Diffuse age-related lumbar mri changes confound diagnosis of single (L5) root lesions



Introduction: L5 radiculopathy has characteristic clinical and electrodiagnostic features including: radicular pain; weakness or denervation of hip abductors, ankle dorsiflexors, and inverters; and pre-ganglionic dorsal foot sensory loss. It is unknown how often patients with this distinctive clinical–electrodiagnostic presentation have isolated L5-root compression on neuroimaging or more widespread, possibly age-related, lumbar neuroforaminal or spinal stenosis. Methods: A study-blinded neuroradiologist quantitated lumbosacral neuroforaminal, lateral recess, and spinal stenosis in 26 consecutive patients with unilateral, clinically and EMG-ascertained L5 monoradiculopathy, and quantitated a global neuroforaminal and spinal stenosis score (SSS). Results: Only 9 patients (35%) had isolated L5-root compression, 14 (54%) had multi-root compression, and 3 (12%) had normal neuroimaging. Increasing age correlated with SSS, and the 9 patients with isolated L5-root compression were significantly younger than patients with multi-root involvement. Conclusions: This study underscores the role of clinical and electrodiagnostic data when interpreting lumbosacral neuroimaging, particularly in older patients. Muscle Nerve 50: 135–137, 2014