Unilateral Foot Drop as the Only Manifestation of Cauda Equina Syndrome: A Case Report and Literature Review

Cauda Equina Syndrome (CES) is a rare but serious neurological emergency resulting from compression of the lumbosacral nerve roots within the spinal canal. It typically presents with bilateral lower limb weakness, saddle anesthesia, and bladder or bowel dysfunction. However, atypical or incomplete clinical presentations may occur and can pose significant diagnostic challenges for clinicians. We report the case of a 32-year-old male who presented with acute unilateral right-sided foot drop as the only neurological manifestation. Magnetic Resonance Imaging (MRI) of the lumbar spine revealed a large lumbar intervertebral disc herniation at the fourth to fifth lumbar vertebral level (L4 - L5) causing compression of the right-sided cauda equina nerve roots. Emergent decompressive laminectomy was performed within 12 hours of diagnosis. The patient underwent postoperative rehabilitation and achieved full motor recovery at one-month follow-up without sensory or autonomic deficits. This case highlights that isolated foot drop may represent an early or incomplete form of CES. Early recognition, prompt imaging, and urgent surgical decompression are crucial to optimize neurological outcomes and prevent progression to irreversible deficits.