Background & Aims
Chronic cervical radicular pain is the common problems that we face in daily clinical practice, with a prevalence of approximately 35% in the population[1]. Cervical radicular pain is caused by herniated disc or spinal canal stenosis[2]. Pulsed radiofrequency (PRF) has been used for the treatment of several types of chronic pain conditions, such as radicular pain, joint pain, myofascial pain, and different types of headaches [3]. In PRF, tissue temperature reaches a maximum of 42?, which prevents unwanted tissue damage[4]. Recently, several clinicians are applying PRF for the management of cervical radicular pain[5]. High voltage pulsed radiofrequency (HVPRF) can be obtained by increasing the generator voltage output during conventional PRF procedure while maintaining electrode temperature at 42°C[6]. However, to our knowledge, there are no studies investigating the effects of high-voltage PRF obtained by manual mode of the RF generator on the treatment of cervical radicular pain.
Methods
It is a prospective, case-control, randomized, double-blind study. This study was conducted on 100 patients who had refractory chronic unilateral cervical radicular pain and they had ? 50% temporary pain relief following an ultrasound guided diagnostic nerve block with 1 mL of 2% lidocaine. Patients were divided according to the type of the performed ultrasound guided radiofrequency procedure into two equal groups (50 patients each):
1-Group (S): Standard voltage pulsed radiofrequency.
2-Group (H): High voltage pulsed radiofrequency.
Primary outcome was designated to be the pain intensity assessed with the VAS at pretreatment and at 1, 3, and 6 months post-intervention intervals. Secondary outcomes, the impact of treatment on the Neck Disability Index which was evaluated before treatment and at 1, 3, and 6 months post-intervention intervals. Demographic data of the patients in both groups, level and the site of cervical disc prolapse, side of radicular pain, and any side effects.
Results
As regards main outcome measures, VAS and NDI scores were statistically insignificant at the pre-intervention time between both groups (P- value were 0.746, 0.545 respectively). While, VAS scores were significantly lower in group (H) compared to group (S) 1 month, 3 months and 6 months after intervention (P- value was <.001). Also, NDI scores were significantly lower in group (H) compared to group (S) 1 month, 3 months and 6 months after intervention (P- value was <.001). As regards demographic data (age, weight, sex) and as regards ASA physical status, involved disc level, direction of disc prolapses and side of radiculopathy; there were no statistically significant differences between both groups (p-value > 0.05). As regards height and BMI; there were statistical differences between both groups (p-value < 0.05) but of no clinical significance.
Conclusions
We found that HVPRF could significantly reduce pain (measured by VAS) and functional disabilities (measured by NDI) compared to standard PRF 1, 3 and 6 months after intervention in patients suffering from unilateral cervical radicular pain which was refractory to conservative managements.
References
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