Pain perception in Parkinson's disease: A systematic review and meta-analysis of experimental studies

Oxycodone or Higher Dose of Levodopa for the Treatment of Parkinsonian Central Pain: OXYDOPA Trial

BACKGROUND

Among the different types of pain related to Parkinson's disease (PD), parkinsonian central pain (PCP) is the most disabling.

OBJECTIVES

We investigated the analgesic efficacy of two therapeutic strategies (opioid with oxycodone- prolonged-release (PR) and higher dose of levodopa/benserazide) compared with placebo in patients with PCP.

METHODS

OXYDOPA was a randomized, double-blind, double-dummy, placebo-controlled, multicenter parallel-group trial run at 15 centers within the French NS-Park network. PD patients with PCP (≥30 on the Visual Analogue Scale [VAS]) were randomly assigned to receive oxycodone-PR (up to 40 mg/day), levodopa/benserazide (up to 200 mg/day) or matching placebo three times a day (tid) for 8 weeks at a stable dose, in add-on to their current dopaminergic therapy. The primary endpoint was the change in average pain intensity over the previous week rated on VAS from baseline to week-10 based on modified intention-to-treat analyses.

RESULTS

Between May 2016 and August 2020, 66 patients were randomized to oxycodone-PR (n = 23), levodopa/benserazide (n = 20) or placebo (n = 23). The mean change in pain intensity was -17 ± 18.5 on oxycodone-PR, -8.3 ± 11.1 on levodopa/benserazide, and -14.3 ± 18.9 in the placebo groups. The absolute difference versus placebo was -1.54 (97.5% confidence interval [CI], -17.0 to 13.90; P = 0.8) on oxycodone-PR and +7.79 (97.5% CI, -4.99 to 20.58; P = 0.2) on levodopa/benserazide. Similar proportions of patients in each group experienced all-cause adverse events. Those leading to study discontinuation were most frequently observed with oxycodone-PR (39%) than levodopa/benserazide (5%) or placebo (15%).

CONCLUSIONS

The present trial failed to demonstrate the superiority of oxycodone-PR or a higher dose of levodopa in patients with PCP, while oxycodone-PR was poorly tolerated. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

TDCS for parkinson's disease disease-related pain: A randomized trial

OBJECTIVE

To evaluate the effects of transcranial direct current stimulation (tDCS) on Parkinson's disease (PD)-related pain.

METHODS

This triple-blind randomized controlled trial included twenty-two patients (age range 38-85, 10 male) with PD-related pain. Eleven subjects received ten sessions of 20 minutes tDCS over the primary motor cortex contralateral to pain at 2 mA intensity. Eleven subjects received sham stimulation. Outcome measures included changes in the Kinǵs Parkinsońs Pain Scale (KPPS), Brief Pain Inventory (BPI), widespread mechanical hyperalgesia (WMH), temporal summation of pain (TS), and conditioned pain modulation (CPM).

RESULTS

Significant differences were found in KPPS between groups favoring the active-tDCS group compared to the sham-tDCS group at 15-days follow-up (p = 0.014) but not at 2 days post-intervention (p = 0.059). The active-group showed significant improvements over the sham-group after 15 days (p = 0.017). Significant changes were found in CPM between groups in favor of active-tDCS group at 2 days post-intervention (p = 0.002) and at 15 days (p = 0.017). No meaningful differences were observed in BPI or TS.

CONCLUSIONS

tDCS of the primary motor cortex alleviates perceived PD-related pain, reduces pain sensitization, and enhances descending pain inhibition.

SIGNIFICANCE

This is the first study to test and demonstrate the use of tDCS for improving PD-related pain.

Constipation and pain in Parkinson's disease: a clinical analysis

Parkinson's Disease (PD) is a neurodegenerative disorder characterized by both motor and non-motor symptoms (NMS). Among NMS, constipation and pain are both highly prevalent and debilitating affecting up to 80% of PD patients and impairing their quality of life. Here, we investigated the relationship between constipation and pain in PD patients. This is a retrospective study assessing the relationship between pain and constipation in a PD patient population from a clinical database of patients attending the outpatient clinic of the movement disorders division, Neurology Unit of Policlinico Tor Vergata, in Rome. Subjects were assessed with the Unified Parkinson's Disease Rating Scale (UPDRS) part III, Hoehn and Yahr (H&Y) stage, King's Parkinson's Disease Pain Scale (KPPS), Brief Pain Inventory (BPI), Non-Motor Symptoms Scale (NMSS) and Beck Depression Inventory (BDI). Patients were further divided in two groups (Group 1, 32 patients with constipation and Group 2, 35 PD patients without constipation) ANOVA and ANCOVA analysis were used to compare the two groups. PD patients with constipation had significantly higher pain severity and pain interference, as measured by the BPI scale and higher total KPPS score, fluctuation-related pain, nocturnal pain, and radicular pain when compared to PD patients without constipation. This study highlights for the first time a possible interplay between constipation and pain in PD that deserves further investigations.

Setting the clinical context to non-motor symptoms reflected by Park-pain, Park-sleep, and Park-autonomic subtypes of Parkinson's disease

Non-motor symptoms (NMS) of Parkinson's disease (PD) are well described in both clinical practice and the literature, enabling their management and enhancing our understanding of PD. NMS can dominate the clinical pictures and NMS subtypes have recently been proposed, initially based on clinical observations, and later confirmed in data driven analyses of large datasets and in biomarker-based studies. In this chapter, we provide an update on what is known about three common subtypes of NMS in PD. The pain (Park-pain), sleep dysfunction (Park-sleep), and autonomic dysfunction (Park-autonomic), providing an overview of their individual classification, clinical manifestation, pathophysiology, diagnosis, and potential treatments.

The effectiveness and safety of non-pharmacological intervention for pain management in Parkinson's disease: A systematic review

Chronic pain is a non-motor symptom affecting from 60 to 80% of patients with Parkinson's disease (PD). PD patients can suffer from different types of pain, either specific or not specific of the disease, and depending on various pathophysiological mechanisms (nociceptive, nociplastic or neuropathic), which can be present at any stage of the disease. Non-pharmacological interventions (NPIs) are essential to complement routine care interventions in PD pain management. Moreover, in the literature, it has been shown that 42% of PD patients are already using complementary therapies. Hence, our aim was to investigate the effectiveness and safety of NPIs for pain management in PD. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Eighteen published randomized control trials (RCTs) were included between 2004 and 2021 leading to a total of 976 PD patients. From them, we reported fifteen different NPIs classified in seven categories: physical exercises, balneotherapy, manual therapy, acupuncture, botanical preparation, body-psychological practice and multiprotection care. Our results have shown that NPIs for PD pain management had a low-to-moderate level of evidence showing mainly favourable results, even if some NPIs presented inconclusive results. Moreover, our review highlighted the clinical relevance of some specific NPIs in PD pain management: NPIs consisting of active physical activities, opposed to passive activities. The safety of NPIs was also confirmed since only few minor transient adverse events were reported. Nevertheless, even if some interesting results were found, the methodology of future studies needs to be more robust and to include comprehensive descriptions in order to offer reliable and sound recommendations to clinicians.

The Underlying Mechanisms of Sleep Deprivation Exacerbating Neuropathic Pain

Pain disrupts sleep, and sleep deprivation or interference can alter pain perception in animals and humans, for example by increasing sensitivity to pain. However, the mechanism by which sleep affects neuropathic pain remains unclear. In this review, we discuss the available evidence from the epidemiologic, clinical, and human, as well as laboratory studies. In previous studies, we have found that sleep deprivation affects various injurious systems, including opioids, dopaminergic, immune, orexins, hypothalamic-pituitary-adrenal axis, and adenosine. At the same time, these systems play a crucial role in neuropathic pain regulation. In the complex interactions between these neurobiological systems, there may be potential regulatory pathways through which sleep deprivation amplifies neuropathic pain. Because of the impact sleep problems and neuropathic pain can have on the patients' quality of life, studying the link between sleep and neuropathic pain is important for neuropathic pain prevention and public health.

Brain structure and cortical activity changes of new daily persistent headache: multimodal evidence from MEG/sMRI

BACKGROUND

New daily persistent headache (NDPH) is a rare but debilitating primary headache disorder that poses a significant burden on individuals and society. Despite its clinical importance, the underlying pathophysiological mechanisms of NDPH remain unclear. In this study, we aimed to investigate the brain structural changes and neural activity patterns in patients with NDPH using multimodal brain imaging analysis of structural magnetic resonance imaging (sMRI) combined with magnetoencephalography (MEG).

METHODS

Twenty-eight patients with NDPH and 37 healthy controls (HCs) were recruited for this study, and their structural and resting-state data were collected by 3.0 Tesla MRI and MEG. We analyzed the brain morphology using voxel-based morphometry and source-based morphometry. In each brain region, MEG sensor signals from 1 to 200 Hz were analyzed using an adapted version of Welch's method. MEG source localization was conducted using the dynamic statistical parametric mapping, and the difference of source distribution between patients with NDPH and HCs was examined.

RESULTS

Our results revealed significant differences in the regional grey matter volume, cortical thickness, and cortical surface area between the two groups. Specifically, compared with HCs, patients with NDPH showed a significant decrease in cortical thickness of the left rostral cortex in the middle frontal gyrus, decreased cortical surface area of the left fusiform gyrus, decreased grey matter volume of the left superior frontal gyrus and the left middle frontal gyrus, and increased grey matter volume of the left calcarine. Furthermore, the power of the whole brain, bilateral frontal lobes, and right temporal lobe in the NDPH group were higher than that in HCs in the ripple frequency band (80-200 Hz). Functional and structural analysis suggested that there were structural changes and abnormal high frequency cortical activity in both frontal and temporal lobes in patients with NDPH.

CONCLUSION

Our findings indicated that patients with NDPH have abnormalities in brain morphology, such as cortical area, cortical thickness, and grey matter volume, accompanied by abnormal cortical neural activity. Brain structural changes in the frontotemporal cortex and abnormalities in cortical ripple activity may be involved in the pathogenesis of NDPH.

[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.

A Survey of People With Parkinson's and Their Carers: The Management of Pain in Parkinson's

BACKGROUND

Pain in Parkinson's is problematic but under treated in clinical practice. Healthcare professionals must understand the impact of pain in Parkinson's and patient preferences for management.

OBJECTIVE

To understand the impact of pain in Parkinson's and to understand current management and preferences for pain management.

METHODS

We conducted a national survey with 115 people with Parkinson's (PwP) and 10 carers. Both closed and open questions were used. The questions focused on how pain affected the individual, healthcare professional involvement in supporting pain management, current pain management strategies and views on future pain management interventions. We used descriptive statistics to summarize closed responses and thematic analysis to summarize open question responses.

RESULTS

70% of participants reported pain impacted their daily life. Pain had a multifactorial impact on participants, affecting movement, mood and quality of life. Improved pain management was viewed to have the potential to address each of these challenges. Pain affected a number of different sites, with low back pain and multiple sites being most frequently reported. Exercise was the most frequently noted strategy (38%) recommended by healthcare professionals for pain management. PwP would value involvement from healthcare professionals for future pain management, but also would like to self-manage the condition. Medication was not suggested as a first line strategy.

CONCLUSIONS

Despite reporting engagement in some strategies to manage pain, pain still has a wide-ranging impact on the daily life of PwP. Results from this survey highlight the need to better support PwP to manage the impact of pain.

Remifentanil requirement for i-gel insertion is reduced in male patients with Parkinson's disease undergoing deep brain stimulator implantation: an up-and-down sequential allocation trial

Background

Laryngeal mask airways have been widely used in clinical practice. The aim of this study was to investigate whether the remifentanil requirement for facilitation of i-gel insertion in Parkinson’s disease (PD) patients undergoing deep brain stimulation (DBS) surgery was different from that in non-PD (NPD) patients undergoing intracranial surgery.

Study design

An up-and-down sequential allocation trial.

Methods

Male patients aged between 40 and 64 years old were enrolled. The first patient in each group (PD and NPD) group received an effect-site concentration (Ce) of remifentanil (Minto pharmacokinetic model) of 4.0 ng.ml⁻¹ during a target-controlled infusion (TCI) of 3.5 μg.ml⁻¹ propofol (Marsh pharmacokinetic model). The next dose of remifentanil was determined by the response of the previous patient. The Ce of remifentanil required for i-gel insertion in 50% of patients (EC₅₀) was estimated by the modified Dixon’s up-and-down method and by probit analysis.

Results

The PD group included 24 patients and the NPD group included 23. The EC₅₀ of remifentanil for i-gel insertion during a TCI of 3.5 μg.ml⁻¹ propofol estimated by the modified Dixon’s up-and-down method in PD patients (2.38 ± 0.65 ng.ml⁻¹) was significantly lower than in NPD patients (3.21 ± 0.49 ng.ml⁻¹) (P = 0.03). From the probit analysis, the EC₅₀ and EC₉₅ (effective Ce in 95% of patients) of remifentanil were 1.95 (95% CI 1.52–2.36) ng.ml⁻¹ and 3.12 (95% CI 2.53–5.84) ng.ml⁻¹ in PD patients and 2.85 (95% CI 2.26–3.41) ng.ml⁻¹ and 4.57 (95% CI 3.72–8.54) ng.ml⁻¹ in NPD patients, respectively.

Conclusions

The remifentanil requirement for successful i-gel insertion is reduced in male PD patients undergoing DBS implantation during propofol TCI induction. Clinicians should closely monitor the remifentanil requirement in patients with PD.

Trial registration

Registered at http://www.chictr.org.cn (ChiCTR1900021760).

A pain-induced tonic hypodopaminergic state augments phasic dopamine release in the nucleus accumbens

Diseases and disorders such as Parkinson disease, schizophrenia, and chronic pain are characterized by altered mesolimbic dopaminergic neurotransmission. Dopamine release in the nucleus accumbens influences behavior through both tonic and phasic signaling. Tonic dopamine levels are hypothesized to inversely regulate phasic signals through dopamine D2 receptor feedback inhibition. We tested this hypothesis directly in the context of ongoing pain. Tonic and phasic dopamine signals were measured using fast-scan controlled-adsorption voltammetry and fast-scan cyclic voltammetry, respectively, in the nucleus accumbens shell of male rats with standardized levels of anesthesia. Application of capsaicin to the cornea produced a transient decrease in tonic dopamine levels. During the pain-induced hypodopaminergic state, electrically evoked phasic dopamine release was significantly increased when compared to baseline, evoked phasic release. A second application of capsaicin to the same eye had a lessened effect on tonic dopamine suggesting desensitization of TRPV1 channels in that eye. Capsaicin treatment in the alternate cornea, however, again produced coincident decreased dopaminergic tone and increased phasic dopamine release. These findings occurred independently of stimulus lateralization relative to the hemisphere of dopamine measurement. Our data show that (1) the mesolimbic dopamine circuit reliably encodes acute noxious stimuli; (2) ongoing pain produces decreases in dopaminergic tone; and (3) pain-induced decreases in tonic dopamine correspond to augmented evoked phasic dopamine release. Enhanced phasic dopamine neurotransmission resulting from salient stimuli may contribute to increased impulsivity and cognitive deficits often observed in conditions associated with decreased dopaminergic tone, including Parkinson disease and chronic pain.

Towards optimising experimental quantification of persistent pain in Parkinson's disease using psychophysical testing

People with Parkinson's disease (PD) may live for multiple decades after diagnosis. Ensuring that effective healthcare provision is received across the range of symptoms experienced is vital to the individual's wellbeing and quality of life. As well as the hallmark motor symptoms, PD patients may also suffer from non-motor symptoms including persistent pain. This type of pain (lasting more than 3 months) is inconsistently described and poorly understood, resulting in limited treatment options. Evidence-based pain remedies are coming to the fore but therapeutic strategies that offer an improved analgesic profile remain an unmet clinical need. Since the ability to establish a link between the neurodegenerative changes that underlie PD and those that underlie maladaptive pain processing leading to persistent pain could illuminate mechanisms or risk factors of disease initiation, progression and maintenance, we evaluated the latest research literature seeking to identify causal factors underlying persistent pain in PD through experimental quantification. The majority of previous studies aimed to identify neurobiological alterations that could provide a biomarker for pain/pain phenotype, in PD cohorts. However heterogeneity of patient cohorts, result outcomes and methodology between human psychophysics studies overwhelmingly leads to inconclusive and equivocal evidence. Here we discuss refinement of pain-PD paradigms in order that future studies may enhance confidence in the validity of observed effect sizes while also aiding comparability through standardisation. Encouragingly, as the field moves towards cross-study comparison of data in order to more reliably reveal mechanisms underlying dysfunctional pain processing, the potential for better-targeted treatment and management is high.

Pain Sensitivity in Schizophrenia Spectrum Disorders: A Narrative Review of Recent Work

Many patients with schizophrenia seem relatively immune to physical pain while others complain of constant pain. This may result from disturbances or alterations of the sensory threshold for pain in populations with psychosis, a possibility for which there is some preliminary evidence. The inconsistency in pain perception may, in part, be explained by the treatments patients receive, but treatment-naïve patients also exhibit differences in response to pain. This suggests that decreased pain sensitivity may represent a specific psychosis endophenotype. Thus far, few experimental studies have investigated sensory thresholds, pain modalities, or other factors contributing to the perception or expression of physical pain in psychosis. A digital search for information on this topic was conducted in PubMed and Google Scholar. The result is a non-systematic, narrative review focusing on recent clinical and experimental findings of pain sensitivity in patients with psychosis. Importantly, physical and mental pain are closely connected constructs that may be difficult to differentiate. Our hope is that the review provides some clarity to the field in the specific context of schizophrenia.

Chronic pain in Parkinson's disease: Clinical and pathophysiological aspects

Pain is an increasingly recognized non-motor symptom of Parkinson's disease (PD), with significant prevalence and strong impact on quality of life of patients. Moreover, pain can occur with various features in PD and several subtypes may coexist in a same patient, leading to a complex presentation and difficult diagnosis and treatment. In this paper we review the clinical manifestations of painful phenomena in PD, with focus on classifications and algorithms allowing to standardize the diagnosis of pain and PD. We also discuss the pathophysiological mechanisms underlying pain in PD, particularly parkinsonian central pain, in regard to recent clinical, neurophysiological and imaging studies.

An acidic heteropolysaccharide from Lycii fructus: Purification, characterization, neurotrophic and neuroprotective activities in vitro

Regeneration of neurites network constitutes a neurotrophic and therapeutic strategy for Parkinson's disease (PD). Increasing evidence is supporting the potential application of natural polysaccharides in prevention or treatment of PD. In this study, an acidic heteropolysaccharide LFP-1 was isolated from Lycii fructus, and purified by ion-exchange and gel filtration chromatography. Structural features of LFP-1 were analyzed with molecular weight (MW) distribution, monosaccharide composition, methylation and nuclear magnetic resonance (NMR) spectra. LFP-1 was a complicated structured polysaccharide with an average MW of 1.78 × 10⁴ Da and composed of highly branched arabinogalactans, homogalacturonan and rhamnogalacturonan moieties. LFP-1 promoted neuronal differentiation and neurite outgrowth in vitro in PC12 cell models. Furthermore, LFP-1 had a significantly protective effect against 1-methyl-4-phenylpyridiniumion (MPP+)-induced neurotoxicity in PD model PC12 cells. These observations unambiguously indicated the neurotrophic and neuroprotective activities of LFP-1, which may be developed for prevention or treatment of neurodegeneration in PD.

Quantitative Sensory Testing (QST) in Drug-Naïve Patients with Parkinson's Disease

BACKGROUND

Pain is highly prevalent in patients with Parkinson's disease (PD), but underlying pathophysiological mechanisms are largely unclear. Alterations in somatosensory processing might contribute to sensory abnormalities in PD.

OBJECTIVE

This study investigated sensory processing in PD patients.

METHODS

We used the standardized "Quantitative Sensory Testing" (QST) protocol (German Research Network on Neuropathic Pain) to investigate 13 somatosensory parameters in 19 PD patients naïve to dopaminergic medication and 19 healthy controls matched for age, gender, and handedness. We tested for differences in sensory parameters between i) drug-naïve PD patients and healthy controls, ii) patients' more and less affected body side, and iii) for an association of somatosensory parameters with disease-specific factors.

RESULTS

We did not observe any significant group differences in somatosensory parameters between PD patients and healthy subjects. In PD patients, QST mean z-scores did not differ between the predominantly and the less affected body side, PD patients with and without PD-specific chronic pain or between different PD subtypes. Age, but not PD disease severity, was associated with a greater loss of function in thermal and mechanical detection thresholds.

CONCLUSIONS

Somatosensory processing, as assessed with the well-established QST protocol, was normal in drug-naïve PD patients. Thus, somatosensory abnormalities previously reported in medicated PD patients might rather be a result of dopaminergic medication, or may occur later in the course of the disease or with increasing age.

Mørch C, S. Palsson T, Boudreau SA. Modifiable motion graphics for capturing sensations

Objective

The purpose of this study was to assess the relationship between an embodied sensory experience and the ability to translate the perception of this experience visually using modifiable motion graphics.

Methods

A custom-designed software was developed to enable users to modify a motion graphic in real-time. The motion graphics were designed to depict realistic visualizations of pain quality descriptors, such as tingling and burning. Participants (N = 34) received an electrical stimulation protocol known to elicit sensations of tingling. The protocol consisted of eight stimulation intensities ranging from 2—6mA delivered, in a randomized fashion and repeated three times, to the index finger. Immediately after each stimulus, participants drew the area of the evoked sensation on a digital body chart of the hand. Participants then modified the motion graphic of tingling by adjusting two parameters, namely the speed (rate of dots disappearing and re-appearing) and density of these dots in the drawn area. Then, participants rated the perceived intensity and selected the most appropriate pain quality descriptor.

Results

There was an increase in the area, density, and perceived intensity ratings as the electrical stimulation intensity increased (P<0.001). The density of the motion graphic, but not speed, correlated with perceived intensity ratings (0.69, P<0.001) and electrical stimulation intensities (0.63, P<0.01). The descriptor ‘tingling’ was predominantly selected in the range of 3–4.5mA and was often followed by ‘stabbing’ as the electrical intensity increased.

Discussion

The motion graphic tested was perceived to reflect a tingling sensation, the stimulation protocol elicited a tingling sensation, and participants adjusted one of the two motion graphic features systematically. In conclusion, an embodied sensation, such as tingling, maybe visually represented similarly between individuals. These findings create research, clinical, and commercial opportunities that utilize psychophysics to explore, visualize, and quantify changes in embodied sensory experiences in response to known stimuli.

Unilateral accumbal dopamine depletion affects decision-making in a side-specific manner

Mechanisms underlying affective and cognitive deficits in Parkinson's disease (PD) remain less studied than motor symptoms. Nucleus accumbens (NAc) is affected in PD and due to its well-known involvement in motivation is an interesting target in this context. Furthermore, PD is frequently asymmetrical, with side-specific deficits aligning with evidences of accumbal laterality. We therefore used a 6-hydroxydopamine (6-OHDA) model to study the role of left and right NAc dopamine depletion in a battery of behavioral tasks. 2 months old male rats were used in all experiments. Habitual-based and goal-directed decision-making, impulsivity, anxiety- and depressive-like behavior and motor performance were tested 3 weeks after left (6-OHDA L) or right (6-OHDA R) NAc lesion was induced. Upon contingency degradation, 6-OHDA R decrease their lever press rate less than Sham and 6-OHDA L, indicating an impairment in the shift from habit-based to goal-directed strategies. On the other hand, 6-OHDA L lesions lead to increased rates of premature responding when delays where increased in the variable delay-to-signal test. Importantly, in both paradigms task acquisition was similar between groups. In the same line we found no differences in the amount of sugared pellets eaten when freely available as well as in both general and fine motor behaviors. In conclusion, left and right NAc play distinct roles in the contingency degradation and impulsivity. More studies are needed to understand the mechanisms behind this functional lateralization and its implications for PD patients.

Widespread Pressure Pain Hyperalgesia Is Not Related to Pain in Patients with Parkinson's Disease

OBJECTIVE

Pain is one of the most frequent nonmotor impairments in Parkinson's disease (PD) and is hypothesized to be associated with altered nociceptive pain processing. Our aims were to investigate differences in widespread pressure pain sensitivity between PD patients with and without pain and healthy controls and to assess the relationship of health-related quality of life and sleep quality with pressure pain sensitivity.

METHODS

Nineteen PD patients with pain (12 men, age = 68 ± 9 years), 19 PD patients without pain (11 men, age = 69 ± 8 years), and 19 matched controls participated. Pressure pain thresholds (PPTs) were assessed bilaterally over the cervical spine, the second metacarpal, and the tibialis anterior by an assessor blinded to the subject's condition. Patients were assessed in a dopamine-medicated (ON) state. Pain intensity (numerical pain rating scale, 0-10), health-related quality of life (39-item Parkinson's Disease Questionnaire), and sleep quality (Pittsburgh Sleep Quality Index) were also assessed.

RESULTS

No significant differences existed between PD patients, with or without pain, and healthy controls on PPTs over the cervical spine, the second metacarpal, or the tibialis anterior muscle (all P > 0.3). PPTs were lower in females than in males in all groups (P < 0.01). In PD patients with pain, worse quality of sleep was associated with higher widespread pressure pain sensitivity (-0.607 < r < -0.535, P < 0.05). No other significant association was observed.

CONCLUSIONS

This study revealed no differences in widespread pressure hyperalgesia between PD patients with or without pain (ON state) and controls. Although dopamine may modulate pain responses, other mechanisms seems to also be implicated in altered nociceptive pain processing in patients with PD.

Características clínicas da doença de Parkinson associadas à dor ao tratamento odontológico

Resumo Introdução A Doença de Parkinson (DP) resulta em condições clínicas desfavoráveis para a saúde bucal e não existe estudo publicado sobre dor ao tratamento odontológico em pacientes com DP. Objetivo Pesquisar associação entre características clínicas da DP e a intensidade de dor em decorrência de tratamentos odontológicos. Material e método Foi utilizada uma amostra consecutiva de 70 pacientes com DP, nos quais foram realizados 217 procedimentos odontológicos invasivos. Tempo de DP foi coletado do prontuário odontológico; estágio da DP foi definido por meio da escala de Hoehn e Yahr; défice cognitivo, por meio do Mini Exame do Estado Mental; depressão, por meio do Inventário de Depressão de Beck; e comprometimento motor, por meio da escala UPDRS/AVD. Os pacientes foram questionados se no último mês sentiram alguma sensação de dormência, formigamento, queimação ou dor bem como dificuldade para sentir cheiros ou gostos. A dor relacionada ao tratamento foi coletada por meio de uma escala numérica de dor com valores de 0 a 10. Resultado O nível de dor percebida pelos pacientes durante o tratamento odontológico não apresentou associação significativa com tempo de DP, estágio da DP, comprometimento motor nem ocorrência de depressão. Maior nível de dor foi estatisticamente mais frequente entre aqueles com défice cognitivo e aqueles que relataram a presença de maior número de sintomas sensitivos, sobretudo dormência e queimação. Conclusão A dor ao tratamento odontológico em pacientes com DP está associada aos sintomas não motores desses pacientes, especificamente o défice cognitivo e a presença de sintomas sensitivos.

An overview of pain in Parkinson's disease

Pain is a common non-motor symptom of Parkinson's disease (PD) and the prevalence of pain among PD patients varies because of the disease stage, co-morbidities, and evaluating tools. Risk factors for pain in PD include an early age of onset, long disease duration, motor complications, concomitant depressive symptoms, female gender, and associated medical conditions. In patients with PD, pain can be classified as musculoskeletal pain, chronic body pain (central or visceral), fluctuation-related pain, nocturnal pain, orofacial pain, pain with discolouration/oedema/swelling, and radicular/neuropathic pain; musculoskeletal pain as the most common type. Potential underlying mechanisms include a disruption of peripheral nociception and alterations in central pain threshold/processing. Genetic polymorphisms in genes that confer pain susceptibility might also play a role in the occurrence of pain in PD. In advanced stage of patients with PD, polyneuropathy could occur in patients using high dosage of levodopa. Pain often correlates to other non-motor symptoms of PD, including depression, sleep, and autonomic symptoms. Dopaminergic drugs, non-dopaminergic medications, botulinum toxin, deep brain stimulation, and physiotherapy have shown some benefits for certain types of PD-related pain. An increased awareness of pain as a common non-motor symptom of PD provides further insights into sensory system dysregulation in this disease. In this review, we aim to summarizes the clinical features of pain in patients with PD and emphasize the latest evidence of pain related to levodopa treatment.

Driving impairment and crash risk in Parkinson disease: A systematic review and meta-analysis

OBJECTIVES

To provide the best possible evidence base for guiding driving decisions in Parkinson disease (PD), we performed a meta-analysis comparing patients with PD to healthy controls (HCs) on naturalistic, on-the-road, and simulator driving outcomes.

METHODS

Seven major databases were systematically searched (to January 2018) for studies comparing patients with PD to HCs on overall driving performance, with data analyzed using random-effects meta-analysis.

RESULTS

Fifty studies comprising 5,410 participants (PD = 1,955, HC = 3,455) met eligibility criteria. Analysis found the odds of on-the-road test failure were 6.16 (95% confidence interval [CI] 3.79-10.03) times higher and the odds of simulator crashes 2.63 (95% CI 1.64-4.22) times higher for people with PD, with poorer overall driving ratings also observed (standardized mean differences from 0.50 to 0.67). However, self-reported real-life crash involvement did not differ between people with PD and HCs (odds ratio = 0.84, 95% CI 0.57-1.23, p = 0.38). Findings remained unchanged after accounting for any differences in age, sex, and driving exposure, and no moderating influence of disease severity was found.

CONCLUSIONS

Our findings provide persuasive evidence for substantive driving impairment in PD, but offer little support for mandated PD-specific relicensure based on self-reported crash data alone, and highlight the need for objective measures of crash involvement.

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

BACKGROUND AND PURPOSE

Pain is highly prevalent in Parkinson's disease (PD), impacting patients' ability, mood and quality of life. Detecting the presence of pain in its multiple modalities is necessary for adequate personalized management of PD. A 14-item, PD-specific, patient-based questionnaire (the King's Parkinson's Disease Pain Questionnaire, KPPQ) was designed corresponding to the rater-based KPP Scale (KPPS). The present multicentre study was aimed at testing the validity of this screening tool.

METHODS

First, a comparison between the KPPQ scores of patients and matched controls was performed. Next, convergent validity, reproducibility (test-retest) and diagnostic performance of the questionnaire were analysed.

RESULTS

Data from 300 patients and 150 controls are reported. PD patients declared significantly more pain symptoms than controls (3.96 ± 2.56 vs. 2.17 ± 1.39; P < 0.0001). The KPPQ convergent validity was high with KPPS total score (r_S  = 0.80) but weak or moderate with other pain assessments. Test-retest reliability was satisfactory with kappa values ≥0.65 except for item 5, Dyskinetic pains (κ = 0.44), and the intraclass correlation coefficient (ICC) for the KPPQ total score was 0.98. After the scores of the KPPS were adapted for screening (0, no symptom; ≥1, symptom present), a good agreement was found between the KPPQ and the KPPS (ICC = 0.88). A strong correlation (r_S  = 0.80) between the two instruments was found. The diagnostic parameters of the KPPQ were very satisfactory as a whole, with a global accuracy of 78.3%-98.3%.

CONCLUSIONS

These results suggest that the KPPQ is a useful, reliable and valid screening instrument for pain in PD to advance patient-related outcomes.

[Parkinson's disease, Alzheimer's disease and oncological diseases in residential geriatric care : Pain frequency and selected healthcare features in comparison]

BACKGROUND

Adequate pain management and palliative care structures are of significant importance in residential nursing homes. Whilst professional pain treatment and palliative care measures are frequently implemented for residents with oncological diseases, this is often not the case for residents with neurological disorders. Such a potential undertreatment is even more challenging when the means of interaction and communication with affected persons are aggravated by impairments in cognitive function.

OBJECTIVE

To examine differences in selected health care service characteristics between nursing home residents with Parkinson's disease, Alzheimer's disease and residents diagnosed with cancer.

MATERIAL AND METHODS

Secondary data analysis of residents' survey and medical record data from 13 nursing homes as part of the study "Action Alliance Pain-free City Münster".

RESULTS

Compared with residents with Parkinson's disease and cancer, nursing home residents with Alzheimer's disease exhibited significantly more severe impairment in cognitive function, less additional pain-associated diagnoses, shorter length of stay in nursing homes and more indications of pain.

CONCLUSION

The generally high level of pain in all observed residents elucidates the principle necessity of adequate pain assessment and an interprofessional pain treatment. Furthermore, there seems to be a still unmet need for specifically adapted pain management strategies especially for the steadily increasing number of people with Parkinson's disease and Alzheimer's disease living in nursing homes. This should be a future high priority task for (nursing) practice and research against the background of the vulnerability of nursing home populations.

Rotigotine transdermal patch and sleep in Parkinson's disease: where are we now?

A wide range of sleep dysfunction complicates Parkinson’s disease during its course from prodromal to palliative stage. It is now increasingly acknowledged that sleep disturbances are thus integral to the disease and pose a significant burden impacting on quality of life of patients. Sleep fragmentation, restless legs syndrome, nocturia, and nocturnal pain are regarded as one of the main components of night-time sleep dysfunction with possible secondary impact on cognition and well-being. The role of dopaminergic therapies, particularly using a continuous drug delivery strategy in managing some of these sleep issues, have been reported but the overall concept remains unclear. This review provides an overview of several aspects of night-time sleep dysfunction in Parkinson’s disease and describes all available published open-label and blinded studies that investigated the use of rotigotine transdermal patch targeting sleep. Blinded studies have suggested beneficial effects of rotigotine transdermal patch on maintenance insomnia and restless legs syndrome in Parkinson’s disease patients. Open-label studies support these observations and also suggest beneficial effects on nocturia and nocturnal pain.