Abnormal movements in complex regional pain syndrome: Assessment of their nature

Abnormal movements may be a clinical feature in complex regional pain syndr ome (CRPS), but their basic nature is unclear. Between August 1989 and Sept ember 1998, patients fulfilling diagnostic criteria for CRPS (I or II) and displaying abnormal movements were entered into a prospective study. Fifty- eight patients, 39 women and 19 men, met entry criteria; 47 had sustained a minor physical injury at work. The patients exhibited various combinations of dystonic spasms, coarse postural or action tremor, irregular jerks, and , in one case, choreiform movements. Patients underwent rigorous clinical a nd laboratory evaluation aimed at characterizing their neurological disturb ance. Surprisingly, no case of CRPS II but only cases of CRPS type I displa yed abnormal movements. In addition to an absence of evidence of structural nerve, spinal cord, or intracranial damage, all CRPS I patients with abnor mal movements typically exhibited pseudo-neurological (nonorganic) signs. I n some cases, malingering was documented by secret surveillance. This study highlights abnormal movements in CRPS as constituting a key clinical featu re that differentiates CRPS I from CRPS It. They are consistently of somato form or malingered origin, signaling an underlying psychoneurological disor der responsible for the entire CRPS profile. (C) 2000 John Wiley & Sons, In c.