Bilateral subthalamic stimulation in Parkin and PINK1 parkinsonism

To study the frequency of different gene mutations in patients with early-onset parkinsonism and bilateral subthalamic nucleus deep brain stimulation (STN-DBS) and the short- and long-term surgical outcome in mutation-positive (MUT+) and -negative (MUT-) patients.

Eighty patients with disease onset at age

We identified 12 mutation carriers (11 Parkin [6 with 2 mutated alleles, 5 with 1 mutated allele], 1 homozygous PINK1). There were no clinical differences between the MUT- and MUT+ patients preoperatively, except for more severe H-Y stage and postural and gait scores in the on-medication state in the MUT+ group. During the first year after surgery, MUT- patients showed better clinical improvement (56% motor UPDRS improvement) compared with MUT+ patients (36%). However, in the long-term follow-up (3-6 years), both groups presented with the same degree of clinical improvement (MUT-: 44% vs MUT+: 42%). Although the MUT+ group showed more severe axial signs preoperatively, MUT- patients developed levodopa- and deep brain stimulation-resistant axial signs within the first 3 to 6 years postoperatively, which diminished the initial benefit soon after surgery.

Patients with Parkin or PINK1 mutations benefit from subthalamic nucleus deep brain stimulation. However, the clinical response is not superior to non-mutation carriers and might be limited by more advanced axial motor symptoms at a relatively early disease stage.