Background Deep brain stimulation (DBS) is an effective and approved therapy for advanced Parkinson’s disease (PD), and a recent study suggests efficacy in mid-stage disease. This manuscript reports the results of a pilot trial investigating preliminary safety and tolerability of DBS in early PD. Methods Thirty subjects with idiopathic PD (Hoehn & Yahr Stage II off medication), age 50–75, on medication ≥ 6 months but < 4 years, and without motor fluctuations or dyskinesias were randomized to optimal drug therapy (ODT) (n=15) or DBS+ODT (n=15). Co-primary endpoints were the time to reach a 4-point worsening from baseline in the UPDRS-III off therapy and the change in levodopa equivalent daily dose from baseline to 24 months. Results As hypothesized, the mean UPDRS total and part III scores were not significantly different on or off therapy at 24 months. The DBS+ODT group took less medication at all time points, and this reached maximum difference at 18 months. With a few exceptions, differences in neuropsychological functioning were not significant. Two subjects in the DBS+ODT group suffered serious adverse events; remaining adverse events were mild or transient. Conclusions This study demonstrates that subjects with early stage PD will enroll in and complete trials testing invasive therapies and provides preliminary evidence that DBS is well tolerated in early PD. The results of this trial provide the data necessary to design a large, phase III, double-blind, multicenter trial investigating the safety and efficacy of DBS in early PD.

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Summary To identify novel late-onset Alzheimer disease (LOAD) risk genes, we have analyzed Amish populations of Ohio and Indiana. We performed genome-wide SNP linkage and association studies on 798 individuals (109 with LOAD). We tested association using the Modified Quasi-Likelihood Score (MQLS) test and also performed two-point and multipoint linkage analyses. We found that LOAD was significantly associated with APOE (P=9.0×10-6) in all our ascertainment regions except for the Adams County, Indiana, community (P=0.55). Genome-wide, the most strongly associated SNP was rs12361953 (P=7.92×10-7). A very strong, genome-wide significant multipoint peak (recessive HLOD=6.14, dominant HLOD=6.05) was detected on 2p12. Three additional loci with multipoint HLOD scores >3 were detected on 3q26, 9q31, and 18p11. Converging linkage and association results, the most significantly associated SNP under the 2p12 peak was at rs2974151 (P=1.29×10-4). This SNP is located in CTNNA2, which encodes catenin alpha 2, a neuronal-specific catenin known to have function in the developing brain. These results identify CTNNA2 as a novel candidate LOAD gene, and implicate three other regions of the genome as novel LOAD loci. These results underscore the utility of using family-based linkage and association analysis in isolated populations to identify novel loci for traits with complex genetic architecture.

Background Deep brain stimulation (DBS) of the subthalamic nucleus is an accepted therapy for advanced Parkinson’s disease (PD). In animal models, pharmacologic ablation and stimulation of the subthalamic nucleus have resulted in clinical improvement and, in some cases, improved survival of dopaminergic neurons. DBS has not been studied in the early stages of PD, but early application should be explored to evaluate safety, efficacy, and the potential to alter disease progression. Methods We are conducting a prospective, randomized, single-blind clinical trial of optimal drug therapy (ODT) compared to medication plus DBS (ODT + DBS) in subjects with Hoehn & Yahr Stage II idiopathic PD who are without motor fluctuations or dementia. We report here subject screening, enrollment, baseline characteristics, and adverse events. Results 30 subjects (average age 60 ± 6.9 years, average duration of medicine 2.1 ± 1.3 years, average UPDRS-III scores 14.9 on medication and 27.0 off medication) are enrolled in the ongoing study. Twelve of 15 subjects randomized to DBS experienced perioperative adverse events, the majority of which were related to the procedure or device and resolved without sequelae. Frequently reported adverse events included wound healing problems, headache, edema, and confusion. Conclusion This report demonstrates that subjects with early stage PD can be successfully recruited, consented and retained in a long term clinical trial of DBS. Our ongoing pilot investigation will provide important preliminary safety and tolerability data concerning the application of DBS in early stage PD.