Post-traumatic Spinal Cord Tethering

Spinal cord injury can lead to changes in the way spinal fluid flows around the spinal cord within the spinal canal as well as the way the spinal cord and rootlets normally move within the spinal canal. Scar tissue, which forms after a traumatic spinal cord injury, between the spinal cord and rootlets and the covering of the spinal cord (dura mater), impairs the normal flow of spinal fluid around the spinal cord and places the spinal cord and rootlets on a bit of traction.

This scarring of the spinal cord and rootlets to the dura is called “tethering”. Such tethering along with the changes in spinal fluid flow and loss of spinal cord and rootlet elasticity can lead to a complex of symptoms occurring anywhere from two months after a spinal cord injury to more than 40 years later, the most common being:

  • Progressive loss of sensation and strength in the arms, trunk, and legs
  • Worsening respiratory function
  • Worsening bowel, bladder, or sexual function
  • New or worsening spasticity of the legs, trunk, and arms
  • New or worsening pain in parts of the body where the sensation is absent or abnormal
  • New or worsening blood pressure regulation (high or low) and sweating commonly referred to as AD (autonomic dysreflexia)

If these symptoms become significant and refractory to all other treatments, then surgery becomes an option to arrest the progression of the symptoms, and in many, allow symptom resolution and functional return.

Spinal Cord Untethering with Expansion Duraplasty

With such surgery the spinal cord and rootlets are carefully released from their tethering to the dura, thereby improving spinal fluid flow within the spinal canal and improving the normal motion of the spinal cord and rootlets within the spinal canal. The spinal fluid space is then expanded with a graft of unscarred dural substitute (expansion duraplasty) from our tissue bank to minimize the chance of spinal cord re-tethering.

Post-traumatic Syringomyelia

In some, spinal cord tethering, with its impairment of spinal fluid flow and traction injury to the spinal cord, can contribute to the formation of a fluid filled cavity called a cyst or a syrinx within the spinal cord tissue itself. When a syrinx (cyst) forms within the injured spinal cord, it is known as post-traumatic syringomyelia.

The symptoms of post-traumatic syringomyelia are identical to those of post-traumatic spinal cord tethering:

  • Progression of loss of sensation and strength in the arms, trunk, and legs
  • Worsening respiratory function
  • Worsening bowel, bladder, or sexual function
  • New or worsening spasticity of the legs, trunk, and arms
  • New or worsening pain in parts of the body where the sensation is absent or abnormal
  • New or worsening blood pressure regulation (high or low) and sweating commonly referred to as AD (autonomic dysreflexia)

If these symptoms become significant and refractory to all other forms of treatment, then surgery becomes an option to arrest the progressive loss of function and in many, allow symptom resolution and functional return.

Spinal Cord Untethering with Expansion Duraplasty/possible Syrinx(cyst) shunting

For post-traumatic syringomyelia, spinal cord untethering with expansion duraplasty is performed. In our experience this is sufficient to allow the syrinx to collapse 80% of the time. In the 20% wherein collapse of the syrinx does not occur after spinal cord untethering alone, determined during the surgery, a small tube(shunt) is placed into the syrinx cavity to allow the syrinx fluid to drain into the spinal fluid space. If the syrinx is very large, the syrinx fluid is sometimes shunted to the peritoneal space in the abdominal cavity.