Characterization of nociplastic pains in Parkinson’s disease (PD) with the PD pain classification system (PD-PCS).

MYLIUS V; PEREZ LLORET, SANTIAGO; FISCH N; GOZENBACH R; KAGI G; MOLLER J; BRUGGER F; CIAMPI DE ANDRADE D

Congreso; 25th International Congress of Parkinson?s Disease and Movement Disorders; 2022

Objective To describe the new category of nociplastic pain (NP). We defined Parkinson´s disease (PD)-related pains and allocated them to a mechanistic category by using the PD Pain Classification System (PD-PCS) questionnaire [1].Background: NP has been defined as pain with altered nociception following the exclusion of neuropathic and nociceptive pain [2]. NP pain in PD have been poorly described, which difficult their diagnosis and treatment.Methods: We evaluated 100 non-demented PD patients during the On phase in three centres by the PD-PCS questionnaire, which defines PD-related pain when 1 out of 4 criteria are met: pain is present at the beginning of the disease, or is aggravated at the Off-phase, or during dyskinesia, or responds to dopaminergic treatment. Then, the pain syndrome is allocated to a pain mechanism (neuropathic, nociceptive, and NP) in a hierarchical fashion. Finally, a severity score is obtained including intensity, frequency, and impact. In addition, demographic data, motor symptoms, pain (BPI), wearing-off (WOQ9), quality of life (PDQ8), mood (HADS), and cognition (MMSE, MoCA) were assessed.Results: The mean disease duration was 75 yrs (mean age: 718 yrs). MDS-UPDRS III and IV scores were 3013 and 44 points. 92% of the patients presented with at least one pain (1.91), with a duration of 7.510 yrs, and a rating of 3.72 on the numeric rating scale. 9% had neuropathic (2% central, 7% peripheral), 57% nociceptive (48% localized, 16% myofascial pain), 27% NP (21% leg motor restlessness pain, 5 % non-motor off, 2% others), and 54% exhibited non PD-related pain. NP patients presented with longer disease duration, higher motor scores, and more Off time. However, dopaminergic responsiveness of pain was similar in both groups (43 vs 44 %). Patients with NP pains had lower MMSE and MoCA scores. Finally, the severity score of NP was lower compared to other kind of pains. Conclusion: Our results, obtained by the recently validated PD-PCS, suggest that NP is the second most common pain in PD including mostly motor restlessness and non-motor off pains with a relatively low severity score. However, pain assessment may be limited due to cognitive deterioration [3]. The findings of longer disease duration and increased off time in patients with NP pains, suggest that an optimized dopaminergic schedule may improve them.