Allen RJ, Horiuchi G, Wu C, Friends JW, Campbell KR; University of Puget Sound, Tacoma, WA. rallen@ups.edu.

PURPOSE: When treating complex regional pain syndrome (CRPS) somatosensory desensitization frequently allows patients to reduce light touch intolerance. Other tactile stimuli may still produce allodynia and restrict function. Recent literature found that for thermal intolerance, desensitization is somatosensory modality specific. This study's purpose was to evaluate pressure desensitization for reducing pressure induced allodynia and related functional deficits in patients with CRPS who had desensitized to light touch and thermal variation, yet manifested functional deficits from pressure sensitivity. SUBJECTS: Single subject design involving two patients. Patient 1 was a 43 year-old female with one-year history of lower extremity CRPS. She displayed no fine touch allodynia or thermal intolerance; yet, marked sensitivity to plantar pressure limited ambulation and driving distance. Patient 2 was a 27 year-old male fork-lift operator with two-year history of upper extremity CRPS. He was unable to work more than two hours/day, due to pressure intolerance. Both patients had stable medication dosage and function following prior therapy. METHODS & MATERIALS: Patients completed a ten-week daily pressure desensitization protocol of rolling progressively harder balls using the painful skin field. Desensitization dosing involved three-minutes exposure, two-minutes rest, and a second three-minute exposure. Pressure tolerance in kg/cm² on a simulated accelerator pedal (patient 1) and hydraulic control knob (patient 2) were measured for the affected and unaffected limbs. For patient 1 data on driving time, ambulation distance, and weekly pain medication usage was collected. Patient 2 was tracked on daily hours of equipment operation. Changes in gait abnormalities (patient 1), hand function (patient 2), self-reported functional changes and usage, and reports of pain quality and intensity were recorded. ANALYSIS: Dependent variables were assessed for two-week baseline, weekly throughout treatment, and during three-month follow-up. Data was graphed for empirical assessment and percent changes calculated. RESULTS: Patients showed post-treatment increases in pressure tolerance of 312% (patient 1) and 212% (patient 2), bringing affected appendages to a tolerance level equal to the unaffected side in both cases. Patient 1's, walking distance increased 0.8 to 2.7 miles without antalgic signs, driving distance increased from less than ten-minutes to greater than thirty-minutes without aggravating pain, and Tramadol usage dropped from 305 mg/wk to 56 mg/wk. The patient with UE involvement showed similar improvements, and increased average work hours with heavy equipment from 1.8 hours/day to 4.7 hours/day. CONCLUSION: For these patients with CRPS, pressure desensitization yielded notable improvements in pressure tolerance and performance of related functional activities. FUNDING SOURCE: None

Copyright 2004 by the American Physical Therapy Association

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