March is Multiple Sclerosis (MS) awareness month. MS is a debilitating disease of the central nervous system that disrupts communication between the brain and body and is often accompanied by secondary conditions like pain, muscle weakness, vertigo, headache, and visual disturbances. It is considered a demyelinating disease which means it destroys part of your nerve cells called myelin — the protective coating that increases the speed of signals traveling through them. MS is unique in that it is chronic and relapsing in nature. It is believed to result from an autoimmune response where the body’s own immune system attacks its nerve tissue. This demyelination (also known as plaques) can be seen on advanced imaging in the brain as well as the spinal cord primarily in the neck region. Other diagnostic hallmarks of this condition include abnormal cells (known as oligoclonal bands) found in the cerebrospinal fluid, which leads us into some interesting theories when talking about the upper neck.
While the cause and the cure are yet unknown, there are some interesting aspects of MS to consider. For decades cases have been written discussing the correlation of head and neck injuries like whiplash and the onset of MS. Some of these cases have even ended with large settlements in court. While there is still no causal link between these injuries and MS, scientist like Dr. Charles Poser of Harvard states that these injuries may act as a trigger in already susceptible individuals. By understanding the mechanisms of whiplash, we can begin to build a theoretical framework around how these injuries may contribute to the pathogenesis or exacerbation of multiple sclerosis.
In a whiplash trauma the neck is forced into hyper extension and then hyper flexion. Even at speeds as slow as 8mph, this acceleration-deceleration force can cause the head to move 18 inches, at a force as great as 7 G’s. The damage occurs due to the transfer of energy through the spinal column and not simply the impact itself. This rapid change in the cervical spine causes over stretching of the spinal cord and shearing of the nerve fibers. In research this is known as a traumatic axonal injury. This mechanical injury causes a chemical and inflammatory reaction in the spinal cord that may be the tip of the iceberg for those already susceptible to multiple sclerosis. Besides the spinal cord injury itself, muscle strains, ligament damage, and structural misalignments (subluxation) also occur during a whiplash that contribute to the lasting effects on the nervous system and how it will recover.
Another interesting connection between whiplash and MS involves something called cerebrospinal fluid. As we mentioned before, this fluid acts like a cushion to the brain and spinal cord during movement. It has also recently been discovered as the Glymphatic system, in that it works as a waste clearance system for the brain and spinal cord, much like the immune system. This system functions mainly during sleep, and works by eliminating cellular debris, metabolic waste, and distributing a variety of biochemical compounds throughout the nervous system. Studies show changes in biological markers in CSF following trauma to the cervical spine. Rapid changes in pressure in CSF during whiplash injuries can also cause physical damage to the nerve fibers of the spinal cord and brain.
One of the most interesting mechanisms being studied is obstruction of cerebrospinal fluid flow. Using advancements in imaging, companies like FONAR have made amazing discoveries in CSF dynamics and diseases by looking at the spine with upright functional MRI. Researcher Raymond V Damadian and David Chu discovered that when scanning a patient with MS, there was a build-up of CSF in the ventricles of the brain. Coincidentally in MS, the plaque like lesions are usually concentrated adjacent to the ventricles in the brain. Upon investigating the history of several patients with the same image findings, almost all of them had suffered some form of traumatic injury to the neck in their past. Since then, many researchers like Dr. Michael Flanagan and Dr. Scott Rosa have conducted studies on the compelling hypothesis that obstructions to cerebrospinal fluid can cause a build-up in pressure in the ventricles of the brain and caused a leak of fluid into the brain tissue. This fluid also contains proteins, some of which are known to be antigens that can stimulate antibody production.
Could this leakage of fluid stimulate an immune complex reaction in the brain and nerve tissue like what is seen in autoimmune conditions — triggering the genesis of MS? Could past trauma like a whiplash affect the structural alignment and integrity of the upper cervical spine and contribute to the blockage of CSF flow? If these structural misalignments are not corrected, is it plausible that the inflammatory cascade from the mechanical injury to the spine and brain during the whiplash will continue and progress into a chronic condition? Advanced imaging has demonstrated that this is in fact entirely anatomically plausible! Imaging studies have shown that when the atlas vertebra shifts in a rotational direction, the transverse process may compress a major venous pathway from the brain. By putting all of this together we can reach a very fascinating discovery for the 400,000 people affected by MS in the United States. It is possible that a past head or neck injury, like whiplash, may leave behind structural displacements of the upper neck which contribute to the chronic obstruction of what is now known as the immune clearance pathway of the nervous system. These changes over time may very well be what triggers the onset and progression of neurodegenerative diseases like Multiple Sclerosis. Further study is warranted investigating this mechanism and the implications of fluid dynamics.
http://www.bmj.com/content/313/7067/1228.1 https://www.ncbi.nlm.nih.gov/pubmed/18352834 https://www.ncbi.nlm.nih.gov/pubmed/25947369 https://www.liebertpub.com/doi/abs/10.1089/089771503322385782 http://www.fonar.com/news/100511.htm