Parkinson's disease‐cognitive rating scale: A new cognitive scale specific for Parkinson's disease

Abstract

Cognitive defects associated with cortical pathology may be a marker of dementia in Parkinson's disease (PD). There is a need to improve the diagnostic criteria of PD dementia (PDD) and to clarify the cognitive impairment patterns associated with PD. Current neuropsychological batteries designed for PD are focused on fronto-subcortical deficits but are not sensitive for cortical dysfunction. We developed a new scale, the Parkinson's Disease-Cognitive Rating Scale (PD-CRS), that was designed to cover the full spectrum of cognitive defects associated with PD. We prospectively studied 92 PD patients [30 cognitively intact (CogInt), 30 mild cognitive impairment (MCI), 32 PDD] and 61 matched controls who completed the PD-CRS and neuropsychological tests assessing the cognitive domains included in the PD-CRS. Acceptability, construct validity, reliability, and the discriminative properties of the PD-CRS were examined. The PD-CRS included items assessing fronto-subcortical defects and items assessing cortical dysfunction. Construct validity, test-retest and inter-rater reliability of PD-CRS total scores showed an intraclass correlation coefficient >0.70. The PD-CRS showed an excellent test accuracy to diagnose PDD (sensitivity 94%, specificity 94%). The PD-CRS total scores and confrontation naming item scores-assessing "cortical" dysfunction-independently differentiated PDD from non-demented PD. Alternating verbal fluency and delayed verbal memory independently differentiated the MCI group from both controls and CogInt. The PD-CRS appeared to be a reliable and valid PD-specific battery that accurately diagnosed PDD and detected subtle fronto-subcortical deficits. Performance on the PD-CRS showed that PDD is characterized by the addition of cortical dysfunction upon a predominant and progressive fronto-subcortical impairment.

Mild Cognitive Impairment and Parkinson’s Disease - Something to Remember

“…Although as yet, not all aspects of this work have been fully replicated, there is nonetheless an emerging consensus from clinical [27,28] and genetic studies [29] that the basic principles are true. Furthermore, studies using a range of imaging modalities including structural MRI [30], SPECT [31] and FDG-PET [32] to investigate PD patients with cognitive impairment support the hypothesis that pathological changes in posterior cortical regions are associated with progression to dementia in PD.…”

Predicting dementia in Parkinson disease by combining neurophysiologic and cognitive markers

“…We estimated broadband time series of neuronal activation for voxels with peak activation for 6 frequency bands (delta [0.5-4 Hz], theta [4][5][6][7][8], alpha1 [8][9][10], alpha2 [10][11][12][13], beta [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], and gamma [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48], using an average time window of 232 (range: 118-433) seconds as input for the beamformer computations. This resulted in a total of 6 sets (one for each frequency band) of 78 time series (one for each AAL region).…”

“…3,4 Substantial heterogeneity in the range of early-stage cognitive deficits exists, 5 but whether their specific nature or rate of development improves prediction of PDD conversion is still uncertain. [6][7][8][9] Neurophysiologic measures may be ideal biomarkers to complement cognitive testing in studying cognitive decline and dementia development in PD. Low peak frequency and oscillatory slowing (high theta power) in EEG recordings have previously been identified as independent predictors of dementia incidence in PD, 9 with a predictive ability exceeding that of cognitive testing.…”

Quality of Life in Parkinson’s Disease – Patient, Clinical and Research Perspectives

“…In addition to these general scales, there are scales that assess individual symptoms such as the Parkinson Fatigue Scale (PFS), 39 Parkinson's Disease Sleep Scale (PDSS) 40 and the Parkinson's Disease Cognitive Rating Scale (PD-CRS). 41 Another instrument that captures non-motor symptoms (and motor symptoms) in PD is the PS-23 scale.…”