Long-term electrical capsular stimulation in patients with obsessive-compulsive disorder

Area of Science:

• Neurosurgery
• Neuromodulation
• Psychiatry

Background:

• Lesioning procedures for severe obsessive-compulsive disorder (OCD) are irreversible and carry risks.
• Treatment-resistant OCD requires alternative therapeutic strategies.
• Chronic electrical stimulation presents a potential alternative to ablative surgery.

Purpose of the Study:

• To evaluate the efficacy of chronic electrical capsular stimulation as a replacement for bilateral anterior capsulotomy.
• To assess the long-term effectiveness of this neuromodulation technique in severe, treatment-resistant OCD patients.

Main Methods:

• Stereotactic implantation of quadripolar electrodes in the anterior limbs of the internal capsules in six OCD patients.
• Double-blind clinical assessments by psychiatrists and psychologists.
• A blinded random crossover design was employed for four patients to compare stimulation-on and stimulation-off conditions.

Main Results:

• Significant reduction in Yale-Brown Obsessive Compulsive Scale scores during stimulation-on (mean 19.8) versus stimulation-off (mean 32.3).
• Sustained symptom reduction for at least 21 months post-surgery.
• Observed changes in regional brain activity using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), including decreased frontal metabolism.

Conclusions:

• Chronic electrical capsular stimulation effectively reduces core OCD symptoms in severe, long-standing, treatment-refractory cases.
• The procedure demonstrates sustained efficacy for up to 21 months.
• Neuromodulation via capsular stimulation induces measurable changes in brain activity.