Chiari Fact #19
A tethered spinal cord can also be a pathological cofactor of a Chiari Malformation. Tethering can happen anywhere in the spine, but it is most common in the lumbar region after the spinal cord has turned into a strand of fibrous tissues, known as the filum terminale. The filum should be free-floating in the cerebrospinal fluid. When the filum is tethered it pulls downward, causing the filum, spinal cord, and the brainstem (which is attached at the top of the spinal cord) to tighten and the brainstem often elongates and descends. As the brainstem descends below the foramen magnum (the hole at the bottom of the skull), the cerebellar tonsils often do as well. When both the cerebellar tonsils and the lower part of the brainstem (the medulla oblongata) herniate below the foramen magnum, it becomes what is known as a Chiari 1.5 (which is a good indicator of an Acquired Chiari Malformation). Tethered Cord is almost always associated with a Heritable Disorder of Connective Tissue (HDCT), the most common of which are Ehlers-Danlos syndromes (EDS).
For more information about:
Chiari & TCS:
https://chiaribridges.org/spine-pulled-tight-a-guide-to-understanding-tethered-cord-syndrome/
Acquired Chiari Malformations:
https://www.ncbi.nlm.nih.gov/pubmed/21215551
