Somatosensory profiles in subgroups of patients with myogenic temporomandibular disorders and fibromyalgia syndrome

Abstract

Some patients with myofascial pain from temporomandibular disorders (TMD) report pain in extra-trigeminal body regions. Our aim was to distinguish TMD as regional musculoskeletal pain syndrome (n=23) from a widespread pain syndrome (FMS; n=18) based on patients' tender point scores, pain drawings and quantitative sensory testing (QST) profiles. Referenced to 18 age- and gender-matched healthy subjects significant group differences for cold, pressure and pinprick pain thresholds, suprathreshold pinprick sensitivity and mechanical detection thresholds were found. Pain sensitivity in TMD patients ranged between those of FMS patients and healthy controls. The group of TMD patients was inhomogeneous with respect to their tender point count with an insensitive group (n=12) resembling healthy controls and a sensitive TMD group (n=9) resembling FMS patients. Nevertheless sensitive TMD patients did not fulfil diagnostic criteria for FMS in regard to widespread pain as shown by their pain drawings. TMD subgroups did not differ with respect to psychological parameters. The sensitive subgroup was more sensitive compared to healthy controls and to insensitive TMD patients in regard to their QST profile over all test areas as well as to their tenderness over orofacial muscles and trigeminal foramina. However, sensitive TMD patients had a short pain duration arguing against a transition from TMD to FMS over time. Data rather suggest an overlap in pathophysiology with FMS, e.g. a disturbance of central pain processing, in this subgroup of TMD patients. Those patients could be identified on the basis of their tender point count as an easy practicable screening tool.

Quantitative sensory testing somatosensory profiles in patients with cervical radiculopathy are distinct from those in patients with nonspecific neck–arm pain

“…Mechanisms underlying cold evoked pain are still not fully understood [5,70] and likely include both peripheral [74,61] and central nervous mechanisms [80,79,15,38]. Further, cold hypersensitivity is not necessarily associated with the presence of pain or with nerve damage as evidenced in patients with painless peripheral nerve injuries [41], by patients with FM [34,9,40,54,11] and by patients with depression without pain [40]. While psychological factors can enhance pain sensitivity [56], our patients with neck-arm pain demonstrated scores within the normal range for anxiety and depression and measurements of cold sensitivity were not affected by adjustments for anxiety or depression.…”

“…zscore < -1.96 or > 1.96 standard deviation) of our HC were calculated within each group for each test site on the symptomatic body side. In contrast to group comparison, this analysis allows the identification of individual differences and identification of possible subgroups of patients within a specific diagnostic patient group [40,54,50,11,76]. This documentation can be useful when group mean values may not differ to HC data and therefore present as false-negative [50].…”

Chronicity factors of temporomandibular disorders: a critical review of the literature

“…26 Researchers have distinguished between TMD as a regional or widespread pain syndrome on the basis of the identification of a "sensitive" TMD subgroup that had symptoms resembling fibromyalgia and differed from an "insensitive" TMD subgroup. 27 Mechanisms contributing to pain amplification include decreased function in pain inhibitory systems and enhancement of pain facilitatory pathways. Pain amplification may be both an inherited trait and a phenotype that can develop over time in response to emergent biological processes or environmental exposures.…”

Effects of Acupuncture on Sensory Perception: A Systematic Review and Meta-Analysis

“…Recently, efforts are increasing to comprehensively characterize painful conditions by means of QST [136][137][138][139]. Attempts are made to classify patients on the basis of symptoms, signs, or patterns of somatosensory abnormalities [139][140][141].…”

“…Attempts are made to classify patients on the basis of symptoms, signs, or patterns of somatosensory abnormalities [139][140][141]. Those might reflect the underlying pathological mechanisms [142] and might, therefore, be related to different treatment responses [137,143].…”