A few years ago, when I worked in a pain management clinic, I once cared for a patient who had chronic lower back pain with occasional numbness and right leg weakness. For treatment, he received lower back steroid injections every 3 months. Despite his lower back pain, he tried to remain as active as possible by walking a few blocks in his neighborhood each morning.
One morning, as this patient was on his stroll, his right leg began to give out, and he was unable to return home on his own. After he called his wife to pick him up, he immediately called our office for an appointment. We sent him for a magnetic resonance image (MRI) of his lower back. The results revealed a herniated L5 disc; it was touching his spinal nerves with 1 mm of space to spare. He was immediately referred to a neurosurgeon for a consultation to discuss lower back surgery. This patient was diagnosed with cauda equina syndrome (CES).
Cauda Equina Syndrome (CES) and Cauda Medulla Syndrome (CMS)
● Cauda equina syndrome (CES) and Cauda medulla syndrome (CMS) are neuromuscular and urogenital conditions caused by the pressing of lumbosacral nerve roots.
● CES compresses nerves below the level of the conus medullaris, typically at the L3-L5 vertebrae, and CMS compresses the nerves from T12 to L2 vertebrae in the lower thoracic and upper lumbar area.
● Both syndromes have overlapping anatomy; consequently, patients present to the clinic with the same symptoms.
● According to Dawodu (2018), “the spinal cord tapers and ends at the first and second lumbar vertebrae in an average adult. The most distal bulbous part of the spinal cord is called the conus medullaris, and its tapering end continues as the filum terminales. Distal to the end of the spinal cord is a collection of nerve roots, which are horsetail-like in appearance and hence called the cauda equina (Latin for horse tail)” (Paragraph 1).
Causes
The compression of the nerves can be caused in several ways:
● spinal stenosis
● disc herniations
● intradural disc rupture
● spinal stenosis secondary to other conditions
● traumatic injuries
● tumors
● infections
● arteriovenous (AV) malformation or hemorrhage
● iatrogenic injuries
Symptoms
● pain
● numbness and weakness in the lower back, pelvis, and legs
● foot drop
● loss of bowel and bladder control
● sexual dysfunction
● paralysis
A medical emergency can result depending on the severity of these symptoms. People experiencing any of these symptoms should seek a consultation with a neurologist or neurosurgeon for an assessment that requires a magnetic resonance image (MRI) of the lumbar spine and a myelogram to assess damage to the spinal cord.
Treatment
● The best treatment for CES is to fix the underlying cause. This requires removing the cause of the compressed nerves to prevent permanent neurological damage. Symptoms are likely to improve during post-surgical recovery; however, some patients may have permanent neurological damage, chronic pain, and mental health issues related to the impact of the chronic conditions on their relationships and life. Therefore, a psychiatric consult may also be necessary.
● Cauda Equina steroid injections, administered by a pain management specialist, will only provide temporary relief, and may have multiple side effects, such as high blood pressure, diabetes, and osteoporosis, due to long-term steroid use.
that causes low back pain and sciatica. The patient needs surgical decompression and spinal fusion.
References
American Association of Neurological Surgeons. (2020). Cauda Equina Syndrome. https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Cauda-Equina-Syndrome
Dawodu, S.T. (2018). Cauda Equina and Conus Medullaris Syndromes. https://emedicine.medscape.com/article/1148690-overview#a5
NIH. (2020). Cauda Equina Syndrome. https://rarediseases.info.nih.gov/diseases/10987/cauda-equina-syndromeYok_onepiece. (2020). [MRI Image]. A lateral projection of lumbar spine x-ray showing degenerative
spondylolisthesis at L5/S1 level that causes low back pain and sciatica.
https://www.shutterstock.com/image-photo/lateral-projection-lumbar-spine-xray-showing-1774387022