TREATMENT OF SEVERE, RECALCITRANT REFLEX SYMPATHETIC DYSTROPHY - ASSESSMENT OF EFFICACY AND SAFETY OF THE 2ND-GENERATION BISPHOSPHONATE PAMIDRONATE

The objective of the study was to assess the efficacy and the safety o f pamidronate (APD) in recalcitrant reflex sympathetic dystrophy (RSD) . Ten women and 13 men with a mean (+/-standard deviation, SD) age of 44+/-11 years were included. The involved sites were: the ankle (n=10) , the foot (n=7), the hand (n=3), the hip (n=2), the knee (n=2) and th e shoulder (n=1). Some patients had more than one site involved. Mean (+/-SD) duration of the disease was 15+/-13 months. RSD was in pseudo- inflammatory phase in 16 patients and in ischaemic phase in 7 patients . RSD was post-traumatic in 17 cases; 11 patients have been previously treated unsuccessfully by sympathetic blockades. APD was administred intravenously (perfusion) to a dose of 1 mg/kg/day during 3, 2 or one day. Fourteen patients received APD during 3 consecutive days whereas 7 patients have been treated during 2 consecutive days and 2 patients only during 1 day mainly due to adverse events. Efficacy was assessed by a decrease of pain=visual analogic scale (VAS, 0-100 mm) and verbal scale (PVS, range 0-3). Moreover, the patient and the observer have e stimated the efficacy of the treatment on a verbal scale (EVS, range 0 -3). Measurements of these parameters were performed immediately befor e the treatment and 7, 30, 60 and 90 days later. The maximun duration after treatment was 9 months. A significant decrease of VAS and PVS we re observed between D0 and D30 (p=0.0002 and p=0.0002 respectively), D 0 and D60 (p=0.0004, p=0.0004 respectively), and D0 and D90 (p=0.00003 , p=0.0001 respectively). A significant increase of EVS was only obser ved between D0 and D90 (p=0.03). Adverse events were noted in 14 patie nts: transient fever (n=6), venous inflammation (n=2), transient sympt omless hypocalcaemia (n=3), nausea (n=1), lymphopenia (n=1), transient hypertension (n=1). These results suggest an efficacy of APD in recal citrant RSD. Double-blind placebo controlled studies are required to b ack up these preliminary results.