title: Recurrent postoperative CRPS I in patients with abnormal preoperative sympathetic function.
abstract: OBJECTIVE
  A complex regional pain syndrome of an extremity that has previously resolved can recur after repeat surgery at the same anatomic site. Complex regional pain syndrome is described as a disease of the autonomic nervous system. The purpose of this study was to evaluate preoperative and postoperative sympathetic function and the recurrence of complex regional pain syndrome type I (CRPS I) in patients after repeat carpal tunnel surgery.
  
  
  METHODS
  Thirty-four patients who developed CRPS I after initial carpal tunnel releases and required repeat open carpal tunnel surgeries were studied. Laser Doppler imaging (LDI) was used to assess preoperative sympathetic function 5-7 days prior to surgery and to assess postoperative sympathetic function 19-22 days after surgery or 20-22 days after resolution of the CRPS I. Sympathetic nervous system function was prospectively examined by testing reflex-evoked vasoconstrictor responses to sympathetic stimuli recorded with LDI of both hands. Patients were assigned to 1 of 2 groups based on LDI responses to sympathetic provocation. Group I (11 of 34) patients had abnormal preoperative LDI studies in the hands that had prior surgeries, whereas group II (23 of 34) patients had normal LDI studies. Each patient in this study had open repeat carpal tunnel surgery.
  
  
  RESULTS
  In group I, 8 of 11 patients had recurrent CRPS I, whereas in group II, 3 of 23 patients had recurrent CRPS I. All of the recurrent CRPS I patients were successfully treated with sympathetic blockade, occupational therapy, and pharmacologic modalities. Repeat LDI after recurrent CRPS I resolution was abnormal in 8 of 8 group I patients and in 1 of 3 group II patients.
  
  
  CONCLUSIONS
  CRPS I can recur after repeat hand surgery. Our study results may, however, identify those individuals who may readily benefit from perioperative therapies.
  
  
  METHODS
  Prognostic I.
authors.affiliation: United Pain Medicine, P.A., Sherwood, AR 72120, USA. epmo@epmo.info
authors.forename: William E
authors.initials: WE
authors.lastname: Ackerman
authors.forename: Mahmood
authors.initials: M
authors.lastname: Ahmad
mesh_terms: D000328:Adult; D000588:Amines / Q000627:therapeutic use; D000700:Analgesics / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001340:Autonomic Nerve Block; D002349:Carpal Tunnel Syndrome / Q000601:surgery*; D000068579:Celecoxib; D003000:Clonidine / Q000627:therapeutic use; D003509:Cyclohexanecarboxylic Acids / Q000627:therapeutic use; D005260:Female; D000077206:Gabapentin; D006225:Hand / Q000098:blood supply; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D009788:Occupational Therapy; D011183:Postoperative Complications / Q000503:physiopathology*; D011300:Preoperative Care; D011446:Prospective Studies; D011720:Pyrazoles / Q000627:therapeutic use; D012008:Recurrence; D012018:Reflex / Q000502:physiology; D012019:Reflex Sympathetic Dystrophy / Q000503:physiopathology* / Q000628:therapy; D012039:Regional Blood Flow / Q000502:physiology; D012086:Reoperation; D013449:Sulfonamides / Q000627:therapeutic use; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014661:Vasoconstriction / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000627:therapeutic use
chemical_list: D000588:Amines; D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D003509:Cyclohexanecarboxylic Acids; D011720:Pyrazoles; D013449:Sulfonamides; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D000068579:Celecoxib; D003000:Clonidine