Multiple sclerosis is a debilitating disease that affects many Americans. The condition is known to cause demyelination of nerves, which affects its ability to transmit information from the brain to the body and vice versa. It is similar to electrical wiring in a house. What would happen if the plastic covering on some of the wires in a house wore through and the wires actually broke? When this occurs, household items would not work appropriately. For example, the lights may not turn on or appliances might suddenly shut off. This is clearly problematic. Research continues to grow but the underlying mechanisms are not well understood. In a complicated disease like this, there are more than likely many factors involved.
Could Structural Maladies of the Craniocervical Junction be A Contributing Factor to Multiple Sclerosis?
To answer this, we must first understand its possible involvement. Multiple sclerosis is associated with periventricular lesions. These are scars that occur around a chamber in the core of the brain called the ventricles. Is it a coincidence that these scars are located in the periventricular tissue of multiple sclerosis patients? Are these lesions a clue to an underlying degenerative process? The ventricles of the brain are responsible for cerebrospinal fluid (CSF) production and circulation. The CSF bathes the brain. It is responsible for removing waste as well as supplying the brain with the nutrients necessary for proper function. The unobstructed flow of CSF is essential for brain metabolism. If it is blocked, this will increase hydrostatic pressure and cerebrospinal fluid can potentially leak out of the ventricular system into surrounding tissues. It is similar to filling a balloon with water. The balloon can only expand so much before the force of water pushing out from within causes a disruption and water starts pouring out.
Can CSF Circulation be Impeded?
There are a number of ways it can be, but this article will focus on inhibited drainage from the brain. The majority of substances entering and leaving the skull pass through the foramen magnum of the craniocervical junction. It is a bottleneck, no different than a traffic jam occurring on a two lane highway. An accident can stop cars for hours before it is cleared. The same phenomenon can occur within the body. Cerebrospinal fluid is drained from the brain through the venous system. Part of this system passes through the bottleneck to the brain, the craniocervical junction. Therefore, anything that affects this area can block the venous system and hinder outflow from the brain. This will cause a backup of CSF and increased hydrostatic pressure that could cause leakage into the periventricular space.
Two possible mechanical sources for obstructed venous flow include forward head posture and atlas malalignment. The craniocervical junction hosts particularly sturdy ligaments called dentate ligaments. Their job is to anchor the spinal cord in place during all motions of the head and neck. Tension can pass to the contents of the craniocervical junction through these ligaments. Forward head posture is abnormal anterior positioning of the head relative to the thorax and shoulders. For every inch the head moves forward from normal, an extra ten pounds of tension is added to the contents of the cervical spine. This can increase intramedullary pressure on the venous system draining CSF from the brain which could cause a backup of CSF and increased hydrostatic pressure. This is similar to stepping on a garden hose. When pressure from outside the hose is added, the amount of water reaching the end is reduced.
Also, misalignment of the atlas vertebra can cause a similar increase in pressure. The atlas is responsible for the majority of neck and head rotation. This incredible amount of motion subjects it to the potential for possible abnormal alignment. It has a close relationship with the dentate ligaments and stress can be transmitted to the contents of the craniocervical junction secondary to improper position. A recent publishing (Dworkin and Smith. 2015 Karger) utilized standing MRI to observe CSF flow pre and post atlas correction and displayed an improvement. In addition to increased pressure secondary to atlas misalignment, they also cited jugular vein compression by the atlas transverse process as a possible mechanism.
The backed up CSF is more than likely filled with toxic wastes that are meant to be cleared from the brain. Is it possible that this waste could initiate a cascade of immune responses that attacks the myelin of nerves when it leaks out of the ventricles? This is merely speculation. However, the position of the lesions in multiple sclerosis may be an indicator of a potential mechanism that contributes to the disease.
Multiple sclerosis is a very complicated disease. The different systems do not act in isolation. It is probable that this condition is secondary to multiple different interactions within the entire body. Hopefully, this article brings to light a potential mechanism that is not frequently addressed. More research needs to be conducted, but the mechanism presented may very well be involved.