Analyzing the subcortical dementia syndrome of Parkinson's disease using the RBANS

Abstract

On mental status examinations, groups of equally impaired patients with subcortical (Huntington's disease, HD; Parkinson's disease, PD) or cortical (Alzheimer's disease, AD) dementias exhibit different patterns of neuropsychological deficits. Using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS), classification accuracies of 90% or greater have been reported for individual patients with AD or HD. To test the generality of the RBANS classification algorithm, we studied patients with dementia (AD and PDD) and without dementia (PDND). Classification accuracies were AD: 87%, PDD: 78%, and PDND: 39%. Comparisons of performance on subtests of the RBANS showed that all groups performed more poorly on tests that require motor skill or rapid information processing and that memory performance by the PD groups was not improved by procedures that enhance encoding and facilitate retrieval. The RBANS is useful for discriminating patterns of cognitive impairment in PD and AD, but only if the diagnosis of dementia is established independent of the RBANS test results. Cognitive slowing is not specific to subcortical dementia and current concepts of memory dysfunction in PD may require re-examination.

Parkinson's disease dementia: Definitions, guidelines, and research perspectives in diagnosis

“…In tests such as the letter cancellation test and others, PD-D and DLB groups are slower, have greater variability over time, and make more errors than AD subjects. [33][34][35] Whereas fluctuations in attention are viewed as characteristic of DLB, 29% of PD-D patients show a similar waxing and waning of vigilance. 35 MEMORY.…”

“…Again, in the PD-D group, the mean subcortical impairment score was greater than the cortical score, with the opposite pattern for the AD group. 34 Although relatively accurate at distinguishing groups, heterogeneity and overlap precludes individual patient identification.…”

The impact of depressive symptoms in early Parkinson disease

“…15 The primary outcome of the clinical trials was change in total UPDRS scores from baseline until investigators determined that the subject needed symptomatic therapy due to disability from PD symptoms.…”

Neuropsychological Functions and SPECT Neuroimaging in Parkinson’s Disease

“…In a test involving letter cancellation, it was found that PDD and DLB groups were slower and showed more errors than an AD group (Noe et al, 2004). Another study employing a composite index of attention noted greater deficits in PDD than AD patients (Beatty et al, 2003). Finally, when attention was measured in terms of variability in performance over time in a series of reaction time tasks, it showed that 29% of the PDD patients had attentional fluctuations compared to 42% of those with DLB (Ballard et al, 2002).…”