Deep brain stimulation is known to treat the symptoms of stiffness, slow movement, and tremor in people with Parkinson's disease. Researchers are now a step closer to understanding exactly how this electrical stimulation of specific areas in the brain works.
It is thought that part of the underlying problem for people with Parkinson's is the overactivity of certain nerve cells. This overactivity affects the way that information flows from one circuit within the brain to another. In a paper published in the Journal of Neuroscience, researchers describe an experiment using deep brain stimulation that has demonstrated how the technique improves information flow between circuits, probably by calming down the overactive cells.
The researchers tested eye movements in 14 patients and 10 healthy controls. They electrically stimulated an area of the brain called the globus pallidus interna. They showed that this deep brain stimulation partially reverses deficits in voluntary control of eye movements, restoring some control.
The experiment showed improvement in information transfer between higher, cognitive, brain circuits and lower-level motor systems. This may mean that stimulation of the globus pallidus interna could have a positive effect on those symptoms of Parkinson's disease that are not directly movement-related.
Research: Pallidal Deep Brain Stimulation Improves Higher Control of the Oculomotor System in Parkinson's Disease, Chrystalina A. Antoniades, Pedro Rebelo, Christopher Kennard, Tipu Z. Aziz, Alexander L. Green, and James J. FitzGerald, Journal of Neuroscience, doi: 10.1523/JNEUROSCI.2317-15.2015, published 23 September 2015.