My approach to PD has always been “as long as it will not hurt you, it’s probably okay, as long as you don’t use it as your sole method of treatment.” By “hurt you” I mean physical damage or injury, worsening of PD, significant pain, or mental/psychological damage. I would include giving false hope or making unfounded claims as being harmful to patients, emotionally, financially, and often physically.
There are clearly some well-educated, conservative chiropracters who offer treatments locally for a variety of well-established conditions. As long as PD patients are aware that there is no good scientific evidence either way regarding effectiveness for PD and they look carefully at what is being offered or claimed by the chiropracter, then they may choose to try it.
Of particular concern, however, is when fantastical, non-scientific claims are being made. These can be found locally as well as nationally. I would caution patients to avoid some treatments in particular, especially those that are invasive. “Functional Cranial Release,” for instance, is a non-scientific and somewhat risky procedure that is being touted as a treatment for just about everything, including PD. It involves a balloon being inserted into the nasal passages, then expanded, then contracted and removed, with claims that it is restoring or correcting cranial abnormalities. It is further claimed that this procedure treats Alzheimer’s, headaches, migraines, ringing in the ears, fibromyalgia, and the list goes on and on. The purported mechanism of patient improvement is by “improving blood flow and oxygenation” to the brain and “releasing nerves.” Patients are reportedly dramatically improved and, sometimes, told they can stop taking their medications. Nasal damage has been clearly documented in some patients who underwent this procedure.
This meets the classic criteria for a scam: unproven claims, lack of scientific evidence, miraculous reversal of degenerative processes, panacea (good for anything), aggressive marketing with glowing testimonials, lack of anatomical/physiological basis in reality. See http://www.quackwatch.com/
To summarize, patients should not avoid chiropracters as a group, but, just as in any profession, there are a few practitioners and treatments who should be avoided at all cost.