A literature search was performed by the author of this web page using PubMed and Medline search engines online.  Keywords "craniosacral therapy" as well as "cranial bone motion" and "cranial osteopathy" were used in the search, and yielded limited results.  

Pure proponent literature was limited to review articles and contained references to osteopathic literature dated between 1939 and 1990, as well as to unpublished theories by the fathers of osteopathic medicine and osteopathy in the cranial field (Stills and Sutherland, respectively).  Scientific trials cited were anecdotal (i.e. Sutherland's helmet experiment at the turn of the 20th century).  No studies were found that established efficacy of treatment, nor were there any head-to-head trials comparing craniosacral therapy to other treatment options for any given disease (i.e. craniosacral therapy vs. non-steroidal anti-inflammatory agents for the treatment of arthritis).

Pure opponent literature was also very scarce, and was limited to books and journals dedicated to refuting quackery.  Established scientific facts were cited as evidence of claim (i.e. that cranial sutures are non-moveable joints) as opposed to recent trials.

There was a modest amount of seemingly objective literature on the subjects of cranial bone motion and reliability for palpation of the cranial rhythmic impulse (CRI) by therapists.  In a good 1997 meta-analysis of the cranial bone motion controversy in the Journal of Orthopaedic and Sports Physical Therapy, it was concluded by the authors that there is not enough evidence on either side of the argument at present to make a definitive statement on the motion of cranial bones in adulthood.  They cite a 1976 orthodontic study of the changes in the human frontozygomatic suture with age as a good model for future studies.  This study showed that the frontozygomatic suture remains a functional articulation until late in life (it does not undergo synostosis until the eighth decade of life) and is capable of orthodontic remodeling during adulthood.

In a recent study published by the Journal of Manipulative and Physiological Therapeutics in March/April of 2001, the reliability for palpation of the CRI at the head and sacrum by two craniosacral therapists was challenged.  Part of the study design involved the simultaneous palpation of the CRI in a given patient by both therapists: one palating at the head, and the other at the sacrum.  According to the "core-link" hypothesis in craniosacral therapy, the CRI should be felt in the sacrum at the same time as it is felt in the head.  The two examiners were blinded to each other visually by means of a partition and also to sound by means of ambient noise, and they each recorded their own palpation of the CRI with a silent foot pedal.  After examining 11 healthy volunteers in this way, it was concluded that the results fail to support the validity of the "core-link" hypothesis of craniosacral therapy.  In other words, the two therapists reported different values of the CRI as simultaneously palpated at the head and sacrum, respectively.