Research

Stefani A, Roberto C, Livia B, Mariangela P, Alberto C, Salvatore G, Fabio P, Andrea R, Cesare I, Francesco M, Antonella P. (2009). Non-motor functions in parkinsonian patients implanted in the pedunculopontine nucleus: Focus on sleep and cognitive domains.. , J Neurol Sci. 2009 Sep 16. [Epub ahead of print].

This is a follow-up article from an earlier study (see citation below) that looked at the efficacy of bilateral deep brain stimulation of both the Subthalamic Nucleus (STN) and the Pedunculopontine (PPN; another target under evaluation for the surgical treatment of PD).  The researchers initially wanted to look at the efficacy of both targets combined on motor functioning in the person with Parkinson ’s disease (PWP).  Their findings suggested that both targets were effective in reducing motor difficulties but more so for DBS-STN (STN 54% vs. PPN 32% improvement).  The follow-up study focused on how this dual-targeted treatment affects various non-motor functions in the PWP, specifically sleep and cognition.  The authors found that all six of the patients were classified as poor sleepers but with the PPN and STN in specific settings, patients had an increase in the quality of nighttime sleep as compared to DBS-STN settings alone.  Patients also reported less “restlessness, psychosis, and daytime sleepiness.”  In regard to cognitive functioning, the patients were found to have better working memory, executive functioning, response times, and delayed memory with various settings of the PPN as compared to when the PPN stimulator settings were off.  Metabolism changes in various frontal lobe brain areas were also found and discussed (we would refer the reader to the article for those details).  The authors purported that although the DBS-PPN was not as efficacious as the DBS-STN for motor improvement, it did have less cognitive side effects, which suggests it may be used as an alternative for patients that do not qualify for STN due to existing cognitive deficits.  They noted that research must continue to look into how the DBS works in various sites in the brain as well as maximizing the PWP’s quality of life as well as reduction in motor difficulties.