We read with great interest the paper “Efficacy of transforaminal epidural magnesium administration when combined with a local anesthetic and steroid in the management of lower limb radicular pain” (Awad et al., 2021). We congratulate the authors on conducting the research which suggests addition of magnesium sulphate to local anaesthetic and steroid in transforaminal epidural injection prolonged effectiveness of block both in pain and functions.

However, we would like to point out a discrepancy in the methodology. The authors in the aim of the study mentioned—“The aim of our study was to evaluate the efficacy of magnesium sulphate, injected with a lidocaine and steroid in the anterior epidural space using the transforaminal epidural approach, in relieving unilateral lower limb radicular pain because of disc prolapse.” However, in the methods section, it is mentioned—“Group C: all patients received through the transforaminal epidural approach 2 ml of bupivacaine (0.5%), 1 ml of methylprednisolone (40 mg) and 1 ml of normal saline (0.9%) for a total volume of 4 ml; and Group M: all patients received through the transforaminal epidural approach 2 ml of bupivacaine (0.5%), 1 ml of methylprednisolone (40 mg) and 1 ml of preservative-free magnesium (200 mg) for a total volume of 4 ml.” Thus, the local anaesthetic which was injected is mentioned as lidocaine in the aim and bupivacaine in the methodology. This confused us. Kindly clarify as to which local anaesthetic was given for the study purposed.

In the article, the secondary outcome was mentioned as the improvement of functional ability and the satisfaction level of the patients after procedure. However, the authors evaluated only functional ability by Modified Oswestry Disability Questionnaire. Satisfaction level of patients was not assessed. Were the patients satisfied after the procedure?

Medical management of the patients was also not mentioned. This can have influential bias in an interventional study. Was the medical management homogenous in all patients?

Also, did the authors note any side effects of transforaminal epidural magnesium sulphate? In the meta-analysis of Wang et al. (2017), regarding neuraxial magnesium sulphate in cesarean section, adverse effects like post-operative nausea/vomiting, hypotension, pruritus, shivering, bradycardia, respiratory depression and headache were assessed. As pain clinicians, we would like to know if these side effects should be assessed in the present technique of transforaminal epidural magnesium.

All authors declare no conflict of interest.