Abstract

Objective: To evaluate the validity of nerve root sedimentation sign in diagnosis of central lumbar canal spinal stenosis.
Methodology: This is a cross sectional analytic study of 711 patient’s magnetic resonance image (MRI) examination, from 1st of April 2019 until 1st of December 2020 for patients complaining from low back pain with or without sciatica. The patients were divided in three groups according to lumbosacral spine MRI findings: Group I individuals with normal MRI, Group II with lumbar disc prolapse and Group III with lumbar canal stenosis. We measured the spinal canal and dural sac diameter at each level from first lumbar (L1) to fifth lumbar (L5) vertebrae. We looked for nerve root sedimentation sign above and below these levels.
Results: Positive nerve root sedimentation sign was seen in 15.2 % of normal MRI group, 50.42% of disc prolapse group and in 86.4% of lumbar canal stenosis group. The sensitivity and specificity of nerve root sedimentation sign for the diagnosis of lumbar canal stenosis were 86.4% and 84.74, respectively.
Conclusion: The nerve root sedimentation sign is sensitive but not specific for diagnosis of lumbar canal stenosis and can be used as added tool to clinical examination for diagnosis of lumbar canal stenosis.

Key words: Nerve root sedimentation sign, Lumbar canal stenosis, Magnetic resonance image.