Magnetic resonance imaging predictors of outcome after surgical intervention for cervical spondylotic myelopathy

Background: Cervical spondylotic myelopathy (CSM) is a commonly seen spinal cord disease. There are no well-defined indications and optimal timing for surgical intervention. Therefore, defining predictors for outcome after surgical intervention will have great advantage in taking decisions for interventions.Methods: A consecutive series of all patients having signs and symptoms of cervical spondylotic myelopathy admitted to Department of Neurosurgery, Medical College, Thiruvananthapuram who underwent decompressive surgery with or without stabilization in one year were studied. Pre-operative magnetic resonance imaging (MRI) findings were correlated with post-operative surgical outcomes (Nurick grade) after 3 months of follow up. The pattern of spinal cord signal intensity was classified as: group A (MRI N/N) - no SI T1WI or T2WI, group B (MRI N/Hi) - no SI T1WI and high SI on T2WI and, group C (MRI Lo/Hi) - low SI T1WI and high SI on T2WI. CSM clinical outcomes were evaluated using Nurick grading system, which was used pre- and post-operatively (pre op and post op).Results: Post operatively improvement was seen in 75% of group A and 61.35 % of group B patients, but among group C only 25% patient improved according to Nurick grading pre op and post op.Conclusions: Patients with high intramedullary signal intensity on T2WI may experience a good surgical outcome. A less favorable surgical outcome is predicted by the presence of low intramedullary signal on T1WI.