Conus Medullaris Syndrome

What is Conus Medullaris Syndrome?

Conus medullaris Syndrome is  located at the end of the spinal cord and constitutes a bundled, tapered end of the cord nerves. Nerves passing through the conus medullaris apparently control the bladder, genitals, bowels and legs structures of the body.

The conus medullaris passes near the first two lumbar vertebrae and ends up at the cauda equina, a bundled sac of nerves and nerve roots. Consequently, problems affecting conus medullaris often spread to the cauda equina. Conus medullaris syndrome is a secondary damage to the spinal cord as a result of injuries to the lumbar vertebrae.

Conus medullaris is an incomplete injury to the spinal cord which rarely causes paralysis as compared to other spinal cord injuries. A person suffering from conus medullaris syndrome may depict symptoms that indicate the malfunction of the nerves surrounding the conus medullaris.

The failure is brought about by pressure exerted by structures such as hematoma and tumor on the conus medullaris.

 Conus Medullaris Syndrome Picture 1


Conus medullaris syndrome cannot be entirely described as a disease in its right, rather, it is a product of spinal trauma. In most scenarios, a blow to the back in a car accident or a gunshot is mainly to blame. But in other instances, spinal cord malfunctions and infections caused by spinal tumors and spinal stenosis can also cause the disorder.

The following are proven causes of the disease:

  • Localized infection in the lower spine
  • Spinal abscess
  • Spinal cord tumor
  • Degenerative arthritis of the spinal cord
  • Injury to the spine
  • Epidural abscess


Symptoms of conus medullaris syndrome include back pains, leg numbness, loss of bladder control, impotence, difficulty walking, and numbness in the groin and inner thighs, among others.

Below are some of the symptoms to look out for conus medullaris syndrome:

  • Severe low back pain.
  • Jarring or strange sensations such as buzzing, numbness, or tingling.
  • Failure of body organs such as the bowel and the bladder thereby causing difficulties in controlling and eliminating waste products.
  • Impotence and sexual dysfunction.
  • Weakness, tingling, and numbness of the feet and the entire lower limb.
  • Sensation in the lower limbs from causes that are not clinically explained. For instance, you might be feeling uncomfortable with your legs due to itchiness that is not well explained by an allergic response.
  • Pain in inner thighs and the groin region.
  • Stool inconsistence
  • Urinary inconsistence


The evaluation of the disorder starts in the hospital after critical examination and diagnosis by a specialized doctor. Someone suffering from the disease may show physical features that include:

  • Diminished reflex action due to the absence of tendons especially in the lower limbs.
  • Muscle weakness.
  • Reduced anal sphincter tone.
  • Sensory abnormalities in the lower limbs and the perineum.


Testing offers the best way to confirm for sure whether you are affected by the disease or not. The test is the necessary and surest way of diagnosing conus medullaris syndrome. The following tests can be carried out together or independently to evaluate medullaris syndrome.

Bone X-Rays of the spine

  • Normal spine
  • Bone scan
  • Myelogram
  • Compression fractures
  • MRI scanning of the spine
  • CT scanning of the spine

Conus Medullaris Syndrome Picture 2

Tissue biopsy:

This is conducted in case the disease is caused by pressure from a tumor.

Risk factors

  • A recent lumbar puncture
  • Back injury
  • Blood clotting disorders
  • Blood thinners like Coumadin


If you have Conus medullaris syndrome, seek immediate assistance from a doctor in case of the following symptoms:

  • Incontinence
  • Worsening pain in the groin and thighs
  • Worsening back pains
  • Difficulty in walking
  • Difficulty in urinating
  • Worsening leg weakness

Proven Facts

  • Conus medullaris is caused by pressure exerted by any body structure.
  • The outlook depends on the primary cause.
  • Of 10 patients who have lost control of their legs as a result of the disorder, only one will be able to regain the control of their legs.


The symptoms manifested by conus medullaris are similar to those of cauda equina syndrome. However, the two conditions are treated separately.

Conus medullaris syndrome is characterized by sudden symptoms on both sides of the body, while cauda equina syndrome develops over time and is characterized by uneven symptoms that are concentrated on one side of the body and appear at a later stage of life after infection.

Some other useful tips for differentiating the two disorders include:

  • Conus medullaris syndrome typically causes mild to moderate pain, if any, while cauda equina syndrome results in severe pain that persists if not quickly treated.
  • Impotence is mostly associated with conus medullaris syndrome than cauda equina syndrome.
  • Conus medullaris syndrome can be easily caused by injuries, lesions or infections. On the other hand, cauda equina is always caused by either an infection or a lesion.
  • Pain in the lower back is more likely associated with conus medullaris syndrome than cauda equina.
  • The conus medullaris only interferes with the Achilles reflex, while cauda equina syndrome eliminates both Achilles and patellar reflexes.

Conus Medullaris Syndrome Picture 3


Depending on the extent of an injury, a doctor may conduct MRI imaging of your spine and entire lower back to ascertain a possible conus medullaris syndrome infection. In the case of an infection, there are plenty of treatment options available. These include:

Spinal decompression surgery is always helpful, and in case it leaves a trace in the form of remains such as remnants of a bullet or tumors, your doctor may surgically remove them and restore the normal functional state of the spine. Radiation comes in handy in case symptoms are due to cancer.

Where infections are the cause of the symptoms or an injury was severe and led to the infection, you may need to use antibiotics or intravenous. Physical therapy may also be a good way of regaining function. In essence, treatment is focused on the primary cause. The general treatment goals are to prevent complications by minimizing the extent of the injury.


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  2. McKinley W, Santos K, Meade M et-al. Incidence and outcomes of spinal cord injury clinical syndromes. J Spinal Cord Med. 2007;30 (3): 215-24. Free text at pubmed – Pubmed citation
  3. Bradley WG. Neurology in Clinical Practice: Principles of diagnosis and management. P363
  4. Metastatic spinal cord compression: Diagnosis and management of patients at risk of or with metastatic spinal cord compression. Full Guideline. November 2008. Developed for NICE by the National Collaborating Centre for Cancer. ©2008 National Collaborating Centre for Cancer

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