# Comparison of the clinical efficacy of ultrasound-guided GON blockade using low and high concentrations of bupivacaine in chronic migraine

## TL;DR

This study compared low and high concentrations of bupivacaine for occipital nerve blocks in chronic migraine patients and found similar long-term effectiveness.

## Contribution

Demonstrates that a lower concentration of bupivacaine achieves similar outcomes to the standard concentration in GON blocks for chronic migraine.

## Key findings

- No statistical difference in pain outcomes between 0.3% and 0.5% bupivacaine at 3 months postblock.
- Both groups showed significant reductions in pain days and intensity after treatment.
- Lower bupivacaine concentration may reduce risks without compromising effectiveness.

## Abstract

In this study, it was aimed to retrospectively compare the effect of greater occipital nerve (GON) block performed with ultrasonography using low (0.3%) and high (0.5%) concentrations of bupivacaine on pain scores and patient satisfaction in chronic migraine (CM).

The mean number of days with pain, the mean duration of pain in the attacks, and the highest numerical rating scale (NRS) scores recorded in the 1 month preblock and 1 and 3 months postblock of 80 patients (40 for Group 1, 0.3% bupivacaine; 40 for Group 2, 0.5% bupivacaine) who underwent ultrasonography-guided GON block were recorded from the patient file data. According to the protocol applied by our clinic, GON block was applied to each patient 6 times with the same procedures, in total.

While there was a statistically significant difference between the groups in terms of the number of days with pain and the maximum NRS score in the 1-month preblock evaluation (p = 0.01, p < 0.001), at 3 months postblock, no statistical difference was observed in terms of the number of days with pain, duration of pain, or NRS score (p = 0.961, p = 0.108, and p = 0.567). In the intragroup evaluations, at 3 months postblock, the number of days with pain decreased from 17.5 days to 7 days in Group 1 and from 24.0 days to 8.0 days in Group 2. The duration of pain and maximum NRS values were statistically significantly decreased in the intragroup evaluation in both groups pre and postblock.

Complications arising from the procedure and the local anesthetic used are essential points to consider in applying GON block. In CM treatment using GON block application, a similar effect to the standard local anesthetic application (0.5%) can be achieved by administering local anesthetic at a lower dose (0.3%).