Tender points/fibromyalgia vs. trigger points/myofascial pain syndrome: a need for clarity in terminology and differential diagnosis.

OBJECTIVE: This study reviews the clinical distinctions between fibromyalgia (FM) and myofascial pain syndrome (MPS), which represent two separate and distinct soft-tissue syndromes. The major aim of this article is to clarify the terminology associated with these syndromes and clearly define the parameters of differential diagnosis and treatment.

DATA SOURCES: Pertinent articles in the chiropractic and medical literature are reviewed with an emphasis on the literature published from 1985-1994.

STUDY SELECTION: Studies were selected that emphasized differential diagnosis of FM and MPS, as well as individual articles on either FM or MPS.

DATA SYNTHESIS: The literature on fibromyalgia and myofascial pain syndromes has grown considerably since 1985. It is now clear that there are several important differences between FM and MPS. The most important criteria for differential diagnosis are the presence of tender points (TePs) and widespread, nonspecific, soft tissue pain in FM, compared with regional and characteristic referred pain patterns with discrete muscular trigger points (TrPs) and taut bands of skeletal muscle in MPS. The etiology of TePs is still unknown and it is uncertain which specific soft tissues are tender in FM patients. Myofascial TrPs are found within a taut band of skeletal muscle and have a characteristic "nodular" texture upon palpation. TrPs are thought to develop after trauma, overuse or prolonged spasm of muscles. Local treatment applied to TePs is ineffective, yet specific treatment of TrPs is often dramatically effective.

CONCLUSION: FM and MPS are two different clinical conditions that require different treatment plans. FM is a systemic disease process, apparently caused by dysfunction of the limbic system and/or neuroendocrine axis. It often requires a multidisciplinary treatment approach including psychotherapy, low dose antidepressant medication and a moderate exercise program. MPS is a condition that arises from the referred pain and muscle dysfunction caused by TrPs, which often respond to manual treatment methods such as ischemic compression and various specific stretching techniques. Both of these conditions are seen routinely in chiropractic offices; therefore, it is important for field practitioners to understand these distinctions.