Bilateral deep brain stimulation of the pedunculopontine nucleus for Parkinson’s disease
Plaha, P. & Gill, S. (2005) Bilateral deep brain stimulation of the pedunculopontine nucleus for Parkinson’s disease , Neuroreport. Nov 28; 16(17):1883-7
The purpose of this article was to look at stimulation of the Pedunculopontine nucleus (PPN) in 2 patients with PD, specifically for better control of gait and postural instability. They reviewed the literature that suggests stimulation of the STN or GPi improves many of the motor features of PD but does not assist with gait or postural instability predominantly in the "off" medication state. They reviewed animal literature that showed stimulation of the PPN increases motor activity. They also discussed that in autopsy studies researchers have found that patients with motor dysfunction (in various diseases) had signs of dysfunction in this nucleus. Patient 1 (60 years old, duration of disease 30 years) and Patient 2 (60 years old, duration of disease 12 years) went through multiple motor/balance tests prior to and after surgery to evaluate the success of bilateral stimulation placement in the PPN. Generators were turned on after 24 hours and adjusted over the course of a few days. They found that both patients had improvement in gait, postural instability, and other motor features of PD in both the on and off medication states. The authors noted there were no medical or cognitive complications for either patient. They also discussed the stimulation parameters and found in both patients that lower frequencies worked better than higher frequencies. It should be noted that there was a relatively short follow-up time of these patients and that they should be followed long term to fully evaluate improvement in motor functions as well as other possible long term effects. They concluded by discussing the proposed pathways of the PPN that improve gait and postural and recommend that additional research focus on the PPN to improve motor functioning in patients with PD.