Pain Severity and Interference in Different Parkinson's Disease Cognitive Phenotypes

Axial postural abnormalities and pain in Parkinson's disease

Axial postural abnormalities and pain are two main determinants of poor quality of life in patients with Parkinson's disease (PD). Indeed, a detailed characterization of pain and other non-motor symptoms in patients with PAs has not been provided yet. The aim of this study is to assess the phenomenology of pain and other non-motor symptoms in PD patients with Pisa syndrome and camptocormia compared to PD patients without axial postural abnormality. Forty-five PD participants were equally distributed in three groups: patients with Pisa syndrome (PS), patients with Camptocormia (CC), and patients without postural abnormalities (PD). Pain characteristics were assessed by Kings Parkinson's Pain Scale (KPPS), brief pain inventory (BPI), and numeric pain rating scale (NRS). All participants completed clinical assessments by non-motor symptom scale (NMSS), and movement disorder society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) parts II-III. Patients with and without axial postural abnormalities showed one or more types of pain, being fluctuation, nocturnal, chronic, and musculoskeletal the most frequently reported in Pisa Syndrome and camptocormia. PD group compared with PS and CC groups showed differences in the KPPS, NMSS, BPI pain severity and interference, and NRS total scores. No significant differences were found between PS group compared with CC group with exception of the NMSS total scores. PD patients with Pisa syndrome or camptocormia have a higher burden of musculoskeletal, chronic and fluctuation pain than PD patients without axial postural abnormalities, suggesting different etiologies of pain and possible different treatments.

Relationships Between Cognitive Screening Composite Scores and Pain Intensity and Pain Disability in Adults With/At Risk for Knee Osteoarthritis

OBJECTIVES

Chronic pain, cognitive deficits, and pain-related disability are interrelated. The prevalence of chronic pain and undiagnosed cognitive difficulties in middle age and older adults is increasing. Of the cognitive systems, executive function and episodic memory are most relevant to chronic pain. We examined the hypothesis that cognitive screening composite scores for executive function and memory would negatively associate with pain intensity and pain disability in a group of middle-aged and older adults with knee pain with or at risk for osteoarthritis.

METHODS

A total of 120 adults (44 men/76 women), an average age of 59 years, participated in the study. Demographic, health history, clinical pain, and cognitive measures were completed. Relationships between pain intensity, pain disability, and the Montreal Cognitive Assessment (MoCA) total and composite scores were examined with relevant covariates in the model.

RESULTS

MoCA raw scores ranged from 13 to 30 with a mean score of 23.9. Pain intensity was negatively associated with overall MoCA total and executive function and memory composite scores. Pain disability over the previous 6 months was negatively associated with executive function, while pain disability over the past 48 hours was not associated with executive function.

CONCLUSION

The results of the current study demonstrates associations between pain metrics and cognitive domain scores within a common cognitive screening tool.

Gait subgroups among older adults with chronic pain differ in cerebellum and basal ganglia gray matter volumes

BACKGROUND

Current literature regarding morphological gray matter atrophy in chronic pain is mixed, inhibiting our ability to understand neurological mechanisms of chronic pain. The inconsistent findings may be due to the presence of subgroups within the older adult chronic pain population that differ in gait performance, as gait and gray matter have been previously associated. These gait subgroups, however, have been inadequately characterized in prior work and have not been compared across gray matter measures. Therefore, the purpose of this study was to identify and characterize gait subgroups within the older adult chronic pain population, and to evaluate differences in gray matter measures between subgroups.

METHODS

The present study was a secondary analysis of the Neuromodulatory Examination of Pain and Mobility Across the Lifespan (NEPAL) study. A subset of older participants (n = 40) completed assessments to evaluate psychological status, cognitive abilities, pain characteristics, and spatiotemporal gait performance using an instrumented gait mat. Gray matter measures were obtained from a T1-weighted anatomical scan using Freesurfer's recon-all function.

RESULTS

After data reduction, a hierarchical cluster analysis identified three gait clusters: A Normal Gait cluster (n = 12), a Shuffle Gait cluster (n = 15), and an Unsteady Gait cluster (n = 13). Clusters differed in gait velocity, stride length, step width, double support percentages, and stride length variability. The Shuffle Gait cluster exhibited reduced gray matter volumes in the cerebellum, caudate, putamen, and pallidum, as well as a worse pain severity when compared to the Normal Gait cluster (p < 0.05). The Shuffle Gait cluster also had less gray matter in the cerebellum and caudate when compared to the Unsteady Gait cluster (p < 0.05).

CONCLUSIONS

Our results confirm the existence of gait subgroups among the older adult chronic pain population and gray matter differences observed between groups support the need for the consideration of subgroups within this population for future pain, mobility, and aging studies.

More than Hurt Feelings: The Wear and Tear of Day-to-Day Discrimination in Adults with Chronic Pain

OBJECTIVE

To examine the extent to which self-reported experiences of discrimination are associated with pain interference among men and women with chronic non-cancer pain.

METHODS

Data are from the Study of Midlife in the United States (MIDUS) Refresher Cohort. The analytic sample consisted of 207 adults with chronic pain (54.2 ± 12.8 years; 53.6% female) who completed the Major Experiences of Discrimination and Everyday Discrimination scales. Regression analyses examined cross-sectional relations between discrimination and pain interference.

RESULTS

On average, the level of pain interference was moderate in the sample (mean = 3.46, standard deviation = 2.66; observed range 0-10). Approximately a third of respondents reported at least one major discriminatory event in their lifetime, while 22% reported three or more discriminatory lifetime events. Everyday discrimination scores averaged 14.19 ± 5.46 (observed range 0-33). With adjustment for sociodemographics, physical health, cognitive and psychological factors, social isolation, and loneliness, everyday discrimination was associated with increased pain interference (B = 0.099; 95% confidence interval [CI]: 0.02 to 0.17).

CONCLUSION

These findings add weight to the importance of day-to-day experiences of interpersonal discrimination by documenting independent associations with functional interference in adults with chronic pain.