Working Diagnosis:
Foot drop secondary to lumbar disc herniation

Treatment:
The patient needed urgent surgical decompression and was admitted the evening the MRI results came in. The patient was treated with urgent microdiscectomy. Surgery revealed there was a large lumbar disc herniation that was displaced dorsally. Once the disc fragments were removed, the nerve was noted to be much more supple. Once all the fragments were removed, there did not appear to be any additional compression. The patient did well after surgery. There were no immediate problems with bowel movements or urinating but still had mild foot drop. He followed-up with rehabilitation physical therapy.

Outcome:
10-days post-op he has returned and has stated his left foot drop has improved some, and he is able to extend his left toe again. He has been doing well with physical therapy and is slowly trying to run again.

Author's Comments:
This case was interesting because a majority of herniated discs are self-limited resolving in a few weeks, however this patient's herniated disc persisted for 3 months and progressively worsened. The main learning point that we wanted to convey is that lumbar disc herniation secondary to increased axial loading on the lower back may lead to potentially devastating injuries that, left untreated, may lead to chronic pain and disrupt sensory and motor innervation to lower extremities, bladder, and bowel. Therefore early identification and treatment are important to regain function and return to daily activities.

Editor's Comments:
This case highlights the sequelae of a lumbar disc herniation, but one must keep cauda equina syndrome in the differential diagnosis as well.
For a diagnosis of CES, one or more of the following must be present: (1) bladder and/or bowel dysfunction, (2) reduced sensation in the saddle area, or (3) sexual dysfunction, with possible neurologic deficit in the lower limb (motor/sensory loss, reflex change).


History should therefore include questions to assess for bladder, bowel, or sexual dysfunction (erections).

Physical examination should evaluate for saddle anesthesia. Reflexes are less important, but there should be a comment on symmetry or lack thereof.

MRI imaging should include an axial view if possible.

References:
Ahn UM, Ahn NU, Buchowski JM, Garrett ES, Sieber AN, Kostuik JP. Cauda equina syndrome secondary to lumbar disc herniation—a meta-analysis of surgical outcomes. Spine. 2000;25(12):1515–1522.
Chang HS, Nakagawa H, Mizuno J. Lumbar herniated disc presenting with cauda equina syndrome. Long term follow-up of 4 cases. Surg Neurol. 2000;53:100–105. doi: 10.1016/S0090-3019(99)00180-9.
Gardner A, Gardner E, Morley T. Cauda equina syndrome: a review of the current clinical and medico-legal position. Eur Spine J. 2011 May;20(5):690-7. doi: 10.1007/s00586-010-1668-3. Epub 2010 Dec 31

Return To The Case Studies List.