Clinical Features And Treatment Of Foramen Magnum Meningiomas

Objective:To explore the clinical features, diagnosis and treatment for the patients with foramen magnum meningiomas.Methods:Clinical data of 13 patients with foramen magnum meningioma who were diagnosed and hospitalized in Qilu Hospital from July 1997 to February 2009 were retrospectively analyzed. The characteristics of epidemiology, clinical manifestations, radiological features, diagnosis and differential diagnosis, microsurgical treatment, pathological types, postoperative complications and management, and follow-up outcome are discussed. The series included 6 males and 7 females. The patients ranged in age from 10 years to 64 years (mean age,44.8 years). The average duration from presenting symptoms to diagnosis was about 20 months (range,20 days-8 years). The common manifestations of foramen magnum meningioma were headache and cervico-occipital pain in 9 patients, sensory disturbance in 7, gait ataxia in 3, bucking and dysphagia in 6. All patients were diagnosed preoperatively by magnetic resonance imaging (MRI) and (or) computed tomography (CT), one patient accepted magnetic resonance angiography (MRA), and one was inspected by digital subtraction angiography (DSA). Based on the axial MRI films, meningiomas were attached to ventrolateral to the neural axis in 5 patients, ventral in 4, dorsal in 2, and dorsolateral in 2. Ten of the patients accepted microsurgical treatment. The choice of surgical approach was made according to tumor location. Suboccipital midline approach was performed in 4 patients with dorsal or dorsolateral tumor, and six patients with ventral or ventrolateral tumor used far lateral approach. A partial condylar resection was performed in 2 patients to enhance the exposure, vertebral artery was shifted in 3, and a fusion procedure was accomplished in 1. After surgery, resection extent was evaluated with Simpson grade, and prognosis was assessed with Karnofsky Performance Scale (KPS).Results:Total resection (Simpson Gradeâ… andâ…¡) was achieved in 6 cases, subtotal resection in 1, and great partial resection in 3. Pathological examination revealed meningiomas which include 2 meningothelial meningiomas and 1 transitional meningioma. In immediate postoperative period, all patients obtained improvement in symptoms. No surgical mortality occurred in this series. Postoperatively, one patient presented with hoarse voice, one suffered from deterioration of hoarse voice, one fluidified subcutaneouly, three presented with infection in operative field, and one experienced pulmonary infection. All these complications improved obviously or vanished before discharged. Follow-up data were obtained in 5 patients. The mean duration of follow-up was 36 months (range, 2 months -6 years). No tumor recurrence was observed in MRI films in all patients. They were evaluated with Karnofsky Performance Scale:100 scores in one patient, 90 in three, and 80 in one.Conclusions:â‘ The incidence of foramen magnum meningiomas is rarely low. The clinical manifestation of foramen magnum meningioma is insidious, of which headache and cervico-occipital pain are common.â‘¡The diagnosis for foramen magnum meningiomas depends on imageology. Since MRI can offer information of precise three-dimensional location and adjacent structures, it is the optimal method of preoperative diagnosis.â‘¢Microsurgery is the primary choice for most patients and the outcome of radical surgery is satisfactory. Proper surgical approaches and microsurgical techniques are guarantee of a successful operation, and the biological features of the tumor are the determinative factor of removal extent.