[Lumbar canal stenosis with overactive bladder presenting urinary incontinence developed by walking: a case report]

A 74-year-old male complained of lower back pain, paresthesia of the bilateral feet and urinary incontinence. Urinary incontinence manifested at rest and worsened with walking. He had a history of surgery for prostatic cancer. Lumbar magnetic resonance imaging (MRI) demonstrated lumbar canal stenosis at the L4/5 level. The investigations including a cystometrogram manifested an overactive bladder caused by lumbar canal stenosis. His clinical symptoms were unresponsive to conservative treatment and posterior decompression at the L4/5 level was performed surgically to treat lumbar canal stenosis. Postoperatively, his symptoms were relieved. Overactive bladder presenting urinary incontinence that deteriorates with walking due to lumbar canal stenosis is suspected of being caused by circulatory disturbance of the cauda equine or conus medullaris. Emergency treatment including surgery is required for urinary retention in patients with lumbar canal stenosis; however, some degree of urinary disturbance may persist even after prompt and adequate surgery. Overactive bladder such as the present case should be considered as a possible symptom of lumbar canal stenosis, and surgical treatment for lumbar canal stenosis may be considered in the 'overactive bladder' stage before urinary retention begins, if the patient does not respond to conservative treatment.