Cauda equina syndrome is a neurologic emergency where damage to the lumbosacral plexus leads to loss of lower motor neuron function. Trauma, tumors or abscesses, large lumbar disk herniation, and spinal stenosis are some of the etiologies of this condition.

Onset is typically gradual but can be acute. Signs and symptoms include severe back pain that may radiate into one or both legs, saddle anesthesia, leg weakness or paraplegia, urinary or bowel dysfunction, sexual dysfunction, and gait disturbance. There may be reduced or absent patellar, Achilles, anal, and bulbocavernosus reflexes.

Prognosis depends on severity and duration of compression or damage to the affected nerves.