What's the role of GPi DBS on patients who have undergone pallidotomy?

One of the ongoing challenges in functional neurosurgery is managing Parkinson’s disease (PD) patients who become refractory to prior ablative procedures, such as pallidotomy, but remain candidates for neuromodulation. This case report discusses the feasibility and rationale of performing deep brain stimulation (DBS) of the globus pallidus internus (GPi) following unsuccessful pallidotomy. A 69-year-old male was diagnosed with PD in 2011, initially presenting with left-hand resting tremor. Symptoms progressed to bilateral limbs by 2015, accompanied by bradykinesia and freezing episodes, worsening significantly from 2020. He became refractory to levodopa, qualifying for surgical intervention. In February 2023, he underwent left-sided pallidotomy due to asymmetric, medication-resistant symptoms and financial constraints that limited access to DBS. However, symptom control was transient, and he deteriorated again. In January 2024, he successfully underwent GPi-DBS after securing the necessary equipment. The procedure was uneventful, and postoperatively, he showed complete resolution of motor symptoms without new neurological deficits. Pallidotomy was chosen initially as a cost-effective, effective first-line ablative option, particularly for asymmetric PD. However, as the disease progressed, DBS offered a more adjustable and bilateral therapeutic approach. The success of DBS after pallidotomy supports its neurofunctional feasibility, with no adverse interactions between the prior lesion and electrode placement. This case illustrates that DBS is not only safe but also effective after failed pallidotomy, reinforcing its role as a viable second-line intervention. It also highlights the persistent impact of financial barriers in determining initial surgical options. In conclusion, DBS following pallidotomy is a feasible and advisable strategy in advanced PD, provided the center has appropriate infrastructure. This sequential approach expands treatment possibilities for patients with progressive disease and underscores the importance of access to neuromodulation technologies.