The relevance of age and disease duration for intervention with subthalamic nucleus deep brain stimulation surgery in Parkinson disease

The optimal age and disease duration for consideration of deep brain stimulation (DBS) surgery are not well characterized in patients with Parkinson disease. The aim of this study was to assess variation in motor response to surgery among subgroups stratified by age and disease duration.A total of 46 patients referred for DBS were recruited for the study. Preoperative dyskinesia and rigidity scores were recorded, and then patients received bilateral subthalamic nucleus stimulation. Preoperative motor scores were then compared with postoperative scores over 1 year.At 1 year postoperatively, patients with ≤ 10 years' disease duration showed a significant (45%) reduction in rigidity and a significant (64%) reduction in dyskinesia. Patients with10 years disease also showed a significant (70%) reduction in dyskinesia at 1 year postoperatively, but failed to show significant improvement in rigidity (31% reduction). Patients70 years old showed a significant (58%) improvement in rigidity and a significant (53%) improvement in dyskinesia. Finally, patients ≥ 70 years old showed a significant (90%) improvement in dyskinesia, but failed to show any significant change in rigidity at 1 year postoperatively.The postoperative improvement in rigidity for younger patients with shorter disease duration may indicate that performing early surgery maximizes the benefit of DBS. However, older patients with primarily dyskinesia symptoms also appear to have significant clinical improvement, and DBS can offer relief from this common consequence of long-term levodopa use.