Neuropsychology of Cortical versus Subcortical Dementia Syndromes
Department of Psychiatry, University of California, San Diego, San Diego, California, United StatesSeminars in Neurology (Impact Factor: 1.79). 03/2007; 27(1):7-21. DOI: 10.1055/s-2006-956751
Neuropsychological studies have shown that there are several prominent differences in the patterns of cognitive deficits that occur in neurodegenerative disorders that have their primary etiology in either cortical or subcortical brain dysfunction. Quantitative and qualitative differences are apparent across many cognitive domains, including memory (in all its aspects), attention, executive functions, language and semantic knowledge, and visuospatial abilities. These distinct patterns of deficits have been broadly characterized as forming cortical and subcortical dementia syndromes. Differentiating between cortical and subcortical dementia provides a heuristically useful model for understanding brain-behavior relationships in neurodegenerative diseases and may improve the ability to clinically distinguish among various dementing disorders.
[Show abstract] [Hide abstract]
- "The neurobiological correlates of VM impairment in BDI remain unclear, as declarative memory is a complex process involving, amongst others, medial temporal (MT; hippocampus and associated structures ) and frontal regions. An appraisal of memory defi cits in patients with frontal/frontostriatal dysfunction (e.g., Parkinson ' s, Huntington ' s and anterior circulation infarcts) versus those with MT lobe dysfunction (e.g., Alzheimer ' s) has led to the construction of differential memory profi les which can help distinguish which region is disordered (Table I) (Delis et al. 2000;Salmon and Filoteo 2007). Patients with frontal lesions appear to have impaired recall with comparatively preserved learning across trials, resulting in a normal learning slope (Brown and Marsden 1988;Delis et al. 1991;Baldo et al. 2002). "
ABSTRACT: Objectives. Verbal memory (VM) impairment is a trait feature of bipolar I disorder (BDI) that is present at illness onset and associated with functional outcome. However, little is known about the morphological abnormalities underlying this deficit early in the disease course. This study examined the neurobiological correlates of VM impairment in euthymic newly diagnosed patients, with attention to frontal and medial temporal (MT) structures known to contribute to VM. Methods. Euthymic patients with BDI recently recovered from their first episode of mania (n = 42) were compared with healthy subjects (n = 37) using measures of the California Verbal Learning Test (CVLT-II) associated with frontal and MT functioning. A subset of participants had 3T MRI scan (n = 31 patient group, n = 30 healthy subject group). Hippocampal and prefrontal volumes were analyzed using FreeSurfer 5.1 and correlated with their corresponding CVLT-II subscores. Results. Patients showed decreased performance in total learning as well as short and long delay verbal recall. Consistent with MT dysfunction, they also showed deficits in recognition discriminability and learning slope. In the patient group only, left hippocampal volumes were negatively correlated with these measures. Conclusions. These results suggest that anomalous MT functioning is involved with VM impairment early in the course of BDI.
[Show abstract] [Hide abstract]
- "PD is also associated with cognitive decline, with anywhere between 24– 31% becoming demented . PD dementia is considered a subcortical dementia, with associated deficits ranging from simple motor ability to higher-order cognitive functions . Despite the high incidence of neurocognitive dysfunction in PD, the relationship between HRT and dementia in those with Parkinson's disease has received considerably less attention. "
ABSTRACT: Over the past two decades, there has been a significant amount of research investigating the risks and benefits of hormone replacement therapy (HRT) with regards to neurodegenerative disease. Here, we review basic science studies, randomized clinical trials, and epidemiological studies, and discuss the putative neuroprotective effects of HRT in the context of Alzheimer's disease, Parkinson's disease, frontotemporal dementia, and HIV-associated neurocognitive disorder. Findings to date suggest a reduced risk of Alzheimer's disease and improved cognitive functioning of postmenopausal women who use 17β-estradiol. With regards to Parkinson's disease, there is consistent evidence from basic science studies for a neuroprotective effect of 17β-estradiol; however, results of clinical and epidemiological studies are inconclusive at this time, and there is a paucity of research examining the association between HRT and Parkinson's-related neurocognitive impairment. Even less understood are the effects of HRT on risk for frontotemporal dementia and HIV-associated neurocognitive disorder. Limits to the existing research are discussed, along with proposed future directions for the investigation of HRT and neurodegenerative diseases.
[Show abstract] [Hide abstract]
- "These differences seem to be most pronounced when comparing AD and subcortical VaD (Laukka et al., 2009; Oosterman & Scherder, 2006). This pattern is consistent with previous findings of prominent deficits in free recall and recognition for cortical dementias and executive function deficits in subcortical dementias (Libon, Price, Garrett, & Giovannetti, 2004; Salmon & Filoteo, 2007). However, other studies have failed to observe differences in cognitive performance between AD and VaD (Looi & Sachdev, 1999; Sachdev & Looi, 2003). "
ABSTRACT: We investigated differences between Alzheimer's disease (AD) and vascular dementia (VaD) from the appearance of the first cognitive symptoms, focusing on both time of onset and rate of accelerated decline for different cognitive functions before dementia diagnosis. Data from a longitudinal population-based study were used, including 914 participants (mean age = 82.0 years, SD = 5.0) tested with a cognitive battery (word recall and recognition, Block Design, category fluency, clock reading) on up to four occasions spanning 10 years. We fit a series of linear mixed effects models with a change point to the cognitive data, contrasting each dementia group to a control group. Significant age-related decline was observed for all five cognitive tasks. Relative to time of diagnosis, the preclinical AD persons deviated from the normal aging curve earlier (up to 9 years) compared to the preclinical VaD persons (up to 6 years). However, once the preclinical VaD persons started to decline, they deteriorated at a faster rate than the preclinical AD persons. The results have important implications for identifying the two dementia disorders at an early stage and for selecting cognitive tasks to evaluate treatment effects for persons at risk of developing AD and VaD.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.