The cranio-sacral membrane system & its disorders

According ot the osteopathic and chiropractic teachings, the “Cranio-sacral system” is composed of the: skull, vertebral column, sacrum, and coccyx. The skull includes the: face, teeth, and calvarium. The calvarium is composed of cranial bones joined by sutures, which are composed of fibrous tissue with propioceptive sensory supply (Via the sutural ligaments)

The “Cranio-sacral membrane system” is composed of the craniosacral system plus the membranous sheath enveloping the central nervous system. This membranous sheath is made up of the “Meninges”, which is a connective tissue that is continuous with the fascial system of the body. This fascial system of the brain, which transports the body’s “Meridian system”, includes the: falx cerebelli, tentorium cerebelli, pituitary diaphragmatic sella, membranous labyrinth, cranial nerves sheaths, ophthalmic sclera, and perinureum, and dural tube meninges. The dural sheath that covers the spinal cord from the foramen magnum to the sacrum is also known as the “Core link

The whole cranio-sacral membrane system forms a closed hydraulic system that contains the central nervous system and its cerebrospinal fluid, and it acts as a cerebrospinal fluid (CSF) pump by its elastic stretching mechanism, creating the “CSF cranial rhythmic motion”, first described by Sutherland in 1939. According to many authors, this motion frequency is 6-12 cycles / minute

According to Upledger, the rate of CSF formation is determined by the propioceptive sensation of the autonomic nervous system supplying the cranial sutures, working as a pressure thermostat to achieve CSF homeostasis between the rates of CSF formation from the choroid plexus to the rate of absorption of CSF into the venous system in the sagittal sinus

 The membranous system is highly sensitive and innervated by sensory & autionomic nervous supply from the trigeminal nerve and the first 3 spinal segments (Spinal trigeminal nucleus & tract). The whole dural system is attached mainly to the “Sphenoid bone” in superiorly the calvarium, and to the “Sacrum & coccyx” inferiorly. The dura matter can be considered as the “Skin” of the central nervous system!

 In 1927, Cushing described the CSF motion as the “3rd circulation”, after the cardiovascular (1st) and the lymphatic (2nd) circulations. The average CSF that circulate in the CNS is 150 ml, with the maximum CSF production per day equals to 500 ml, after reabsorption. A significant amount of the CSF absorbed into the dural venous system ends up in the lymphatic system. Moreover, the CSF can reach the cebtral nervous system (CNS) extracellular fluid via the “Virchow-Robin spaces” in the CNS

Dysfunction of the craniosacral pump, typically due to vertebral malalignment or sublaxation, results in “CSF stagnation”, which has been associated with brain aging, and neurodegenerative disorders. CSF, like plasma to tissues, is important to the health of the CSN. CSF carries the following functions to the CNS:

1) Maintain electrolytes balance

2) Acid-base (pH) balance

3) Nutritional function for astrocytes & glial cells 

4) Works as the “Lymphatic system” for the CNS

5) Transport hormones to the CNS

6) Transport neurotransmitters & neuropeptides within the CNS


Selected references

1. Upledger JE et al. Craniosacral therapy: what it is, how it works. 2008; North Atlantic Books; 1st edition

2. Upledger JE et al. Craniosacral therapy. 1983; Eastland Press; 1st edition