Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.The cause is usually a disc herniation in the lower region of the back. Other causes include spinal stenosis, cancer, trauma, epidural abscess, and epidural hematoma. The diagnosis is suspected based on symptoms and confirmed by medical imaging such as MRI or CT scan.CES is generally treated surgically via laminectomy. Sudden onset is regarded as a medical emergency requiring prompt surgical decompression, with delay causing permanent loss of function. Permanent bladder problems, sexual dysfunction or numbness may occur despite surgery. A poor outcome occurs in about 20% of people despite treatment. About 1 in 70,000 people is affected every year. It was first described in 1934. Signs and symptoms
Signs and symptoms of cauda equina syndrome include:
Severe back pain
Saddle anesthesia (see diagram), i.e., anesthesia or paraesthesia involving S3 to S5 dermatomes,: 26  including the perineum, external genitalia and anus; or more descriptively, numbness or "pins-and-needles" sensations of the groin and inner thighs which would contact a saddle when riding a horse. Bladder and bowel dysfunction,: 216  caused by decreased tone of the urinary and anal sphincters. Detrusor weaknesses causing urinary retention and post-void residual incontinence as assessed by bladder scanning the patient after the patient has urinated.
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