The Clinical Usefulness of Translabyrinthine Approach for Removal of the Vestibular Schwannomas

OBJECTIVE: To determine the feasibility of translabyrinthine approach in the vestibular schwannoma patients, the authors reviewed eighteen consecutive cases, focusing at their functional outcome and operative complications. MATERIALS AND METHOD: To evaluate the functional outcome, we reviewed preoperative radiological findings such as size of tumors and location of jugular bulb as well as the preoperative neurological status including audiometric analysis and cranial nerve function in 18 patients, diagnosed as vestibular schwannoma. Also the surgical outcome was evaluated according to the functional preservation of facial nerve and incidence of the surgical complication as well as the extent of surgical resection. RESULTS: The age of patients ranged from 21 to 62 years, with a mean of 50 years. Of 18 patients operated in our center by the translabyrinthine approach, wide exposure with total removal of the mass was possible in 16 cases (88.8%). The facial nerve was anatomically preserved in 88.8%. At six-month follow-up, facial nerve function was good(Grade I-II) in 15 patients(83%) and acceptable(I-IV) in all patients. Although the jugular bulb was highly placed is five patients, gross total resection was possible without facial nerve injury in all patients by the translabyrinthine approach. One patient experienced CSF leakage after surgery, but there was no patient with disabling deficit. CONCLUSION: Use of the translabyrinthine approach for removal of vestibular schwannomas resulted in good anatomical and functional preservation of the facial nerve, with minimal incidence of morbidity and no mortality. In cases of high jugular bulb impacted into mastoid bone, total removal was possible by displacing the jugular bulb with Surgicel cellulose and placement of bone wax.

Microsurgical Anatomy in Transoral Odontoidectomy

No abstract available.

The Clinical Applicability of Transoral Transpharyngeal Approach to the Craniovertebral Junction Lesions

No abstract available.

Stereotactic Evacuation of Spontaneous Intracerebral Hemorrhage

The best treatment modality for spontaneous intracerebral hemorrhage still remains to be controversial. Stereotactic surgery can be performed safely and easily but its indication and optimal timing of operation have to be determined. We treated 80 patients with spontaneous intracerebral hemorrhage by stereotactic surgery from October 1994 to December 1997. We investigated clinical status of the patients before and after surgery, amount of hematoma, evacuation rate, timing of operation, transcranial Doppler sonography(TCD), and computerized tomography(CT) findings. The results were as follows: 1) The outcome of early surgery(within 24 hours of bleeding) was better than that of late surgery(after 24 hours of bleeding)(p=0.034). 2) The outcome was better in the patient with higher evacuation rate(p=0.014). 3) TCD monitoring showed beneficial effect of surgery on hemodynamic status. We conclude that the early surgery within 24 hours after bleeding is correlated with the better outcome, and TCD monitoring is useful for evaluation of perioperative hemodynamic change.

Foix-Alajouanine Syndrome: Case Report

Acute or subacute myelopathy with spontaneous thrombosis of the veins in a patient with a spinal arteriovenous malformation(AVM) has been referred to as "Foix-Alajouanine syndrome(FAS)". A previously healthy 15-year-old girl developed neurological illness with progressive lower extremity weakness and low back pain. The MRI demonstrated the diffuse swelling of the spinal cord around the 10th thoracic level, suggesting myelopathy. Her neurological symptoms deteriorated to paraplegia, voiding difficulty and areflexia. Spinal arteriography did not demonstrate a vascular lesions such as arteriovenous malformation(AVM) or arteriovenous fistula(AVF). Operation revealed diffuse necrosis of the spinal cord and one abnormal thrombosed drainage vein. Progressive clinical illness, the histopathology of the patchy necrosis of spinal cord tissue and many thickened blood vessels are compatible with Foix-Alajouanine syndrome. We report a case of Foix-Alajouanine syndrome with a review of the literature.

Surgical Treatment of Pontine Cavernous Hemangioma

In general, surgical approaches to intrinsic lesions of the brain stem are problematic. We encountered two cases of pontine cavernous hemangioma in which successful removal was possible with the help of intraoperative electrophysiological monitoring. During surgery, somatosensory and auditory evoked potentials, were subject to intraoperative bimodal monitoring. Before the removal of hemangiomas, monopolar stimulation and monitoring of the facial EMG identified facial colliculus on the floor of the fourth ventricle. During and after surgery, there was some increase in the amplitude of BAEP and SSEP, and the authors recognized that post-surgical E-P information correlated well with surgical outcome. We observed marked improvement of preoperative neurological deficits, and follow-up brain MRI showed that the hemangiomas had been completely removed. These favorable results demonstrate the usefulness of intraoperative electrophysiological monitoring, and indicate the appropriacy of more aggressive surgical treatment of symptomatic cavernous hemangioma of the brain stem.

Double Primary Intracranial Tumors: Report of Two Cases

The simultaneous occurrence of multiple primary brain tumors of histologically different types is very rare, and accounts for only about 0.4% of all the primary brain tumors. Recently, we experienced two cases of double primary intracranial tumors in combinations of meningioma-glioblastoma and pituitary adenoma-lymphoma. First case is a 55-year-old woman who underwent surgery due to a mass in her left posterior parietal area detected by brain magnetic resonance imaging(MRI), and it was histologically confirmed as atypical meningioma. After radiation treatment, a new mass was detected in the right temporal lobe on follow-up MRI and glioblastoma was confirmed after the second operation. Second case is a 50-year-old woman who was found to have multiple masses in the suprasellar and right thalamic region. They were confirmed as pituitary adenoma and malignant lymphoma by transsphenoidal adenoidectomy (TSA) and stereotactic biopsy, respectively. Case 1 and 2 showed metachronous and synchronous development of secondary intracranial tumors, respectively. In case one, although the patient received radiotherapy, the radiation field was far from the second tumor and the latency period between irradiation and the appearance of the second tumor was too short. Therefore, in this case, we concluded that radiation did not play a major role in the development of the new tumor.

Metabolic Ratio of FDG-PET and Histologic Grading in Cerebral Gliomas

To assess the degree of malignancy in cerebral gliomas at the time of diagnosis, we compared the metabolic ratio using 18F-fluorodeoxyglucose(FDG)-Positron Emission Tomography(PET) with histologic grading and proliferative index(Ki-67) of cerebral gliomas. Materials for this study were histologically-examined 21 gliomas and they were divided into glioblastomas as group 1, anaplastic gliomas as group 2, and low-grade gliomas as group 3. The visual analysis of FDG-PET images showed hypermetabolic lesions in 14(87.5%) out of 16 high-grade gliomas (glioblastomas and anaplastic gliomas), and hypometabolic lesions in 4(80%) out of 5 low-grade gliomas. Tumor to cerebellum ratio(T/Cbll) in FDG-PET was used as metabolic ratio and the values of T/Cbll in each group were 1.30+/-0.10, 0.73+/-0.07, 0.70+/-0.07, respectively. In comparision of T/Cbll between group 1 with remaining two groups, differences were statistically significant(p=0.0002, p=0.0002, respectively), however, there was no statistical difference between group 2 and group 3. The values of Ki-67 were 24.16+/-5.66 in group 1, 8.10+/-2.70 in group 2, 5.46+/-1.23 in group 3, and differences were statistically significant between group 1 and group 2, 3(p=0.015, p=0.015, respectively), but there was no statistical difference between group 2 and group 3. The correlation between T/Cbll and Ki-67 was good and statistically significant(p=0.0047). In conclusion, the visual and semiquantitative analysis of FDG-PET would be helpful in determining the degree of malignancy in cerebral gliomas.