Spinal Stenosis (Page 3)

Spinal Anatomy and the Major Types of Stenosis:

• Foraminal stenosis. As the nerve root is about to leave the canal through a side hole (lateral foramen), a bone spur (osteophyte) that has already developed from a degenerating disc can press on that nerve root. This type of stenosis is also called lateral spinal stenosis. This is by far the most common form of spinal stenosis. 72% of cases of foraminal stenosis occur at the lowest lumbar level, trapping the emerging nerve root (which comprises a major part of the sciatic nerve).
• Central stenosis. A choking of the central canal, called central spinal stenosis in the lumbar (low back) area can compress the sack containing the horse’s tail (cauda equina, or cauda equine) bundle of loose nerve filaments. Central spinal stenosis is more common at the second from the lowest lumbar spinal level and higher and is largely caused by a bulging of the disc margin plus a major overgrowth or redundancy of a ligament (ligamentum flavum) which is there to help protect the dura. This overgrowth is caused by segmental instability usually from a degenerating disc between adjacent vertebrae. The ligament arises from under the flat laminas of the vertebrae and the inside part of the facet joints (stabilizing joints located on each side at the back of the spine segments).
• Far lateral stenosis. After the nerve has left the spinal canal it can also be compressed beyond the foramen by either a bony spur protrusion or a bulging or herniated disc. When this happens, it is called far lateral stenosis.

<<Previous Page

Continue article>>

Click here for treatment for Spinal Stenosis