Comparison of the Oswestry Disability Index and Magnetic Resonance Imaging Findings in Lumbar Canal Stenosis: An Observational Study

STUDY DESIGN: Cross-sectional study. PURPOSE: The aim of the study was to determine relationship between the degrees of radiologically demonstrated anatomical lumbar canal stenosis using magnetic resonance imaging (MRI) and its correlation with the patient's disability level, using the Oswestry Disability Index (ODI). OVERVIEW OF LITERATURE: The relationship between the imaging studies and clinical symptoms has been uncertain in patients suffering from symptomatic lumbar canal stenosis. There is a limited number of studies which correlates the degree of stenosis with simple reproducible scoring methods. METHODS: Fifty patients were selected from 350 patients who fulfilled the inclusion criteria. The patients answered the national-language translated form of ODI. The ratio of disability was interpreted, and the patients were grouped accordingly. They were subjected to MRI; and the anteroposterior diameters of the lumbar intervertebral disc spaces and the thecal sac cross sectional area were measured. Comparison was performed between the subdivisions of the degree of lumbar canal stenosis, based on the following: anteroposterior diameter (three groups: normal, relative stenosis and absolute stenosis); subdivisions of the degree of central canal stenosis, based on the thecal sac cross-sectional area, measured on axial views (three groups: normal, moderately stenotic and severely stenotic); and the ODI outcome, which was also presented in 20 percentiles. RESULTS: No significant correlation was established between the radiologically depicted anatomical lumbar stenosis and the Oswestry Disability scores. CONCLUSIONS: Magnetic resonance imaging alone should not be considered in isolation when assessing and treating patients diagnosed with lumbar canal stenosis.

Cortical Blindness Following Spinal Surgery: Very Rare Cause of Perioperative Vision Loss

A 38-year-old man was operated with posterior spinal decompression and pedicle screw instrumentation for his L2 fracture with incomplete neurological deficit. In the recovery, he complained of blindness in both eyes after twelve hours. Computed tomographic scan and magnetic resonance angiography revealed bilateral occipital lobe infarcts. He remained permanently blind even after three years follow-up. Though rare, perioperative vision loss is a potential complication following spine surgery in prone position. We report a rare occurrence of cortical blindness following lumbar spine surgery.