Trial of Pulsed Radiofrequency for Sciatica and Disc Herniation

Overview

Transforaminal epidural injection of treatments, commonly steroids (TFESI), is offered to people with sciatica and might improve symptoms, reduce disability and speed up return to normal activities (NICE guidelines) Imaging-guided TFESI has traditionally been performed in the sciatica context because injection is administered directly to the nerve root, which relieves the pain markedly; however, the maintenance time is usually short. Treatment with radiofrequency for pain management is in clinical use since decades primarily with nerve lesioning (thermoablation) once the specific pain tributary nerve is identified. Pulsed radiofrequency (PRF) with neuromodulation intention (not lesioning) has been shown to be effective in reducing some types of chronic pain, both degenerative and neuropathic. Pulsed radiofrequency has been also extensively used in the context of acute and subacute sciatica due to disc herniation without sufficient level of evidence. In a prospective RCT, comparing prf directed to dorsal root ganglia and Tfesi in patients with sciatica did not allow conclusions on efficacy because of limitations of the trial. In that trial, only few participants completed the study due to violation of trial protocol translating the results as not consistent. One retrospective trial, in which the use of Prf in addition to tfesi was evaluated in patients with acute and subacute sciatica, demonstrated rapid pain relief onset and prolonged maintenance; the overall efficacy was superior to that of the single method treatment (either tfsei or prf). The investigators conducted a randomized, double-blind, controlled trial (Pulsed Radiofrequency in Addition to Tfesi for Sciatica \[PRATS\]) to determine if PRF in addition to TFESI leads to better outcomes in the management of patients with acute and subacute sciatica due to disc herniation, compared to TFESI alone.

The investigators conducted a multicenter, prospective, randomized trial among patients with at least 6 weeks of sciatic pain to determine whether a strategy of PRF in addition to TFESI leads to better outcomes during the first year than does a strategy of TFESI only means for sciatica treatment. Eligible patients were 18 to 75 years of age, had a radiologically confirmed disk herniation, and had received a diagnosis from an attending neurologist of an incapacitating lumbosacral radicular syndrome that had lasted for at least 12 weeks. Correlation of magnetic resonance imaging (MRI) findings with symptoms was registered. Patients presenting with cauda equina syndrome, muscle paralysis, or insufficient strength to move against gravity were excluded. Other exclusion criteria were cardiac pace-maker implant, pregnancy, or severe coexisting disease. The occurrence of another episode of symptoms similar to those of the current episode during the previous 12 months, previous spine surgery and spondylolisthesis were not considered contraindications but bony stenosis. A computer-generated permuted-block scheme was used for randomization, with an unstratified variable-block size of 2 and 4. The order of blocks was also randomized with patients assigned (1:1) to PRF/TFESI (treatment) or TFESI (control). A few hours before randomization, the patients were evaluated again, and those who had recovered from their symptoms at that time were excluded from the trial.