The famous neurosurgeon Dr. Harvey Cushing stated that cerebrospinal fluid (CSF) flow is the third circulation of the brain. More recently in chapter six of Clinical Neurology published by Lippencott in 2006, Dr. Joseph Madson and others elaborated on Dr. Cushings description of CSF flow. They stated that CSF pulsations are the fourth circulation of the brain.
The open sutures, as seen in the picture, on an infants skull are called fontanelles , which means little fountains. They are known as “soft spots” in layman’s terms. The soft spots were so named because you can feel the pulsations of the brain at the fontanelles.
The fontanelles separate the plates of bone that cover the brain called membranous bones. They are called membranous bones because they grow within the outside covering of the brain and develop along with the brain. The membrane of the brain is made of dura mater, which means hard mother in Latin, so the soft spots aren’t as soft as they appear. They are actually relatively tough and difficult to penetrate. If you look closely at the infant skull above you will notice that the edges of the sutures are relatively smooth compared to the adult skull below. The sutures develop their characteristic shape as an infant matures. In either case, like all bones, their shapes are caused by the stresses that strained them.
If a baby becomes dehydrated the soft spots will sink. On the other hand, if the volume of cerebrospinal fluid in the brain increases, such as in hydrocephalus, the soft spots will feel tense and bulge outward. Typically, the fontanelles eventually disappear and the membranous bones are joined by their opposing surface that form into the shapes of surgical sutures. Hense the joints of the skull are called sutures.
Hydrocephalus in children is caused by blockage of CSF flow. The blockage of CSF flow causes the volume of CSF in the brain to increase. The increase in CSF volume causes the sutures to stay open and the head to increase in size. On the other hand, in some cases, there is premature closing of the sutures called craniosynostosis. Most cases of craniosynostosis cause mild almost imperceptible malformations of the skull and have no impact on health. In certain cases, however, premature closure of the sutures can cause hydrocephalus due to resistance to growth and development of the brain and subsequently CSF volume.
In any case, the shape of the soft spots and sutures of the skull are a reflection of cranial hydrodynamics, which is fluid mechanics in the brain and skull. The fluid mechanics are the result of electrical, circulatory and respiratory waves. Those waves are further amplified and modified by upright posture.
Strong CSF pulsations are a sign of good circulation and health. Weak pulsations are a sign of ill health and old age. On the other hand, when they get out of hand, waves can move boulders in rivers and tear apart the most imposing shorelines and obstacles. They can also cause malformations of the skull, as well as cause the sutures to stay open, as mentioned above. The pulsations of the brain also cause the irregular wave-like shapes of the sutures. They even leave little impressions on the inside roof of the skull where special valves, called arachnoid granulations, squirt CSF into the venous drainage system of the skull called dural sinuses.
If the pulsations can shape, indent and move the bones of the skull they can easily compress, dent and deform the brain and, in fact, they do. When the heart contracts a considerable amount of blood is driven into the brain, which compresses the brain, veins and CSF pathways. This drives venous blood and CSF out of the cranial vault and brain. When the heart relaxes, the brain, veins and CSF pathways expand which draws blood into the tissues of the brain, and pulls waste out of tissue spaces and into the drainage system ready to be removed on the next cycle. The heart thus causes the brain to rhythmically expand and contract.
Problems occur when waves get out of control. I liken them to rogue waves and describe them in more detail on my prior post. When CSF volume gets out of control it can damage the brain. Likewise, when CSF waves get out of control they can damage the brain as well. The basal cisterns (wells) that surround the brainstem and cerebellum with CSF, are the first place to experience the brunt of rogue waves and the most likely to suffer the consequences. I suspect that chronic pounding from rogue waves can cause damage.
Rogue waves may play a role in arachnoid cysts, cystic ventricles as in Dandy-Walker syndrome and the variant of Parkinson’s called multisystem atropy or Shy-Drager. It most likely plays a role in empty sella syndrome and hormonal problems, as well as other conditions. I further suspect that one of the likely sources for destructive rogue waves in the brain comes from the cervical spine.
The first and most likely source of rogue waves is from malformations and misalignments in the upper cervical spine. Another is backjets due to whiplash, a phrase coined by Dr. Frans Schelling. Still another cause of the destructive, reflected waves is spondylosis lower down in the cervical spine.
Spondylosis is the term for degeneration of the spine. Among other things, spondylosis compresses the spinal canal and vertebral veins, which affects blood and CSF flow, as well as causing standing waves in the basal cisterns of the brain. Blockage of the vertebral veins affects blood and CSF flow in the brain. Overtime, chronic pounding from standing waves (clapotis-see prior posts) in the basal cisterns can compress the parts they surround and damage the brain. I will discuss spondylosis, seawalls and standing waves in next post.
For further information on related topics go to my website at www.upright-health.com.