Functional outcome after surgical treatment of intramedullary spinal cord tumors: experience with 78 patients

Objective: To analyze factors with impact on the functional outcome for patients with surgically treated intramedullary spinal cord tumors (IMSCT) and to point out characteristics of the different histological entities. Setting: Neurosurgical Department, University of Essen, Germany. Methods: Between 1990 and 2000, a consecutive series of 78 patients were referred to our institution and underwent surgical treatment. There were 46 (59%) male and 32 (41%) female patients. Mean age was 43.3 years. Functional outcome was analyzed depending on histological features, age, tumor localization and the extension of involved spinal segments. The mean follow-up period was 34.4 months. Operative removal of the IMSCT was performed under standard microsurgical conditions with intraoperative monitoring of somatosensory-evoked potentials (SSEP). Results: The most frequently involved localization was the cervical and cervicothoracic region (55%) followed by the thoracic region (32%) and the medullar conus (13%). The most frequent IMSCTs were neuroepithelial tumors in 44 patients (56.5%) including 32 patients with ependymomas, 15 astrocytomas, and two lesions without further histological classification. Non-neuroepithelial tumors included 10 metastases, nine cavernomas, eight hemangioblastomas, one dermoidal cyst and one enterogenetic cyst. Complete tumor removal was achieved in 65 cases (83.3%) and subtotal resection in nine cases. In four cases a biopsy was performed only. The overall postoperative neurological state was improved or unchanged in 51 patients (65.4%) and worsened in 27 patients (34.6%). A favorable functional outcome was observed in 94.1% of patients with vascular tumors, in 61.3% of patients with low-grade neuroepithelial tumors and in 53.3% of patients with malignant tumors. Conclusions: The strongest predicting factor of functional outcome was the preoperative neurological condition beyond the histological differentiation of the IMSCT. Although there was no outcome difference with respect to the age and tumor extension, thoracically located IMSCTs proved to harbor an increased risk of postoperative surgical morbidity.