Approach Considerations
Specific treatment is directed at the primary cause; these are discussed in other articles. The general treatment goals are to minimize the extent of injury and to treat ensuing general complications. [87]
Other medical treatment options are useful in certain patients, depending on the underlying cause of the cauda equina syndrome. Anti-inflammatory agents and steroids can be effective in patients with inflammatory processes, including ankylosing spondylitis.
Patients with cauda equina syndrome secondary to infectious causes should receive appropriate antibiotic therapy. Patients with spinal neoplasms should be evaluated for the suitability of chemotherapy and radiation therapy.
Methylprednisolone should be administered. It treatment must be started within 8 hours of injury. No evidence exists of any benefit if it is started more than 8 hours after injury; on the contrary, late treatment may have detrimental effects.
Administration of ganglioside GM1 sodium salt beginning within 72 hours of injury may be beneficial; the dose is 100 mg IV qd for 18-32 days.
Tirilazad mesylate (a nonglucocorticoid 21-aminosteroid) has been proven to be of benefit in animals and is currently under investigation. It inhibits lipid peroxidation and hydrolysis in the same manner as glucocorticoids.
Caution should be used in all forms of medical management for cauda equina syndrome. Any patient with true cauda equina syndrome with symptoms of saddle anesthesia and/or bilateral lower extremity weakness or loss of bowel or bladder control should undergo no more than 24 hours of initial medical management. If no relief of symptoms is achieved during this period, immediate surgical decompression is necessary to minimize the chances of permanent neurologic injury.
Emergency Department Care
No proven medical treatment exists, and therapy generally is directed at the underlying cause of cauda equina syndrome. For penetrating trauma, steroids have not shown significant benefit.
Surgery is controversial. The timing of decompression is controversial, with immediate, early, and late surgical decompression showing varying results. [15, 88, 89] For mechanical compression of the cauda due to disk herniation, surgical intervention may be indicated.
Practice guidelines for the management of low back pain have been created. [90, 91, 92]
Admit patients to the appropriate service (usually neurology, neurosurgery, or orthopedic surgery) with frequent neurologic checks. Ideally, the admitting physician or service should examine the patient at the time of admission. Patients in whom acute cauda equina syndrome is being considered should not be treated or investigated on an outpatient basis without evaluation by a consultant and/or appropriate imaging.
Rehabilitation
The rehabilitation team, especially the spinal cord injury rehabilitation physician and occupational and physical therapists, should be involved as soon as possible. The team will set goals in the rehabilitation unit toward maintaining and improving endurance, with the ability to be independent in activities of daily living on discharge from the hospital or long-term care facility.
The rehabilitation goals are to maximize the medical, physical, psychological, educational, vocational, and social function of the patient. To maximize medical function, ensure adequate prevention and treatment of possible medical complications already discussed, especially deep venous thrombosis, bladder and bowel problems, and decubitus ulcers
Physical therapy
Perform range of motion and strengthening exercises, sitting balance, transfer training, and tilt table as tolerated (because of tendency to orthostatic hypotension). Tilt table should start at 15 degrees, progressing by 10 degrees every 15 minutes up to about 80 degrees with the necessary precautions.
Other activities include the following:
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Wheelchair propulsion training
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Standing table exercises
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Functional electrical stimulation for increased muscle tone
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Lower extremity orthoses to aid balance and walking
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Ambulation exercises
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Family training and community skills
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A home exercise program
Occupational therapy
Conduct the following:
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Wheelchair training, especially for advanced wheelchair activities
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Transfer training
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Activities of daily living program with assistive devices for dressing, feeding, grooming, bathing, and toileting
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Motor coordination skills training
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Shower program
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Upper extremities training to increase strength for the increased demands of wheelchair propulsion and walking with assistive devices
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Home evaluation
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Family training
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A home exercise program
Orthotic/assistive devices may be needed for functional household ambulation and, if possible, community ambulation. This entails prescribing and training in proper use of knee-ankle-foot orthoses (KAFO) with forearm crutches for support; for lower lesions, KAFOs or AFOs with canes or crutches may be needed. In addition to the above, bathtub bench, transfer boards, pressure-relieving seats, and wheelchairs are devices that may be needed. The patient should be assessed for these needs prior to discharge from the acute rehabilitation setting.
Consultations
Consultations to different specialties are needed for acute care and follow-up care. Neurosurgery/spinal orthopedics consultation should assess the need for urgent surgical spinal decompression. Posterior decompression and stabilization offers at least equivalent neurologic outcomes as nonoperative or anterior approaches and has the additional benefits of surgeon familiarity, shorter hospital stays, earlier rehabilitation, and ease of nursing care. [16]
Plastic surgery may be needed if severe skin breakdowns occur.
For rehabilitation, the initial consultation may prevent possible complications, including contractures, and may offer the patient advice on bladder/bowel management, wound management, and the required physical therapy/occupational therapy and assistive devices; this would include follow-up, involvement of social workers, and vocational rehabilitation experts for home adaptation (needed on discharge).
A dietitian is needed to advise on optimizing the diet to ensure adequate caloric and protein intake. Patients with these syndromes often have an increase in metabolism associated with the healing process.
Long-Term Monitoring
Follow up with the rehabilitation team, including the spinal cord injury rehabilitation physician, physical therapist, and occupational therapist. These professionals are responsible for monitoring community and home integration and following improvements in the patient's strength, coordination, transfer, activities of daily living, and ambulation.
Follow up with a primary care physician to monitor posthospital medications and other laboratory tests.
Patients with any renal or bladder complications and impotence should undergo regular follow-up, because they have an increased tendency for recurrent urinary tract infection and calculi. [19] Yearly cystoscopy is recommended for patients with suprapubic catheters to help detect early bladder malignancies.
Regular follow-up urodynamic studies, renal ultrasound, and general cancer screening should be performed.
Prevention and Treatment of Complications
For deep venous thrombosis/pulmonary embolism, patients should use antiembolic compression stockings and subcutaneous heparin for 3 months as prophylaxis. Low-molecular-weight heparin also has been approved for prophylaxis. Ultrasound of the lower extremities may need to be done as an initial screening test with follow-up later. For neurogenic bladder, patients may require bladder catheterization.
In August 2011, onabotulinumtoxinA was approved by the US Food and Drug Administration for urinary incontinence in patients with neurologic conditions (eg, spinal cord injury, multiple sclerosis) who have overactive bladder. Therapy consists of 30 intradetrusor injections via cystoscopy. Trials have shown patients who received onabotulinumtoxinA had significant reduction in urinary incontinence episodes and improved urodynamics compared with placebo at 12 weeks. [93, 94, 95]
Pressure ulcers may be prevented by eliminating pressure, optimizing wound-healing environment, and debriding if necessary.
For impotence, use of a phosphodiesterase type 5 inhibitor (eg, sildenafil [Viagra]) is becoming popular. Other drugs for erectile dysfunction include yohimbine, papaverine, and alprostadil. Methods to promote coitus and/or ejaculation could also be used; these include implantable penile prostheses or vibrator stimulation.
Patients may require use of stool softener or manual evacuation for fecal incontinence.
Heterotopic ossification (HO) can be confirmed by a triple-phase bone scan with associated elevation in serum levels of alkaline phosphatase and phosphate, especially in the early stage. Treatment includes stretching exercises, disodium etidronate (20 mg/kg qd x 2 wk, then 10 mg/kg for as long as 12 wk), radiation, and surgical excision. Surgery is done only when the HO has matured or stabilized, which is evident by stable plain x-ray, normal alkaline phosphatase level, and decline in triple-phase bone scan activity.
Pain should be treated appropriately based on its origin; treatment may include narcotics in the acute setting and tricyclic antidepressants later. Patient education, biofeedback, and relaxation techniques may also be used.
Nerve root ischemia is partially responsible for the pain and decreased motor strength associated with cauda equina syndrome. As a result, vasodilatory treatment can be useful in some patients. Mean arterial blood pressure should be maintained above 90 mm Hg to maximize blood flow to the spinal cord and nerve roots.
Treatment with lipoprostaglandin E1 and its derivatives has been reported to be effective in increasing blood flow to the cauda equina region and reducing symptoms of pain and motor weakness. This treatment option should be reserved for patients with modest spinal stenosis with neurogenic claudication. No benefit has been reported in patients with more severe symptoms or patients with radicular symptoms.
Use of orthoses is advised to prevent contractures. Use of antispasticity medications also is encouraged. Other medications include dantrolene, diazepam, clonidine, and tizanidine. Nerve blocks also could be done to relieve spasticity; appropriate agents include phenol, botulinum toxin, or local anesthetics.
Surgical Decompression
In acute compression of the conus medullaris or cauda equina, surgical decompression as soon as possible becomes mandatory. The goal is to relieve the pressure on the nerves of the cauda equina by removing the compressing agent and increasing the space in the spinal canal. Traditionally, cauda equina syndrome has been considered a surgical emergency, with surgical decompression considered necessary within 48 hours after the onset of symptoms, and preferably performed within 6 h of injury. [61, 96, 97, 98]
For patients in whom a herniated disk is the cause of cauda equina syndrome, a laminotomy or laminectomy to allow for decompression of the canal is recommended, followed by gentle retraction and discectomy.
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 neurological damage.
Surgical treatment may be necessary for decompression or tumor removal, especially if the patient presents with acute onset of symptoms. Surgical treatment may include laminectomy and instrumentation/fusion for stabilization or discectomy. Other surgical care may entail wound care (eg, debridement, skin graft, and skin flap/myocutaneous flap).
Many clinical and experimental reports have presented data on the functional outcome based on the timing of surgical decompression. [4] Several investigators have reported no significant differences in the degree of functional recovery as a function of the timing of surgical decompression. [96, 97, 99] Even with these findings, however, most investigators recommend surgical decompression as soon as possible after the onset of symptoms to offer the greatest chance of complete neurologic recovery.
On discharge from the surgical ward, patients often are transferred to an acute rehabilitation unit, from which they may be discharged, transferred to a subacute unit, or transferred to long-term care, depending on the level of long-term disability.
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Muscle groups, surface anatomy, peripheral sensory innervation, and dermatomes of the anterior lower limb. This image should be correlated with Tables 1 and 2 in the text. Image courtesy of Nicholas Y. Lorenzo, MD.
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Muscle groups, surface anatomy, peripheral sensory innervation, and dermatomes of the posterior lower limb. This image should be correlated with Tables 1 and 2 in the text. Image courtesy of Nicholas Y. Lorenzo, MD.
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Conus/epiconus infarction in the setting of sickle cell crisis. Image courtesy of Matthew J. Baker, MD.
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Conus/epiconus infarction in the setting of sickle cell crisis in the same patient shown in the above image. Image courtesy of Matthew J. Baker, MD.
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Conus/epiconus infarction in the setting of sickle cell crisis in the same patient shown in the images above. Image courtesy of Matthew J. Baker, MD.
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Illustration demonstrating the relevant anatomy of the cauda equina region.
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Illustration demonstrating an example of cauda equina syndrome secondary to a spinal neoplasm.
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Sagittal MRI of a patient with cauda equina syndrome secondary to a large lumbar disk herniation.
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Epidural abscess with effacement of thecal sac in a 56-year-old man.
Tables
|
Conus Medullaris Syndrome |
Cauda Equina Syndrome |
Presentation |
Sudden and bilateral |
Gradual and unilateral |
Reflexes |
Knee jerks preserved but ankle jerks affected |
Both ankle and knee jerks affected |
Radicular pain |
Less severe |
More severe |
Low back pain |
More |
Less |
Sensory symptoms and signs |
Numbness tends to be more localized to perianal area; symmetrical and bilateral; sensory dissociation occurs |
Numbness tends to be more localized to saddle area; asymmetrical, may be unilateral; no sensory dissociation; loss of sensation in specific dermatomes in lower extremities with numbness and paresthesia; possible numbness in pubic area, including glans penis or clitoris |
Motor strength |
Typically symmetric, hyperreflexic distal paresis of lower limbs that is less marked; fasciculations may be present |
Asymmetric areflexic paraplegia that is more marked; fasciculations rare; atrophy more common |
Impotence |
Frequent |
Less frequent; erectile dysfunction that includes inability to have erection, inability to maintain erection, lack of sensation in pubic area (including glans penis or clitoris), and inability to ejaculate |
Sphincter dysfunction |
Urinary retention and atonic anal sphincter cause overflow urinary incontinence and fecal incontinence; tend to present early in course of disease |
Urinary retention; tends to present late in course of disease |
Nerve Root |
Pain |
Sensory Deficit |
Motor Deficit |
Reflex Deficit |
L2 |
Anterior medial thigh |
Upper thigh |
Slight quadriceps weakness; hip flexion; thigh adduction |
Slightly diminished suprapatellar |
L3 |
Anterior lateral thigh |
Lower thigh |
Quadriceps weakness; knee extension; thigh adduction |
Patellar or suprapatellar |
L4 |
Posterolateral thigh, anterior tibia |
Medial leg |
Knee and foot extension |
Patellar |
L5 |
Dorsum of foot |
Dorsum of foot |
Dorsiflexion of foot and toes |
Hamstrings |
S1-2 |
Lateral foot |
Lateral foot |
Plantar flexion of foot and toes |
Achilles |
S3-5 |
Perineum |
Saddle |
Sphincters |
Bulbocavernosus; anal |
Muscle |
Nerve |
Root |
Iliopsoas |
Femoral |
L2, 3, 4 |
Adductor longus |
Obturator |
L2, 3, 4 |
Gracilis |
Obturator |
L2, 3, 4 |
Quadriceps femoris |
Femoral |
L2, 3, 4 |
Anterior tibial |
Deep peroneal |
L4, 5 |
Extensor hallucis longus |
Deep peroneal |
L4, 5 |
Extensor digitorum longus |
Deep peroneal |
L4,5 |
Extensor digitorum brevis |
Deep peroneal |
L4, 5, S1 |
Peroneus longus |
Superficial peroneal |
L5, S1 |
Internal hamstrings |
Sciatic |
L4, 5, S1 |
External hamstrings |
Sciatic |
L5, S1 |
Gluteus medius |
Superior gluteal |
L4, 5, S1 |
Gluteus maximus |
Inferior gluteal |
L5, S1, 2 |
Posterior tibial |
Tibial |
L5, S1 |
Flexor digitorum longus |
Tibial |
L5, S1 |
Abductor hallucis brevis |
Tibial (medial plantar) |
L5, S1, 2 |
Abductor digiti quinti pedis |
Tibial (lateral plantar) |
S1, 2 |
Gastrocnemius lateral |
Tibial |
L5, S1, 2 |
Gastrocnemius medial |
Tibial |
S1, 2 |
Soleus |
Tibial |
S1, 2 |
Features |
Cauda Equina Syndrome |
Conus Medullaris |
Vertebral level |
L2-sacrum |
L1-L2 |
Spinal level |
Injury to the lumbosacral nerve roots |
Injury of the sacral cord segment (conus and epiconus) and roots |
Severity of symptoms and signs |
Usually severe |
Usually not severe |
Symmetry of symptoms and signs |
Usually asymmetric |
Usually symmetric |
Pain |
Prominent, asymmetric, and radicular |
Usually bilateral and in the perineal area |
Motor |
Weakness to flaccid paralysis |
Normal motor function to mild or moderate weakness |
Sensory |
Saddle anesthesia, may be asymmetric |
Symmetric saddle distribution, sensory loss of pin prick, and temperature sensations (Tactile sensation is spared.) |
Reflexes |
Areflexic lower extremities; bulbocavernosus reflex is absent in low CE (sacral) lesions |
Areflexic lower extremities (If the epiconus is involved, patellar reflex may be absent, whereas bulbocavernosus reflex may be spared.) |
Sphincter and sexual function |
Usually late and of lesser magnitude; lower sacral roots involvement can cause bladder, bowel, and sexual dysfunction |
Early and severe bowel, bladder, and sexual dysfunction that results in a reflexic bowel and bladder with impaired erection in males |
EMG |
Multiple root level involvement; sphincters may also be involved |
Mostly normal lower extremity with external anal sphincter involvement |
Outcome |
May be favorable compared with conus medullaris syndrome |
The outcome may be less favorable than in patients with CES |
