Implantation of autologous peripheral nerve tissue to the nucleus basalis of Meynert in patients with Parkinson's disease during deep brain stimulation surgery: a 2-year report of safety, feasibility, and clinical response.

OBJECTIVE

Parkinson's disease (PD) is characterized by both motor and nonmotor symptoms, including cognitive impairment. Neuronal loss in the nucleus basalis of Meynert (NBM) plays a role in the presentation of cognitive impairment in PD. The implantation of peripheral nerve tissue (PNT) might provide neuroprotective and regenerative capabilities and has shown promising open-label outcomes. The aim of this study was to investigate the safety, feasibility, and clinical outcomes of implanting PNT to the NBM in patients with PD.

METHODS

Seven participants with PD underwent bilateral deep brain stimulation (DBS) electrode implantation to the globus pallidus internus plus unilateral PNT regenerating sural nerve graft to the NBM. Participants were monitored at 6-month intervals postoperatively. Clinical outcome measures included neuropsychological, motor, nonmotor, and quality of life ratings.

RESULTS

All participants completed the 6- and 12-month visits and 5 completed the 24-month visit. There were no serious adverse events related to the study intervention. Neuropsychological performance results were similar to those of patients who underwent DBS standard-of-care procedures without graft implantation. Motor and quality of life ratings were slightly worse, with slight improvements in overall nonmotor scores.

CONCLUSIONS

Unilateral implantation of PNT to the NBM was determined as a safe and feasible procedure such that it did not substantially increase the risk for cognitive decline and dementia beyond rates typically observed in late-stage PD. The current study targeted the NBM, an area not associated with motor symptoms, and the mild progression of motor and quality of life ratings suggest that PNT support might have target-specific clinical effects. These findings support the need for further research in this area, including larger studies that use appropriate control groups.