What exactly is Craniosacral Therapy or Sacro-Occipital Technique (SOT)? These two systems of healing are gentle methods that balance the bodies structural and neurological systems. This is done by correcting abnormal spinal, cranial membrane motion and restoring normal motion of the fluid that baths the brain and spinal cord referred to as cerebrospinal fluid (CSF). The corrections are directed to the cranial bone structures, temporomandibular joint, upper cervical (neck) vertebra, pelvis, the triangular bone located in the lower back called the sacrum and sometimes the coccyx or tailbone. These areas are crucial, because the spinal membrane also known as the spinal meninges attaches to these structures. By the way, this is the same membrane that can get infected and is known as spinal meningitis. It is also the same membrane that is pierced when getting an epidural injection.
When the spinal meninges arrives at the level of the skull it attaches along the inside of the skull/cranial bones. It then enters the skull and covers the brain and spreads out in a tentlike structure dividing the brain into different sections. It is then referred to as the dura or dura mater. You may recall reading about people who have had trauma to the head and developed a subdural hematoma. This is simply a blood clot located below this membrane.
We will later discuss more of the anatomy of this membrane and its importance. Understanding the anatomy can give you a better appreciation of the potential influence of this healing approach.
We will also discuss some of the preliminary research done to date. However, more research needs to done to understand the clinical effectiveness of this gentle treatment.
A QUICK HISTORY OF SOT AND CRANIOSACRAL
In the early 1900’s, while a student at the American School of Osteopathy in Kirksville, Missouri, William G. Sutherland was fascinated with the design and jig-saw like fittings of the human skull, called sutures. Even though he was taught that the human skull and it sutures fuse and calcify, he thought the design and patterns of skull/cranial bone connections were really designed for subtle motion. Convinced that this was the case he experimented on himself and others and found with gentle palpation that rhythmic motion could be felt.
Major Bertrand DeJarnette, D.O., D.C., in 1918 went to Detroit, Michigan to work in the auto industry. He was severely crippled by an explosion. He found over the several years that both osteopathic and chiropractic treatments provided tremendous relief. Having an engineering background and having graduated with an osteopathic and chiropractic degree went on to develop Sacro-Occipital Technique.
ANATOMY OF THE CRANIAL AND SPINAL DURA
The dura mater is a tough fibrous layer of tissue that surrounds the brain and has direct attachments along the inner lining of the skull/cranial bones. The middle layer or arachnoid contains blood vessels, loose connective tissue, cerebrospinal fluid (CSF) and nerve tissue. Some of the nerves come from nerves derived from the upper cervical region, a nerve from the brain stem called the trigeminal nerve and nerves that come from the neck and upper back area that wrap around the blood vessels entering the skull. This is why chiropractic treatments can have very beneficial effects with respect to headaches. The last layer is the pia mater and directly surrounds the brain tissue.
The dura can be thought of as tough saran wrap surrounding the brain and along the entire spine. The dura also divides the brain into different compartments and is tent-like in structure. The falx cerebri and tentorium membranes are the main part of this dural system and attach to one another. There are parts that surround the main nerve to the eyes called the optic nerve, the pituitary gland and other cranial nerves that go to the eyes, ears, vestibular apparatus to maintain balance/equilibrium and other cranial nerves that exit the base of the skull.
The dura also forms spaces in the brain called ventricles. One of the main ventricles contains the choroid plexus where the CSF is produced. The CSF does travel along the entire spinal cord both in the middle of the spinal cord called the central canal and along the periphery. The dura once it leaves the base of the skull is then referred to as the meninges. The meninges acts as saran wrap around the spinal cord and CSF flows between the meninges and the spinal cord. Furthermore, the meninges forms a “sleeve” around the spinal nerves as they leave the bony spinal column. The dura then blends into the surrounding coating of the nerve called the epi neurium. The CSF does flow into these spinal nerves as well. It is believed that the CSF travels the length of most nerves.
The meninges firmly attaches to the large opening at the base of the skull that the spinal cord passes through and it is called the foramen magnum. It also firmly attaches to the second and third vertebra in the neck. There are looser attachments to the vertebra via the dentate ligaments. There is a firm attachment lower in the spine at the level of the second sacral segment which is a triangular shaped bone in the lower back. Finally, it firmly attaches to the tailbone /coccyx at the filum terminalis.
The entire dura and meninges is attached and tension along any part of this membrane whether it is in the skull, upper vertebra, sacrum, pelvis or tailbone can distort this membrane. Think of a nylon stocking, if you pull on a section of the stocking it distorts along the length of the stocking. The meninges and dura act in the same manner. In the illustration below think of the dura like a closed pulley system. This has the potential for affecting brain, cranial and spinal nerve function. It also can influence blood flow and CSF flow throughout the brain and spinal cord.
CRANIAL BONE MOTION AND THE DURA
The skull consists of 22 bones which includes the jaw. The bones are connected together like a jigsaw puzzle at what are called cranial sutures. We were taught in school that these bones do not move, fuse and calcify as you age. We were also taught that the skull simply was for protection of the brain. However, this simplistic model of the skull is being questioned and that some research suggests that a lot more is involved with the brain and cranium.
A basic tenet of SOT and Craniosacral Therapy is that the bones of the skull do indeed move slightly, influencing dural / meningeal tension, CSF flow, blood flow and neurological function.
In 1971, Viola Frymann D.O., using a transducer found a rhythmic motion of cranium of 10-14 cycles/minute. Weiss M. Heifitz M.D. , in the Journal of Neurosugery 1981, found skull expansion with increased intracranial pressure. In the Journal of Human Physiology 2001, researcher ME Moskalenko, using NMR tomograms and transcranial ultrasound Doppler Echography, found the cranial volume rhythmically changed 6-14 cycles/min by 12-15 ml. He found the cranial sutures to change 380 micrometers to 1millimeter. .He found that these cycles appear to be linked to blood supply, oxygen consumption of the brain tissue and CSF circulation. Researchers, Michael Retzlaff and Mitchell F. Roppel in 1976, using light scanning microscopy to exam primate sutures found connective tissue, blood vessels, nerve fibers in the sutures and described a pattern of wavy collagen fibers arranged to monitor elongation of these fibers in the sutures. In 1978, John Upledger, D.O. found nerve fibers and nerve receptors normally found in movable joint in human suture samples. In 1987, Upledger and Metzlaff found not only connective tissue, a vascular network, nerve network and receptors in a primate suture, but also traced a nerve that went into the brain and terminated in the brain where CSF is produced. This discovery suggests that the cranial sutures have a direct effect on CSF production. So it theorized that as the sutures expand they help slow CSF production and if the sutures get compressed they send signals to increase CSF production. This might be how the body regulates CSF pressure and fluid dynamics in the dura.
There is more research, but more to be done. Certainly this explains some aspects of craniosacral and SOT treatments.
HOW DOES ONE GET DURAL/MENINGEAL IMBALANCES?
Lets go back to anatomy to help explain why we develop dural tension and imbalance. The dura/meninges attaches to a few key areas of the body. The cranial bones, base of the skull, upper vertebra, sacrum and tailbone. These areas can be influenced by the muscles/ tendons and fascia that attach to these structures. There are important jaw muscles that attach to the bones of the skull and have direct influence on cranial motion. Therefore, potentially having your jaw open for long periods of time during dental procedures could cause problems. Poor fitting dentures, crowns, braces and other dental appliances can cause indirect dural tension by abnormal muscular function.
The upper neck when misaligned can lead to abnormal dural tension. Remember the 2nd and 3rd cervical vertebra have direct dural attachments. Furthermore, there is a muscle in the upper cervical area called the rectus capitis minor that attaches to the dura. This area can often lead to tension type of headaches at the back of the skull. Muscular imbalances can occur from trauma like whiplash, poor postural habits like studying/reading with hands propping up the neck or chin, poor supportive pillow, sleeping on your stomach , poor supportive chair while at the computer. Chronic mental stress may cause you to contract your neck, upper back, facial and jaw muscles.
Injuries, falls, poor muscular balance to your lower back, hips and tailbone may also cause dural torue/tension.
TREATMENTS FOR DURAL IMBALANCES
The treatment for dural/ meningeal imbalance is very gentle. It often involves contacting different bones of the skull and applying gentle pressure as you breath slowly. The spots selected help remove the sutural “jams” and releases the dural tension. A gentle method utilizing specialized blocks helps to remove dural tension in the lower spinal regions. It is important to remove the tension both at the upper and lower ends of the dura to get a proper restoration of function.
There is another approach we use that is called PRY technique. Which stands for pitch, roll and yaw. This is another method to check to see if the upper and lower tension of the dura is balanced. We usually have the patient put there head and pelvis into different positions relative to one another and check for dural tension. Again, the corrections are very gentle.
Realigning the jaw and balancing the surrounding muscles is vitally important. At times working with a dentist to balance the jaw and removing improper occlusion is necessary to stabilize the dural motion.
Another factor to consider are the feet. There are important reflexes in the joints of the foot and ankle that influences muscular activity in the lower back, shoulders, neck and jaw. If the feet are not corrected the dural tension will return due to poor muscular balance.
Zinc deficiencies seem to be associated with reoccurring cranial imbalances. It is suspected that zinc is involved in CSF production.
Some very recent research performed by Jeffrey Iliff , PhD., at the University of Rochester Medical Center, has found a very fast and efficient CSF fluid pathway in the brain. The CSF has been shown to enter the brain rapidly and remove amyloid beta deposits (which leads to Alzheimers) found between the brain cells into the surrounding veins. So, this gives further reason to ensure there is proper CSF flow to remove toxins in the brain and prevent possible neural degeneration. There is an interesting YouTube video on this research.