D鈥橲ouza, Shawn; Shah, Harsh P.; Seshadri, Vikram; Toms, Jamie; D鈥橦aese, Pierre; Dawant, Benoit M.; Li, Rui; Chen, Jeffrey; Opem, Careniena; Koch, Paul; Larson, Paul; Holloway, Kathryn L. (2026). . Neuromodulation.
Deep brain stimulation (DBS) of the globus pallidus internus (GPi), a brain region involved in movement control, can reduce dyskinesias鈥攗ncontrolled movements often caused by long-term levodopa treatment in Parkinson disease. However, outcomes can vary depending on where stimulation is delivered. This study analyzed 69 patients with Parkinson disease who received GPi-DBS to identify brain locations and connections associated with improvement or worsening of dyskinesias. Researchers mapped the location and estimated effects of stimulation and examined the structural and functional brain networks connected to these areas. They identified a 鈥渟weet spot鈥� associated with greater improvement in the lower back portion of the GPi and just below it, as well as a separate region associated with less favorable outcomes. Nerve fibers passing beneath the GPi, near a pathway called the Ansa Lenticularis, were also linked to reduced dyskinesias. In contrast, stronger functional connections with movement-related regions, including the supplementary motor and premotor areas, were associated with worse outcomes. These findings were confirmed in a separate group of patients, suggesting that both the precise location of stimulation and its connections with wider brain networks may help predict and potentially improve dyskinesia outcomes after GPi-DBS.
Graphical Abstract
