Spinal and Paraspinal Plexiform Neurofibromas in Patients with Neurofibromatosis Type 1: A Novel Scoring System for Radiological-Clinical Correlation.

BACKGROUND AND
PURPOSE: Neurofibromatosis type 1 is a common tumor predisposition syndrome. The aim of this study was to characterize the radiologic presentation of patients with neurofibromatosis type 1 with widespread spinal disease and to correlate it to clinical presentation and outcome.
MATERIALS AND METHODS: We conducted a historical cohort study of adult patients with neurofibromatosis type 1 with spinal involvement. Longitudinal clinical evaluation included pain and neurologic deficits. Radiologically, spinal involvement was classified according to a novel classification system, and a radiologic risk score was calculated.
RESULTS: Two hundred fifty-seven adult patients with neurofibromatosis type 1 are followed in our center. Thirty-four of these patients qualified for inclusion in this study. Three independent factors were found to be associated with increased risk for neurologic deficit: 1) bilateral tumors at the same level in the cervical region that approximated each other, 2) paraspinal tumors at the lumbar region, and 3) intradural lesions. On the basis of these factors, we calculated a combined risk score for neurologic deficits for each patient. We found a clear correlation between patient status and the calculated radiologic risk score. Patients with neurologic deficits were found to have a higher risk score (9 ± 8.3) than patients without neurologic deficits (2.5 ± 2.9, P < .05). Patients who progressed during the follow-up period had significantly higher scores at presentation than patients with stable conditions (9.9 ± 8.73 versus 3.9 ± 5.3, respectively; P < .05).
CONCLUSIONS: In this series, neurologic deficit is correlated with tumor burden and subtype. We found no direct correlation with tumor burden and pain. Our novel radiologic classification scoring system may be used to predict increased risk for neurologic morbidity.