A number of studies have demonstrated that deep-brain stimulation (DBS) can improve mobility, ADLs and QOL measures in patients with advanced PD with severe motor complications (Deep-Brain Stimulation for Parkinson’s Disease Study Group. N Engl J Med 2001;345:956-963. Deuschl et al. N Engl J Med 2006;355:896-908; free full text at www.nejm.org/doi/pdf/10.1056/NEJMoa060281).

The EARLYSTIM study has now investigated the potential benefits of subthalamic stimulation at an earlier stage (Schuepbach et al. N Engl J Med 2013;368:610-622). The two-year study randomized 251 PD patients (mean age 52 years) with early motor complications to medical therapy with and without neurostimulation.

Mean quality of life, as assessed by the PDQ-39, showed a 7.8-point improvement with DBS versus  a worsening of 0.2 points with medical therapy. DBS was also superior to medical therapy with respect to motor disability, ADLs, levodopa-induced motor complications, and time to good mobility and no dyskinesia.

Serious adverse events occurred in 54.8% with stimulation/medical therapy and 44.1% with medical therapy alone. Serious adverse events relating to surgery or the device occurred in 17.7% of patients in the DBS group.

Comment
Dr. Michel Panisset: This is a well-designed and -conducted study.  It reproduced what a smaller study by the same group had suggested. The conclusion of the study is likely to change the way patients are assessed for deep-brain functional surgery for PD.  Initially, this type of surgery was primarily offered to the most advanced patients. Then some data suggested that patients being operated on earlier would benefit more from the surgery. And now, the EARLYSTIM study suggests that significantly younger patients with shorter disease duration do significantly better than the best medical treatment – at a time in the disease evolution when we expect patients don’t have such a complicated syndrome that they have exhausted all medical options.  And this is even taking into account the increased number of visits to the clinic for stimulator adjustment! Will we see more patients knocking at neurosurgeons’ doors while they are relatively well?  Time will tell. But I would guess that as we become busier with more PD patients, there will be growing pressure on governments and third-party payors to increase their budgets for the surgical teams.