2.5. Assignment of interventions and blinding
BLIND
Participants will be randomized using a computer-generated scheme to either treatment group: low-voltage group and high-voltage group. Immediately prior to the procedure, procedure-performing physician (S.P.) will open a sequentially numbered opaque envelope with group assignment listed inside. All participants will remain blind to the group assignment before, during, and after the PRF and all efforts will be made to provide identical treatment experiences. The injection procedure and type of drug used for treatment will be not revealed to the patients until study completion. The researcher who gathered post-procedure data also will be blind to group assignment.