Neurosurgery for Cauda Equina Syndrome

Updated: Nov 03, 2021
Author: Nazer H Qureshi, MD; Chief Editor: Brian H Kopell, MD 



In the United States, approximately 1-3% of patients who undergo spinal surgery for cauda equina (CE) syndrome (CES) have either atraumatic or traumatic types of CES.[1] CES has no predilection for any race or either sex. Although CES can occur at any age, it is most often seen in adults in whom the spinal canal may already be compromised and stenosed.

The prognosis for CES improves if a definitive cause (eg, lumbar disk herniation[2] ) is identified and management is instituted early.[3] Surgical treatment may be necessary for decompression or tumor removal, especially if the patient presents with acute onset of symptoms. Surgical decompression should be performed if the patient is medically stable and able to undergo the procedure.[4, 5, 6, 7]  Surgery has been demonstrated to be safe in pregnant patients; however, obstetric support is advisable in case complications occur to the fetus.[8]

In acute compression of the conus medullaris or CE, surgical decompression as soon as possible becomes mandatory. In a more chronic presentation with less severe symptoms, decompression could be performed when medically feasible and should be delayed to optimize the patient's medical condition; with this precaution, decompression is less likely to lead to irreversible neurologic damage.

Technical Considerations


Images depicting CES can be seen below.

Sagittal MRI of a patient with cauda equina syndro Sagittal MRI of a patient with cauda equina syndrome secondary to a large lumbar disk herniation.
Illustration demonstrating the relevant anatomy of Illustration demonstrating the relevant anatomy of the cauda equina region.
Illustration demonstrating an example of cauda equ Illustration demonstrating an example of cauda equina syndrome secondary to a spinal neoplasm.

Go to Cauda Equina and Conus Medullaris Syndromes and Tumors of the Conus and Cauda Equina for complete information on these topics.


A systematic review and meta-analysis of 22 studies by Kumar et al evaluated long-term outcomes in 852 patients with CES from lumbar disk herniation who underwent surgical decompression (492 males, 360 females; mean age, 44.6 ± 5.5 years).[2] On follow-up (mean, 39.2 months; minimum, 12 months), persistent bladder dysfunction was oberved in 43.3%, persistent bowel dysfunction in 31.1%, sensory deficit in 53.3%, motor weakness in 38.4%, and sexual dysfunction in 40.1%. Decompression within 48 hours of symptom onset of symptoms was associated with a better outcome with regard to bladder function than later decompression (24.6% rate of persistent dysfunction vs 50.3%).

In a study of long-term core outcomes in 61 patients who underwent surgical decompression for acute CES secondary to massive lumbar disk prolapse (mean age at presentation, 43 years; mean follow-up, 58.2 months, Barker et al reported bladder dysfunction in 33% of patients (with 10% requiring a urinary catheter), bowel dysfunction in 38%, sexual dysfunction in 53% (with 47% reporting genital numbness), and significant back pain in 67% (with 44% requiring further investigation and 10% further intervention for management of lower back pain).[9]  Half of the patients reported moderate or worse depression, and 40% of working-age patients were no longer able to work because of CES.



Surgical Treatment of Cauda Equina Syndrome

The role of surgery for cauda equina syndrome (CES) is to relieve pressure from the nerves in the cauda equina (CE) region and to remove the offending elements. Surgical treatment may include laminectomy and instrumentation/fusion for stabilization or diskectomy.[10, 11] After spinal surgery, internal stabilization with fixation devices may be needed in the same operative setting or at a later date.

Routine preoperative care is recommended. The goal of preoperative care is to make sure that the patient gets to the operating room in the recommended time frame to maximize chances of a complete recovery.

The intraoperative use of somatosensory and motor-evoked potentials (SSEPs) may be helpful in monitoring the patient.

Timing of surgery

The timing of surgical decompression is controversial, with immediate, early, and late surgical decompression showing varying results.[12, 13] In CES with acute compression, the dictum was to operate on an emergency basis within 6 hours,[14]  but several authors disputed the clarity of the data supporting this practice.[4, 5, 6, 1, 15, 16]

Hussain et al reported no differences at a 16-month follow-up among patients who underwent surgery within 5 hours and those who underwent surgery within 24 hours.[17] Furthermore, a small prospective study reported no difference in outcome at 3 and 12 months after surgical decompression performed at less than 24 hours, at 24-48 hours, and within more than 48 hours after the onset of CES.[18]

One study reported significant differences in outcome when surgery was delayed for more than 24 hours after bladder paralysis.[19] In addition, a significantly worse outcome was observed in incontinent patients; however, duration of symptoms did not influence the outcome.[18] Thongtrangan et al, in a study of trauma-induced cases of CES, recommended that surgery be performed within 48 hours of syndrome onset and reported that bladder function, if expected to recover, would return within 3 months.[20]

Another study determined that decompressive surgery within 24 hours after onset of autonomic symptoms in incomplete CES reduced bladder dysfunction at initial follow-up after surgery; however, no difference in outcome was observed in CES with retention regarding timing of operation.[21]

The authors found that in 36 cases with incomplete CES of less than 24 hours, normal bladder function was seen at follow-up in all except four patients.[21] In 64 cases of incomplete CES of less than 48 hours, normal bladder function was seen at follow-up in all except 10 patients, but in 75 cases with incomplete CES of more than 48 hours, 42 (56%) had bladder dysfunction. For the 35 patients with CES with retention, operating within 24, 48, or 72 hours made no obvious difference to bladder outcome.

A study of the outcome of surgery for intradural CE and conus medullaris tumors reported overall neurologic improvement in 62% of patients.[22] The reversibility of preoperative symptoms was found to be related to the interval between symptom onset and the time of surgery and to the presence of preoperative neurologic deficits. Ependymoma and carcinoma metastases were associated with a higher morbidity. The findings suggested that early surgery is advisable because more than 94% of patients maintain at least their preoperative status and more than 60% improve during follow-up.

In a study of 14 patients with CES who presented with low back pain, sciatica, and impaired sphincteric disturbance, surgery resulted in relief of back or leg pain and sensory improvement in all patients; full return of urination and defecation in 12; and improvement in lower-extremity strength in nine.[23] The surgical procedures were all performed 1-3 months after the onset of sphincteric disturbance.

A study of 33 patients with CES from lumbar disk herniation found that operation within 24 hours led to significant improvements in motor strength.[24]

A large study (N = 20,924) that evaluated the timing of surgery for CES between 2000 and 2014 confirmed that performance of decompression within 0 or 1 day after patient admission is associated with improved inpatient outcomes, including lower complication and mortality rates.[25]

Postoperative Care

Routine postoperative care is necessary for all patients. The recovery time depends on the duration and the extent of symptoms of CES and a multitude of other factors, including the etiology.

Postoperative physical and occupational therapies are often beneficial to the patient’s progress. Some patients may require inpatient or outpatient rehabilitation; therefore, a physical medicine and rehabilitation consultation should be considered early in the course of management.


If therapy is delayed, potential problems include residual weakness, incontinence, impotence, and sensory abnormalities. These problems may persist even with prompt decompression. Follow-up depends on the needs of the patient and recovery potential.

Ever-present adverse events of any spinal surgery include paralysis, along with urinary bladder, bowel, and sexual dysfunction. The specific risks of surgical complications for widely varied procedures and equally varied etiologies are beyond the scope of this article.