What is the Difference Between Cauda Equina and Conus Medullaris Syndrome

The key difference between cauda equina and conus medullaris syndrome is that cauda equina syndrome occurs when there is compressive damage in the L1-L5 region of the spinal cord, while conus medullaris occurs when there is compressive damage in the T12-L2 region of the spinal cord.

Spinal cord injury is an injury or damage to the spinal cord due to temporary or permanent changes in the spinal cord. It affects the spinal cord’s normal motor, sensory, or autonomic function. Some well-known examples of spinal cord injuries are cauda equina syndrome, conus medullaris syndrome, tetraplegia, syringomyelia, quadriplegia, transverse myelitis, etc.

CONTENTS

1. Overview and Key Difference
2. What is Cauda Equina Syndrome
3. What is Conus Medullaris Syndrome
4. Similarities – Cauda Equina and Conus Medullaris Syndrome
5. Cauda Equina vs Conus Medullaris Syndrome in Tabular Form
6. Summary – Cauda Equina vs Conus Medullaris Syndrome

What is Cauda Equina Syndrome?

Cauda equina syndrome is a disorder due to the compression of a collection of nerve roots called the cauda equina. These nerve roots are at the bottom of the spinal cord and affect the legs and bladder. They are shaped like a horse’s tail. Cauda equina syndrome normally affects around 1 in 65,000 people. Moreover, it affects males as equally as females. It is caused by birth anomalies, lumbar spinal stenosis, injuries to the lower back such as from a car accident or gunshot, a herniated disk in the lumbar region, lumbar spine surgery complications, spinal arteriovenous malformation, spinal hemorrhages, spinal infections like meningitis and spinal tumors.

The symptoms of this condition may include numbness in the back and legs, sciatica, problems having sex, urinary or fecal incontinence, urinary retention, weakness or paralysis in the lower extremities, lower back pain, burning, prickling, tingling or numbness in the lower limbs, and problems with reflexes.

Cauda equina syndrome can be diagnosed through physical examination, CT scan, MRI, and myelogram. Furthermore, treatment options for cauda equina syndrome may include medications such as hyoscyamine, oxybutynin, and tolterodine to improve bowel or bladder function, lumbar laminectomy, physical therapy, and occupational therapy.

What is Conus Medullaris Syndrome?

The conus medullaris is the terminal end of the spinal cord. Conus medullaris syndrome is caused by an injury to the conus medullaris and lumbar nerve roots. In fact, this syndrome is a result of traumatic injuries of the thoracolumbar region of the spine. Conus medullaris can be caused by lumbar canal stenosis, trauma, tumors, and vascular lesions infection such as epidural abscess. Moreover, the symptoms of this condition may include severe back pain, upper and lower motor neuron deficits, saddle anesthesia, loss of bladder reflex (urinary retention), loss of bowel reflex (incontinence), lower limb motor weakness, paresthesia, and numbness.

Conus medullaris syndrome can be diagnosed through physical evaluations and MRI imaging of the lower back and spine. Available treatment options for this syndrome are pain medications, intravenous or oral antibiotics, physical therapy, and spinal decompression surgery.

What are the Similarities Between Cauda Equina and Conus Medullaris Syndrome?

• Cauda equina and conus medullaris syndrome are two different types of spinal cord disorders due to spinal cord injury.
• Both spinal cord disorders can be caused by lumbar spinal stenosis, tumor, traumatic injuries, etc.
• Both disorders may cause similar symptoms, such as lower back and lumber pain, weakness, lower motor neuron deficit, urinary or fecal incontinence, and urinary retention.
• They can be diagnosed through physical examination and imaging tests.
• They are treated through specific medications and surgeries.

What is the Difference Between Cauda Equina and Conus Medullaris Syndrome?

Cauda equina syndrome occurs when there is compressive damage to the spinal cord region of L1-L5, while conus medullaris occurs when there is compressive damage to the spinal cord region of T12-L2. Thus, this is the key difference between cauda equina and conus medullaris syndrome. Furthermore, cauda equina syndrome only has the lower motor neuron deficit, while conus medullaris has a combination of upper and lower motor neuron deficits.

The below infographic presents the differences between cauda equina and conus medullaris syndrome in tabular form for side-by-side comparison.

Summary – Cauda Equina vs Conus Medullaris Syndrome

Cauda equina and conus medullaris syndrome are two different types of spinal cord disorders due to spinal cord injury or damage. Both these conditions may have similar characteristics, such as lower back and lumber pain, weakness, lower motor neuron deficit, urinary or fecal incontinence, and urinary retention. Cauda equina syndrome occurs due to compressive damage to the L1-L5 region of the spinal cord. Conus medullaris occurs due to compressive damage to the T12-L2 region of the spinal cord. So, this is the key difference between cauda equina and conus medullaris.

Reference:

1. “Cauda Equina Syndrome: Symptoms, Treatment & Causes.” Cleveland Clinic.
2.“Anatomy, Back, Spinal Cord.” StatPearls – NCBI Bookshelf.

Image Courtesy:

1. “MRI of the lumbar spine with abscess in the posterior epidural space, causing cauda equina syndrome” By Jing Jing Chan and Jen Jen Oh – (2016). “A rare case of multiple spinal epidural abscesses and cauda equina syndrome presenting to the emergency department following acupuncture.” International Journal of Emergency Medicine 9 (1). DOI:10.1186/s12245-016-0116-5. ISSN 1865-1372 (CC-BY 4.0) via Commons Wikimedia
2. “Cardimage 2842722 01335862646499” By Бекемгүл – Own work (CC BY-SA 4.0) via Commons Wikimedia