Subthalamic Stimulation Improves Quality of Life of Patients Aged 61 Years or Older With Short Duration of Parkinson's Disease

Objective: The optimal timing of subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) is a topic of ongoing debate. In patients with short disease duration an improvement of quality of life (QoL) has been demonstrated for patients aged younger than 61 years. However, this has not been systematically investigated in older patients yet. We hypothesized that patients aged 61 years or older experience a significant QoL improvement after STN-DBS with no difference in effect sizes for groups of patients with short and longer disease duration. Materials and Methods: From four centers (Cologne, London, Manchester, Venice) we identified "older patients" aged 61 years or older with short (<= 8 years) or longer disease duration and compared QoL, motor impairment, complications, medication requirements, and Mini-Mental State Examination (MMSE) on baseline and five months after surgery. Results: Mean age/disease duration in 21 subjects with shorter disease duration were 65.5/6.3 years compared to 66.8/14.6 in 33 subjects with longer disease duration. The short disease duration group was affected by less baseline motor complications (p = 0.002). QoL in the short/longer disease duration group improved by 35/20% (p = 0.010/p = 0.006), motor complications by 40/44% (p = 0.018/p < 0.001), and medication requirements by 51/49% (both p < 0.001). MMSE remained unchanged in both groups. Conclusion: Patients aged 61 years or older benefited from STN-DBS regardless of short (<8 years) or longer (>8 years) disease duration. Our results contribute to the debate about DBS selection criteria and timing and call for prospective confirmation in a larger cohort.