Basilar Invagination: Transoral Microsurgical Endoscopically-Controlled Odontoidectomy without Palatotomy in Extreme form of Basilar Invagination.

Objective Transoral odontoidectomy in the treatment of basilar invagination is surgically challenging. Incision of the soft palate significantly increases rostral exposure of the clivus but is associated with a high incidence of speech and swallowing difficulties after surgery. We present a patient suffering from severe compression of the medulla oblongata due to an extreme form of basilar invagination treated successfully with the resection of dens via a transoral nasopharyngeal approach without palatotomy. Setting Microsurgical endoscopic-assisted odontoidectomy through a transoral epipharyngeal approach was performed with subsequent craniocervical stabilization in a 21-year-old patient suffering from progressive myelopathy due to compression of the medulla oblongata and associated progressive syringomyelia. Results The 21-year-old man was initially treated with suboccipital craniotomy and duroplasty in another institution. After initial improval he subsequently developed progressive ataxia, dysphagia, a bulbar speech, and weakness of the extremities. Beside ventral compression, he developed a secondary Chiari's malformation and a holospinal syringomyelia. Resection of the dens was successfully accomplished via a microsurgical transoral epipharyngeal endoscopic-controlled odontoidectomy without palatotomy. One week after odontoidectomy, posterior craniocervical stabilization was performed. All preoperative symptoms and signs improved significantly and the patient leads an independent life 4 years after odontoidectomy. On follow-up magnetic resonance imaging (MRI), the syringomyelia completely resolved. Conclusions Palatotomy with its potential adverse effects can usually be avoided even for the treatment of extreme forms of basilar invagination. The link to the video can be found at: https://youtu.be/CBKE4n94W4g .

Is Falcine Meningioma a Diffuse Disease of the Falx? Case Series and Analysis of a "Grade Zero" Resection.

BACKGROUND: Falcine meningiomas have unique characteristics including their high rates of recurrence, association with high grade pathology, increased male prevalence, and potential for diffuse involvement of the falx. OBJECTIVE: To address these issues in a substantial series of falcine meningiomas and report on the impact of extent of resection for this distinct meningioma entity. METHODS: Retrospective analysis of characteristics and outcomes of 59 falcine meningioma patients who underwent surgery with the senior author. A "Grade Zero" category was used when an additional resection margin of 2 to 3 cm from the tumor insertion was achieved. RESULTS: For de novo falcine meningiomas, gross total resection (GTR) was associated with significantly decreased recurrence incidence compared with subtotal resection (P ≤ .0001). For recurrent falcine meningiomas, median progression-free survival (PFS) was significantly improved for GTR cases (37 mo vs 12 mo; P = .017, hazard ratio (HR) .243 (.077-.774)). "Grade Zero" resection demonstrated excellent durability for both de novo and recurrent cases, and PFS was significantly improved with "Grade Zero" resection for recurrent cases (P = .003, HR 1.544 (1.156-2.062)). The PFS benefit of "Grade Zero" resection did not achieve statistical significance over Simpson grade 1 during the limited follow-up period (mean 2.8 yr) for these groups. CONCLUSION: The recurrence of falcine meningiomas is related to the diffuse presence of tumor between the leaflets of the falx. Increased extent of resection including, when possible, a clear margin of falx surrounding the tumor base was associated with the best long-term outcomes in our series, particularly for recurrent tumors.

Foramen Magnum Meningioma: Microsurgical Endoscopic-Controlled Resection via a Lateral Suboccipital Retrocondylar Approach with Preservation of Posterior Arch of Atlas Integrity.

Objective Surgical treatment of foramen magnum (FM) meningiomas is challenging due to proximity of the tumor to critical neurovascular structures, namely, the lower brainstem/upper cervical cord, vertebral artery, PICA, and lower cranial nerves. Controversies in microsurgical resection of meningiomas in this location include the necessity for condyle drilling and the need for vertebral artery mobilization. However, a laminectomy or hemilaminectomy of the C1 posterior arch is usually routinely performed. We herein present microsurgical, endoscopic-controlled resection of a FM meningioma via a posterolateral retrocondylar suboccipital craniotomy with preservation of the integrity of the posterior arch of the atlas. Setting Our patient, a 57-year-old patient, suffered from right-sided hemiparesis due to a right-sided ventrolateral FM meningioma compromising the medulla oblongata and upper cervical cord. The tumor at the craniocervical junction was resected through a posterolateral suboccipital retrocondylar craniotomy. Results Radical resection of the FM meningioma was accomplished via a lateral suboccipital retrocondylar craniotomy with preservation of posterior arch of atlas integrity. The postoperative course was uneventful with full preservation of neurological function. Preoperative hemiparesis subsided completely after surgery. Conclusion Anterior-laterally located FM meningiomas can be safely and completely resected via a suboccipital retrocondylar craniotomy. A laminectomy or hemilaminectomy of the posterior arch of C1 is not routinely required for complete and safe resection of these tumors at the craniocervical junction. Neuroendoscopy is beneficial for control of complete tumor resection. The link to the video can be found at: https://youtu.be/DBk6qoJ6OzQ .

Spontaneous cerebellar hemorrhage--experience with 57 surgically treated patients and review of the literature.

The treatment of spontaneous cerebellar hemorrhage is still discussed controversially. We analyzed a series of 57 patients who underwent surgical evacuation of a cerebellar hematoma at our department. Preoperative clinical and radiological parameters were assessed and correlated with the clinical outcome in order to identify factors with impact on outcome. The overall clinical outcome according to the Glasgow Outcome Scale at the last follow-up was good (GOS 4-5) in 27 patients (47%) and poor (GOS 2-3) in 16 patients (28%). Fourteen patients (25%) died. The initial neurological condition and the level of consciousness proved to be significant factors determining clinical outcome (p = 0.0032 and p = 0.0001, respectively). Among radiological parameters, brain stem compression and a tight posterior fossa solely showed to be predictive for clinical outcome (p = 0.0113 and p = 0.0167, respectively). Overall, our results emphasize the predictive impact of the initial neurological condition on clinical outcome confirming the grave outcome of patients in initially poor state as reported in previous studies. The hematoma size solely, in contrast to previous observations, showed not to be predictive for clinical outcome. Especially for the still disputed treatment of patients in good initial neurological condition, a suggestion can be derived from the present study. Based on the excellent outcome of patients with good initial clinical condition undergoing surgery due to secondary deterioration, we do not recommend preventive evacuation of a cerebellar hematoma in these patients.

AVM resection after radiation therapy--clinico-morphological features and microsurgical results.

A subgroup of patients initially treated by radiosurgery underwent surgical resection because of recurrent hemorrhage or neurological deterioration. In a retrospective study, we want to analyze the clinical features of these patients and evaluate the effect of microneurosurgery in such rare constellations. Moreover, we hope to find answers about failure of radiation therapy in these cases by correlation of radiobiological and histopathological data. Over a 16-year-period, eight patients with cerebral arteriovenous malformation (AVM) underwent surgical resection, who previously were treated by radiosurgery. The mean duration between radiation therapy and final resection was 7 years. Preoperative evaluation revealed Spetzler-Martin grade III (n=5) and IV (n=3) AVMs. Histological examination was achieved in all resected lesions. Mean neurological follow-up was 14 months. Indications for surgical resection were intracerebral hematoma, progressive neurological deficit, and epilepsy. In comparison to the initial angiographic study before radiation therapy, preoperative angiography revealed newly developed "en passant" feeding vessels and stenosis of the main venous drainage in some patients. The mean Rankin score for all patients was 2.75 before and 3.25 after surgical resection. Postoperatively, three patients (38%) developed neurological deterioration. Histological examination of the resected tissue revealed significant radiation-induced pathology in six patients. We did not see correlation between radiation doses and severity of histolopathological radiation-induced changes. Postoperative angiography confirmed total AVM resection in all patients. AVMs insufficiently treated by radiation bear an increased surgical risk. Often, angiographic studies revealed a more complicated morphology. Microsurgical resection was extremely challenging and led to unfavorable outcomes in many of the patients.

Decompressive laminoplasty in multisegmental cervical spondylotic myelopathy: bilateral cutting versus open-door technique.

PURPOSE: The aim of the study was to evaluate patients with multisegmental cervical spondylotic myelopathy (MCM) surgically treated via a dorsal approach. Two different laminoplasty techniques were compared by assessment of enlargement of the spinal canal and the neurological outcome. METHODS: Thirteen patients (mean age 49 years, 11 males) underwent decompressive laminoplasty over a 7-year period. The average duration of symptoms was 21 months. The pre- and postoperative degree of myelopathy was assessed by both the Nurick grading and the Japanese Orthopaedic Association myelopathy score (JOA score). Preoperatively, the mean Nurick grade was 3.1 and the mean JOA score was 11. Two different techniques of expansive laminoplasty were used. Six patients underwent a bilateral cutting (BL) technique with retropositioning of the laminae and bilateral mini-plating (BL group). Seven patients were operated on by simple open-door (OD) laminoplasty with unilateral mini-plating (OD group). Postoperatively, CT scans were obtained for all patients to measure the sagittal diameter of the spinal canal. The mean clinical and radiological follow-up was 33 months. RESULTS: Four to five laminae were involved in all patients.The mean operation time was 180 min. Complications occurred in two patients of BL group, with immediate postoperative neurological deterioration due to ventral displacement of the laminae. Overall, the average sagittal diameter (SD) of the spinal canal increased from 9.2 +/- 1.3 mm to 12.4 +/- 1.3 mm after surgery. The average enlargement of SD was significantly higher for the OD group (p < 0.0075 ). In total, the improvement rate was 38% according to the Nurick grading and 69% according to the JOA score. For the OD group, improvement rates were 57% (Nurick) and 71% (JOA). CONCLUSIONS: Decompressive laminoplasty is comparable with anterior surgery in neurological outcome. The OD technique seems to be superior to our BL technique regarding both the enlargement of SD and complication rate.

Anterior clinoidal meningiomas: functional outcome after microsurgical resection in a consecutive series of 106 patients. Clinical article.

OBJECT: In this study, the authors' goal was to analyze a series of patients treated microsurgically for an anterior clinoid process (ACP) meningioma in regard to long-term functional outcome. METHODS: The authors retrospectively analyzed clinical data in a consecutive series of 106 patients who underwent microsurgical treatment for an ACP meningioma at 2 neurosurgical institutions between 1987 and 2005. The main presenting symptoms of the 84 female and 22 male patients (mean age 56 years) were visual impairment in 54% and headache in 28%. Physical examination revealed decreased visual acuity in 49% and a visual field deficit in 26%. Tumors were primarily resected via a pterional approach. Meningioma extensions invading the cavernous sinus, present in 29% of the patients, were not removed. Complete tumor resection (Simpson Grade I and II) was achieved in 59% of the cases. RESULTS: Postoperatively, visual acuity improved in 40%, was unchanged in 46%, and deteriorated in 14%. A new oculomotor palsy was observed in 8 patients (8%). Clinical and MR imaging data were available in 95 patients for a mean postsurgical period of 6.9 years (1.5-18 years) and revealed tumor recurrence in 10% and tumor progression after subtotal resection in 38%. Clinical deterioration on long-term follow-up consisting primarily of ophthalmological deficits was observed in 14% of the cases. CONCLUSIONS: Acceptable functional results can be achieved after microsurgical resection of ACP meningiomas; however, long-term treatment remains challenging due to a high tumor recurrence and progression rate.

Spinal meningiomas: critical review of 131 surgically treated patients.

This study was undertaken to analyze the functional outcome of surgically treated spinal meningiomas and to determine factors for surgical morbidity. Between January 1990 and December 2006 a total of 131 patients underwent surgical resection of a spinal menigioma. There were 114 (87%) female and 17 (13%) male patients. Age ranged from 17 to 88 years (mean 69 years). The mean follow-up period was 61 months (range 1-116 months) including a complete neurological examination and postoperative MRI studies. The pre- and postoperative neurological state was graded according to the Frankel Scale. Surgery was performed under standard microsurgical conditions with neurophysiological monitoring. In 73% the lesion was located in the thoracic region, in 16% in the cervical region, in 5% at the cervico-thoracic junction, in 4.5% at the thoraco-lumbar junction and in 1.5% in the lumbar region. Surgical resection was complete in 127 patients (97%) and incomplete in 4 patients (3%). At the last follow-up the neurological state was improved or unchanged in 126 patients (96.2%) and worse in 4 patients (3%). Permanent operative morbidity and mortality rates were 3 and 0.8%, respectively. Extensive tumour calcification proved to be a significant factor for surgical morbidity (P < 0.0001). Radical resection of spinal meningiomas can be performed with good functional results. Extensive tumor calcification, especially in elderly patients proved to harbor an increased risk for surgical morbidity.

Meningiomas of the falcotentorial junction: selection of the surgical approach according to the tumor type.

BACKGROUND: We retrospectively analyzed a series of patients harboring a FT meningioma with regard to clinical presentation, surgical technique, and follow-up results. METHODS: Clinical data in a consecutive series of 13 patients treated for a meningioma of the FT junction were retrospectively reviewed. Tumors were classified into 4 types according to their dural origin and tumor extent as depicted from preoperative MRI. RESULTS: Main presenting symptom in 9 women and 4 men (mean age, 56 years) was headache (69%) and gait disturbance (54%). Clinical examination revealed gait ataxia in 62% of the patients. The tumor displaced the vein of Galen inferiorly in 6 patients, superiorly in 2, and medially in 5 cases. The main surgical approach to the meningioma was via an occipital interhemispheric route (10 patients). Additional resection of the falx and/or incision of the tentorium was performed in 6 cases each. A complete resection (Simpson grade 1 and 2) was achieved in 85% of patients. Permanent surgical morbidity was 23%. One tumor recurrence in an atypical meningioma was observed after the mean follow-up period of 6.2 years (range, 1-14 years) with clinical and MRI examination and had to be reoperated. Eighty-five percent of the patients regained full daily activity on follow-up. CONCLUSIONS: The surgical approach should be tailored to the dural origin and extent of the tumor as depicted from preoperative MRI. Preservation of the straight sinus and Galenic venous system is recommended.

The impact of subarachnoid hemorrhage on regional cerebral blood flow and large-vessel diameter in the canine model of chronic vasospasm.

OBJECTIVE: The aim of this study was to correlate changes in regional cerebral blood flow (rCBF) to the degree of cerebral vasospasm in the canine two-hemorrhage model of subarachnoid hemorrhage (SAH). METHODS: SAH was induced in 13 adult beagle dogs using the two-hemorrhage model. Eleven beagle dogs served as controls. Angiography of the basilar artery and measurements of rCBF with colored microspheres were performed on days 1 and 8. Diameter of the basilar artery was calculated at equidistant points from the angiogram. RESULTS: In controls, basilar artery diameter (mm) and rCBF (mL/min/g) were equal on days 1 and 8. In the SAH group, basilar artery diameter decreased significantly (1.27 +/- 0.17 [mean +/- SD]-0.84 +/- 0.15 mm). rCBF decreased significantly (P < .05) in the cerebrum (1.69 +/- 0.54 [mean +/- SD]-1.06 +/- 0.45 mL/min/g), cerebellum (1.18 +/- 0.40-0.80 +/- 0.32 mL/min/g), and brain stem (0.81 +/- 0.33-0.51 +/- 0.21 mL/min/g). However, decrements in CBF were not correlated to the reduction in vessel caliber in the corresponding vascular territory. CONCLUSION: Induced SAH in the canine model produces a significant impairment in rCBF irrespective of the degree of vasospasm of large cerebral vessels. The findings support the presumptive role of the microvasculature in regard to delayed cerebral ischemia after SAH.

Dural involvement in primary extradural meningiomas of the cranial vault.

OBJECT: The authors retrospectively analyzed a consecutive series of patients with cranial vault primary extradural meningioma (PEM), with particular regard to the tumor's dural involvement. The pertinent literature was reviewed. METHODS: Clinical data were retrospectively obtained in a consecutive series of 16 patients treated for a PEM at two institutions between 1992 and 2004. The authors created a classification system based on dural involvement of the tumors. Nine women and six men (mean age 55 years) presented with a painless, slowly progressive swelling. Preoperative magnetic resonance (MR) imaging revealed dural enhancement at the site of tumor in 11 patients. On surgical inspection, the tumor infiltrated the dura in all but three patients. Histological examination of tissue samples demonstrated tumor infiltration of the dura in all 14 patients in whom the dura had been resected. Three recurrent tumors were observed on follow-up examination during a mean period of 5.8 years (range 1.5-13 years) and required extirpation. In addition to one patient in whom there was histological evidence of malignancy, the other two cases involved two patients in whom no apparent dural involvement was observed during the first surgery. In a review of the literature, the authors found that histological examination showed dural involvement in 22%; the dura was not histologically evaluated in the remaining patients (78%). Postoperative follow-up data exceeding 2 years were only provided in two of the reported cases. CONCLUSIONS: Tumor infiltration of the dura should be assumed in PEMs of the cranial vault, and resection of the dura at the site of craniotomy is recommended to prevent tumor recurrence.

Tuberculum sellae meningiomas: functional outcome in a consecutive series treated microsurgically.

OBJECTIVE: The objective of this study was to analyze a series of patients harboring a tuberculum sellae meningioma with regard to clinical presentation and long-term functional outcome. METHODS: Data in a consecutive series of 62 patients harboring a tuberculum sellae meningioma treated microsurgically between 1990 and 2003 were retrospectively reviewed. RESULTS: The mean age of the 46 women and 16 men enrolled in the study was 53 years (range = 29-81 years). The presenting symptom was visual compromise in 87.1% of the patients, and examination revealed decreased visual acuity in 79% and impaired visual fields in 64.5% of the patients. In addition, 14.5% of the patients had preoperative hormonal abnormalities. Simpson grades I and II resections, usually via a pterional approach, were achieved in 90.3% of the patients. Postoperatively, vision improved in 53.2%, remained unchanged in 29.8%, and deteriorated in 17.0% of the patients. The intraoperative finding predicting an unfavorable visual outcome was a thin atrophic optic nerve, encasement of the nerve, or tumor adhesion to its undersurface. Of the patients, 12.9% required permanent postoperative hormonal replacement. After a mean follow-up period of 6.0 years (range = 18 months-14 years), 88.7% of the patients resumed normal life activity and 2 recurrent tumors were observed (3.2%) and reoperated. CONCLUSIONS: Preoperative magnetic resonance imaging provides reliable information with regard to dislocation of critical vascular structures. However, the relationship between optic nerves and tumors (eg, adhesion and encasement) affected postoperative results and can only be fully appreciated during microsurgery. Visual outcome may be improved by preserving the microvasculature supplying the optic apparatus.

Foramen magnum meningiomas: clinical outcome after microsurgical resection via a posterolateral suboccipital retrocondylar approach.

OBJECTIVE: We analyzed a consecutive series of patients operated for a foramen magnum (FM) meningioma located on the ventral aspect of the medulla oblongata via a posterolateral suboccipital retrocondylar approach with regard to long-term surgical outcome. METHODS: Clinical data in a consecutive series of 25 patients experiencing a meningioma attached to dura of the anterior or anterolateral FM rim were retrospectively reviewed. RESULTS: The most common symptoms of the 19 women and six men (mean age, 59.2 yr) was cervico-occipital pain (72%) and gait disturbance (32%). Clinical examination revealed gait ataxia in 48% of the patients. As depicted from preoperative magnetic resonance imaging (MRI), dural attachment of the meningioma at the FM rim was anterior in 36% and anterolateral in 64% of cases. Tumor removal was accomplished via a posterolateral suboccipital retrocondylar approach in all patients. A Simpson Grade 2 resection was achieved in 96% of the patients. Permanent surgical morbidity and mortality rates were 8 and 4%, respectively. No tumor recurrence was observed after a mean follow-up period of 6.1 years (range, 1-14 yr) with clinical and MRI examination, and 80% of the patients have regained full daily activity. CONCLUSION: Anterior and anterolateral FM meningiomas that displace the medulla/spinal cord can be safely and completely resected via a posterolateral suboccipital retrocondylar approach. A tumor remnant should be left on critical neurovascular structures in cases with poor arachnoid dissection planes.

Spinal intradural juxtamedullary cysts in the adult: surgical management and outcome.

OBJECTIVE: Intradural nonneoplastic cysts compressing the spinal cord are rare lesions. We retrospectively analyzed a series of patients harboring this entity with regard to clinical and radiological features, surgical management, and follow-up results. METHODS: In a retrospective study, we reviewed the medical charts, radiological investigations, and follow-up data of 11 women and 10 men (mean age, 43.6 yr) with intradural juxtamedullary spinal cysts, which were consecutively treated microsurgically at our institutions between January 1995 and January 2003. All lesions were approached via a laminectomy, hemilaminectomy, or laminoplasty at the corresponding vertebral levels and histopathologically verified. The patients were routinely scheduled for clinical follow-up 2 and 6 months after surgery. Baseline postoperative magnetic resonance imaging (MRI) was ordered 6 months after surgery. Thereafter, follow-up was performed at 1-year intervals, with neurological examination and MRI. RESULTS: According to presenting symptomatology, two main patient groups could be differentiated: one group with a myelopathic syndrome (10 patients) and another group with a predominant radicular pain syndrome (8 patients). Histopathological examination revealed 16 arachnoid cysts, 4 neuroepithelial cysts, and 1 cervical nerve root cyst. Most arachnoid cysts (12 cases) were located on the dorsal aspect of the thoracic spinal cord. The mean craniocaudal extension of these cysts was 3.7 vertebral levels, and complete resection was performed. In four patients, the arachnoid cyst was situated ventral to the spinal cord and involved up to 17 vertebral levels. These patients had a history of major spinal trauma, and the cyst was generously fenestrated at its greatest circumference as depicted on preoperative MRI scans. The four neuroepithelial cysts and the cervical nerve root cyst were located on the ventral or ventrolateral aspect of the spinal cord, and their maximum sagittal extension was two spinal vertebral levels. Symptoms in all but two patients demonstrated major improvement; in particular, radiating pain disappeared immediately after surgery. There was no cyst recurrence on MRI after a mean follow-up period of 3.2 years. CONCLUSION: Intradural cysts should be considered in the differential diagnosis of lesions causing myelopathy and/or a radicular pain syndrome. Microsurgical resection or generous fenestration in cysts with large craniocaudal extensions effectively ameliorated patients' symptomatology. A description of the first documented case of a surgically treated intradural cervical nerve root cyst is provided.

Meningiomas of the posterior petrous bone: functional outcome after microsurgery.

OBJECT: The aim of this study was to analyze a subgroup of patients harboring cerebellopontine angle meningiomas originating from the posterior petrous bone in regard to clinical presentation, surgical anatomy, complications, and long-term functional postoperative results. METHODS: Data in a series of 51 patients with meningiomas of the posterior petrous bone who had undergone microsurgical treatment at the authors' institution between 1989 and 2002 were retrospectively reviewed. The patient population consisted of 46 women and five men with a mean age of 53 years (range 22-70 years). The main symptom on first admission was impaired hearing in 41%, dizziness in 20%, and tinnitus in 18% of the patients. Results of physical examination and audiological testing revealed hypacusis in 65% of patients, cerebellar ataxia in 31%, and impairment of the fifth cranial nerve in 26%. All patients underwent surgical treatment via a lateral suboccipital approach. Intraoperatively, the tumor was found to be attached to the postmeatal dura in 37%, the premeatal dura in 27.5%, the suprameatal dura in 19.6%, the inframeatal dura in 7.8%, and centered on the porus acusticus in 5.9% of cases. Tumor extension into the internal acoustic meatus was present in seven patients. Tumor resection was categorized as Grade I in 14 patients, Grade II in 29, Grade III in six, and Grade IV in two patients, according to the Simpson classification system. The site of displacement of the cranial nerves was predictable in up to 84% of patients, depending on the dural origin of the tumor as depicted on preoperative magnetic resonance (MR) imaging studies. Postoperatively, a new and permanent facial paresis was observed in five patients (9.8%). In 38 patients in whom both pre- and postoperative audiological data were available, hearing function deteriorated after surgery in 18.4% and improved in 7.9%. Clinical and MR imaging postsurgical data from a mean period of 5.8 years (range 13 months-13 years) were available in all patients. Forty-four patients (86%) resumed normal daily activity. Tumor recurrence was observed in two patients (3.9%), and both underwent a second surgery. CONCLUSIONS: Preoperative detailed analysis of MR imaging data gives the surgeon a clue about the dislocation of critical neurovascular structures, particularly the cranial nerves. Nonetheless, the exact relationship of the cranial nerves to the tumor (dislocation, adherence, infiltration, and splaying of nerves) can only be fully appreciated during surgery.

Tentorial meningiomas: clinical results in 81 patients treated microsurgically.

OBJECTIVE: Even during the microsurgical era, tentorial meningiomas present a formidable surgical challenge when tumor involves critical neurovascular structures. We report our experience with tentorial meningioma with regard to clinical presentation, diagnostic workup, microsurgical technique, complications, and follow-up results. METHODS: In a retrospective study, we reviewed the medical charts, neuroimaging data, and follow-up data of patients treated microsurgically for tentorial meningioma in our department between January 1989 and June 2002. Patients were routinely scheduled for clinical and radiological follow-up 6 months and 1 year after surgery. Thereafter, follow-up was performed every 1 or 2 years on the basis of the results of each follow-up examination. RESULTS: The main presenting symptoms of the patients (69 women and 12 men) were headache (75%), dizziness (49%), and gait disturbance (46%). The leading neurological signs were gait ataxia (52%) and cranial nerve deficits (28%). Extent of tumor resection was Simpson Grade I in 29 patients, Grade II in 45 patients, Grade III in 1 patient, Grade IV in 4 patients, and unknown in 2 patients. Permanent surgical morbidity and mortality were 19.8 and 2.5%, respectively. Clinical and magnetic resonance imaging follow-up was available in 74 patients for a period ranging from 1 to 13 years (mean, 5.9 yr). Of these, 64 patients (86%) have resumed normal life activity. Seven patients had tumor recurrence and four underwent reoperation. CONCLUSION: Careful preoperative planning of the surgical approach tailored to tumor location and extent is a prerequisite to achieve radical microsurgical tumor resection with minimal morbidity and mortality. Resection of an infiltrated but patent venous sinus is not recommended.