Sensory signs in complex regional pain syndrome and peripheral nerve injury

Abstract

This study determined patterns of sensory signs in complex regional pain syndrome (CRPS) type I and II and peripheral nerve injury (PNI). Patients with upper-limb CRPS-I (n=298), CRPS-II (n=46), and PNI (n=72) were examined with quantitative sensory testing according to the protocol of the German Research Network on Neuropathic Pain. The majority of patients (66%-69%) exhibited a combination of sensory loss and gain. Patients with CRPS-I had more sensory gain (heat and pressure pain) and less sensory loss than patients with PNI (thermal and mechanical detection, hypoalgesia to heat or pinprick). CRPS-II patients shared features of CRPS-I and PNI. CRPS-I and CRPS-II had almost identical somatosensory profiles, with the exception of a stronger loss of mechanical detection in CRPS-II. In CRPS-I and -II, cold hyperalgesia/allodynia (28%-31%) and dynamic mechanical allodynia (24%-28%) were less frequent than heat or pressure hyperalgesia (36%-44%, 67%-73%), and mechanical hypoesthesia (31%-55%) was more frequent than thermal hypoesthesia (30%-44%). About 82% of PNI patients had at least one type of sensory gain. QST demonstrates more sensory loss in CRPS-I than hitherto considered, suggesting either minimal nerve injury or central inhibition. Sensory profiles suggest that CRPS-I and CRPS-II may represent one disease continuum. However, in contrast to recent suggestions, small fiber deficits were less frequent than large fiber deficits. Sensory gain is highly prevalent in PNI, indicating a better similarity of animal models to human patients than previously thought. These sensory profiles should help prioritize approaches for translation between animal and human research.

Divergent Sensory Phenotypes in Nonspecific Arm Pain: Comparisons With Cervical Radiculopathy

“…The presence of bidirectional sensory abnormalities in both groups in this study is consistent with data from a similar cohort of people with neck and arm pain, 34 as well as other cohorts with neuropathies and complex regional pain syndrome. 5,6 This further supports the argument for the assessment of sensory phenotypes in patient populations on the basis that heterogeneity with respect to sensory phenotypes exists within patient cohorts; hence, people with the same condition could warrant different approaches to assessment and treatment. 6,35 The identification of different sensory phenotypes within NSAP is an important finding.…”

“…[5][6][7][8][9][10] In studies of NSAP, the presence of hypoesthesia to vibration has previously been recorded, [11][12][13] which may suggest the presence of a minor neuropathy 11,12 and/or altered central processing, 13 possibly secondary to pain. 14 Furthermore, we recently reported the presence of sensory hypersensitivity to pressure, cold, and heat as characteristic of NSAP, whereas hypoesthesia to vibration explained a small percentage of the variance (11%).…”

Seeing the body produces limb-specific modulation of skin temperature

“…Several psychiatric and neurological conditions involving disruptions of body representation have also been found to feature disordered thermoregulation, including complex regional pain syndrome (CRPS) [15,16], schizophrenia [17], phantom limb pain [18] and self-injurious behaviour [19]. CRPS, for example, is associated with increased pain, decreased tactile sensitivity on the affected limb [20,21], somatosensory disinhibition [22] and reduced temperature on the affected limb [15,16]. Intriguingly, vision of the body has the opposite effects in healthy participants, reducing pain [3,4], enhancing tactile sensitivity [1,2], enhancing somatosensory inhibition [5] and increasing limb temperature (this study).…”

Short-term effects of orthognathic surgery on somatosensory function and recovery pattern in the early postoperative period

“…JMPQ and QST probably assess different functions of the peripheral nervous system (PNS) and central nervous system (CNS). QST mainly reflects the function of the PNS and, to some extent, of the CNS; brain areas associated with sensory detection and cognition may be involved (17,18). In contrast, MPQ reflects psychophysical function (19), including cognition, affect, and memory, which is not evaluated by the QST.…”