According to I. Jon Russell, M.D., Ph.D., a highly respected FM researcher and clinical practitioner, "the most dramatic laboratory abnormality, found in most FM patients (>80%), is a consistently elevated, stable level of cerebrospinal fluid (CSF) substance P (SP). All of the four research groups that have studied the levels of this neuropeptide in FM cerebrospinal fluid have found similarly elevated levels despite populations of patients from different ethnic backgrounds."
(Source: Pro Health's Healthwatch newsletter, Vol. XII, No. 1, 2003. Read complete article at http://www.immunesupport.com/Library/showarticle.cfm/ID/4178/HealthWatch/HealthWatch-Spring-2003