Recurrence rates and functional outcome after resection of intrinsic intramedullary tumors

Intramedullary tumors account for 2-4% of all CNS neoplasms. Surgical resection is challenging because of aggravated neurological impairment in up to 64% of patients. We analyzed a consecutive series of patients with intramedullary tumors and focused on the extent of resection, functional outcome, and tumor recurrence.

53 patients (23 women and 30 men; mean age 46.3 years) were included who had undergone microsurgical resection for intramedullary spinal tumors. We reviewed the patient records for tumor size, edema, intratumoral hemorrhage, consistency, midline detection, resection method, extent of resection, histopathology, and recurrence. Outcome was measured by the Karnofsky Score (KPI), the McCormick score (MCS), and the Medical Research Council Neurological Performance Score (MRC-NPS).

The most frequent diagnosis was ependymoma (37.7%), lymphoma (13.2%) and astrocytoma (11.3%). The majority of tumors were located in the thoracic spine (62.2%). Gross total resection was achieved in 73.6% and most successful in patients with ependymal histology (p<0.01). Tumor recurrence - observed in 11.3% - was significantly associated with age >65 years, astrocytic histology, higher tumor grades, and higher Ki-67 labeling. At follow-up, MCS and MRC-NPS showed significantly better results than prior to resection (p<0.001), and pain and sensory deficits had improved in 67.9% and 64.2% of patients, respectively. Microsurgical resection improved the neurological status significantly. Pain and sensory deficits showed higher improvement rates than paresis and vegetative dysfunction.

Our data help identify patients at risk of tumor recurrence and classify the course of postoperative neurological performance.