SURGICAL RESULTS OF 100 INTRAMEDULLARY TUMORS IN RELATION TO ACCOMPANYING SYRINGOMYELIA

DURING THE PERIOD from 1977 to August 1992, 100 intramedullary tumors in 94 patients were operated on in the Department of Neurosurgery at t he Nordstadt Hospital in Hannover, Germany. Of these, 45% presented wi th associated syringes. A syrinx was more likely to be found above (49 %) than below (11%) the tumor level. In 40%, a syrinx could be identif ied above and below the tumor level. Ependymomas and hemangioblastomas were the most common tumor types to be associated with syringes. Astr ocytomas tended to demonstrate syringes less often. Regardless of hist ology, the higher the spinal level, the more likely a syrinx was encou ntered. In general, the presence of an associated syrinx favored the r esectability of the tumor, because it indicated a displacing rather th an an infiltrating tumor. Patients with syringomyelia tended to recove r from surgery sooner. However, surgical results and long-term prognos is were not influenced significantly by an associated syrinx. The most important factor determining long-term outcome was the preoperative l evel of neurological function. We propose that factors independent of the tumor, disturbances of cerebrospinal fluid and extracellular fluid flow in particular, have major roles in the pathogenesis of syrinx fo rmation associated with intramedullary tumors.