2) decrease the chance of repeated bleeding by reducing the number of moyamoya vessels. During the period from June 1989 through February 1991, 8 moyamoya diseases associated with intraventricular hemorrhage were operated by STA-MCA anastomosis plus EMS. Results are as follows : 1) Slightly female dominancy in incidence(5 : 3), and all of the patients were middle aged(range 32 to 55 years). 2) All of the patients had sudden onset of headache, and most patients whad neck stiffness and vomiting. 3) In all of the patients, confirmatory diagnosis could be done by angiography, and all of the patients had gypical angiographic findings of moyamoya disease. 4) All of the patients had IVH in brain CT scan. 5) All of the patients were surgically treated : STA-MCA anastomosis plus EMS. 6) The postoperative revascularization rate was 89%(8 sides in 9 sides). 7) The postoperative results were excellent in 5, good in 1, and death in 2. The rarity of such lesions in KOrea and their surgical results are reviewed briefly.

Anterolateral Instrumentation and Spinal Stabilization in the Treatment of Fractures of the Thoracolumbar Area

In the treatment of fractures of the thoracolumbar junctiion area, surgical intervention was performed when posterior part of veretbral body, posterior structure supporting ligaments were involved and body compression more than 40%. Number of cases satisfying above criteria were seven between Aug. 1990 and Jun. 1991. Age distribution ranged from 15 to 57 years. Sex ratio was 4:3(F:M). Four patients presented with nerve root sign, one patient with cauda equina signs, and two patients were normal neurologically. In all cases, spinal canal decompression, internal instrument fixation, and bone fusion with iliac bone were performed via anterolateral approach. After surgical treatment, neurological deficits disappeared and kyphotic angle returned to normal range of thoracolumbar junction area in all cases. Percentage of body compression was improved from preop. 55% to postop. 21% in average. According to above results, we concluded that anterior instrumental fixation combined with bone fusion using iliac bone was supperior to posterior approach in providing biomechanical stability and decompression of protruding ventral bone fragments.

Cavernous Hemangioma on the Frontal Lobe

Cerebral cavernous hemangioma is very rare disease in the cerebral vascular malformations. We experienced a case of this vascular malformations at the left frontal lobe near the cortex which had symptoms and signs of abrupt generalized tonic-clonic seizure. This malformation is encountered more commonly in adult in the third to fifth decade, and is found most frequently in the white matter of the cerebral hemisphere. The value of computerized tomography(C-T) in the detection of such malformations is stressed. Good result was obtained by the microsurgical approach to these malformations.