神經性疼痛在類風濕性關節炎的盛行率

Prevalence of neuropathic pain in patients with rheumatoid arthritis

目的：研究在類風濕性關節炎病人中，發生神經性疼痛的比例；同時，也調查罹病時間長短和發生神經性疼痛的關係。方法：將葛魯蘋教授翻譯的Brief Pain Inventory （BPI，原作者Dr. Cleeland） 以問卷調查的方式在南部某醫學中心過敏免疫風濕科門診調查類風濕性關節炎病人的神經性疼痛盛行率；感覺神經測試也一併記錄在問卷中。病人之發炎指數紅血球沈降速率 （ESR） 和C-反應蛋白（CRP） 也記錄在問卷中，以研究這兩者之間是否有相關。問卷調查時間自2008年三月起至六月底止。結果：一百位符合1987年美國風濕病學院類風濕性關節炎診斷標準的病人接受問卷調查；其中25人因資料不足而排除。75個病人資料進行統計。其中以女性病人佔多數 （62位女性，84%），平均年齡為55.64歲，平均罹病時間為11.08年，近九成病人 （67/75, 89.33%） 陳述在求診前一週內出現疼痛情形。在這65位病人，以0為“不痛＂到10為“這輩子沒這麼痛過＂的疼痛指數量表，他們最痛的疼痛指數平均為5.74分 （範圍從1分到10分），最輕微的疼痛平均為1.78分 （範圍從0分到9分），過去一週大部分時間的疼痛指數為3.54分 （範圍從0分到10分）。在67位有陳述疼痛病人，他們的平均罹病時間是11.19年；其中40位 （59.70%） 病人出現allodynia，47位 （70.15%） 病人出現altered pinprick threshold。結論：文獻指出allodynia及altered pinprick threshold和神經性疼痛的強烈相關性，在我們類風濕性關節炎合併疼痛的病人中出現神經性疼痛的比例達79.10% （53/67）。然而，罹病時間的長短和神經性疼痛的表現並沒有正相關。

Objective: To study the prevalence of possible neuropathic pain in patients with rheumatoid arthritis (RA) in addition to investigating the correlation between disease duration and occurrence of neuropathic pain. Methods: A questionnaire containing Brief Pain Inventory by Dr. Cleeland translated into Chinese was given to patients with RA in the rheumatologic outpatient department from March 2008 to June 2008 in a tertiary center in southern Taiwan. Objective sensory testing was also carried out with results recorded in the questionnaire. Latest level of serological markers for inflammation, erythrocyte sedimentation rate and C-reactive protein, of the patient were documented for investigation on possible correlation. Results: One hundred patients fulfilling the 1987 revised criteria of the American College of Rheumatology for RA participated. Twenty-five patients were excluded due to insufficient background information for analysis. Of the seventy-five patients analyzed, female patients predominated (62 female, 84%), mean age was 55.64 years, average disease duration was 11.08 years, and 67/75 (89.33%) of the patients reported pain within one week prior to the clinic visit. Among the sixty-seven patients complaining of pain, they rated their worst pain intensity as 5.74 (range 1 to 10) on a numeric rating scale, with least pain intensity as 1.78 (range 0 to 9), and pain intensity most of the time as 3.54 (ranged 0 to 10). Among the 67 RA patients complaining of pain upon query, their average disease duration was 11.19 years; allodynia and altered pinprick threshold were found in 40 patients (59.70%) and 47 patients (70.15%), respectively. Conclusion: Review of the literature states allodynia and altered pinprick threshold to be pathognomonic of neuropathic pain. 53 of the 67 patients (79.10%) complaining of pain showed positive for at least one objective sensory test. Nearly 80% of patients have neuropathic pain. Our study found that disease duration of RA does not correlate well with occurrence of allodynia or altered pinprick threshold. Patients with 2-year duration of RA may demonstrate a positive result for both allodynia and altered pinprick threshold; however, eight out of our seventy-five study subjects (10.1%) with over a 10-year disease duration (range 10-40 years) were negative for both.