Objective and importance: To demonstrate the pattern of activation associated with electrical stimulation through bilateral deep brain stimulation electrodes placed within the anterior limb of the internal capsule to the level of the ventral striatum for treatment of obsessive-compulsive disorder.
Clinical presentation: A 44-year-old man with a 26-year history of obsessive-compulsive disorder underwent functional magnetic resonance imaging (fMRI) and deep brain stimulation-evoked cortical potential testing after bilateral implantation of deep brain stimulation leads. Stimulation was delivered independently through the distal two contacts of each percutaneously extended lead using an external pulse generator. On postoperative Day 2, we used a 3-Tesla magnetic resonance system to measure changes in the fMRI blood oxygen level-dependent signal using stimulation parameters that were predetermined to demonstrate behavioral effects.
Intervention: All studies were well tolerated. Trial stimulations performed intraoperatively as well as on postsurgical Day 1 were associated with acutely elevated mood and reduced anxiety. Although the benefit achieved acutely was relatively symmetric between the bilaterally placed leads, follow-up programming showed a clear advantage to right-sided stimulation. Three of the four fMRI trials demonstrated good activation, with the fourth being moderately corrupted by motion artifact. The beneficial effects observed with right-sided stimulation were associated with activation of the ipsilateral head of the caudate, medial thalamus, and anterior cingulate cortex as well as the contralateral cerebellum. The distribution of the cortical evoked potentials was consistent with the locus of cortical activation observed with fMRI.
Conclusion: High-frequency stimulation via a lead placed in the anterior limb of the internal capsule induced widespread hemodynamic changes at both the cortical and subcortical levels including areas typically associated with the pathogenesis of obsessive-compulsive disorder.