A look and the Anatomy of the Skull

Rarely do we think of the brain being under pressure… however, the brain is susceptible to pressure in ways that we are just beginning to understand. I will discuss this in this article. But first, we need to understand some basic anatomy. 

A look and the Anatomy of the Skull

The purpose of the skull is to encase and protect our precious brain. It was once thought that the joints of the skull were immobile. However, our body, in its wisdom, chose not to fuse these bones of the skull together. The 22 bones of our head and face are joined with articulating joints called sutures. A suture is a fibrous joint holding these cranial bones together. Sutures are lined with connective tissues called Sharpeys fibers.   

Each suture has a tiny amount of motion from the elasticity inherent in these fibrous joints. The extent of movement is these joints minuscule in comparison to all other joints.

Why did the skull need sutures and not just fuse into one bone?

Cranial Pliability: the advantages

Having cranial pliability offers our skull an adsorption factor. This pliability helps to minimize the impact of any head trauma. This design of the sutures allows the skull to have a crumple factor. During a head trauma, the crumple effect is able to dissipate forces away from the brain. By not fusing, the skull is better adapted for trauma and also any changes due to intracranial pressure, like an occasional sinus infection, etc.

The Meninges: What covers the Brain 

The brain has a covering called the meninges. These meninges are triple a layer of connective tissue surrounding the brain and the spinal cord. They help to both enclose and protect the nervous system. 

The meninges have 3 layers: the outermost layer is the dura mater, (tough Mother in Latin), the middle layer arachnoid mater and pia mater.  

Within a space in the meninges, the subarachnoid space, there is a fluid known as cerebrospinal fluid, or CSF, which surrounds and nourishes the brain. The CSF is an important brain fluid that we are just now beginning to fully understand.

Researchers have discovered that tension in the upper neck muscles can affect the meninges via a connective tissue attachment. Cranial tension can, therefore, be created from muscle tension and from head trauma. 

The Meninges and Cranial Tension  

The Meninges Other than the trauma of a direct impact, there are other forces that can affect the cranial bones and joints. New anatomical discoveries in the last 25 years have changed our view of the brain giving us greater insight into how sensitive the brain is to muscular tension and vertebral positioning. 

These discoveries uncover additional mechanisms of headaches and migraines. 

How Neck Tension > affects your Brain

In 1995 anatomists discovered that our sub occipital muscles, the tiny muscles at the base of the neck, actually attach to our brain and spinal cord, via the dura. 1. The dura is the outermost layer of the meninges. 

Rectus Capitis Posterior Minor, Rectus Capitis Posterior Major & Obliquus Capitis Inferior connect to the dura mater between the top 2 vertebrae of the neck, C1 and C2,  with a thickening of the spinal dura mater at the attachment (1). In 1998 a major neck ligament, the ligamentum nuchae (LN)  was found to also attach to the dura between C1 and C2 (2). Rigidity of LN is found in patients with neck trauma and chronic subluxations. 

The implication of these findings is that muscular tension of these muscles can transfer via the dura mater, to the brain. Thus neck tension can cause dural tension, which is a tugging of the brain and spinal cord! 

The brain itself does not feel pain, however, the dura is extremely sensitive. 

Trigeminal Ganglia, Venous drainage, and Dural Tension

Two important structures run in the meninges: venous sinuses and the trigeminal ganglia lye sandwiched in the layers of the meninges. We know that venous drainage is important for the brain. Why? Because the brain, 2% of our body mass, use 20% of the body's energy! Energy usage creates waste products that must leave the brain. Massive energy means the brain generates massive waste. 

Can tension on the dura mater have a negative effect on the brain drainage? 

Most likely. 

We could call this condition a Toxic Brain. 

Nerve Tension: the trigeminal nerve under pressure

And then there is the trigeminal nerve. Could tension on the dura tension affect the trigeminal nerve that housed in it's lining? Most likely! Could this be a cause of migraines? 

I would describe migraine as the worst pain imaginable. The pain that I felt was an extreme nerve pain accompanied by throbbing sensations. Below is my migraine experience: 

My Migraine Experience:

As a child, I was once at a family party where I suddenly succumbed to my worst headache ever. Several bites into a pink half circle coconut dessert (my favorite BTW) I had to excuse myself from the table. After several aspirins, I was ushered into a bedroom. I found I had to cover my head with a pillow, to minimize all light and sound. It felt as if the sides of my brain were in a vice grip and on fire. Any light or sound that leaked in only exacerbated the problem. 

The one thing that seemed to help me the most, was an ice pack applied to the base of the neck. After several applications of ice, I was able to rejoin the party, an hour or so later. I felt pale and nauseated from the experience, as I tried to be pleasant and engage with friends and family, as best I could. 

My condition became an excuse for us to leave. I rode home crouched in the backseat of the care, with my coat clutched over my head. I also recall the warmth of my mother's hands as she massaged my head and neck later that night, once I was tucked in bed. That whole experience was a doozy. 

This latest research points dural tension as major causation of headaches and migraines. Dural tension has also been linked to cases of weakness of extremities and affects in brain performance

Youve got some nerve: The Muscular Neurological Connection

To summarize anatomists have shown us the direct connection between neck muscles to the cover of the brain, called the meninges, attaching to the outer layer called the dura mater. The dura has connections with the Trigeminal, the Occipital (C1 spinal nerve) nerves, and the Cervical Plexus. Muscular tension producing a traction force on the dura mater exerts a pull or tension on these important neurological structures. This tension may be a major cause of of headaches.

The cause of Migraines: is it Dural Tension?

The symptoms of meningitis (inflammation of the meninges) are closely related to many of the symptoms of migraine. “...the symptoms of a bad migraine – nausea, vomiting, light and sound sensitivity, throbbing headaches – mimic the symptoms of meningitis (3). To what extent is the infection causing these symptoms versus an irritation of the trigeminal nerve? For a migraine to elicit similar symptoms as meningitis, implies that a mechanical force on the dura can cause a similar irritation to the trigeminal nerve as an infection might. As the trigeminal nerve innervates the meninges, tension on the trigeminal activates the pain nerve fibers in the meninges.   

“In a migraine attack, the trigeminal nerve, which possesses pain fibers, is somehow activated, enervating the sensitive area in the meninges."

Dural tension is a plausible mechanism for activation of the trigeminal nerve, and just might be the leading cause of of migraine.   

How do we treat this?  

In my next article, I will cover the adjustments that I perform to address and correct dural tension.