Network analysis in Gamma Knife capsulotomy for intractable obsessive-compulsive disorder.

Area of Science:

• Neurosurgery
• Neurology
• Radiosurgery

Background:

• Treatment-refractory obsessive-compulsive disorder (OCD) poses significant challenges.
• Gamma-knife Ventral Capsulotomy (GVC) is an emerging treatment option for severe OCD cases.

Purpose of the Study:

• To investigate the neural underpinnings of GVC's efficacy in OCD patients.
• To identify white matter tracts predictive of clinical outcomes following GVC.

Main Methods:

• Exploratory study of 8 treatment-refractory OCD patients undergoing GVC with 3-year follow-up.
• Correlation analysis between lesion characteristics (MR imaging) and symptom improvement (Y-BOCS).
• Diffusion MRI tractography to identify neural networks associated with successful GVC outcomes.

Main Results:

• Mean Y-BOCS reduction of 19.6, achieving a 63% response rate after three years.
• Significant correlation between decreased left ventral diencephalon volume and symptom improvement (r=-0.83, p=0.039).
• Tractography indicated streamlines connecting the prefrontal cortex and subthalamic nucleus are associated with clinical response.

Conclusions:

• GVC demonstrates efficacy in a subset of patients with treatment-refractory OCD.
• Treatment effects may be mediated by the anterior limb of the internal capsule (ALIC) connecting the prefrontal cortex (PFC) and subthalamic nucleus (STN).
• Interpatient variability and small sample size necessitate further validation.