Parkinson’s fighters often complain about unexplained pain in the form of burning, aching, itching, or tingling sensations that have no direct relation to motor symptoms of the disease. Scientists have discovered a novel brain network that has a strong link to this chronic pain in Parkinson’s disease (PD).
As per a research report in the journal eLife, a subset of neurons in part of the brain (the subthalamic nucleus) is a potential target for pain relief in the neurodegenerative disorder. The subthalamic nucleus can also be targeted to relieve pain in dementia and certain forms of migraines.
Lead author of the research journal, Arnaud Pautrat said, “In this study, we set out to determine whether the subthalamic nucleus is involved in translating a harmful stimulus such as injury into pain and whether this information transmission is altered in Parkinson’s.” Pautrat’s team started the experiment by using electrophysiology to gauge the firing of electrical signals in nerve cells in the subthalamic nucleus of rats. The stimulation temporally activated nerve cells. To know where the pain signals to the subthalamic nucleus were coming from, the team looked at two brain structures: the superior colliculus and the parabrachial nucleus.
Blocking their activity revealed that both structures play a crucial role in transmitting pain information to the subthalamic nucleus. A direct communication pathway also exists between the parabrachial nucleus and the subthalamic nucleus. Thus, it was concluded that this pathway is expected to be involved in the beneficial effects of Deep Brain Stimulation (DBS) on pain in Parkinson’s. These novel insights could help to target stimulation to specific parts of the brain to work as a pain reliever.
Till now, Deep Brain Stimulation treatment in the subthalamic nucleus has been shown to help patients with the movement-related symptoms of Parkinson’s. But, as per this recent study, it can also reduce pain. The mechanism to minimize pain is still unclear and demands further research.