Pain physician
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The sacroiliac joint (SIJ) is a major source of pain in patients with chronic low back pain. Radiofrequency ablation (RFA) of the lateral branches of the dorsal sacral rami that supply the joint is a treatment option gaining considerable attention. However, the position of the lateral branches (commonly targeted with RFA) is variable and the segmental innervation to the SIJ is not well understood. ⋯ Widespread variability of lateral branch exit points from the dorsal sacral foramen and possible contributions from L5 dorsal rami and superior gluteal nerve were disclosed by the current study. Hence, SIJ RFA treatment approaches need to incorporate techniques which address the diverse SIJ innervation.
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The association between epidural fibrosis and recurrent symptoms after lumbar spine surgery remains a matter of debate in scientific literature and the underlying pathophysiological mechanism has not been clearly elucidated. ⋯ Rather than direct stimulation of nociceptors in the epidural scar tissue, other factors should relate epidural fibrosis and recurrent symptoms after lumbar spine surgery. Osteopontin seems to play a role in the formation of epidural fibrosis.
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Epidural and intrathecal injections of methylprednisolone acetate (MPA) have become the most commonly performed interventional procedures in the United States and worldwide in the last 2 decades. However neuraxial MPA injection has been dogged by controversy regarding the presence of different additives used in commercially prepared glucocorticoids. We previously showed that MPA could be rendered 85% free of polyethylene glycol (PEG) by a simple physical separation of elements in the suspension. ⋯ Results of the present study identified a cytotoxic effect of commercially available MPA with preservatives or with a "clear phase" containing higher concentrations of preservatives on primary isolated rat DRG sensory neurons. This was shown by TUNEL positive assay and by increased caspase-3 expression as one of the final executing steps in apoptotic pathways in DRG neurons. However, our results showed no statistically significant difference between the control cells (saline-treated) and cells treated with MPA with reduced concentrations of preservatives, pointing out that either PEG or myristylgamma-picolinium chloride (MGPC) or their combination have harmful effects on these cells. Reduction of concentrations of preservatives from commercially available MPA suspensions by using the simple method of inverting vials for 2 hours could be considered useful in clinical practice to enhance the safety of this depot steroid when injected neuraxially.