Clinical and Computed Tomography Evaluation of Plate and Screw on the Cervical Lateral Mass: A Modified Magerl's Technique

OBJECTIVE: To determine the clinical and radiological safety of 15 consecutive patients managed with plate and screw fixation systems applied to the cervical lateral mass. METHODS: 15 patients who underwent posterior cervical and T1 arthrodesis were reviewed from Jan 2002 to Dec 2004. Posterior cervical screw and plate fixation was applied on the lateral mass of the cervical spine. The authors have tried lateral mass screw fixation using a modified Magerl's technique (20 degrees lateral and 20~30 degrees rostral screw trajectory) under preliminary radiological study. The average patient age was 39.73 degrees+/-11.00 years, and the average follow-up period was 9.73 degrees+/-6.77 months. Computed tomography scans taken after surgery were reviewed to confirm the attempted screw trajectory correct and safety. RESULTS: Three of 93 lateral mass screws were malpositioned but clinical damage was not noted. Two of 8 pedicle screws on the T1 vertebrae were not placed on the correct pedicle area. Screw and plate loosening was observed in one case but was not subjected to an additional procedure because of maintained screw position observed during follow-up periods. CONCLUSION: The results of this study indicate that lateral mass screw fixation using the Modified Magerl's technique on the cervical lateral mass may provide safe and effective application on the patients. In addition, the chance of incorrectly placed screws was higher in T1 pedicle screw fixation than in lateral mass screw fixation of the cervical area.

Purely Extradural Spinal Meningioma of the Cervical Spine

Spinal meningiomas located purely in the extradural space are rare, and they may easily be confused with malignant neoplasm. We report an unusual case of a purely extradural spinal meningioma mimcking metestatic neoplasm. A 38-year-old woman had neck pain and left side weakness. MRI scan revealed extradural spinal mass. Preoperative and intraoperative diagnosis was metastatic carcinoma, but permanent diagnosis was extradural meningioma.

Purely Extradural Spinal Meningioma of the Cervical Spine

Spinal meningiomas located purely in the extradural space are rare, and they may easily be confused with malignant neoplasm. We report an unusual case of a purely extradural spinal meningioma mimcking metestatic neoplasm. A 38-year-old woman had neck pain and left side weakness. MRI scan revealed extradural spinal mass. Preoperative and intraoperative diagnosis was metastatic carcinoma, but permanent diagnosis was extradural meningioma.

Somatosensory Evoked Potentials in Aneurysmal Subarachnoid Hemorrhage with Delayed Cerebral Ischemic Deterioration

Somatosensory evoked potentials(SEPs) reflect the functional integrity of the central neural pathways, and as such may be used to assess function that remains during variety of cerebral insults. To evaluate the utility of SEPs during cerebral ischemic deterioration due to aneurysmal subarachnoid hemorrhage, SEPs were measured in 43 patients with subarachnoid hemorrhage, among them 24 patients had no cerebral ischemic deterioration(group 1) and 19 patients had cerebral ischemic deterioration(group 2). In group 1, central conduction time(CCT) were measured on the day of admission(CCT1), the seventh day(CCT2), and the twenty-first day(CCT3) after aneurysmal rupture. In group 2, CCT were measured on the day of admission(CCT1), during(CCT2) and after resolution(CCT3) of cerebral ischemic deterioration. CCT2 of the both cerebral hemispheres were different significantly between two group(p=0.01). In group 2, there was stastically significantly difference between CCT1 and CCT2(p<0.01), and significant correlation between clinical grade and CCT was noted, especially in grade III, and IV. Therefore it is suggested that the central latencies of the SEPs are seemed to be a sensitive tools as indicators of the onset and extent of a cerebral ischemic deterioration due to aneurysmal subarachnoid hemorrhage.