Conus Medullaris

Conus medullaris is the cone-shaped end of the spinal cord. It is normally located between the end of the thoracic vertebrae (T12) and the beginning of the lumbar vertebrae (L1), though sometimes the conus medullaris is found between L1 and L2. Nerves that pass through the conus medullaris control the legs, genitals, bladder and bowel.

At the pointed end of the conus medullaris, the nerve roots of the spinal cord continue in a dangling formation called the cauda equina, which resembles a horse’s tail. Because the conus medullaris resides in the lower back, injuries or conditions of the lumbar spine can affect this terminal end of the spinal cord.
When the nerves in the conus medullaris are unable to function properly due to unwanted pressure or constriction, the resulting condition is called conus medullaris syndrome. There are many factors that can contribute to this nerve pressure, including:

  • Infection
  • Spinal stenosis (narrowing of the spinal column)
  • Trauma
  • Spinal tumors
  • Degenerative arthritis of the spine
  • Deep vein thrombosis, or blood clots, in the spinal veins

While some spinal nerve symptoms like sciatica are unilateral, meaning they only affect one side of the body, injuries involving the conus medullaris are generally bilateral, meaning symptoms will appear on both sides of the body. Symptoms can include lower back pain, in addition to tingling, weakness and loss of feeling in the groin, legs, thighs and feet. More severe symptoms include altered motor functions, impotence, difficulty walking and loss of bowel and bladder function. Anyone who experiences these symptoms should seek emergency medical care immediately, as it could lead to paralysis.

Some less serious spinal conditions like bulging discs, herniated discs, sciatica and foraminal stenosis have symptoms that mimic the symptoms of problems with the conus medullaris. That’s why it’s advisable to seek a proper diagnosis for any spinal condition, so that an appropriate treatment plan can be implemented. At Laser Spine Institute, we offer several state-of-the-art, minimally invasive outpatient procedures to treat a range of spinal conditions, and we may be able to help you find relief from neck and back pain.