Objective:
Implicit skill learning is hypothesized to depend on nondeclarative memory that operates independent of the medial temporal lobe (MTL) memory system and instead depends on cortico striatal ...circuits between the basal ganglia and cortical areas supporting motor function and planning. Research with the Serial Reaction Time (SRT) task suggests that patients with memory disorders due to MTL damage exhibit normal implicit sequence learning. However, reports of intact learning rely on observations of no group differences, leading to speculation as to whether implicit sequence learning is fully intact in these patients. Patients with Parkinson's disease (PD) often exhibit impaired sequence learning, but this impairment is not universally observed.
Method:
Implicit perceptual-motor sequence learning was examined using the Serial Interception Sequence Learning (SISL) task in patients with amnestic Mild Cognitive Impairment (MCI;
n
= 11) and patients with PD (
n
= 15). Sequence learning in SISL is resistant to explicit learning and individually adapted task difficulty controls for baseline performance differences.
Results:
Patients with MCI exhibited robust sequence learning, equivalent to healthy older adults (
n
= 20), supporting the hypothesis that the MTL does not contribute to learning in this task. In contrast, the majority of patients with PD exhibited no sequence-specific learning in spite of matched overall task performance. Two patients with PD exhibited performance indicative of an explicit compensatory strategy suggesting that impaired implicit learning may lead to greater reliance on explicit memory in some individuals.
Conclusion:
The differences in learning between patient groups provides strong evidence in favor of implicit sequence learning depending solely on intact basal ganglia function with no contribution from the MTL memory system.
Cognitive decline creates substantial morbidity and cost in Parkinson's disease (PD) and clinicians have limited tools for counseling patients on prognosis. We aimed to use data from a randomized, ...controlled trial of isradipine in Parkinson's disease (STEADY-PD III) to determine which objective cognitive domain deficits drive patient complaints of cognitive symptoms.
Neuro-Quality of Life (Neuro-QoL) Cognition: General Concerns (GC), and Cognition: Executive Function (EF) (subjective measures), were administered at baseline, 1, 2, and 3 years in 324 people with PD. Baseline Montreal Cognitive Assessment (MoCA) was divided into 4 domains: visuospatial/executive, memory, attention, and language (objective measures). Spearman rank correlations and multiple regression models adjusted for other clinical variables evaluated associations between baseline Neuro-QoL domains and individual MoCA domains. Multiple regression models evaluated the association between baseline MoCA domain performance and Neuro-QoL change over three years. Cox proportional hazards predicted development of PD-MCI based on baseline and time-varying Neuro-QoL reporting.
Higher MoCA memory performance was associated with better Neuro-QoL-GC (β = 0.75, SE = 0.391, p = 0.05) and Neuro-QoL-EF (β = 0.81, SE = 0.36, p = 0.02) at baseline. There was a trend for baseline MoCA memory to predict the degree of subjective cognitive decline on the Neuro-QoL-EF (β = 0.70, SE = 0.42, p = 0.09). Baseline depression and anticholinergic use were associated with worsened Neuro-QoL-EF and Neuro-QoL-GC. Increasing subjective cognitive complaints in Neuro-QoL-EF were associated with development of PD-MCI over 3 years of follow-up (HR = 0.95, CI = 0.90–1.0, p = 0.039).
Objective memory impairment may be a stronger predictor than executive or visuospatial dysfunction for the presence of subjective cognitive complaints in early PD.
•Cognitive dysfunction is present in early, untreated PD.•Better objective memory performance was associated with higher quality of life in cognitive domains.•Depression and anticholinergics were associated with worsened quality of life in cognitive domains.•Subjective reports of executive dysfunction are associated with future mild cognitive impairment in PD.
Abstract
Mobile and wearable device-captured data have the potential to inform Parkinson’s disease (PD) care. The objective of the Clinician Input Study was to assess the feasibility and clinical ...utility of data obtained using a mobile health technology from PD patients. In this observational, exploratory study, PD participants wore a smartwatch and used the
Fox Wearable Companion
mobile phone app to stream movement data and report symptom severity and medication intake for 6 months. Data were analyzed using the Intel® Pharma Analytics Platform. Clinicians reviewed participants’ data in a dashboard during in-office visits at 2 weeks, 1, 3, and 6 months. Clinicians provided feedback in focus groups leading to dashboard updates. Between June and August 2017, 51 PD patients were recruited at four US sites, and 39 (76%) completed the 6-month study. Patients streamed 83,432 h of movement data from their smartwatches (91% of expected). Reporting of symptoms and medication intake using the app was lower than expected, 44% and 60%, respectively, but did not differ according to baseline characteristics. Clinicians’ feedback resulted in ten updates to the dashboard during the study period. Clinicians reported that medications and patient reported outcomes were generally discernable in the dashboard and complementary to clinical assessments. Movement, symptoms, and medication intake data were feasibly translated from the app into a clinician dashboard but there was substantial attrition rate over 6 months. Further enhancements are needed to ensure long-term patient adherence to portable technologies and optimal digital data transfer to clinicians caring for PD patients.
Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease. Traditionally, attention has focused on the motor symptomatology of PD, but it is now ...appreciated that the nonmotor symptoms affecting neuropsychiatric, sleep, autonomic, and sensory domains occur in up to 88% of PD patients and can be an important source of disability. Nonmotor manifestations of PD play a significant role in the impairment of disease‐related quality of life. The cause of nonmotor manifestations of PD is multifactorial, but to a large extent, these manifestations are related to the nature of the neurodegenerative process and the widespread nondopaminergic neuropathological changes associated with the disease. Recognition of nonmotor disability is essential not only for ascertaining the functional status of patients but also for better appreciating the nature of the neurodegenerative process in PD. In addition, a number of nonmotor manifestations can precede the onset of motor symptoms in PD and can be used as screening tools allowing for early disease identification and for trials of possible disease‐modifying interventions. This article reviews depression, sleep, and autonomic dysfunction in PD. Ann Neurol 2008;64 (suppl):S65–S80
The Movement Disorder Society revised version of the Unified Parkinson’s Disease Rating Scale (MDS‐UPDRS) parts 2 and 3 reflect patient‐reported functional impact and clinician‐reported severity of ...motor signs of Parkinson’s disease (PD), respectively. Total scores are common clinical outcomes but may obscure important time‐based changes in items. We aim to analyze longitudinal disease progression based on MDS‐UPRDS parts 2 and 3 item‐level responses over time and as functions of Hoehn & Yahr (H&Y) stages 1 and 2 for subjects with early PD. The longitudinal item response theory (IRT) modeling is a novel statistical method addressing limitations in traditional linear regression approaches, such as ignoring varying item sensitivities and the sum score balancing out improvements and declines. We utilized a harmonized dataset consisting of six studies with 3573 subjects with early PD and 14,904 visits, and mean follow‐up time of 2.5 years (±1.57). We applied both a unidimensional (each part separately) and multidimensional (both parts combined) longitudinal IRT models. We assessed the progression rates for both parts, anchored to baseline H&Y stages 1 and 2. Both the uni‐ and multidimensional longitudinal IRT models indicate significant worsening time effects in both parts 2 and 3. Baseline H&Y stage 2 was associated with significantly higher baseline severities, but slower progression rates in both parts, as compared with stage 1. Patients with baseline H&Y stage 1 demonstrated slower progression in part 2 severity compared to part 3, whereas patients with baseline H&Y stage 2 progressed faster in part 2 than part 3. The multidimensional model had a superior fit compared to the unidimensional models and it had excellent model performance.
Objective
To determine the evolution of numerous neuropsychiatric symptoms and cognitive abilities in Parkinson disease from disease onset.
Methods
Prospectively collected, longitudinal (untreated, ...disease onset to year 5), observational data from Parkinson's Progression Markers Initiative annual visits was used to evaluate prevalence, correlates, and treatment of 10 neuropsychiatric symptoms and cognitive impairment in Parkinson disease participants and matched healthy controls.
Results
Of 423 Parkinson disease participants evaluated at baseline, 315 (74.5%) were assessed at year 5. Eight neuropsychiatric symptoms studied increased in absolute prevalence by 6.2–20.9% at year 5 relative to baseline, and cognitive impairment increased by 2.7–6.2%. In comparison, the frequency of neuropsychiatric symptoms in healthy controls remained stable or declined over time. Antidepressant and anxiolytic/hypnotic use in Parkinson disease were common at baseline and increased over time (18% to 27% for the former; 13% to 24% for the latter); antipsychotic and cognitive‐enhancing medication use was uncommon throughout (2% and 5% of patients at year 5); and potentially harmful anticholinergic medication use was common and increased over time. At year 5 the cross‐sectional prevalence for having three or more neuropsychiatric disorders/cognitive impairment was 56% for Parkinson disease participants versus 13% for healthy controls, and by then seven of the examined disorders had either occurred or been treated at some time point in the majority of Parkinson disease patients. Principal component analysis suggested an affective disorder subtype only.
Interpretation
Neuropsychiatric features in Parkinson disease are common from the onset, increase over time, are frequently comorbid, and fluctuate in severity.
•Free-water imaging, fixel-based analysis, and NODDI were applied.•Longitudinal 1-year progression effects in PD, MSAp, and PSP were investigated.•MSAp and PSP had longitudinal impairment in various ...descending sensorimotor tracts.•PSP had reduced fiber density in transcallosal tracts.
Advanced diffusion imaging which accounts for complex tissue properties, such as crossing fibers and extracellular fluid, may detect longitudinal changes in widespread pathology in atypical Parkinsonian syndromes. We implemented fixel-based analysis, Neurite Orientation and Density Imaging (NODDI), and free-water imaging in Parkinson’s disease (PD), multiple system atrophy (MSAp), progressive supranuclear palsy (PSP), and controls longitudinally over one year. Further, we used these three advanced diffusion imaging techniques to investigate longitudinal progression-related effects in key white matter tracts and gray matter regions in PD and two common atypical Parkinsonian disorders. Fixel-based analysis and free-water imaging revealed longitudinal declines in a greater number of descending sensorimotor tracts in MSAp and PSP compared to PD. In contrast, only the primary motor descending sensorimotor tract had progressive decline over one year, measured by fiber density (FD), in PD compared to that in controls. PSP was characterized by longitudinal impairment in multiple transcallosal tracts (primary motor, dorsal and ventral premotor, pre-supplementary motor, and supplementary motor area) as measured by FD, whereas there were no transcallosal tracts with longitudinal FD impairment in MSAp and PD. In addition, free-water (FW) and FW-corrected fractional anisotropy (FAt) in gray matter regions showed longitudinal changes over one year in regions that have previously shown cross-sectional impairment in MSAp (putamen) and PSP (substantia nigra, putamen, subthalamic nucleus, red nucleus, and pedunculopontine nucleus). NODDI did not detect any longitudinal white matter tract progression effects and there were few effects in gray matter regions across Parkinsonian disorders. All three imaging methods were associated with change in clinical disease severity across all three Parkinsonian syndromes. These results identify novel extra-nigral and extra-striatal longitudinal progression effects in atypical Parkinsonian disorders through the application of multiple diffusion methods that are related to clinical disease progression. Moreover, the findings suggest that fixel-based analysis and free-water imaging are both particularly sensitive to these longitudinal changes in atypical Parkinsonian disorders.
Innovative tools are urgently needed to accelerate the evaluation and subsequent approval of novel treatments that may slow, halt, or reverse the relentless progression of Parkinson disease (PD). ...Therapies that intervene early in the disease continuum are a priority for the many candidates in the drug development pipeline. There is a paucity of sensitive and objective, yet clinically interpretable, measures that can capture meaningful aspects of the disease. This poses a major challenge for the development of new therapies and is compounded by the considerable heterogeneity in clinical manifestations across patients and the fluctuating nature of many signs and symptoms of PD. Digital health technologies (DHT), such as smartphone applications, wearable sensors, and digital diaries, have the potential to address many of these gaps by enabling the objective, remote, and frequent measurement of PD signs and symptoms in natural living environments. The current climate of the COVID-19 pandemic creates a heightened sense of urgency for effective implementation of such strategies. In order for these technologies to be adopted in drug development studies, a regulatory-aligned consensus on best practices in implementing appropriate technologies, including the collection, processing, and interpretation of digital sensor data, is required. A growing number of collaborative initiatives are being launched to identify effective ways to advance the use of DHT in PD clinical trials. The Critical Path for Parkinson’s Consortium of the Critical Path Institute is highlighted as a case example where stakeholders collectively engaged regulatory agencies on the effective use of DHT in PD clinical trials. Global regulatory agencies, including the US Food and Drug Administration and the European Medicines Agency, are encouraging the efficiencies of data-driven engagements through multistakeholder consortia. To this end, we review how the advancement of DHT can be most effectively achieved by aligning knowledge, expertise, and data sharing in ways that maximize efficiencies.