Heterogeneity in Alzheimer’s/Vascular Spectrum Dementia

Author(s):  
Sheina Emrani ◽  
Melissa Lamar ◽  
Catherine C. Price ◽  
Victor Wasserman ◽  
Emily Matusz ◽  
...  

Alzheimer’s disease (AD) and vascular dementia (VaD) are considered to be the two most common types of dementia with each of these dementia syndromes believed to represent more or less independent entities. While mixed dementia syndromes are acknowledged, the prevailing point of view continues to suggest that AD and VaD represent disorders with different underlying etiology. This chapter will review some of the recent neuropathological and neuropsychological literature suggesting considerable heterogeneity between AD and VaD. It is our contention that the literature reviewed in this chapter supports the notion that neuropsychological syndromes seen in AD/VaD dementia, in addition to their underlying biological substrate, are best understood as existing along a clinical/pathological continuum or spectrum. This heterogeneity should be leveraged to construct a more sophisticated and heuristically meaningful way to classify patients with dementia.

Alzheimer’s disease and vascular dementia are acknowledged as the two most common types of dementia. Each of these dementia syndromes are associated with prodromal clinical syndromes, often referred to as mild cognitive impairment. Recent research has demonstrated considerable heterogeneity regarding the underlying neuropathology associated with these dementia syndromes and their prodromal disorders. Thus, it is often difficult to understand how or what underlying biological substrate is actually responsible for the alterations in neurocognition and behaviour as seen in clinical evaluations. This inherent neuropsychological and neuropathology heterogeneity calls into question current paradigms used for diagnosis and clinical trials designed to treat these disorders. This volume summarizes our current understanding regarding the inherent clinical, neuropathological, and biological heterogeneity in Alzheimer’s disease, vascular dementia, and mild cognitive impairment and suggests that these disorders are best viewed as existing along a continuum rather than treated as separate and distinct clinical syndromes. In this book, we put forth the point of view that dementia such as Alzheimer’s disease and vascular dementia; and subtle pre-dementia syndromes such as mild cognitive impairment are best viewed as existing along a continuum rather than distinct and separate disorders.


2021 ◽  
Vol 18 ◽  
Author(s):  
Panoraia I. Siafaka ◽  
Gökce Mutlu ◽  
Neslihan Üstündağ Okur

Background: Dementia and its related types such as Alzheimer’s disease, vascular dementia and mixed dementia belong to brain associated diseases, resulting in long-term progressive memory loss. These diseases are so severe that can affect a person's daily routine. Up to date, treatment of de- mentias is still an unmet challenge due to their complex pathophysiology and unavailable efficient pharmacological approaches. The use of nanotechnology based pharmaceutical products could possibly improve the management of dementia given that nanocarriers could more efficiently deliver drugs to the brain. Objective: The objective of this study is to provide the current nanotechnology based drug delivery systems for the treatment of various dementia types. In addition, the current diagnosis biomarkers for the mentioned dementia types along with their available pharmacological treatment are being dis- cussed. Method: An extensive review of the current nanosystems such as brain drug delivery systems against Alzheimer’s disease, vascular dementia and mixed dementia was performed. Moreover, nan- otheranostics as possible imaging markers for such dementias were also reported. Results: The field of nanotechnology is quite advantageous for targeting dementia given that nanoscale drug delivery systems easily penetrate the blood brain barrier and circulate in the body for prolonged time. These nanoformulations consist of polymeric nanoparticles, solid lipid nanoparticles, nanostruc- tured lipid carriers, microemulsions, nanoemulsions, and liquid crystals. The delivery of the nan- otherapeutics can be achieved via various administration routes such as transdermal, injectable, oral, and more importantly, through the intranasal route. Nonetheless, the nanocarriers are mostly limited to Alzheimer’s disease targeting; thus, nanocarriers for other types of dementia should be developed. Conclusion: To conclude, understanding the mechanism of neurodegeneration and reviewing the cur- rent drug delivery systems for Alzheimer’s disease and other dementia types are significant for medical and pharmaceutical society to produce efficient therapeutic choices and novel strategies based on mul- tifunctional and biocompatible nanocarriers, which can deliver the drug sufficiently into the brain.


2003 ◽  
Vol 15 (S1) ◽  
pp. 111-114 ◽  
Author(s):  
Gabriel Gold

Although vascular dementia was described over a century ago, it remains a difficult and challenging diagnosis. Several sets of clinical criteria have been published in an effort to establish the presence or absence of vascular dementia in a standardized fashion. Clinical studies have demonstrated that they identify different groups of patients and are thus not interchangeable. Retrospective clinicopathological correlations have shown that most are insufficiently sensitive, although they are generally relatively specific. They accurately exclude pure Alzheimer's disease but may include 9% to 39% of mixed dementia cases (Alzheimer's disease and vascular dementia combined). Further studies are needed to develop better performing criteria that could lead to a broad consensus on the clinical diagnosis of vascular and mixed dementia.


1996 ◽  
Vol 15 (6) ◽  
pp. 286-290 ◽  
Author(s):  
Philip B. Gorelick ◽  
David L. Nyenhuis ◽  
David C. Garron ◽  
Elizabeth Cochran

1996 ◽  
Vol 8 (3) ◽  
pp. 413-424 ◽  
Author(s):  
Gregory R. J. Swanwick ◽  
Robert F. Coen ◽  
Brian A. Lawlor ◽  
Denis O'Mahony ◽  
J. Bernard Walsh ◽  
...  

Despite new developments in the concept of vascular dementia, the Hachinski Ischemic Score (HIS) and its modified versions continue to be widely used in the clinical differentiation of Alzheimer's disease (AD) and ischemic vascular dementia (IVD). The sensitivity of the HIS and two modified versions in the diagnosis of AD, IVD, and single infarcts in a large, geriatric population with mild cognitive impairment (N = 100) was evaluated. Sensitivity for identification of AD was greater than 90% but was less than 70% for IVD. Over one third of patients with one or more infarcts on computed tomographic brain scans and 63% of mixed cases were classified as having probable AD. It is concluded that ischemic scores may be useful at predicting prevalence rates if individual case accuracy is ignored. Despite being sensitive to identifying AD, ischemic scores are insensitive to both cerebral infarction and IVD and cannot reliably exclude IVD. Finally, patients with mixed dementia should not be expected to have intermediate scores.


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