Internationally renowned general neurosurgeon, Dr. Petra Klinge, et al, have published new research, Diseased filum terminale as a cause of tethered cord syndrome in Ehlers Danlos syndrome: histopathology, biomechanics, clinical presentation, and outcome of filum excision.
Many people with Ehlers-Danlos syndrome (EDS) suffer from back and leg pains and in addition, neurological symptoms, including bowel and bladder issues. This symptom constellation is known as tethered cord syndrome (TCS) and is typically diagnosed in people in whom the MRI reveals a shortened or thickened filum terminale (FT).
The FT is a fibrous band anchoring the spinal cord to the skeleton, i.e., the coccyx. Surgical transection of the filum is an accepted procedure in people suffering from TCS under the condition that the MRI reveals a diseased filum.
Patients who are not diagnosed by MRI with a diseased filum are classified as “occult tethered cord syndrome” and are rarely considered for surgical treatment. This restrictive treatment strategy is based on the lack of an understanding how a radiologically normal FT could cause a TCS.
Dr. Klinge et al’s study reveals for the first time profound congenital and in addition acquired collagen abnormalities of the of the FT in EDS, which are not visible in the MRI. They show that such pathology affects the biomechanics of the FT indicating that in EDS patients with TCS the spinal cord is exposed to stretch forces causing pain, neurological symptoms, and bladder and bowel problems. Their novel understanding of the pathology of TCS in EDS patients is impressively supported by the improvement of such symptoms following surgical tethered cord release. They conclude that EDS is a risk factor for TCS, which can be treated by FT resection even if radiographically “occult”.
Though their study is based on many patients, at this point surgery for occult TCS in EDS patients should still be conducted under the conditions of clinical trials with supervision by institutional review boards because there are still many unknowns when it comes to clinical decision making for surgery. Particularly, they see the need for improvement of diagnostic and outcome measures in a larger number of patients. As next research step, they see the need for a multicenter registry.
Petra M Klinge 1, Vikas Srivastava 2, Abigail McElroy 3, Owen P Leary 3, Zahra Ahmed 2, John E Donahue 4, Thomas Brinker 5, Philippe De Vloo 6, Ziya L Gokaslan 3
