The value of nerve blocks in the diagnoses and treatment of complex regional pain syndrome type 1: a series of 14 cases.

Objectives: Complex regional pain syndrome type 1 (CRPS-1) can progress to joint stiffness, which may be related to pain and/or capsule-ligament contracture. In this context, it is difficult to distinguish the respective causative roles of pain and contractures. Nerve blocks (NBs) can be used to determine the aetiology of joint stiffness. Subsequent treatment will depend on whether contractures are present or not. The objective of the present study was to evaluate the diagnostic and therapeutic value of the nerve blocks in the management of joint stiffness caused by CRPS-1.

Design Of The Study: A retrospective case series.

Methods: Implementation of NBs in subjects with joint stiffness caused by CRPS-1. Primary efficacy criterion: an increase in the range of joint movement. Secondary criteria: pain level, treatment decision, duration of therapeutic NBs, return to work.

Results: Fourteen patients with joint stiffness underwent 17 NBs. Ten NBs (59%) were associated with the normalization of the range of joint movement (i.e. the absence of contractures and the presence of an isolated pain component), prompting the implementation of physical therapy during NBs ("therapeutic NBs") in 90% of these cases. Three NBs (18%) were associated with a partial increase in the range of joint movement (i.e. a background of joint stiffness due to a combination of pain and contracture), prompting the implementation of a therapeutic NB in all of these cases. Four NBs (23%) were not associated with any increase in the range of joint movement (i.e. pure contractures), prompting consultation with a surgeon in all of these cases. Forty-three percent of the patients have since returned to work.

Conclusions: Nerve block is a valuable diagnostic and therapeutic option in the management of joint stiffness caused by CRPS-1.