Neuropsychological profiles associated with subcortical white matter alterations and Parkinson's disease: implications for the diagnosis of dementia.

Despite the emergence of a number of new classification systems, the diagnosis of cerebrovascular dementia remains controversial. Also controversial is the significance of periventricular and deep white matter alterations (WMA) as seen on magnetic resonance imaging (MRI). To further clarify this issue, MRI scans were used to regroup patients clinically diagnosed with Alzheimer's disease (AD) or subcortical ischemic vascular dementia (IVD) into cohorts presenting with either little versus significant WMA on MRI.

Declarative and procedural learning, quantitative measures of the hippocampus, and subcortical white alterations in Alzheimer's disease and ischaemic vascular dementia.

This research investigated whether subjects with Alzheimer's disease (AD) and ischaemic vascular dementia (IVD) associated with periventricular and deep white matter alterations can be dissociated on tests of declarative and procedural memory, as well as on MRI indices of white matter alterations and the size of the hippocampal formation. The California Verbal Learning Test (CVLT) and the Pursuit Rotor Learning Tests (PRLT) were used to measure declarative and procedural memory, respectively. Subjects with IVD obtained a higher score on the CVLT recognition discriminability index; however, on the PRLT total time on target, carry-over between trial blocks, and slope calculated for all test trials was low.

Implicit and explicit memory in young, old, and demented adults.

Previous study of scopolamine and memory (Grober et al., 1989) showed that young adults given moderate or high doses of scopolamine maintained maximum cued recall in spite of a dose-dependent decrement in free recall when memory was assessed by cued selective reminding (CSR), a procedure which circumvents inattention and induces semantic processing. Intact recall by CSR indicates either that scopolamine impairs memory indirectly through effects on attention and information processing or that it impairs explicit memory but not implicit memory.