Neuropsychology, neuroimaging or motor phenotype in diagnosis of Parkinson’s disease-dementia: which matters most?

Abstract

Parkinson's disease (PD) is a neurodegenerative disorder affecting not only the motor system but also the cognitive and behavioral domains. Although there are many studies addressing the issue of cognition, a universally recognized method to diagnose patients with dementia is still lacking. The aim of this study was to determine which neuropsychological test is the most reliable in the diagnosis of dementia in PD and to establish if mini mental state examination (MMSE) is enough to detect this condition. We studied 200 consecutive PD patients through an extensive neuropsychological battery, clinical evaluation and brain magnetic resonance imaging over a period of 4 years. A logistic regression model was used to evaluate the interplay between possible risk factors and the accuracy of different neuropsychological tests. PD patients with dementia performed significantly worse in all the tests as compared to patients with PD alone: phonological verbal fluency, attentional matrices, Rey auditory verbal learning test and digit span were the most useful tools. Age and disease duration were correlated with cognitive impairment. No relevant differences were detected in phenotype, affected body side at onset, levodopa equivalent daily dose or neuroimaging findings (except for the occurrence of atrophy). Despite reasonable accuracy of MMSE (90%), its positive predictive value is only 74%. Using at least 3 neuropsychological tests, among those more significant detected with logistic regression analysis, the positive predictive value rises to 91%. In conclusion, the use of an extensive neuropsychological battery is still recommended in the diagnosis of dementia in PD.

CERAD test performance and cognitive impairment in Parkinson's disease

“…It has also been suggested that the transition from PD to PDD is characterized by an addition of more posterior cortical cognitive symptoms, such as problems in episodic memory, visuospatial deficits, and language processing, to the more fronto‐striatally mediated executive/attentive impairments . This has been corroborated by a recent study , showing that PDD patients were impaired compared with non‐demented patients on measures of attentive/executive functions (e.g. verbal fluency) as well as those of learning and episodic memory.…”

Phonemic and semantic verbal fluency tasks: normative data for elderly Brazilians

“…The verbal fl uency tasks are frequently used to evaluate cognitive changes, characterize the performance profi les in healthy aging and in neurodegenerative diseases (Di Biasio et al, 2012;Martyr et al, 2012). Fast and easy to administer, these tasks can be managed individually or as being present in some assessment protocols (Dubois, Slachevsky, Litvan, & Pillon, 2000;Fillenbaum et al, 2008).…”

Validation of Neuropsychological Tests to Screen for Dementia in Chinese Patients With Parkinson’s Disease

“…34 Moreover, the study by Di Biasio et al also recommended the use of an extensive neuropsychological battery in the diagnosis of dementia in patients with PD. 10 Other neuropsychological assessment batteries include RVR, BD, DS, and FOME. These tests usually test multiple separate cognitive domains that may collapse to form composite measures.…”

“…The utilization of an extensive neuropsychological battery has been recommended. 10 The objective of the present study was to determine the specificity, sensitivity, and accuracy of various neuropsychological tests, including Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Block Design (BD), Fuld Object Memory Evaluation (FOME), Digit Span (DS), and Rapid Verbal Retrieve (RVR), and any of their combinations in Chinese patients with PD, and to identify the best short screening test for dementia in PD in order to facilitate clinical diagnosis.…”