Cavernous angiomas within the internal auditory canal.

OBJECT: The aim of this study was to describe the symptomatology, radiological features, and surgical treatment of patients with cavernous angiomas within the internal auditory canal (IAC). METHODS: The authors reviewed the cases of seven patients with cavernous angiomas in the IAC that had been surgically treated in the 22-year period between 1983 and 2005. All the patients had presented with sensorineural hearing loss, and four suffered from tinnitus. Four patients also reported facial symptoms such as hemispasm or progressive palsy; one of these patients had presented with sudden facial paresis due to intrameatal tumor hemorrhage. According to computed tomography (CT) results, the lesions caused enlargement of the IAC. Interestingly, these same angiomas showed variable features on magnetic resonance (MR) imaging, making their differentiation from intrameatal vestibular schwannomas (VSs) sometimes impossible. In all patients the lesions were totally removed via the suboccipital retrosigmoid approach. They could be dissected away from the facial nerve in five cases, whereas in two cases, because of the location of the lesion, the seventh cranial nerve had to be sectioned and repaired with a sural nerve graft. Transient worsening of seventh cranial nerve symptoms occurred in two patients, with postoperative improvement in each of them. The cochlear nerve could not be functionally preserved because of its extreme adherence to the tumor, although its continuity was preserved in four patients. Complete deafness was the only postoperative complication. CONCLUSIONS: Cavernous angiomas of the IAC are very uncommon lesions that can imitate the symptoms of VSs. Although it is the most sensitive study available, MR imaging does not show sufficiently specific findings to differentiate the two lesion types. Thus, the preoperative diagnosis must be based on patient symptoms plus the CT and MR imaging features.

Meningiomas of the cerebellopontine angle with extension into the internal auditory canal.

OBJECT: Only some meningiomas of the cerebellopontine angle (CPA) extend into the internal auditory canal (IAC) or arise from its dural lining. The authors investigated cases of CPA tumors in which the meningioma was inserted in the dura mater in or at the ICA or infiltrated a cranial nerve. METHODS: The authors reviewed patient charts including surgical and clinical records, intraoperative recordings of auditory evoked potentials, records of postoperative auditory examinations, and imaging studies. In a series of 421 patients harboring CPA meningiomas, 72 patients in whom there was dural involvement of the IAC were investigated. Total tumor resection was achieved in 86.1%. In 34 patients, opening of the IAC was required for total tumor removal; this procedure did not influence the patient functional outcome. Among patients with secondary involvement of the IAC, anatomical preservation of the facial and cochlear nerves was obtained in 94%, whereas among patients in whom the lesion arose from the dura in or at the IAC these values were 80 and 75%, respectively. Functional preservation of the seventh and eighth cranial nerves in cases of tumor extension within the IAC was 86 and 77%, respectively, whereas in cases in which the IAC was involved it was only 60%. In four of five patients in whom the tumor had its origin in the dura mater within the IAC, the seventh or eighth cranial nerve had to be sacrificed to achieve tumor removal because of the lesion's infiltrative behavior. Facial nerve reconstruction by sural grafting was performed in the same operative procedure. CONCLUSIONS: Meningiomas of the CPA involving the IAC require special surgical management. Dural involvement of the IAC requires opening by using a diamond drill, a procedure that does not influence cranial nerve outcome. The increased rate of cranial nerve morbidity is attributed to the infiltrative behavior of these meningiomas. If affected nerve segments have to be sacrificed, immediate reconstruction enables satisfactory long-term results.

Sphenoid wing meningiomas with osseous involvement.

BACKGROUND: Sphenoid wing meningiomas (SWMs) with osseous involvement are neurosurgically challenging because of their position within the skull base and their high rates of recurrence. Sufficient resection of these meningiomas requires extensive surgical exposure. We report on 82 patients with meningiomas infiltrating the sphenoid wing, analyzing radiological appearance and its influence on surgical management. METHODS: Charts of the patients including surgical records, clinical reports, histological examinations, imaging studies, and meticulously focusing questionnaires were reviewed. RESULTS: Among the 82 patients with osseous-involved SWMs, the mean age was 52.2 years in the female group and 54.7 years in the male group with a mean follow-up of 66.23 months (24-206). Histological evaluation revealed World Health Organization grade I meningiomas in 94% of case patients, tumor infiltration of examined bone in all case patients, and proliferation rates of 2.2% Ki-67. Magnetic resonance imaging appearance of the SWMs demonstrated various densities as well as Gd enhancement within the affected bone. Recurrence rates in this subgroup of SWMs are higher (>30%) compared with meningiomas without osseous involvement (11.6%). CONCLUSION: Osseous involvement in SWMs accounts for lower resection and higher recurrence rates than meningiomas in other locations. In those cases with involvement of the cavernous sinus, a subtotal but extensive removal combined with bony decompression of the cranial nerves at the superior orbital fissure and optic canal frequently produces good functional and cosmetic results.

Microvascular decompression to treat hemifacial spasm: long-term results for a consecutive series of 143 patients.

OBJECTIVE: The concept of neurovascular decompression for the treatment of hemifacial spasm is now widely accepted. In this study, we report our long-term results for 145 cases treated with this procedure. METHODS: The results of 145 microvascular decompressions to treat hemifacial spasm (performed between 1980 and 1998) among 143 patients (62.2% female patients and 37.8% male patients; mean age, 54.5 yr) are presented. The onset of symptoms was typical in 95.9% of cases and atypical in 4.1%. Platysma muscle involvement was observed for 24.5% of patients, with a higher incidence among female patients (74.3%). Patients were monitored with annual questionnaires. Twenty-six patients were lost to follow-up monitoring, and 117 are still undergoing follow-up monitoring, with an average period of 9.6 years (range, 1-17.6 yr). RESULTS: At discharge, 69 patients (59%) were spasm-free and 48 patients (41%) experienced further spasm. At 6 months, the number of spasm-free patients had increased to 108 (92.3%), whereas only 9 patients (7.7%) complained of hemifacial spasm; 44 patients were spasm-free at an average time of 15 weeks. In follow-up examinations (average period, 9.4 yr), 106 patients were spasm-free. Seven patients experienced only temporary relief, with recurrence after 4.5 years. Two patients were spasm-free after 4 or 6 weeks, and the recurrence of spasm was observed 1 year later. Two patients were never completely spasm-free. Among the patients who did not undergo previous surgery elsewhere, only two experienced recurrence. CONCLUSION: Deafness was the main postoperative complication (8.3%); most of those cases (66%) occurred before the routine use of intraoperative evoked potential monitoring. Analysis of our series demonstrates that this surgical procedure involves very low risk, is well tolerated by elderly patients, is associated with very low recurrence rates, and is a definitive treatment for more than 90% of cases.

Meningiomas of the internal auditory canal.

OBJECTIVE: Meningiomas arising primarily within the internal auditory canal (IAC) are notably rare. By far the most common tumors that are encountered in this region are neuromas. We report a series of eight patients with meningiomas of the IAC, analyzing the clinical presentations, surgical management strategies, and clinical outcomes. METHODS: The charts of the patients, including histories and audiograms, imaging studies, surgical records, discharge letters, histological records, and follow-up records, were reviewed. RESULTS: One thousand eight hundred meningiomas were operated on between 1978 and 2002 at the Neurosurgical Department of Nordstadt Hospital. Among them, there were 421 cerebellopontine angle meningiomas; 7 of these (1.7% of cerebellopontine angle meningiomas) were limited to the IAC. One additional patient underwent surgery at the Neurosurgical Department of the International Neuroscience Institute, where a total of 21 cerebellopontine angle meningiomas were treated surgically from 2001 to 2003. As a comparison, the incidence of intrameatal vestibular schwannomas during the same period, 1978 to 2002, was 168 of 2400 (7%). There were five women and three men, and the mean age was 49.3 years (range, 27-59 yr). Most patients had signs and symptoms of vestibulocochlear nerve disturbance at presentation. One patient had sought treatment previously for total hearing loss before surgery. No patient had a facial paresis at presentation. The neuroradiological workup revealed a homogeneously contrast-enhancing tumor on magnetic resonance imaging in all patients with hypointense or isointense signal intensity on T1- and T2-weighted images. Some intrameatal meningiomas showed broad attachment, and some showed a dural tail at the porus. In all patients, the tumor was removed through the lateral suboccipital retrosigmoid approach with drilling of the posterior wall of the IAC. Total removal was achieved in all cases. Severe infiltration of the facial and vestibulocochlear nerve was encountered in two patients. There was no operative mortality. Hearing was preserved in five of seven patients; one patient was deaf before surgery. Postoperative facial weakness was encountered temporarily in one patient. CONCLUSION: Although intrameatal meningiomas are quite rare, they must be considered in the differential diagnosis of intrameatal mass lesions. The clinical symptoms are very similar to those of vestibular schwannomas. A radiological differentiation from vestibular schwannomas is not always possible. Surgical removal of intrameatal meningiomas should aim at wide excision, including involved dura and bone, to prevent recurrences. The variation in the anatomy of the faciocochlear nerve bundle in relation to the tumor has to be kept in mind, and preservation of these structures should be the goal in every case.

Transition from meningeal melanocytoma to primary cerebral melanoma. Case report.

The authors describe the first case of an intracranial transition of a melanocytoma into a primary malignant melanoma within a short time. A 37-year-old woman presented with progressive brainstem syndrome due to a tumor, originally diagnosed and treated 12 years earlier, that extended from the petroclival area to the anterior craniocervical junction. The histological workup following subtotal tumor resection of the initial tumor had revealed the typical features of a fibrous melanocytic meningioma without increased proliferation. Ten years after the patient had completed treatment for the melanocytic meningioma, control neuroimaging demonstrated growth of the residual tumor with compression of the brainstem. Another neurosurgical intervention revealed a dark tumor of hard consistency. At this time immunohistochemical examinations demonstrated melanocytic features (expression of vimentin, S100 protein, and melan A) of the lesion with focally increased proliferation (5% of Ki-67-positive cells) but no higher mitotic activity. Clinical signs of deterioration along with imaging-confirmed tumor progression precipitated another operation within 7 months. A neuropathological examination revealed epithelial and anaplastic changes and indicated that the MIB-1 indices were greater than 25%. Pleomorphic changes and a focal high mitotic activity led to the diagnosis of a primary cerebral malignant melanoma. The patient's later clinical course consisted of a rapid diffuse meningeal spread of the lesion throughout the entire brain and spine. Despite whole-brain and stereotactic radiation therapy as well as chemotherapy, the patient died 4 months after the last neuropathological diagnosis. Although grossly resembling a meningioma, melanocytomas lack the former's histological and immunohistochemical features. The biological behavior of a melanocytoma is variable and recurrence may happen after subtotal resection, but intracranial transition into a malignant melanoma has not been observed previously.

Intraventricular meningiomas: a review of 16 cases with reference to the literature.

BACKGROUND: Primary intraventricular meningiomas are notably rare with an incidence of 0.5 to 3% among all intracranial meningiomas. We present a series of 16 patients with histologically verified intraventricular meningiomas, the clinical and neuroradiological findings, and surgical results. METHODS: The charts of the patients including surgical records, discharge letters, histologic records, follow up records and imaging studies were analyzed retrospectively from 1978 to 2001. RESULTS: Collectively, 110 primary intraventricular tumors were surgically resected in our neurosurgical department from 1983 through 2001. There were 16 patients with primary intraventricular meningiomas. Thirteen (81.3%) of these tumors were located in the lateral ventricles, one (6.2%) in the third and two (12.5%) in the forth ventricle. Mean age was 47.1 years and there was no difference in incidence between the sexes. The most common presenting symptoms and signs were headache, mental change, and hemianopia. Other symptoms included gait ataxia, vertigo, hemiparesis, double vision, aphasia, and alexia/agraphia. On CT and MR studies most of the lateral ventricular meningiomas were located in the trigone (11 cases), two tumors originated at the level of foramen of Monro or in the frontal horn. The tumors were approached via a transcortical parieto-occipital (11 cases), transcallosal (3 cases), or median suboccipital (2 cases) route. Total removal was achieved in 15 out of 16 cases. There was no operative mortality. Clinical improvement was seen in symptoms like headaches, paresis, cerebellar signs and visual disturbances, whereas mental change showed less improvement. CONCLUSIONS: Although intraventricular meningiomas are quite rare, they represent an important differential diagnosis of intraventricular neoplasms. They can reach a substantial size by the time of diagnosis, yet total removal can be achieved in most cases.

Outcome of medical and surgical management in intractable idiopathic trigeminal neuralgia.

BACKGROUND: The neurovascular conflict in trigeminal neuralgia is an intractable condition; medical treatment is usually of long duration and can be annoying for both patients and clinicians. AIM: This prospective study was designed to assess the outcome of microvascular decompression (MVD) in patients with more than 3 years' history of intractable idiopathic trigeminal neuralgia (TN) and poor response to drugs. MATERIALS AND METHODS: Twenty-one patients (8 females and 13 males) with intractable idiopathic TN (group 1) underwent MVD and were followed up for 2 years. Group 2 (n = 15), which included 6 females and 9 males, received pharmacotherapy. The outcome responses of pain relief were evaluated using a 10-cm visual analog scale (VAS) and the Barrow Neurological Institute (BNI) scoring system. The patients' morbidity was recorded as well. RESULTS: All patients fulfilling the inclusion criteria were offered MVD surgery. Freedom from pain was achieved immediately after surgery in 95.2% (n = 20) of patients in group 1, and 90.5% (n = 19) had sustained relief over the follow-up period. There were no statistical significance recurrences or surgical complications in group 1 (P>0.5), while 53.3% (n = 8) of the subjects in group 2 showed poor response with pharmacotherapy over the same period of time and many patients experienced drug intolerance that had statistical significance (P<0.01). CONCLUSION: Early MVD in TN can help patients avoid the side effects of drugs and the adverse psychological effects of long-term pharmacotherapy and prolonged morbidity.

Olfactory groove meningiomas: clinical outcome and recurrence rates after tumor removal through the frontolateral and bifrontal approach.

OBJECTIVE: Olfactory groove meningiomas account for 8 to 13% of all intracranial meningiomas. Surgical removal is often performed through the bifrontal, unilateral subfrontal (frontolateral), or pterional approach. We report on the clinical outcome and recurrence rate after surgical treatment of olfactory groove meningiomas in our neurosurgical department. METHODS: A retrospective study was conducted by analyzing the charts of the patients, including surgical records, discharge letters, histological records, follow-up records, and imaging studies. RESULTS: A total of 1800 meningiomas were operated on between 1978 and 2002 in our department. There were 82 patients with olfactory groove meningiomas, including 63 women and 19 men with a mean age of 57.8 years (age range, 33-91 yr). Most patients presented with mental disturbance. Tumors were operated through the bifrontal (n = 46), frontolateral (n = 34), and pterional (n = 2) approaches. Total tumor removal (Simpson Grade 1 or 2) was achieved in most cases (91.2% frontolateral, 93.5% bifrontal). Perioperative mortality was 4.9% (four out of 82 patients, all operated through the bifrontal approach). The overall recurrence rate was 4.9%, with four patients requiring surgery. The mean follow-up period was 63.4 months (range, 4-270 mo). CONCLUSION: Olfactory groove meningiomas were removed mainly through two different surgical approaches. Even in large tumors, high rates of total tumor resection could also be achieved with low recurrence rates using the simple and minimally invasive frontolateral approach. In recent years, we have preferred to use the frontolateral approach, which provides quick access to the tumor with less brain exposure while still enabling total tumor removal with a low morbidity rate and no mortality.

Olfactory groove meningiomas: clinical outcome and recurrence rates after tumor removal through the frontolateral and bifrontal approach.

OBJECTIVE: Olfactory groove meningiomas account for 8 to 13% of all intracranial meningiomas. Surgical removal is often performed through the bifrontal, unilateral subfrontal (frontolateral), or pterional approach. We report on the clinical outcome and recurrence rate after surgical treatment of olfactory groove meningiomas in our neurosurgical department. METHODS: A retrospective study was conducted by analyzing the charts of the patients, including surgical records, discharge letters, histological records, follow-up records, and imaging studies. RESULTS: A total of 1800 meningiomas were operated on between 1978 and 2002 in our department. There were 82 patients with olfactory groove meningiomas, including 63 women and 19 men with a mean age of 57.8 years (age range, 33-91 yr). Most patients presented with mental disturbance. Tumors were operated through the bifrontal (n = 46), frontolateral (n = 34), and pterional (n = 2) approaches. Total tumor removal (Simpson Grade 1 or 2) was achieved in most cases (91.2% frontolateral, 93.5% bifrontal). Perioperative mortality was 4.9% (four out of 82 patients, all operated through the bifrontal approach). The overall recurrence rate was 4.9%, with four patients requiring surgery. The mean follow-up period was 63.4 months (range, 4-270 mo). CONCLUSION: Olfactory groove meningiomas were removed mainly through two different surgical approaches. Even in large tumors, high rates of total tumor resection could also be achieved with low recurrence rates using the simple and minimally invasive frontolateral approach. In recent years, we have preferred to use the frontolateral approach, which provides quick access to the tumor with less brain exposure while still enabling total tumor removal with a low morbidity rate and no mortality.

Medial sphenoid wing meningiomas: clinical outcome and recurrence rate.

OBJECTIVE: To provide clinical data concerning the visual outcome and recurrence rate of medial sphenoid wing meningiomas in consideration of two different subgroups of this tumor entity. METHODS: Among 256 sphenoid wing meningiomas, there were 108 medial sphenoid wing meningiomas of globoid shape. They were classified into Group 1 (without cavernous sinus involvement) and Group 2 (with cavernous sinus involvement). En plaque meningiomas were excluded from the analysis. The charts of the patients including surgical records, discharge letters, follow-up records, and imaging studies were analyzed retrospectively. RESULTS: There were 39 Group 1 tumors and 69 Group 2 tumors. For microsurgical tumor removal, the frontolateral (15.7%) or the pterional approach (84.3%) was performed. Total resection was achieved in 92.3% of patients with Group 1 tumors and 14.5% of those with Group 2 tumors. Radiological recurrence was observed in 7.7% (Group 1 tumors) and 27.5% (Group 2 tumors). The mean follow-up time was 79.04 months (6.59 yr). Improvement of visual function (or stable visual function) was observed in 56% (44%) of patients with Group 1 tumors, in 30% (60%) with newly diagnosed Group 2 tumors, and 10% (70%) undergoing recurrent surgery for Group 2 tumors. CONCLUSION: Group 1 meningiomas present a more favorable subgroup with fortunate visual outcome. In Group 2 tumors, visual improvement was less favorable and radical removal is limited because of cavernous sinus infiltration, with consequential higher recurrence rates. Patients harboring recurrent Group 2 tumors with deteriorating visual function profit from microsurgery because vision can be preserved on the same preoperative level in the majority.

Tuberculum sellae meningiomas: clinical outcome considering different surgical approaches.

OBJECTIVE: Tuberculum sellae meningiomas present a special challenge because of their proximity to arteries of the anterior circulation, anterior visual pathways, and the hypothalamus. The authors report on the clinical outcome after surgical treatment of tuberculum sellae meningiomas in our neurosurgical department. METHODS: A retrospective study was conducted analyzing the charts of the patients, including surgical records, discharge letters, histological records, follow-up records, and imaging studies. Patients with associated neurofibromatosis Type 2 were excluded from the study. RESULTS: One thousand eight hundred meningiomas were operated on between 1978 and 2002. Seventy-two of these patients had tuberculum sellae meningiomas; four had undergone previous surgical procedures in outside hospitals. Fifty-five patients were women; 17 were men. Their mean age was 54.3 years (range, 30-86 yr). All patients had visual disturbances at presentation. Tumors were operated through the bifrontal approach (n = 21, from 1978 through 1995), the pterional/frontotemporal approach (n = 21, from 1982 through 2002), and the frontolateral approach (n = 30, from 1984 through 2002). Total tumor removal was achieved in most patients (Simpson 1 + 2, 91.7%). The perioperative mortality rate was 2.8% (two out of 72 patients). Immediate postoperative improvement of visual disturbance was observed in 65% of patients. Visual improvement was dependent on the duration of preoperative visual symptoms, but not on preoperative visual acuity or tumor size. The visual improvement rate was significantly better in patients who underwent frontolateral tumor resection (77.8%) compared with those who underwent bifrontal craniotomy (46.2%). The overall recurrence rate was 2.8% (two out of 72 patients). The mean follow-up time for all patients was 4 to 238 months (mean, 45.3 mo [3.8 yr]). CONCLUSION: From 1978 through 2002, tuberculum sellae meningiomas were removed microsurgically using three different surgical approaches. Considering the operative morbidity and mortality, the frontolateral and pterional approach provided remarkable improvement compared with the bifrontal approach. These approaches allowed quick access to the tumor and were minimally invasive with less brain exposure, but still engendered high rates of total tumor removal. By comparison, the frontolateral approach provided the best results concerning visual outcome while representing the least invasive surgical approach.

Facial and cochlear nerve function after surgery of cerebellopontine angle meningiomas.

OBJECTIVE: Meningiomas of the cerebellopontine angle (CPA) share a common location, but their site of dural origin and their relationship to surrounding neurovascular structures of the CPA are variable. The clinical presentation and outcome after surgical resection are different because of the diversity of this tumor entity. We report on a series of 421 patients with CPA meningiomas, with special emphasis on the analysis of the preoperative and postoperative facial and cochlear nerve function in relation to the site of dural attachment and main tumor location in the CPA cistern. METHODS: Among 421 patients, the charts of 347 patients with complete clinical data, including the history and audiograms, imaging studies, surgical records, discharge letters, histological records, and follow-up records, were reviewed retrospectively. Data about preoperative and postoperative facial nerve function were available in 334 patients, and audiometric analysis was conducted in 333 patients. Patients with neurofibromatosis Type 2 were excluded from the study. RESULTS: There were 270 women and 77 men, with a mean age of 53.4 years (range, 17.6-84 yr). Among these patients, 32.9% of the tumors originated at the petrous ridge anterior to the inner auditory canal (IAC) (Group 1), 22.2% showed involvement of the IAC (Group 2), 20.2% were located superior to the IAC (Group 3), 11.8% were inferior to the IAC (Group 4), and 12.9% were posterior to the IAC, originating between the IAC and the sigmoid sinus (Group 5). Patients presented with disturbance of Cranial Nerves V-VIII, the lower cranial nerves, and ataxia, depending on the main tumor location. Tumor resection was performed through a suboccipital-retrosigmoidal approach in the semisitting position in 95% of the patients. A combined supratentorial-infratentorial presigmoidal approach was performed in 5%. Total tumor removal (Simpson Grade 1 and 2) was achieved in 85.9% and subtotal removal in 14.1%. The best initial postoperative facial and auditory nerve function was observed in tumors belonging to Groups 3 and 5. Recovery from preoperative deafness was observed in 1.8% of patients. On long-term follow-up, good facial nerve function (House-Brackmann Grade 1 or 2) was observed in 88.9% of patients. Hearing preservation among patients with preoperative functional hearing was documented in 90.8% on long-term follow-up. CONCLUSION: Although the outcome of facial and cochlear nerve function is different in CPA meningiomas, depending on the topographic classification of these tumors, preservation of the cochlear nerve is possible in every tumor group and should be attempted in every patient with CPA meningioma. It has to be kept in mind that recovery of hearing was also observed in patients with preoperative profound hearing deficits.