First comprehensive tool for screening pain in Parkinson's disease: the King's Parkinson's Disease Pain Questionnaire

The Impact of Fatigue on Sleep and Other Non-Motor Symptoms in Parkinson's Disease

Fatigue is a common non-motor symptom in Parkinson's disease (PD), but even so, it may still be underdiagnosed or misdiagnosed in current practice due to its non-specific manifestations. The aims of this study were to investigate the prevalence of fatigue in PD patients compared to healthy controls and to identify the main characteristics and associations of fatigue with other non-motor symptoms and the impact of fatigue on sleep disturbances in Parkinson's disease.

MATERIALS AND METHODS

case-control study in which 131 PD patients and 131 age- and sex-matched controls were enrolled. Main characteristics of fatigue, sleep, and other non-motor symptoms were assessed using specific validated questionnaires.

RESULTS

According to the Chalder fatigue scale, fatigue is more prevalent in PD patients (38.16%) compared to healthy controls (26.71%). Fatigue was identified in 46.54% of the PD patients using the Parkinson's Fatigue Scale (PFS-16). PD patients with fatigue presented a worse motor status, more sleep disturbances (insomnia, daytime sleepiness), a broader spectrum of non-motor symptoms (pain, anxiety, urinary disturbances), worse cognitive performances, a lower level of happiness, and worse quality of life compared to PD patients without fatigue.

CONCLUSION

Fatigue is a common symptom of PD and needs to be assessed, considering its consequences on quality of life. Sleep disturbances have a great influence over fatigue in PD patients.

Translation, cultural adaptation and validation of the Arabic version of the king's Parkinson's disease pain scale

PURPOSE

Pain in Parkinson's disease (PD) is a highly prevalent non-motor symptom occurring in this population. The King's PD Pain Scale (KPPS) was developed to assess pain in people with PD. This study aimed to provide a cross-cultural adaptation and translation of the KPPS into the Arabic language (A-KPPS), and to investigate the construct and convergent validity, internal consistency, and reliability of the translated scale.

MATERIALS AND METHODS

The English KPPS was translated into Arabic and back-translated into English by an independent translation team. The Arabic version was tested in 103 native Arabic speaking PD patients. We assessed construct validity, convergent validity, and test-retest reliability of the A-KPPS using factor analysis method, comparison with other valid and reliable measures, and using intra-class correlations, respectively.

RESULTS

The A-KPPS had three main factors "somatic pain", "visceral and burning pain" and "orofacial pain", rather than the original four factors scale. The A-KPPS correlated with measures of disease motor severity, depression, anxiety, quality of life and pain (p < 0.05). Furthermore, the A-KPPS total score had high test-retest reliability (ICC = 0.9).

CONCLUSIONS

The A-KPPS demonstrated moderate to good validity and reliability. The A-KPPS can facilitate the assessment and treatment of pain in Arabic-speaking people with PD worldwide.

Statistical analysis and generative Artificial Intelligence (AI) for assessing pain experience, pain-induced disability, and quality of life in Parkinson's disease patients

The Parkinson's Disease (PD) is a chronic neurodegenerative condition characterized by motor symptoms such as tremors, rigidity, and bradykinesia, which can significantly impact various aspects of daily life. Among these aspects, pain is a prominent element. Despite the widespread use of therapies aimed at improving symptoms and quality of life, effective pain management is essential to enhance the quality of life of individuals affected by this disease. However, a detailed understanding of the factors associated with pain in PD is still evolving. In this study, we examined the disability caused by pain and the pain experienced by PD patients using two validated questionnaires, namely the Parkinson's Disease Questionnaire (PDQ) and the King's Parkinson's Disease Pain Questionnaire (KPPQ). Customized questions were also included to further explore the pain experience and management strategies adopted by PD patients. Through statistical analysis, we explored the relationships between questionnaire scores, socio-demographic data, and other relevant variables. Additionally, generative Artificial Intelligence (AI) was employed to gain a deeper understanding of patient responses. The results indicate the extent and impact of pain in PD and provide valuable insights for more targeted and personalized management. This study lays the foundation for future research and the development of interventions aimed at improving the quality of life for individuals affected by this condition.

Validation study of the Japanese version of the King's Parkinson's Disease Pain Scale and the King's Parkinson's Disease Pain Questionnaire

INTRODUCTION

The King's Parkinson's Disease Pain Scale (KPPS)/King's Parkinson's Disease Pain Questionnaire (KPPQ) was developed as a tool to quantitatively assess pain in patients with Parkinson's disease (PwPD). Here, we conducted a Japanese multicenter validation study to verify the reliability of KPPS/KPPQ in Japanese PwPD.

METHODS

PwPD, ≥20 years, with unexplained pain were included; those with a definitive primary cause of pain other than PD were excluded. A total of 151 patients who fulfilled the criteria were analyzed, and test-retest reliability was investigated in 25 individuals.

RESULTS

The 151 patients included 101 women (66.9 %); mean age 68.3 ± 9.9 years, mean disease duration 9.2 ± 5.2 years. The most frequent pain type in the KPPS classification was musculoskeletal pain (82.8 %). There was a positive correlation between KPPS total score and the Non-Motor Symptoms Scale (NMSS) total score, NMSS item 27, the Parkinson's disease sleep scale-version 2 (PDSS-2) total score, PDSS-2 item 10, the Parkinson's Disease Questionnaire-8 (PDQ-8) summary index and PDQ-8 item 7. Cronbach's alpha of KPPS was 0.626 (0.562-0.658) and the intraclass correlation coefficient of test-retest reliability was 0.740. Cronbach's alpha of KPPQ was 0.660 (0.617-0.705) and a test-retest reliability of kappa coefficient was 0.593 (0.0-1.0).

CONCLUSIONS

KPPS correlated well with other scales for assessing pain. KPPS correlated well with patients' quality of life, non-motor symptoms, and sleep disturbances. The reproducibility of KPPS/KPPQ makes it suitable for continuous evaluation of the same patient. On the other hand, the internal consistency of KPPS/KPPQ is rather low.

Higher cortical excitability to negative emotions involved in musculoskeletal pain in Parkinson's disease

OBJECTIVE

Changes in brain structure and neurotransmitter systems are involved in pain in Parkinson's disease (PD), and emotional factors are closely related to pain. Our study applied electroencephalography (EEG) to investigate the role of emotion in PD patients with chronic musculoskeletal pain.

METHODS

Forty-two PD patients with chronic musculoskeletal pain and 38 without were enrolled. EEG data were recorded under resting conditions, and while viewing pictures with neutral, positive, and negative content. We compared spectrum power, functional connectivity, and late positive potential (LPP), an event-related potential (ERP), between the groups.

RESULTS

PD patients with pain tended to have higher scores for the Hamilton Rating Scale for Depression (HRSD). In the resting EEG, mean β-band amplitude was significantly higher in patients with pain than in those without. Logistic regression analysis showed that higher HRSD scores and higher mean β-band amplitude were associated with pain. ERP analysis revealed that the amplitudes of LPP difference waves (the absolute difference between positive and negative condition LPP and neutral condition LPP) at the central-parietal region were significantly reduced in patients with pain (P = 0.029). Spearman correlation analysis showed that the amplitudes of late (700-1000 ms) negative versus neutral condition LPP difference waves were negatively correlated with pain intensity, assessed by visual analogue scale, (r = -0.393, P = 0.010) and HRSD scores (r = -0.366, P = 0.017).

CONCLUSION

Dopaminergic and non-dopaminergic systems may be involved in musculoskeletal pain in PD by increasing β-band activity and weakening the connection of the θ-band at the central-parietal region. PD patients with musculoskeletal pain have higher cortical excitability to negative emotions. The changes in pain-related EEG may be used as electrophysiological markers and therapeutic targets in PD patients with chronic pain.

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.

King's Parkinson's Disease Pain Questionnaire: reliability and convergent construct validity

OBJECTIVES

to assess the evidence of reliability and convergent construct validity of the King's Parkinson's Disease Pain Questionnaire.

METHODS

psychometric study of 75 older adults with Parkinson's disease. The instrument was applied by two researchers separately and reapplied by one researcher 15 days later. In terms of reliability, internal consistency was assessed using the Cronbach's alpha test and stability using the intraclass correlation coefficient. Scores of the King's Parkinson's Disease Pain Questionnaire were compared to those of the Geriatric Pain Measure in the assessment of construct validity.

RESULTS

the mean Cronbach's alpha obtained between the three assessments was above 0.60, the intraclass correlation between the three assessments was above 0.90, and there was a weak but significant correlation between the two applied scales.

CONCLUSIONS

the instrument showed adequate evidence of convergent construct validity and reliability, and can be used in clinical practice.

[Characteristics and treatment of pain in Parkinson's disease]

Pain is a representative non-motor symptom in patients with Parkinson's disease (PD). Pain is one of the most common symptoms that plague patients with PD regardless of the stage of the disease, also it can exacerbate other symptoms, such as depression, anxiety or sleep disturbance, and lead to impaired quality of life. However, pain is often not adequately evaluated and treated. PD patients complain of a wide variety of pain, including both PD-related pain which caused by PD-specific symptoms, for example, rigidity, bradykinesia or motor fluctuation, and PD-unrelated pain, and it can be divided into central and peripheral depending on the site of the disorder. In the medical care of the pain, it is important to evaluate the type and severity of the pain using PD-specific assessment scales such as King's PD pain scale and to consider the evidence-based treatment methods according to the pathophysiology of the pain.

Ethnic Disparities in Treatment of Chronic Pain in Individuals with Parkinson's Disease Living in the United Kingdom

Background

Over 80% people with Parkinson's disease (PD; PwP) live with chronic pain.

Objective

Whether ethnic disparities in receipt of appropriate analgesia exist among PwP with chronic pain living in the United Kingdom (UK).

Methods

A retrospective datamining of an existing King's PD Pain Questionnaire validation study dataset enrolling 300 PwP.

Results

69 PwP: 23 Black (57% female), 23 Asian (57% female) and 23 White (65% female) had similar pain burden on the King's PD Pain Scale. Significantly more White PwP (83%) received pain relief compared to Black (48%) and Asian (43%) PwP (p = 0.016). The difference was most evident for opioid analgesics (White 43% vs. Black 4% vs. Asian 4%, p ≤ 0.001).

Conclusions

Ethnic disparities in the analgesic use among PwP with chronic pain living in the UK are evident in this retrospective analysis, prompting large‐scale studies and reinforcement of interventions to tackle the impact ethnicity might have on the successful analgesia.

[Japanese translation and linguistic validation of King's Parkinson's Disease Pain Scale (KPPS) and King's Parkinson's Disease Pain Questionnaire (KPPQ)]

Pain is one of the most frequent non-motor symptoms associated with Parkinson's disease (PD) and it has a great impact on patient's quality of life. Thus, its quantitative evaluation is critical in establishing therapeutic evidence. The King's Parkinson's Disease Pain Scale (KPPS) was introduced as a scale of pain specific to PD in 2015. As a follow-up to the evaluator-based KPPS, the patient-based questionnaire, the King's Parkinson's Disease Pain Questionnaire (KPPQ), was introduced in 2018. We developed a linguistically validated Japanese version of the KPPS and KPPQ, and the process of its construction is reported in this study.

Translation, adaptation and validation of the Bulgarian version of the King's Parkinson's Disease Pain Scale

Background

The purpose of the present study was to translate and cross-culturally adapt the King’s Parkinson’s Disease Pain Scale (KPPS) into Bulgarian and to investigate its psychometric properties in order to provide a validated Parkinson’s disease-specific pain instrument in Bulgarian language (KPPS-BG).

Methods

Translation into Bulgarian and a cultural adaptation were performed to obtain KPPS-BG. A total of 162 patients with idiopathic Parkinson’s disease were screened for pain using the complementary to the KPPS questionnaire – King’s Parkinson’s Disease Pain Questionnaire (KPPQ). KPPS-BG domain and total scores were calculated and internal consistency, construct validity and test-retest reliability were examined for 129 patients having one or more positive items in the KPPQ-BG.

Results

79.6 % of the patients reported one or more types of pain. The most common type was musculoskeletal pain (83.7 %), followed by nocturnal pain (55.0 %), fluctuation-related pain (50.1 %), radicular pain (43.4 %), chronic pain (31.0 %), discoloration, edema/swelling (27.1 %) and, oro-facial pain (14.3 %). Mean KPPS-BG total score was 21.1 ± 17.3 SD. KPPS-BG showed a good reliability (Cronbach’s alpha 0.75). The test-retest reliability of the KPPS-BG was high and the intraclass correlation coefficient was 0.92, demonstrating а good repeatability. KPPS-BG total score was higher in patients with postural instability gait difficulty motor subtype, compared to tremor-dominant or indeterminate subtype. Significant positive correlations were found between KPPS-BG total score and modified H&Y, Movement Disorders Society Unified Parkinson’s Disease Rating Scale part III.

Conclusions

The KPPS-BG constitutes a reliable, comprehensive and useful tool for pain assessment in native Bulgarian patients with Parkinson’s disease.

Diagnosis and Management of Pain in Parkinson's Disease: A New Approach

Pain is a frequent and disabling non-motor feature of Parkinson's disease (PD). The recently proposed PD Pain Classification System (PD-PCS) allows for an association of pain with PD to be determined before being allocated to the main pain mechanism (i.e. nociceptive, neuropathic, and nociplastic). In this article, previous studies on treatments for pain in PD are summarized according to the pain mechanisms. A mechanistic approach to treatment is discussed. We suggest that the first step should be optimizing dopaminergic therapy before other therapy is started. When these treatments remain unsuccessful, further causes of pain must be considered. The role of drugs, invasive treatments, and physiotherapeutic interventions are discussed with a focus on older PD patients and considering polypharmacy, altered pharmacokinetics, and comorbidities.

Parkinson's Disease in Romania: A Scoping Review

Parkinson's disease (PD) is a significant cause of disability, with a fast-growing prevalence. This review summarizes the epidemiological and clinical data, research on the diagnostic approaches and the interventions available in the Eastern European country of Romania. This scoping review follows the recommendations on the scoping review methodology by Joanna Briggs Institute. We searched four databases (up to 27 January 2021). The data of eligible studies were extracted in standardized forms. We identified 149 unique studies from 1133 records, with 11 epidemiological studies, 52 studies investigating clinical aspects of PD, 35 studies on diagnostic tools, and 51 intervention studies. A narrative synthesis is provided and placed in a historical context. Our review revealed a considerable increase in the Romanian research on PD in the latest 15 years, which largely follows international trends. However, we also identified several research gaps that provide useful information for policymakers, public health specialists, and clinicians.

King's Parkinson's disease pain scale cut-off points for detection of pain severity levels: A reliability and validity study

BACKGROUND

Pain is one of the most common non-motor symptoms in Parkinson's disease (PD). Using an appropriate and specific measuring tool would be helpful in managing the pain. King's Parkinson's disease Pain Scale (KPPS) is an instrument designed to specifically measure pain in people with PD.

PURPOSE

This study aimed to examine the psychometric properties of the Persian version of KPPS (KPPS-P) and its cut-off points for pain severity levels.

METHODS

A total of 480 people with PD (with a mean (SD) age of 60.89 (10.98)) were recruited. The acceptability of KPPS-P was calculated. The structural validity and discriminant validity for different levels of pain was explored via the factor analysis, and Receiver Operating Characteristics (ROC) curves, respectively. Internal consistency, test-retest, and inter-rater reliability were estimated by Cronbach's alpha and Interclass Correlation coefficient (ICC). Convergent validity was established between KPPS-P and other scales including Visual Analog Scale-Pain, Douleur Neuropathic 4, Brief Pain Inventory, Short-form McGill Pain Questionnaire-2, and Parkinson's Disease-8.

RESULTS

A significant floor effect was observed. The exploratory factor analysis revealed 4 factors. Cronbach's alpha and ICC values were higher than 0.80. The correlation range between KPPS-P and other scales was 0.35-0.76. Cut-off points of 0, 17, and 68 were obtained to discriminate pain severity levels between no pain, mild, moderate, and severe pain, respectively, with sensitivity and specificity above 0.80.

CONCLUSION

Our results indicate that the Persian version of KPPS not only has acceptable psychometric properties to assess pain in PD but also has the ability to distinguish between different levels of pain severity.

Clinical Rating Scales and Quantitative Assessments of Movement Disorders

This article reviews scales that have been developed for, validated in, and/or frequently used across multiple movement disorders with a focus on assessment of motor and nonmotor symptoms of Parkinson disease. Rating scales used in other disease states include those for essential tremor, dystonia (generalized dystonia, cervical dystonia, and blepharospasm), Tourette syndrome, Huntington disease, tardive dyskinesia, Wilson disease, ataxia, and functional movement disorders. Key features of each scale as well as cited criticisms and limitations of each scale are also discussed. Lastly, the article briefly discusses the emerging role of digital assessment tools (both wearable devices and digital interface applications).

Potential of animal models for advancing the understanding and treatment of pain in Parkinson's disease

Pain is a commonly occurring non-motor symptom of Parkinson’s disease (PD). Treatment of pain in PD remains less than optimal and a better understanding of the underlying mechanisms would facilitate discovery of improved analgesics. Animal models of PD have already proven helpful for furthering the understanding and treatment of motor symptoms of PD, but could these models offer insight into pain in PD? This review addresses the current position regarding pain in preclinical models of PD, covering the face and predictive validity of existing models and their use so far in advancing understanding of the mechanisms contributing to pain in PD. While pain itself is not usually measured in animals, nociception in the form of thermal, mechanical or chemical nociceptive thresholds offers a useful readout, given reduced nociceptive thresholds are commonly seen in PD patients. Animal models of PD including the reserpine-treated rat and neurodegenerative models such as the MPTP-treated mouse and 6-hydroxydopamine (6-OHDA)-treated rat each exhibit reduced nociceptive thresholds, supporting face validity of these models. Furthermore, some interventions known clinically to relieve pain in PD, such as dopaminergic therapies and deep brain stimulation of the subthalamic nucleus, restore nociceptive thresholds in one or more models, supporting their predictive validity. Mechanistic insight gained already includes involvement of central and spinal dopamine and opioid systems. Moving forward, these preclinical models should advance understanding of the cellular and molecular mechanisms underlying pain in PD and provide test beds for examining the efficacy of novel analgesics to better treat this debilitating non-motor symptom.

Toward more focused multimodal and multidisciplinary approaches for pain management in Parkinson's disease

In Parkinson’s disease (PD), pain represents a significant issue in terms of prevalence, clinical features, and treatment. Painful manifestations not strictly related to the disease are often amplified by the motor dysfunction. On the other hand, typical pain problems may specifically concern this vulnerable population. In turn, pain may have a deep impact on patients’ health-related quality of life. However, pain treatment in PD remains an unmet need as only about half of patients with pain use analgesics and pain is often managed by simply increasing doses of PD medications. In this complex scenario, pain treatments should follow multimodal approaches through a careful combination of pharmacological agents with non-pharmacological strategies, depending on the type of pain and the clinical context. A multidisciplinary approach involving medical specialists from different disciplines could be a winning strategy to address the issue. This work is aimed to provide practical suggestions useful for different types of clinicians and care professionals for pain management in this vulnerable population.

Resting-state Functional MRI in Parkinsonian Syndromes

Background

Functional MRI (fMRI) has been widely used to study abnormal patterns of functional connectivity at rest in patients with movement disorders such as idiopathic Parkinson's disease (PD) and atypical parkinsonisms.

Methods

This manuscript provides an educational review of the current use of resting-state fMRI in the field of parkinsonian syndromes.

Results

Resting-state fMRI studies have improved the current knowledge about the mechanisms underlying motor and non-motor symptom development and progression in movement disorders. Even if its inclusion in clinical practice is still far away, resting-state fMRI has the potential to be a promising biomarker for early disease detection and prediction. It may also aid in differential diagnosis and monitoring brain responses to therapeutic agents and neurorehabilitation strategies in different movement disorders.

Conclusions

There is urgent need to identify and validate prodromal biomarkers in PD patients, to perform further studies assessing both overlapping and disease-specific fMRI abnormalities among parkinsonian syndromes, and to continue technical advances to fully realize the potential of fMRI as a tool to monitor the efficacy of chronic therapies.

Relationship of Nocturnal Sleep Dysfunction and Pain Subtypes in Parkinson's Disease

Background

Little research has been conducted regarding the relationship between sleep disorders and different pain types in Parkinson's disease (PD).

Objective

To explore the influence of the various pain subtypes experienced by PD patients on sleep.

Methods

Three hundred consecutive PD patients were assessed with the PD Sleep Scale-Version 2 (PDSS-2), King's PD Pain Scale (KPPS), King's PD Pain Questionnaire (KPPQ), Visual Analog Scales for Pain (VAS-Pain), and Hospital Anxiety and Depression Scale.

Results

According to the PDSS-2, 99.3% of our sample suffered from at least one sleep issue. Those who reported experiencing any modality of pain suffered significantly more from sleep disorders than those who did not (all, P < 0.003). The PDSS-2 showed moderate-to-high correlations with the KPPS (r_S = 0.57), KPPQ (0.57), and VAS-Pain (0.35). When PDSS-2 items 10 to 12 (pain-related) were excluded, the correlation values decreased to 0.50, 0.51, and 0.28, respectively, while these items showed moderate-to-high correlations with KPPS (0.56), KPPQ (0.54), and VAS-Pain (0.42). Among the variables analyzed, multiple linear regression models suggested that KPPS and KPPQ were the most relevant predictors of sleep disorders (as per the PDSS-2), although following exclusion of PDSS-2 pain items, depression was the relevant predictor. Depression and anxiety were the most relevant predictors in the analysis involving the VAS-Pain. Regression analysis, considering only the KPPS domains, showed that nocturnal and musculoskeletal pains were the best predictors of overall nocturnal sleep disorder.

Conclusions

Pain showed a moderate association with nocturnal sleep dysfunction in PD. Some pain subtypes had a greater effect on sleep than others.