Detection of mild cognitive deficits in Parkinson's disease patients with the WAIS–R NI

Abstract

The relative insensitivity of traditional IQ tests to mild cognitive deficits has led investigators to develop a version of the widely used Wechsler intelligence scales that allows quantitative analysis of underlying qualitative responses. This instrument, the Wechsler Adult Intelligence Scale-Revised as a Neuropsychological Instrument (WAIS-R NI) was administered to 16 Parkinson's disease (PD) patients and 30 normal controls (NC). The 2 groups did not differ significantly in mean age or education, or on their mean Mattis Dementia Rating Scale score. Relative to NC participants, PD patients showed decreased visual attention span, longer response latencies, slower visuomotor processing, and more stimulus-bound errors. Many of the WAIS-R NI measures were able to detect cognitive impairment in a greater percentage of patients than the traditional WAIS-R measures, making it easier to identify deficits that could affect quality of life early in the course of the disease. (JINS, 2001, 7, 535-543.)

Distinguishing between Vascular Dementia and Alzheimer's Disease by Means of the WAIS: A Meta-analysis

“…Indeed, based on the literature, we expected more impairment in both the VaD and sVaD group for the following of these tests: Block Design (Johnson, Head, Kim, Starr & Cotman, 1999;Skranes et al, 1997;Wallesch, Curio, Galazsky, Jost & Synowitz, 2001), Digit Symbol Substitution (Boone, Pontón, Gorsuch, González & Miller, 1998;Mahurin, Velligan & Miller, 1998;Peavy et al, 2001), Picture Arrangement (Deckel, 1999;Hasselbalch et al, 1992;Peavy et al, 2001), and Picture Completion (Mahieux et al, 1998;Skranes et al, 1997). Also, the Object Assembly test does reveal frontal processing (Peavy et al, 2001;Randolph et al, 1993) and might involve an executive component. These tests, but not the other WAIS subtests, were also found to have the strongest loading on the same single factor (Ardila, Galeano & Rosselli, 1998) and do represent the Performance subscale of the WAIS, which supports that these tests measure overlapping cognitive abilities.…”

“…It is only for two out of these four tests that we expect a stronger involvement of memory compared to EF processing, namely the Information and Vocabulary subtests (Dobbins & Russell, 1990). Results are unclear with regard to the Comprehension subtest (Butters, Goldstein, Allen & Shemansky, 1998;Peavy et al, 2001;Randolph et al, 1993). Since the Similarities subtest requires both memory functions and executive processing (Dobbins & Russell, 1990;Insingrini & Vazou, 1997;Slachevsky et al, 2004), it is not likely that the VaD and AD patients can be distinguished on this task.…”

Levodopa and executive performance in Parkinson's disease: A randomized study

“…While other cognitive domains may be impaired and eventually lead to dementia in PD, "frontal" type executive impairment predominates over the course of the disease (Emre, 2003). Impairment of attention and memory search strategies, slower visuomotor processing, reduced verbal fluency, impairment of organizational and constructional strategies on learning and copying tasks, and motor programming disturbances are characteristic (Peavy et al, 2001). Particularly affected are tasks that involve incremental, feedback-based learning of cue-outcome associations (Shohamy et al, 2006).…”

The effects of visual, auditory, and mixed cues on choice reaction in Parkinson's disease

“…Executive dysfunctions and other cognitive impairments have been recognized as acting synergistically with motor impairments to lower the QOL of PD patients [3,4,13,14]. The purpose of this study was to investigate whether the processing of sensory information for complex choice reaction was altered in PD patients, since such alteration might be associated with functional impairments in their daily lives [29].…”

“…The classic PD symptom triad of resting tremor, rigidity, and bradykinesia attests to the centrality of the motor symptoms of the disease. Recently, mild cognitive or psychiatric impairments such as bradyphrenia and depression have gained recognition as important issues in the treatment of PD patients recovering from a lengthy illness, in order to improve their quality of life (QOL [3,4]). Cognitive or behavioral impairments in PD indicate that these deficits may be related in some way to the circuit [5,6] between the frontal lobe and basal ganglia, both of which are involved in the selection and inhibition of competing responses [7].…”