The 4S of spinal astrocytoma: specific location, syrinx, spasticity and score on Modified Mccormick Scale (MMS) predict long term outcomes in patients undergoing surgical resection of intramedullary spinal astrocytomas.

Objectives: The aim of this study was to explore the factors that could predict long term clinical outcomes in SA.

Methods: A retrospective study was conducted wherein SA patients undergoing surgical resection with a minimum follow up of 12 months were included in this study. Modified Mccormick Scale (MMS) was utilized to record the neurological status of the patients both preoperatively and at last follow up. Outcomes were assessed as: long term neurological status, that is final MMS grade and neurological deterioration, defined as increase in MMS score as compared to preoperative MMS score. Survival analysis was performed using the kaplan meier curves.

Results: 71 patients were included in this study with mean age of 33.07years. At a mean follow up of 57 months, preoperative MMS was the single independent predictor for moderate-severe neurological deficit (MMS III to V) on multivariate analysis (OR: 30.2, p < 0.001) and had an outstanding AUC of 0.91. Six patients had neurological deterioration at long term follow up. Absence of spasticity (p = 0.028), thoracic-thoracolumbar tumors (p = 0.006), low MMS score (p = 0.01) and hypointense T1 weighted MRI (p = 0.009) were significant predictors of long term neurological deterioration. The median overall survival was 48 months and was significantly higher in low grade tumors (p < 0.001).

Conclusion: The study highlights the efficacy of clinical features as a predictor of long term functional outcomes in SA patients. Role of spasticity as a prognostic factor was explored for the first time in this study.