Self-perceived stigma in Parkinson's Disease in an online sample: Comparison with in-person sample, role of anxiety, and relative utility of four measures of stigma perception.

OBJECTIVE: Persons with Parkinson's disease (PwPD) experience motor and non-motor symptoms that may elicit stigmatization. We investigated whether online assessment would replicate in-person findings of younger age and depression as predictors of stigma perception. We further assessed the predictive value of anxiety, and compared predictors across four stigma measures. METHODS: The online study (n = 347), like the earlier in-person study (n = 362), used the Parkinson's Disease Questionnaire stigma subscale (PDQ-39stigma). It also assessed anxiety and added the Stigma Scale for Chronic Illness (SSCI), Stigmatization Scale, and Mental Health Consumers' Experience of Stigma Scale. We correlated stigma perception scores with demographic/clinical characteristics and conducted hierarchical regression and mediation analyses. RESULTS: Online and in-person predictors of stigma perception with the PDQ-39stigma included younger age (men) and depression (men, women). Depression mediated the relation between stigma perception and motor experiences of daily living (EDLs). In the online sample, when anxiety was added, it predicted stigma perception (PDQ-39stigma, SSCI) and mediated the relation between stigma and both motor and non-motor EDLs (PDQ-39stigma). For all four stigma-perception scales, younger age predicted scores. Multiple additional predictors of PDQ-39stigma and SSCI scores suggest their utility relative to the other two scales. Conclusions: Younger age and depression predicted self-perceived stigma in online and in-person samples, indicating the cross-modal utility of the measure, PDQ-39stigma. In the online sample, anxiety also predicted stigma perception per the PDQ-39stigma and SSCI. We recommend both measures and note that treating depression and anxiety may be important especially in younger PwPD to reduce self-perceived stigma.

Discordance between Reports of Internalized Symptoms in Persons with Parkinson's Disease and Informants: Results from an Online Survey.

BACKGROUND: Self-report of motor and non-motor symptoms is integral to understanding daily challenges of persons with Parkinson's disease (PwPD). Care partners are often asked to serve as informants regarding symptom severity, raising the question of concordance with PwPD self-reports, especially regarding internalized (not outwardly visible) symptoms. OBJECTIVES: Concordance between PwPD and informant ratings of motor and non-motor symptoms was evaluated across multiple domains. METHODS: In 60 PwPD-informant pairs, we compared ratings on 11 online self-report measures comprising 33 total scores, 2/3 of which represented purely internalized symptoms. For discordant scores, multiple regression analyses were used to examine demographic/clinical predictors. RESULTS: Though concordant on 85% of measures, PwPD endorsed more non-motor symptoms, bodily discomfort, stigma, and motor symptoms than informants. For PwPD, younger age, greater disease severity, and female gender predicted discordance. CONCLUSIONS: Discordance between PwPD and informants on measures assessing symptoms that cannot be outwardly observed may require targeted education.

Equal Prevalence of Depression in Men and Women with Parkinson's Disease Revealed by Online Assessment.

OBJECTIVE: Identifying persons needing mental health services is hampered by stigma-related underreporting of symptoms, especially by men. Men with Parkinson's disease (PD) consistently report lower rates of depression than women in in-person studies. We predicted that online anonymity would elicit more gender-based parity in depression endorsement. METHOD: We administered the Beck Depression Inventory-II (BDI-II) online to 344 participants with PD (52% women). Depression was defined as BDI-II score >13 and/or use of antidepressant medications. RESULTS: Overall depression prevalence was consistent with in-person studies, but with no significant difference between men and women. CONCLUSIONS: Online methods may circumvent barriers to depression identification in men with PD.

Changes in Apathy, Depression, and Anxiety in Parkinson's Disease from before to during the COVID-19 Era.

Apathy, depression, and anxiety are common non-motor symptoms of Parkinson's disease (PD). Tracking the changes in such symptoms over time would be valuable not only to determine their natural course during the disease, but also to establish the effects of unusual historical events interacting with the natural course. Having collected data on apathy (Apathy Scale), depression (Beck Depression Inventory-II), and anxiety (Parkinson's Anxiety Scale) in a large sample of persons with PD (PwPD) before the beginning of the COVID-19 era, we followed up with these individuals to investigate the changes in their prevalence of apathy, depression, and anxiety across two timepoints (T1 and T2). Of the original 347 participants, 111 responded and provided complete data at T2. The data collection at T1, before COVID-19, occurred between 2017-2018. The data collection at T2 occurred in 2021 and included the same measures, with the addition of the Coronavirus Impact Scale to assess the effects of the pandemic on the individual participants. Over this period, there was a significant increase in apathy, but not in depression or anxiety. Anxiety and depression, but not apathy, were correlated with the impact of COVID-19.

Perceived stigma and quality of life in Parkinson's disease with additional health conditions.

Background: Parkinson's disease (PD) is associated with perceived stigma and affects quality of life (QoL). Additional health conditions may influence these consequences of PD. Aims: This study assessed the impact of health conditions on perceived stigma and QoL in persons with PD. We hypothesised that individuals with more health conditions would report more stigma and poorer QoL. We also examined the contributions of demographic and clinical characteristics to the correlations between health conditions and perceived stigma/QoL. Methods: We identified 196 eligible participants from the Boston University Online Survey Study of Parkinson's Disease and examined their health history, performance on multiple stigma measures, and scores on the 39-item Parkinson's Disease Questionnaire assessing QoL. Results: At least one health condition was reported by 79% of the sample, with a median of 2 and a range of 0-7 health conditions. More perceived stigma and poorer QoL were associated with thyroid disease, depression, anxiety, and the total number of health conditions. These correlations were related to younger age, less education, and earlier disease onset. Other health conditions (high blood pressure, back/leg surgery, headache, cancer/tumours, and heart disease) were not significantly correlated with stigma or QoL. Conclusions: Having more health conditions, or thyroid disease, depression, or anxiety, was associated with more perceived stigma and poorer QoL, with younger age, less education, and earlier disease onset affecting the associations. It is important to consider the burden of health conditions and how they affect persons with PD with specific clinical characteristics.

Increasing Contrast Improves Object Perception in Parkinson's Disease with Visual Hallucinations.

BACKGROUND: Deficits in basic vision are associated with visual hallucinations in Parkinson's disease. Of particular interest is contrast sensitivity loss in this disorder and its effect on object identification. OBJECTIVES: Evaluate whether increased contrast improves object perception in persons with Parkinson's disease and visual hallucinations, without dementia. METHODS: We assessed 26 individuals with mild to moderate idiopathic Parkinson's disease, half of whom reported one or more episodes of hallucinations/unusual perceptual experiences in the past month, with a letter-identification task that determined the contrast level required to achieve 80% accuracy. Contrast sensitivity was further assessed with a chart that presented stimuli at multiple spatial frequencies. The groups were closely matched for demographic and clinical characteristics except for experience of hallucinations. RESULTS: Relative to participants without visual hallucinations, those with hallucinations had poorer spatial frequency contrast sensitivity and required significantly greater contrast to correctly identify the letters on the identification task. Specifically, participants with hallucinations required a mean contrast of 52.8%, whereas participants without hallucinations required 35.0%. When given sufficient contrast, the groups with and without hallucinations were equally accurate in letter identification. CONCLUSIONS: Compared to those without hallucinations, individuals with Parkinson's disease and hallucinations without dementia showed poorer contrast sensitivity. Once contrast was individually enhanced, the groups were equally accurate at object identification. These findings suggest the potential of visual perception tests to predict, and perception-based interventions to reduce, hallucinations in Parkinson's disease.

Spatial judgment in Parkinson's disease: Contributions of attentional and executive dysfunction.

Spatial judgment is impaired in Parkinson's disease (PD), with previous research suggesting that disruptions in attention and executive function are likely contributors. If judgment of center places demands on frontal systems, performance on tests of attention/executive function may correlate with extent of bias in PD, and attentional disturbance may predict inconsistency in spatial judgment. The relation of spatial judgment to attention/executive function may differ for those with left-side versus right-side motor onset (LPD, RPD), reflecting effects of attentional lateralization. We assessed 42 RPD, 37 LPD, and 67 healthy control participants with a Landmark task (LM) in which a cursor moved horizontally from the right (right-LM) or left (left-LM). The task was to judge the center of the line. Participants also performed neuropsychological tests of attention and executive function. LM group differences were found on left-LM only, with both PD subgroups biased leftward of the control group (RPD p < .05; LPD p < .01; no RPD-LPD difference). For left-LM trials, extent of bias significantly correlated with performance on the cognitive tasks for PD but not for the control group. PD showed greater variability in perceived center than the control group; this variability correlated with performance on the cognitive tasks. The correlations between performance on the test of spatial judgment and the tests of attention/executive function suggest that frontal-based attentional dysfunction affects dynamic spatial judgment, both in extent of spatial bias and in consistency of response as indexed by intertrial variability. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The relation of anxiety and cognition in Parkinson's disease.

OBJECTIVE: Parkinson's disease (PD) has long been conceptualized as a motor disorder, but nonmotor symptoms also manifest in the disease and significantly reduce quality of life. Anxiety and cognitive dysfunction are prevalent nonmotor symptoms, even in early disease stages, but the relation between these symptoms remains poorly understood. We examined self-reported anxiety and neurocognitive function, indexed by measures of executive function (set-shifting and phonemic fluency), categorical fluency, and attention/working memory. We hypothesized that anxiety would correlate with cognitive performance. METHOD: The Beck Anxiety Inventory and cognitive tests (Trail Making, Verbal Fluency, Digit Span) were administered to 77 nondemented adults with mild to moderate idiopathic PD (39 men, 38 women; Mage = 62.9 years). RESULTS: Higher anxiety was associated with more advanced disease stage and severity and with poorer set-shifting when using a derived metric to account for motoric slowing. Depression correlated with greater anxiety and disease severity, but not with cognitive performance. CONCLUSIONS: Our findings support the association of anxiety with a specific domain of executive function, set-shifting, in nondemented individuals with mild to moderate PD, raising the possibility that treatment of anxiety may alleviate aspects of executive dysfunction in this population. (PsycINFO Database Record

Dual tasking in Parkinson's disease: Cognitive consequences while walking.

OBJECTIVE: Cognitive deficits are common in Parkinson's disease (PD) and exacerbate the functional limitations imposed by PD's hallmark motor symptoms, including impairments in walking. Though much research has addressed the effect of dual cognitive-locomotor tasks on walking, less is known about their effect on cognition. The purpose of this study was to investigate the relation between gait and executive function, with the hypothesis that dual tasking would exacerbate cognitive vulnerabilities in PD as well as being associated with gait disturbances. METHOD: Nineteen individuals with mild-moderate PD without dementia and 13 age- and education-matched normal control adults (NC) participated. Executive function (set-shifting) and walking were assessed singly and during dual tasking. RESULTS: Dual tasking had a significant effect on cognition (reduced set-shifting) and on walking (speed, stride length) for both PD and NC, and also on stride frequency for PD only. The impact of dual tasking on walking speed and stride frequency was significantly greater for PD than NC. Though the group by condition interaction was not significant, PD had fewer set-shifts than NC on dual task. Further, relative to NC, PD showed significantly greater variability in cognitive performance under dual tasking, whereas variability in motor performance remained unaffected by dual tasking. CONCLUSIONS: Dual tasking had a significantly greater effect in PD than in NC on cognition as well as on walking. The results suggest that assessment and treatment of PD should consider the cognitive as well as the gait components of PD-related deficits under dual-task conditions. (PsycINFO Database Record

The impact of motor symptoms on self-reported anxiety in Parkinson's disease.

OBJECTIVE: Anxiety is commonly endorsed in Parkinson's disease (PD) and significantly affects quality of life. The Beck Anxiety Inventory (BAI) is often used but contains items that overlap with common PD motor symptoms (e.g., "hands trembling"). Because of these overlapping items, we hypothesized that PD motor symptoms would significantly affect BAI scores. METHODS: One hundred non-demented individuals with PD and 74 healthy control participants completed the BAI. PD motor symptoms were assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). Factor analysis of the BAI assessed for a PD motor factor, and further analyses assessed how this factor affected BAI scores. RESULTS: BAI scores were significantly higher for PD than NC. A five-item PD motor factor correlated with UPDRS observer-rated motor severity and mediated the PD-control difference on BAI total scores. An interaction occurred, whereby removal of the PD motor factor resulted in a significant reduction in BAI scores for PD relative to NC. The correlation between the BAI and UPDRS significantly declined when controlling for the PD motor factor. CONCLUSIONS: The results indicate that commonly endorsed BAI items may reflect motor symptoms such as tremor instead of, or in addition to, genuine mood symptoms. These findings highlight the importance of considering motor symptoms in the assessment of anxiety in PD and point to the need for selecting anxiety measures that are less subject to contamination by the motor effects of movement disorders.

Effects of orthostatic hypotension on cognition in Parkinson disease.

OBJECTIVE: To investigate the relation between orthostatic hypotension (OH) and posture-mediated cognitive impairment in Parkinson disease (PD) using a cross-sectional and within-group design. METHODS: Individuals without dementia with idiopathic PD included 18 with OH (PDOH) and 19 without OH; 18 control participants were also included. Neuropsychological tests were conducted in supine and upright-tilted positions. Blood pressure was assessed in each posture. RESULTS: The PD groups performed similarly while supine, demonstrating executive dysfunction in sustained attention and response inhibition, and reduced semantic fluency and verbal memory (encoding and retention). Upright posture exacerbated and broadened these deficits in the PDOH group to include phonemic fluency, psychomotor speed, and auditory working memory. When group-specific supine scores were used as baseline anchors, both PD groups showed cognitive changes following tilt, with the PDOH group exhibiting a wider range of deficits in executive function and memory as well as significant changes in visuospatial function. CONCLUSIONS: Cognitive deficits in PD have been widely reported with assessments performed in the supine position, as seen in both our PD groups. Here we demonstrated that those with PDOH had transient, posture-mediated changes in excess of those found in PD without OH. These observed changes suggest an acute, reversible effect. Understanding the effects of OH due to autonomic failure on cognition is desirable, particularly as neuroimaging and clinical assessments collect data only in the supine or seated positions. Identification of a distinct neuropsychological profile in PD with OH has quality of life implications, and OH presents itself as a possible target for intervention in cognitive disturbance.

Bistable perception in normal aging: perceptual reversibility and its relation to cognition.

The effects of age on the ability to resolve perceptual ambiguity are unknown, though it depends on frontoparietal attentional networks known to change with age. We presented the bistable Necker cube to 24 middle-aged and OAs (older adults; 56-78 years) and 20 YAs (younger adults; 18-24 years) under passive-viewing and volitional control conditions: Hold one cube percept and Switch between cube percepts. During passive viewing, OAs had longer dominance durations (time spent on each percept) than YAs. In the Hold condition, OAs were less able than YAs to increase dominance durations. In the Switch condition, OAs and YAs did not differ in performance. Dominance durations in either condition correlated with performance on tests of executive function mediated by the frontal lobes. Eye movements (fixation deviations) did not differ between groups. These results suggest that OAs' reduced ability to hold a percept may arise from reduced selective attention. The lack of correlation of performance between Hold and executive-function measures suggests at least a partial segregation of underlying mechanisms.

Perception of Communicative and Non-communicative Motion-Defined Gestures in Parkinson's Disease.

OBJECTIVES: Parkinson's disease (PD) is associated with deficits in social cognition and visual perception, but little is known about how the disease affects perception of socially complex biological motion, specifically motion-defined communicative and non-communicative gestures. We predicted that individuals with PD would perform more poorly than normal control (NC) participants in discriminating between communicative and non-communicative gestures, and in describing communicative gestures. We related the results to the participants' gender, as there are gender differences in social cognition in PD. METHODS: The study included 23 individuals with PD (10 men) and 24 NC participants (10 men) matched for age and education level. Participants viewed point-light human figures that conveyed communicative and non-communicative gestures and were asked to describe each gesture while discriminating between the two gesture types. RESULTS: PD as a group were less accurate than NC in describing non-communicative but not communicative gestures. Men with PD were impaired in describing and discriminating between communicative as well as non-communicative gestures. CONCLUSIONS: The present study demonstrated PD-related impairments in perceiving and inferring the meaning of biological motion gestures. Men with PD may have particular difficulty in understanding the communicative gestures of others in interpersonal exchanges.

Randomized Controlled Trial of a Home-Based Action Observation Intervention to Improve Walking in Parkinson Disease.

OBJECTIVE: To examine the feasibility and efficacy of a home-based gait observation intervention for improving walking in Parkinson disease (PD). DESIGN: Participants were randomly assigned to an intervention or control condition. A baseline walking assessment, a training period at home, and a posttraining assessment were conducted. SETTING: The laboratory and participants' home and community environments. PARTICIPANTS: Nondemented individuals with PD (N=23) experiencing walking difficulty. INTERVENTION: In the gait observation (intervention) condition, participants viewed videos of healthy and parkinsonian gait. In the landscape observation (control) condition, participants viewed videos of moving water. These tasks were completed daily for 8 days. MAIN OUTCOME MEASURES: Spatiotemporal walking variables were assessed using accelerometers in the laboratory (baseline and posttraining assessments) and continuously at home during the training period. Variables included daily activity, walking speed, stride length, stride frequency, leg swing time, and gait asymmetry. Questionnaires including the 39-item Parkinson Disease Questionnaire (PDQ-39) were administered to determine self-reported change in walking, as well as feasibility. RESULTS: At posttraining assessment, only the gait observation group reported significantly improved mobility (PDQ-39). No improvements were seen in accelerometer-derived walking data. Participants found the at-home training tasks and accelerometer feasible to use. CONCLUSIONS: Participants found procedures feasible and reported improved mobility, suggesting that observational training holds promise in the rehabilitation of walking in PD. Observational training alone, however, may not be sufficient to enhance walking in PD. A more challenging and adaptive task, and the use of explicit perceptual learning and practice of actions, may be required to effect change.

Veering in hemi-Parkinson's disease: Primacy of visual over motor contributions.

Veering while walking is often reported in individuals with Parkinson's disease (PD), with potential mechanisms being vision-based (asymmetrical perception of the visual environment) or motoric (asymmetry in stride length between relatively affected and non-affected body side). We examined these competing hypotheses by assessing veering in 13 normal control participants (NC) and 20 non-demented individuals with PD: 9 with left-side onset of motor symptoms (LPD) and 11 with right-side onset (RPD). Participants walked in a corridor under three conditions: eyes-open, egocentric reference point (ECRP; walk toward a subjectively perceived center of a target at the end of the corridor), and vision-occluded. The visual hypothesis predicted that LPD participants would veer rightward, in line with their rightward visual-field bias, whereas those with RPD would veer leftward. The motor hypothesis predicted the opposite pattern of results, with veering toward the side with shorter stride length. Results supported the visual hypothesis. Under visual guidance, RPD participants significantly differed from NC, veering leftward despite a shorter right- than left-stride length, whereas LPD veered rightward (not significantly different from NC), despite shorter left- than right-stride length. LPD participants showed significantly reduced rightward veering and stride asymmetry when they walked in the presence of a visual landmark (ECRP) than in the eyes-open condition without a target. There were no group differences in veering in the vision-occluded condition. The findings suggest that interventions to correct walking abnormalities such as veering in PD should incorporate vision-based strategies rather than solely addressing motor asymmetries, and should be tailored to the distinctive navigational profiles of LPD and RPD.

Effect of visual cues on the resolution of perceptual ambiguity in Parkinson's disease and normal aging.

Parkinson's disease (PD) and normal aging have been associated with changes in visual perception, including reliance on external cues to guide behavior. This raises the question of the extent to which these groups use visual cues when disambiguating information. Twenty-seven individuals with PD, 23 normal control adults (NC), and 20 younger adults (YA) were presented a Necker cube in which one face was highlighted by thickening the lines defining the face. The hypothesis was that the visual cues would help PD and NC to exert better control over bistable perception. There were three conditions, including passive viewing and two volitional-control conditions (hold one percept in front; and switch: speed up the alternation between the two). In the Hold condition, the cue was either consistent or inconsistent with task instructions. Mean dominance durations (time spent on each percept) under passive viewing were comparable in PD and NC, and shorter in YA. PD and YA increased dominance durations in the Hold cue-consistent condition relative to NC, meaning that appropriate cues helped PD but not NC hold one perceptual interpretation. By contrast, in the Switch condition, NC and YA decreased dominance durations relative to PD, meaning that the use of cues helped NC but not PD in expediting the switch between percepts. Provision of low-level cues has effects on volitional control in PD that are different from in normal aging, and only under task-specific conditions does the use of such cues facilitate the resolution of perceptual ambiguity.

Perceptual, cognitive, and personality rigidity in Parkinson's disease.

Parkinson's disease (PD) is associated with motor and non-motor rigidity symptoms (e.g., cognitive and personality). The question is raised as to whether rigidity in PD also extends to perception, and if so, whether perceptual, cognitive, and personality rigidities are correlated. Bistable stimuli were presented to 28 non-demented individuals with PD and 26 normal control adults (NC). Necker cube perception and binocular rivalry were examined during passive viewing, and the Necker cube was additionally used for two volitional-control conditions: Hold one percept in front, and Switch between the two percepts. Relative to passive viewing, PD were significantly less able than NC to reduce dominance durations in the Switch condition, indicating perceptual rigidity. Tests of cognitive flexibility and a personality questionnaire were administered to explore the association with perceptual rigidity. Cognitive flexibility was not correlated with perceptual rigidity for either group. Personality (novelty seeking) correlated with dominance durations on Necker passive viewing for PD but not NC. The results indicate the presence in mild-moderate PD of perceptual rigidity and suggest shared neural substrates with novelty seeking, but functional divergence from those supporting cognitive flexibility. The possibility is raised that perceptual rigidity may be a harbinger of cognitive inflexibility later in the disease course.

Side and type of initial motor symptom influences visuospatial functioning in Parkinson's disease.

BACKGROUND/OBJECTIVES: Visuospatial problems are common in Parkinson's disease (PD) and likely stem from dysfunction in dopaminergic pathways and consequent disruption of cortical functioning. Characterizing the motor symptoms at disease onset provides a method of observing how dysfunction in these pathways influences visuospatial cognition. We examined two types of motor characteristics: Body side (left or right) and type of initial symptom (tremor or symptom other than tremor). METHODS: 31 non-demented patients with PD, 16 with left-side onset (LPD) and 15 with right-side onset (RPD), as well as 17 healthy control participants (HC). The PD group was also divided by type of initial motor symptom, 15 having tremor as the initial symptom and 16 having an initial symptom other than tremor. Visuospatial function was assessed with the Clock Drawing Test. RESULTS: Of the four Clock Drawing scoring methods used, the Rouleau method showed sensitivity to subgroup differences. As predicted, the LPD and non-tremor subgroups, but not the other subgroups, performed more poorly than the HC group. CONCLUSION: The findings provide further evidence for differences in cognition between these subtypes of PD and highlight the importance of considering disease subtypes when examining cognition.

The effect of Parkinson's disease subgroups on verbal and nonverbal fluency.

BACKGROUND: Parkinson's disease (PD) leads to deficits in executive function, including verbal and nonverbal fluency, as a result of compromised frontostriatal circuits. It is unknown whether deficits in verbal and nonverbal fluency in PD are driven by certain subgroups of patients, or how strategy use may facilitate performance. PARTICIPANTS: Sixty-five nondemented individuals with PD, including 36 with right-body onset (RPD; 20 with tremor as their initial symptom, 16 nontremor) and 29 with left-body onset (LPD; 14 with tremor as their initial symptom, 15 nontremor), and 52 normal control participants (NC) took part in the study. MEASUREMENTS: Verbal fluency was assessed using the FAS and Animals tests. Nonverbal fluency was assessed using the Ruff Figural Fluency Test. RESULTS: Both RPD and LPD were impaired in generating words and in using clustering and switching strategies on phonemic verbal fluency, whereas different patterns of impairment were found on nonverbal fluency depending on the interaction of side of onset and initial motor symptom (tremor vs. nontremor). Strategy use correlated with number of correct responses on verbal fluency in LPD, RPD, and NC. By contrast, on nonverbal fluency, strategy use correlated with correct responses for RPD and LPD, but not for NC. CONCLUSION: Our findings demonstrate the importance of considering subgroups in PD and analyzing subcomponents of verbal and nonverbal fluency (correct responses, errors, and strategies), which may depend differently on the integrity of dorsolateral prefrontal cortex, inferior frontal cortex, and anterior cingulate cortex.