Das komplexe regionale Schmerzsyndrom (CRPS): Ein Update

[Complex regional pain syndrome-An interdisciplinary view from the surgical consultation]

Chronic pain disorders are common and have a substantial impact on the patients' daily life. The specific syndrome of complex regional pain syndrome (CRPS, Sudeck's disease) is comparatively rare and characterized by additional sensorimotor, vascular and trophic dysfunctions. The diagnosis is made based on the Budapest criteria and according to clinical symptoms. According to the German national guidelines, multimodal therapy includes drug, rehabilitative and psychosomatic approaches for the reduction of pain and restoration of functionality. Bisphosphonates, steroids and antiepileptic drugs are well-established as medicinal treatment but should always be used in combination with functional therapy. Interventional treatment options are reserved for patients with complicated and enduring symptoms and should be carried out in specialized centers. The course of the disease is highly individual and frequently requires a long-term interdisciplinary treatment.

Local and Systemic Expression Pattern of MMP-2 and MMP-9 in Complex Regional Pain Syndrome

Matrix metalloproteinases (MMP)-2 and MMP-9 play important roles in inflammation as well as in pain processes. For this reason, we compared the concentrations of these enzymes in skin and serum of patients with complex regional pain syndrome (CRPS), other pain diseases and healthy subjects. We analyzed ipsi- and contralateral skin biopsies of 18 CRPS patients, as well as in 10 pain controls and 9 healthy subjects. Serum samples were analyzed from 20 CRPS, 17 pain controls and 17 healthy subjects. All samples were analyzed with ELISA. Concentrations were then compared to clinical data as well as to quantitative sensory testing data.MMP-2 was increased in both ipsi- and contralateral skin biopsies of CRPS patients compared to healthy subjects. While low ipsilateral MMP-2 was associated with trophic changes, contralateral MMP-2 inversely correlated with the CRPS severity. MMP-9 was also locally increased in ipsilateral CRPS skin, and higher ipsi- and contralateral MMP-9 levels correlated with CRPS severity. We conclude that MMP-2 and MMP-9 are differently expressed depending on the clinical phenotype in CRPS. PERSPECTIVE: This article describes an upregulation of MMPs in CRPS and pain controls and shows different expression of MMP-2 and -9 depending on clinical phenotype in CRPS. These results provide evidence that MMP-2 and -9 play a key role in CRPS pathophysiology.