Cognitive performance and neuropsychiatric symptoms in early, untreated Parkinson's disease

Abstract

This study was undertaken to determine the prevalence and correlates of cognitive impairment (CI) and neuropsychiatric symptoms (NPS) in early, untreated patients with Parkinson’s disease (PD). Background Both CI and NPS are common in PD and impact disease course and quality of life. However, limited knowledge is available about cognitive abilities and NPS. Methods Parkinson’s Progression Markers Initiative (PPMI) is a multi-site study of early, untreated PD patients and healthy controls (HCs), the latter with normal cognition. At baseline, participants were assessed with a neuropsychological battery and for symptoms of depression, anxiety, impulse control disorders (ICDs), psychosis, and apathy. Results Baseline data of 423 PD patients and 196 HCs yielded no between-group differences in demographic characteristics. Twenty-two percent of PD patients met the PD-recommended screening cutoff for CI on the Montral Cognitive Assessment (MoCA), but only 9% met detailed neuropsychological testing criteria for mild cognitive impairment (MCI)-level impairment. The PD patients were more depressed than HCs (P < 0.001), with twice as many (14% vs. 7%) meeting criteria for clinically significant depressive symptoms. The PD patients also experienced more anxiety (P < 0.001) and apathy (P < 0.001) than HCs. Psychosis was uncommon in PD (3%), and no between-group difference was seen in ICD symptoms (P = 0.51). Conclusions Approximately 10% of PD patients in the early, untreated disease state met traditional criteria of CI, which is a lower frequency compared with previous studies. Multiple dopaminergic-dependent NPS are also more common in these patients compared with the general population, but others associated with dopamine replacement therapy are not or are rare. Future analyses of this cohort will examine biological predictors and the course of CI and NPS.

The prominent role of serotonergic degeneration in apathy, anxiety and depression inde novoParkinson’s disease

“…Among the wide range of non-motor features, apathy, anxiety and depression, which can also occur separately, are frequently combined at the early, or the premotor stages, of Parkinson's disease (Aarsland et al, 2009;Barone et al, 2009;Boileau et al, 2009;Chaudhuri et al, 2009;de la Riva et al, 2014;Dujardin et al, 2014;Pagonabarraga et al, 2015;Santangelo et al, 2015;Schrag et al, 2015;Weintraub et al, 2015b). Our findings corroborate such observation.…”

Precuneal Thickness and Depression in Parkinson Disease

“…Considering that deficits in single cognitive domains, in particular working memory, attention, visuospatial and executive functions, may represent early nonmotor symptoms of PD [2,3,4] related to cortical changes [13], and that cognitive dysfunction in patients with depression is underpinned by functional and structural alterations within specific brain regions [7], we performed an extensive neuropsychological evaluation that showed no significant differences between D-PD and ND-PD in global cognitive performance and in single domains, excluding the possibility that cognitive profile may explain precuneal cortical thickening.…”

“…Depression represents the most common psychiatric feature of PD [1] affecting from 17 to 22% of patients from the premotor until the advanced phases [2,3,4], leading to a worse quality of life [2]. In addition, depression in the early stages of PD may represent a risk factor for a more pronounced motor and cognitive decline [5].…”

The Everyday Cognition Scale in Parkinson's Disease

“…While the MoCA is a quick assessment and gross measure of cognition, it is possible that it may over-or underestimate cognitive dysfunction. For example, the MoCA was observed to overestimate MCI in PD patients, as a lower number of patients met criteria when administered a full neuropsychological battery (12). With this in mind, the MoCA continues to be widely used across many disciplines in clinical and research samples to determine the possibility of cognitive dysfunction in PD-related dementia.…”