The phenomenology of pain in Parkinson's disease

Pain characterization in patients with Parkinson's disease

BACKGROUND

Patients with Parkinson's disease (PD) often report chronic pain, which is one of the most complex non-motor symptoms. Therefore, this study aims to review the literature on the characteristics of pain in patients with PD.

METHODS

A systematic literature review was conducted following MOOSE recommendations. Observational studies reporting pain in patients with PD were included. No time restrictions were applied, but studies in Portuguese, Spanish, and English were considered. The search was performed in PubMed®, LILACS, and SciELO databases.

RESULTS

Twenty-six articles of observational studies were identified, reporting an average pain prevalence of 67.36%, emphasizing the significance of this symptom in the PD population. Pain was reported in various body regions, including lower limbs, upper limbs, lumbar spine, cervical spine, and other joints. Pain classification varied, encompassing musculoskeletal pain, PD-related pain, neuropathic pain, and dystonic pain, among others.

DISCUSSION

Pain in patients with PD is a prevalent and multifactorial condition, significantly impacting patients' quality of life.

CONCLUSION

Heterogeneity in data across included studies was observed, highlighting the need for additional research to elucidate the underlying mechanisms of pain in patients with PD and develop effective therapeutic strategies to address this symptom and improve the quality of life for individuals living with the disease.

Towards a better Comprehension and Management of Pain and Psychological Distress in Parkinson's: The Role of Catastrophizing

OBJECTIVES

Pain is very prevalent in Parkinson's and challenging to manage. As many people with Parkinson's (PwP) with pain suffer from anxious and depressive symptoms, we examined the role of catastrophizing in mediating the relationship between pain and psychological distress for this population.

METHODS

169 international PwP completed an online survey with socio-demographic and medical data. Participants completed psychometric tests to assess their pain (King's Parkinson's Disease Pain Questionnaire, McGill Pain Questionnaire and Brief Pain Inventory), psychological distress (Beck Depression Inventory and Parkinson Anxiety Scale), pain coping strategies (Coping Strategies Questionnaire) and pain catastrophizing (Pain Catastrophizing Scale).

RESULTS

Depending on the tool used, 82.8% to 95.2% of participants reported pain. 23.5 % and 67.5% of participants showed respectively significant levels of depressive and anxiety symptoms. Psychological distress was significantly correlated with the quality of pain (both sensory and affective dimensions). Statistical models highlighted the mediating role of catastrophizing in the relationship between psychological distress and pain in Parkinson's.

CONCLUSION

These findings offer new perspectives toward understanding the underlying mechanisms of pain in Parkinson's and for effective therapeutic intervention goals to facilitate adaptation to pain symptoms in Parkinson's.

Clinical Symptoms Influencing Parkinson's Patients' Quality of Life in Latvia: A Single-Center Cohort Study

Background and Objectives: Parkinson's disease (PD) is a chronic, progressive illness with a profound impact on health-related quality of life, and it is crucial to know what factors influence the quality of life throughout the course of the disease. This study aimed to evaluate PD patients' motor and non-motor symptoms to compare symptom severity between PD clinical phenotypes and to assess the impact of disease symptoms on quality of life in a cohort of Latvian patients. Materials and Methods: We evaluated 43 patients with Parkinson's disease. Fourteen patients had tremor dominant (TD) PD, twenty-five patients had postural instability/gait difficulty (PIGD), and four patients had a mixed phenotype. Results: The patients' mean age was 65.21 years, and the disease's mean duration was 7 years. The most common non-motor symptoms were fatigue (95.3%), sleep disturbance (83.7%), daytime sleepiness (83.7%), and pain and other sensations (81.4%). PIGD patients had a higher prevalence of depressed mood, daytime sleepiness, constipation, lightheadedness on standing, cognitive impairment, and severe gastrointestinal and urinary disturbances (as assessed using the SCOPA-AUT domains) compared with TD patients. A high prevalence of fatigue was assessed in both disease subtypes. Health-related quality of life significantly statistically correlated with MDS-UPDRS parts III and IV (r = 0.704), the Hoehn and Yahr scale (r = 0.723), as well as the SCOPA-AUT scale's gastrointestinal (r = 0.639), cardiovascular (r = 0.586), thermoregulatory (r = 0.566) and pupillomotor domains (r = 0.597). Conclusions: The severity of motor symptoms, as well as non-motor symptoms, such as fatigue, apathy, sleep problems and daytime sleepiness, pain, and disturbances in gastrointestinal and cardiovascular function, negatively affect PD patients' health-related quality of life. Thermoregulatory and pupillomotor symptoms also significantly affect PD patients' well-being.

Evaluation of perception threshold and pain in patients with Parkinson's disease using PainVision®

Introduction

Pain is one of the most frequent non-motor symptoms occurring in patients with Parkinson's disease (PD). Traditionally, the Visual Analog Pain Scale (VAS), Numerical Rating Scale (NRS), and Wong-Baker Faces Pain Rating Scale (FRS) have been used for clinical pain assessment, but these assessments are subjective at best. In contrast, PainVision^® is a perceptual/pain analyzer that can quantitatively evaluate pain as "pain intensity" based on "current perception threshold" and "pain equivalent current." We evaluated the current perception threshold in all PD patients and pain intensity in PD patients with pain using PainVision^®.

Methods

We recruited 48 patients with PD (PwPD) with pain and 52 PwPD without pain. For patients with pain, we measured current perception threshold, pain equivalent current, and pain intensity using PainVision^®, in addition to evaluation by VAS, NRS, and FRS. For patients without pain, only current perception threshold was measured.

Results

There was no correlation with either VAS or FRS, whereas only weak correlation was identified for NRS (γ = -0.376) with pain intensity. Current perception threshold was positively correlated with duration of the disease (γ = 0.347) and the Hoehn and Yahr stage (γ = 0.259). As a quantitative evaluation of pain, pain intensity by PainVision^® does not correlate with conventional subjective pain assessments.

Discussion

This new quantitative evaluation method of pain may be suitable as an evaluation tool for future intervention research. Current perception threshold in PwPD was related to the duration and severity of the disease and may be involved in peripheral neuropathy associated with PD.

Pain Assessment in Chinese Parkinson’s Disease Patients Using King’s Parkinson’s Disease Pain Scale

Purpose

Patients and Methods

Results

Conclusion

Musculoskeletal Pain in Parkinson's Disease

BACKGROUND

Musculoskeletal pain is commonly experienced in patients with Parkinson's disease (PD). Few studies have investigated the clinical characteristics and risk factors associated with musculoskeletal pain.

OBJECTIVES

To investigate the distribution, clinical characteristics, and factors associated with musculoskeletal pain in a large sample of patients with PD.

METHODS

We enrolled 452 patients from two clinics and used a standardized questionnaire to collect demographic and clinical information. Musculoskeletal pain was diagnosed based on the Ford Classification System, and pain severity was assessed with the numeric rating scale (NRS). Multivariate regression models explored the association between clinical features of PD and quality of life and pain.

RESULTS

Two hundred and six patients (45.58%) reported musculoskeletal pain, typically in their lower limbs and backs. Levodopa resulted in a ≥30% reduction in pain intensity scores in 170 subjects. Female sex (odds ratio [OR], 1.57; 95% CI, 1.07-2.29) and Levodopa-equivalent daily doses (LEDDs; OR, 3.35; 95% CI, 1.63-6.59) were associated with an increased risk for musculoskeletal pain. Pain duration (p = 0.017), motor symptoms (p < 0.001), and depression (p < 0.001) were significantly associated with quality of life.

CONCLUSIONS

The lower limbs and back are common sites of musculoskeletal pain in patients with PD, and up to 82.52% of patients were responsive to Levodopa. Female sex and LEDDs are associated with musculoskeletal pain, suggesting that dopamine deficiencies, and not the motor and non-motor impairment, might be the most critical baseline risk factor of musculoskeletal pain.

Synergistic antiallodynic and antihyperalgesic interaction between L-DOPA and celecoxib in parkinsonian rats is mediated by NO-cGMP-ATP-sensitive K+ channel

Pain is a usual and troublesome non-motor symptom of Parkinson's disease, with a prevalence of 29-82%. Therefore, it's vital to find pharmacological treatments for managing PD-associated pain symptoms, to improve patients' quality of life. For this reason, we tested the possible synergy between L-DOPA and celecoxib in decreasing allodynia and hyperalgesia induced by unilateral lesioning with 6-OHDA into the SNpc in rats. We also tested whether the antiallodynic and antihyperalgesic effect induced by combination of L-DOPA and celecoxib is mediated by the NO-cGMP-ATP-sensitive K⁺ channel pathway. Tactile allodynia and mechanical hyperalgesia were evaluated using von Frey filament. Isobolographic analyses were employed to define the nature of the drug interaction using a fixed dose ratio (0.5: 0.5). We found that acute and sub-acute (10-day) treatment with a single dose of L-DOPA (3-25 mg/kg, i. p.) or celecoxib (2.5-20 mg/kg, i. p.) induced a dose-dependent antiallodynic and antihyperalgesic effect in parkinsonian rats. Isobolographic analysis revealed that the ED₅₀ values obtained by L-DOPA + celecoxib combination was significantly less than calculated additive values, indicating that co-administration of L-DOPA with celecoxib produces synergistic interactions in its antiallodynic and antihyperalgesic effect in animals with nigrostriatal lesions. Moreover, the antiallodynic and antihyperalgesic effects induced by L-DOPA + celecoxib combination were blocked by intrathecal pre-treatment with L-NAME, ODQ, and glibenclamide. Taken together, the data suggest that L-DOPA + celecoxib combination produces an antiallodynic and antihyperalgesic synergistic interaction at the systemic level, and these effects are mediated, at the central level, through activation of the NO-cGMP-ATP-sensitive K⁺ channel pathway.