Objective:

To investigate the correlation between electrode location, volume of tissue activated (VTA), and clinical outcomes in patients with isolated generalized dystonia (IGD) undergoing deep brain stimulation (DBS) of the globus pallidus internus (GPi), identifying predictors of treatment efficacy.

Key Findings:

• Postoperative BFMDRS-M and BFMDRS-D scores were significantly lower than preoperative scores (P < 0.001).
• Electrode positions closer to the ventral GPi were associated with better therapeutic effects (left side: P = 0.004; right side: P = 0.041).
• Preoperative HAMA score was identified as an independent predictor of poor motor outcomes (P = 0.0189). No significant changes were observed in HAMA, HAMD, MOCA, or MMSE scores.

Interpretation:

GPi-DBS significantly improves motor function in IGD patients, highlighting the need for precise electrode targeting and preoperative anxiety assessment to optimize treatment outcomes.

Limitations:

• Small sample size of 17 patients may limit generalizability and introduce bias.
• Lack of significant correlation between VTA and BFMDRS-M improvement rate.

Conclusion:

The study provides clinical evidence for target selection and efficacy prediction in DBS treatment for IGD patients.