Abstract
Patients with Parkinson’s disease (PD) often experience pain, which fluctuates in “on” and “off” states, but the underlying mechanism is unclear. The nucleus accumbens (NAc) is a central component of the mesolimbic dopaminergic pathway involved in pain processing. We conducted resting-state functional magnetic resonance imaging (rsfMRI) analysis to explore the relationship between the neuronal synchronization of NAc with pain-related brain regions and pain intensity in “on” and “off” states. We assessed 23 patients with sporadic PD based on rsfMRI and pain intensity using the revised Short-Form McGill Pain Questionnaire. Patients with PD displayed higher pain intensity scores in the “off” state than in the “on” state. The pain intensity in the “off” state was substantially correlated with the functional connectivity (FC) between the NAc and primary motor/sensory cortices and contralateral NAc. Changes in pain intensity from the “on” to “off” state displayed correlations with those between the right (rNA) and left NAc (lNAc) and the right precentral gyrus (rPreCG) /right insular cortex (rIC) from the “off” to “on” state. Aberrant bilateral NAc and rNAc–rPreCG/rIC FC in the “off” state were closely related to pain symptoms developed from the “on” to “off” states. These results suggest that the NAc in the mesolimbic pathway is related to pain in PD and may help understand the mechanism of pain development in patients with PD.
Highlights
In recent years, researchers have gained interest in non-motor symptoms of Parkinson’s disease (PD)
There was a non-significant trend for higher continuous, intermittent, and neuropathic subscale scores of SF-MPQ-2 in the “off” state than in the “on” state (p = 0.11, 0.12, and 0.12, respectively). These results indicate that patients with PD experience pain, as well as motor disability, during the “off” state in their daily life
We conducted an resting-state functional magnetic resonance imaging (rsfMRI) analysis in patients with PD to explore the relationship between neuronal synchronization of the nucleus accumbens (NAc) and pain
Summary
Researchers have gained interest in non-motor symptoms of Parkinson’s disease (PD). Several non-motor symptoms, including pain, affect patients with PD [1]. Most patients with PD perceive pain as the most challenging symptom at all stages of the disease [2]. Pain symptoms tend to worsen in the “off” state [3]. Oral antiparkinsonian drugs affect the fluctuation of pain, suggesting the dopaminergic fluctuation associated with pain in PD [4]. This pain is often underrecognized and undertreated, which can be attributed to inadequate understanding of the associated mechanism
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
