J Korean Neurosurg Soc 45 : [103][104][105][106] 2009 Intracranial schwannomas preferentially arise from the vestibular branch of the eighth nerve, and rarely from the trigeminal nerve, facial nerve, and lower cranial nerves. Anterior cranial fossa schwannomas are extremely uncommon and few details about them have been reported. The patient was a 39-year-old woman whose chief complaints were anosmia and frontal headache for 2 years. The gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) showed an extra-axial mass from ethmoid sinus to right frontal base region near the midline, with solid enhancement in lower portion and multicystic formation in upper portion. The tumor was totally resected via basal subfrontal approach. At operation, the tumor had cystic portion with marginal calcification and the anterior skull base was destructed by the tumor. The olfactory bulb was involved, and the tumor capsule did not contain neoplastic cells. The histopathological diagnosis was schwannoma. We report a rare case of anterior cranial fossa schwannoma with literature review.

study that analyzed the predicting factors of clinical outcome 13) . We experienced 20 patients for PICA aneurysms with subarachnoid hemorrhage (SAH). And so, we investigated the clinical outcomes after surgery and endovascular treatment and tried to find the predicting factors affecting the outcomes for ruptured PICA aneurysms. MATERIALS AND METHODS Patient populationsBetween April 1996 and December 2010, 1960 intracranial aneurysms were treated at our institution. Among them, we retrospectively reviewed 20 patients of PICA aneurysms with SAH, of which there were 18 females and 2 males with a mean age of 55.9 (range 42-86 years). In our study, all aneurysms were included except fusiform and dissecting aneurysms. Among them, eleven cases were treated with surgical clipping and 9 cases were treated with endovascular treatment. Patients' data include age, sex, side and location of aneurysm, initial HuntHess (H-H) grade, procedure-related complications, follow-up duration, and Glasgow Outcome Scale (GOS) at last follow-up visit. According to GOS, we categorized the two groups into good (GOS 4 and 5) and poor (GOS 1-3) for the statistical anal- INTRODUCTIONIn view of location, posterior inferior cerebellar artery (PICA) aneurysms are reported to most frequently occur in the region where PICA originates in the vertebral artery (VA) 8,12) . When surgical clipping is performed, there are some risks of neurological complications because of the intimate anatomical relationships of the proximal PICA to the brain stem and lower cranial nerves 2,4,11) . Because of difficulty in general anesthesia due to poor general condition, recent advancement in endovascular surgery, and difficulties related with surgery, endovascular treatment is being used as a primary or alternative method for treating these aneurysms 3,6) . For ruptured or unruptured PICA aneurysms, in our knowledge, many authors 2,4,7,8,14,15) reported the clinical outcomes of surgery or endovascular treatment, but there was only one Results : Eleven (55%) and nine (45%) patients were treated with surgical clipping and endovascular treatment, respectively. Among 20 patients, thirteen (65.0%) patients had good outcomes (GOS 4 or 5). There was the statistical significance between initial poor H-H grade, the presence of acute hydrocephalus and poor GOS. Conclusion : In our study, we suggest that initial H-H grade and the presence of acute hydrocephalus may affect the clinical outcome rather than treatment modalities in the ruptured PICA aneurysms.

ObjectiveThe purpose of this large prospective study is to assess the association between the disappearance of the lateral spread response (LSR) before and after microvascular decompression (MVD) and clinical long term results over two years following hemifacial spasm (HFS) treatment.MethodsContinuous intra-operative monitoring during MVD was performed in 244 consecutive patients with HFS. Patients with persistent LSR after decompression (n=22, 9.0%), without LSR from the start of the surgery (n=4, 1.7%), and with re-operation (n=15, 6.1%) and follow-up loss (n=4, 1.7%) were excluded. For the statistical analysis, patients were categorized into two groups according to the disappearance of their LSR before or after MVD.ResultsIntra-operatively, the LSR was checked during facial electromyogram monitoring in 199 (81.5%) of the 244 patients. The mean follow-up duration was 40.9±6.9 months (range 25-51 months) in all the patients. Among them, the LSR disappeared after the decompression (Group A) in 128 (64.3%) patients; but in the remaining 71 (35.6%) patients, the LSR disappeared before the decompression (Group B). In the post-operative follow-up visits over more than one year, there were significant differences between the clinical outcomes of the two groups (p<0.05).ConclusionIt was observed that the long-term clinical outcomes of the intra-operative LSR disappearance before and after MVD were correlated. Thus, this factor may be considered a prognostic factor of HFS after MVD.