Effects of Mecobalamin on the Functional Outcomes of Complex Regional Pain Syndrome Type 1 of the Foot and Ankle.

Background: Because of the unclear pathophysiology and the lack of consensus on the gold standard treatment of complex regional pain syndrome (CRPS), management requires a multidisciplinary approach, with the use of various treatment modalities. Nonetheless, no studies have ever been conducted to uncover the potential of mecobalamin as a treatment for CRPS type 1. Hence, the aim of this clinical trial was to evaluate the effects of mecobalamin on the functional outcomes of patients with CRPS type 1 of the foot and ankle, the total amount of pregabalin ingested, and the duration of pregabalin use in each patient.

Methods: Forty-seven patients diagnosed with acute CRPS type 1 of the foot and ankle were recruited. Patients were randomly allocated into a control group (23 patients) and a mecobalamin group (24 patients), both receiving similar pain control medications and rehabilitation programs. Three divided doses of mecobalamin 1.5 mg/d were provided to the mecobalamin group for the first 3 months, whereas a placebo was administered to the control group. Data were collected from the pretreatment period, and from 1, 3, 6, and 12 months following the treatment.

Results: Both groups had similar demographics. The mean Foot and Ankle Ability Measure (FAAM) activities of daily living (ADL) and FAAM-sport scores in the mecobalamin group at 3 months were 74.5 ± 17.9 and 56.3 ± 22.9, whereas the mean FAAM-ADL and FAAM-sport scores in the placebo group at 3 months were 62.2.5 ± 15.2 and 43.4 ± 14.9, respectively (P < .05). The 36-Item Short Form Health Survey (SF-36) mental health subscale after 3 months were 83.3 ± 9.5 points and 75.8 ± 12.6 points in the mecobalamin and placebo group, respectively (P < .05). However, at other time points of assessment (1, 6, and 12 months), the improvement in symptoms was not distinguishable between the 2 groups. Both the amount and duration of total pregabalin required to achieve similar improvements in pain scores were significantly lower in the mecobalamin group than the control group.

Conclusion: This small study revealed an improvement of the functional outcomes in patients with CRPS type 1 of the foot and ankle who received mecobalamin instead of a placebo at 3 months that was not sustained at 6 and 12 months. We identified an average 39% total reduction in the amount of total pregabalin used in the mecobalamin group in the first 12 months.