To explore a potential link between striatal dopamine transporter re-uptake and musculo-skeletal (MSK) pain in people with Parkinson’s (PwP).

Musculo-skeletal pain is the most frequent pain sub-type (affecting up to 80% of PwP) and appears to be modulated by dopaminergic medication. It is thus conceivable that nigro-striatal dopaminergic pathways might be implicated in the pathogenesis of MSK pain in PwP via central nociceptive processing.

An exploratory, cross-sectional analysis of data from PwP enrolled in the ongoing prospective, observational “Non-motor Longitudinal International Study” (UK National Institute for Health Research Clinical Research Network Number 10084) who underwent Single-photon emission CT (SPECT) scanning with ¹²³I-Ioflupane (DaTSCAN). Age, gender and disease duration were noted and Levodopa Equivalent Daily Dose (LEDD) calculated.

Clinical assessments included: King’s Parkinson’s Disease Pain Scale (KPPS), Hoehn and Yahr (HY) stage and Scales for Outcomes in Parkinson’s Disease Motor scale (SCOPA-Motor).

 Specific DaTSCAN binding ratios were analyzed for each striatum, caudate and putamen.

Differences between the groups were assessed using a Chi-Square test, an independent sample T-test or the Mann-Whitney test, depending on the data distribution (SPSS, Version 26).

44 PwP were included in our analysis; 77% had MSK pain (identified using the KPPS; the MSK+ group) and 23% did not (the MSK- group). Demographic characteristics (MSK+:35% female, MSK-:50% female, p=0.473; age: MSK+:62.47±10.57yrs, MSK-:61.70±10.75yrs, p=0.841), PD-related history (disease duration: MSK+:2.5(0-14)yrs, MSK-:2(1-10)yrs, p=0.841; HY:2(1-4) in both groups, p=0.574; LEDD: MSK+:513.63±349.10mg, MSK-:439±244.01mg, p=0.457) or SCOPA-Motor (MSK+:14.15±8.25, MSK-:12.4±7.34, p=0.55) did not differ significantly. In the MSK+ group, striatal binding ratios were significantly lower (caudate:1.78±0.47 vs. 2.12±0.35, p=0.039; putamen:1.06±0.28 vs. 1.28±0.29, p=0.039; striatum1.45±0.36 vs. 1.73±0.31, p=0.032).