Craniosacral Therapy: Is There Biology Behind the Theory?

Purpose: Craniosacral therapy is used to treat conditions ranging from headache pain and temporomandibular dysfunction to developmental disabilities. It is based, in part, on the biological premise that physical manipulation of the meninges through the cranial vault sutures with low levels of force (~5gms) alters the rhythmic fluctuation of cerebrospinal fluid and intracranial pressure (ICP). The present study was designed to test this hypothesis by simulating a craniosacral "frontal lift" technique and measuring cranial bone movement at the coronal suture and resultant ICP changes in a rabbit model. Methods: Thirteen adult New Zealand white rabbits (Oryctolagus cuniculus) were anesthetized for the duration of the study and 1.2mm "Y" microplates were fixed to the frontal and parietal bones on either side of the coronal suture using 4mm long screws. The ends of the plates were secured to a base plate caudally and to an Instrom load cell rostrally. Continuous epidural ICP measurements were made using a NeuroMonitor transducer positioned through a burr hole in the parietal bone. Distractive loads of 5, 10, 15, and 20 grams were applied sequentially at a rate of 0.5mm/minute to the coronal suture. Baseline and distraction radiographs and ICP were obtained. One subject underwent additional distractive force loads of 100, 500, 1000, 2000, 5000, and 10,000 grams. Plate separation was measured using a digital caliper from the radiographs. Two-way ANOVA was used to assess significant differences in ICP and suture movement.Results: No significant differences were noted between baseline and distraction suture separation (F=0.045; p>0.05) and between baseline and distraction ICP (F=0.279; p>0.05) at any load. No significant (p>0.05) correlations were noted among distractive load, plate movement, and ICP. In the single subject that underwent additional, higher distractive forces, movement across the coronal suture was not seen until the 10,000 gram force which produced 0.91 mm of separation but no ICP changes.Conclusion: Low loads of force, similar to those used clinically when performing a craniosacral "frontal lift" technique, resulted in no significant changes in coronal suture movement or ICP in rabbits. These results suggest a different biological basis for Craniosacral Therapy should be explored