09 July 2020
Electrical stimulation for Parkinson's disease
Published online 6 April 2010
Gait difficulties and falling are among the biggest problems patients with advanced Parkinson's disease face. Medication remains, however, ineffective in improving these complications. Some initial experiments on non-human primates suggest that the pedunculopontine nucleus (PPN) in the brain might be responsible for the control of posture.
Researchers from Canada and Saudi Arabia conducted the first research into the effect of deep brain stimulation of the PPN in patients with advanced Parkinson's disease. The test involved the surgical implantation of electrodes in the PPN area of the brain to produce varying degrees of electrical stimulation.
Following acute stimulation, the double-blinded study on six patients showed an improvement in falls of >70% for those both on and off Parkinson's disease medication. The results lasted for 12 months after the stimulation. Three months after surgery, this was even accompanied by some considerable improvements in gait; however, these decreased 12 months after the initial stimulation. Continuous stimulation of the PPN gave no improvement at 3 or 12 months after surgery. The exact mechanisms-of-action of the stimulation on the PPN remain to be determined, although the researchers do have some hypotheses.
They also note that, at the end of the experiment, there were no permanent adverse effects related to the stimulation. This is important to assess the benefits versus the risks of the procedure. It does not, however, reduce the risks associated with the surgery itself.