1298. Development of a Posterior Fossa Tumor Neurological Grading Scale

Authors: Paige Lundy, MD; Paul Grabb, MD (Kansas City, KS)

Introduction: Many scales (e.g. Rankin, Karnofsky, Glasgow) have been utilized to classify functional or neurological status in relation to head injury, stroke, and brain tumors. These instruments allow clinical findings to be assigned a number that portrays a functional or neurological status primarily related to these adult conditions. These scales do not serve as an adequate descriptor for the most common pediatric neuro-oncological condition of posterior fossa tumors (PFT). In pediatric oncology data bases, measurement tools are lacking to track neurological status related to surgical intervention. Existing instruments account poorly for neurological deficits caused either by the PFT or the surgical interventions in children. We have developed a simple methodology to classify the neurological status in children with PFT. Methods: A Posterior Fossa Tumor Neurological Grade (PFTNG) ranging from 0-5 (5=normal) was developed based on neurological deficits (dysmetria, ataxia, eye and facial motion, lower cranial nerve function) seen in children with PFT at presentation and postoperatively. PFTNGs retrospectively were assigned preoperatively and postoperatively to children (n=47) who underwent surgical resection over three years. Ten children were graded independently by both neurosurgical staff and residents and compared for inter-observer correlation. Grades were also stratified by histopathology. Results: Inter-observer correlation was good. Post-operative correlation in particular was 100%. On average the PFTNG decreased by 1.26 points after surgery. Histopathology did not correlate with presenting or changes in PFTNG. Conclusion: The PFTNG provides a reliable easily applied methodology to describe pertinent neurological findings in children with posterior fossa tumors that is lacking in current data bases. This parameter allows neurological status and surgical morbidity, and adverse treatment effect, to be included in pediatric oncological data bases.