Snapshot A 56-year-old man presents to his primary care physician for back pain. His back pain is worsened when he is walking up a hill or remaining in the standing position for long periods of time. His symptoms improve with sitting or leaning forward. He denies any bowel or bladder incontinence but occasionally experiences lower extremity numbness. An MRI of the lumbar spine demonstrates central canal narrowing. Introduction Definition narrowing of the central canal, lateral recess, or neural foramen Etiology Spondylosis or degenerative arthritis (most common) Progressive disc degeneration leads to disc protrusion and/or disc height loss Ligamentum flavum hypertrophy Facet joint arthropathy and osteophyte Congenital (e.g., achondroplasia) Pathogenesis mechanical compression of the lumbar spinal cord can result in nerve ischemia in the extended position, there is further narrowing of the lumbar spine, resulting in neurogenic claudication neurogenic claudication may also result from increased metabolic demand from the already compressed lumbar spine Presentation Symptoms neurogenic claudication (hallmark) pain with walking or maintaining an erect position that improves with leaning forward or sitting lower extremitiy weakness lower extremity sensory changes Physical exam neurological exam is typically normal Imaging MRI lumbar spine indication imaging study of choice in patients with findings concerning for lumbar spinal stenosis visualizes the bony anatomy, soft tissue structures, and neural structures findings central canal stenosis lateral recess or foramen compression ligamentum flavum hypertrophy Differential Peripheral vascular disease distinguishing factors typically experience tightness and cramping claudication does not improve with flexion of the spine (e.g., walking with a shopping cart) back pain improves with lying flat immediately in lumbar spinal stenosis, the pain still presists when lying flat for a few minutes Peripheral neuropathy distinguishing factors sensory changes will be present whether with or without activity Lumbar disc herniation Treatment Medical analgesics indication used in pain management type of analgesic used depends on side-effect profile (e.g., no NSAIDs in patients with heart disease) medications acetaminophen nonsteroidal antiinflammatory drugs (NSAIDs) Operative surgical decompression indication in patients who fail conservative management Complications Cauda equina syndrome Neurogenic bladder Neuropathic arthropathy