Epidural betamethasone injection in lumbosacral radicular syndrome: Effi cacy evaluation for interlaminar and transforaminal approaches

Abstract

Introduction: Betamethasone is a frequently used steroid for epidural injection, recently incorporated in the Uruguayan pharmaceutical market. Aims: The aim of this study is to evaluate the effi cacy of parasagittal interlaminar and transforaminal epidural betamethasone in unilateral lumbosacral radicular syndrome, utilizing the Brief Pain Inventory (BPI). Material and method: Is a prospective study comparing parasagittal interlaminar and transforaminal epidural betamethasone. Patients with chronic unilateral lumbosacral radicular pain were included. The BPI was administered before and one month after epidural injections. Pain intensity was measured by the Visual Numeric Scale (VNS, question 6 of the BPI) and the Intensity Score. Interference of pain in daily activities was measured by the Interference Score. Satisfactory responses to injections were considered with a 2 points reduction in VNS. The statistical evaluation was performed by paired an unpaired T test to continuous data and Chi Square to evaluate proportions. A p value less than 0.05 was considered statistically signifi cant. Results: Fifty four patients were treated with epidural betamethasone. In 29 the parasagittal interlaminar route was utilized while 25 were treated by the transforaminal route. A 20 % reduction in baseline VNS was observed with the interlaminar route and 36 % reduction with transforaminal approach. Intensity and Interference Scores were also reduced. This reductions were statistically signifi cant when comparing to baseline data (paired t test) but differences between groups were not signifi - cant (unpaired t test). However the number of positive responses as defi ned above was greater in the transforaminal group, 64 % versus 38 % in the interlaminar group, statistically signifi cant difference using the Chi Square analysis (p=0.01). In patients with positive responses, interlaminar and transforaminal betamethasone produce clinical and statistically signifi cant reductions in pain intensity and interference, without difference between groups. Conclusion: Epidural betamethasone produced a reduction in pain intensity and interference utilizing the BPI, by the two routes utilized to access the epidural space. Although no statistically differences were observed in this reductions between groups, the frequency of positive responses were higher when the drug is administered by the transforaminal route. Epidural interlaminar parasagittal betamethasone injection is a reasonable alternative to the transforaminal route, without the neurologic complications described utilizing this technique.