Atypical variant of Baastrup's disease with lumbar stenosis and cauda equina syndrome

Classical Baastrup's disease is a degenerative disorder of the lumbar spine characterized by the approximation of adjacent spinous processes due to excessive lordosis. This results in edema, sclerosis, cyst, bursitis, and midline epidural fibrosis and is often overlooked as a cause of low back pain. Here, we report a patient with atypical Baastrup's disease and lumbar spinal stenosis who presented with a cauda equina syndrome.

A 67-year-old male presented with low back pain of 1 year's duration. This exacerbated over the past 3 weeks, becoming associated with the left lower limb numbness/weakness and bladder dysfunction. The lumbar magnetic resonance (MR) showed atypical Baastrup's disease characterized by multiple ill-defined areas of contrast enhancement in the paraspinal region in conjunction with lumbar canal stenosis. The patient underwent lumbar decompression and exhibited improvement in his neurological deficits postoperatively.

This case highlights the atypical MR features of lumbar Baastrup's disease in conjunction with stenosis. Atypical Baastrup's disease should be differentiated from classical Baastrup's disease or other infectious pathologies (e.g., Pott's disease of the spine) and appropriately treated with timely spinal decompression.