Alzheimer’s disease vascular dementia

Dementia is characterised by a progressive decline in cognitive function. The prevalence of dementia increases with age. With the demographical changes, the number of patients with dementia will increase. There are three major forms of dementia Alzheimer s disease, vascular dementia and a mixed dementia. Beside these, there are several less common subtypes of dementia. 

Ginkgo has been examined in a number of clinical populations, including Alzheimer s disease, vascular dementia, and age-associated cognitive decline. Most studies employed the extracts EGb 761 or LI 1370. Many have methodological flaws including limited sample size or insufficient description of randomization, patient characteristics, measurement techniques, or result presentation, but there are a number of well-controlled studies available for drawing preliminary conclusions (Field and Vadnal 1998). 

Foy, C.J., Passmore, A.P., Vahidassr, M.D., Young, ES., and Lawson, J.T. 1999. Plasma chainbreaking antioxidants in Alzheimer s disease, vascular dementia and Parkinson s disease. OJM... 

Blood plasma TAC was not altered in patients with Alzheimer s disease, vascular dementia, Parkinson s disease and dementia, or Parkinson s disease (F6, F10). However, another study found decreased blood plasma TAC in Alzheimer patients (by 24%) (R12). TAC was decreased in blood plasma of children with Down syndrome (by 26%) (C18). Epileptic patients receiving phenytoin showed decreased TAC of blood sera, apparently due to the oxidative stress induced by the drug (M3). 

Pirttila, T Kim, K.S., Mehta, P.D., Frey, H. and Wisniewski, H.M. (1994) Soluble amyloid (3-proLein in the cerebrospinal fluid from patients with Alzheimer s disease, vascular dementia and controls../. Neurol. Sci. 127, 90-95. 

Many individuals with LA also harbor lacunar and/or cortical infarcts. Presence of LA serves as an intermediate surrogate both for ischemic stroke and intracerebral hemorrhage as they all share similar risk factors and similar pathophysiological mechanisms (Inzitari 2003). LA is widely found in dementing illnesses, such as Alzheimer s disease, vascular dementia, and cerebral autosomal dominant arteri-opathy with subcortical infarcts and leukoencepha-lopathy (CADASIL). Failure of blood supply in the... 

Perfusion hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT) or 2-[ F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) can be used to help to differentiate between Alzheimer s disease, vascular dementia and frontotemporal dementia if the diagnosis is in doubt. 

Trade names Akatinol Axura Ebixa Namenda (Forest) Indications Alzheimer s disease, Vascular dementia Category Adamantane NMDA receptor antagonist Half-life 60-80 hours... 

Figure 46.3 Vitamin Bn status in different types of dementia. AD = Alzheimer s disease DOC = dementia due to other causes VaD = vascular dementia.

Psychotic symptoms in late life (greater than 65 years of age) are generally a result of an ongoing chronic illness carried over from younger life however, a small percentage of patients develop psychotic symptoms de novo, defined as late-life schizophrenia. The 6-month prevalence rate of schizophrenia in the elderly is around 1%. However, other illnesses presenting with psychotic symptoms are common in this population, as approximately one-third of patients with Alzheimer s disease, Parkinson s disease, and vascular dementia experience psychotic symptoms. The majority of data for antipsychotic use in the elderly comes from experience treating these other disease states. 

McCusker SM, Curran MD, Dynan KB, McCullagh CD, Urquhart DD, Middleton D et al. Association between polymorphism in regulatory region of gene encoding tumour necrosis factor a and risk of Alzheimer s disease and vascular dementia a case-control study. Lancet 2001 357 436 139. 

Alzheimer s disease, Parkinson disease, prion diseases (Creutzfeld-Jacob in humans, scrapie in sheep), Huntington disease, dementia with Levy s bodies, sclerosis multiplex and amyotrophic lateral sclerosis, frontotemporal lobar degeneration, and vascular dementia are the most commonly occurring neurodegenerative diseases, with different (and often unknown) pathophysiology, creating serious health care problems and... 

Two neurodegenerative diseases will be considered in greater detail here, Alzheimer s disease and Parkinson s disease, due to the pertinence of herbal medications to their treatment. Also discussed in some detail are vascular dementia and normal aging. Other degenerative conditions may benefit from herbal medications, but have not received the amount of attention in research that the above conditions have. Of particular interest to many degenerative conditions are herbal medications with demonstrated antioxidant and neuroprotective effects. 

Frontal and subcortical lacunar infarcts typically affect attention, language, visuospatial function, and motor programming (Babikian et al. 1990). Compared to patients with Alzheimer s disease, those with vascular dementia show better orientation, recall, and language ability. On... 

Although the meta-analysis by Oken and colleagues examined efficacy in Alzheimer s disease only, improvements have been seen in other conditions such as age-related memory decline and vascular dementia (Kanowski et al. 1996 Haase et al. 1996 Allain et al. 1993). More research is needed to establish the quantitative clinical significance of ginkgo extract. 

Alzheimer s disease (AD) is the most frequent cause of dementia (50-70%), followed by vascular dementia (30 0%) and mixed dementia (15-20%). These prevalent forms of age-related neurodegeneration represent a major problem of health in developed countries, with more than 25 million people affected and probably more than 75 million people at risk during the next 20-25 years worldwide. The prevalence of dementia increases exponentially, from approx. 1% at 60-65 yr to more than 30-35% in people older than 80yr. It is very likely that in those patients older than 75-80 yr most cases of dementia are mixed in nature (degenerative plus vascular), whereas pure AD cases are very rare after 80yr (1-3). 

Fig. 10.8 Absolute genetic variation (AGV) and relative genetic variation (RGV) between Alzheimer s disease and vascular dementia associated with bigenic, trigenic, and tetragenic clusters of Alzheimer s disease (AD)-related genes. APOE, apolipoprotein E PS, presenilin. (Adapted from refs. 12,19,20, and 59.)...

Scacchi, R., De Bernardini, L., Mantuano, E., et al. (1998) DNA polymorphisms of apoUpo-protein B and angiotensin I-converting enzyme genes and relationships with Upid levels in Italian patients with vascular dementia or Alzheimer s disease. Dement. Geriatr. Cogn. Disord., 9, 186-190. 

Wang, H.K., Fung, H.C., Hsu, W.C., et al. (2006) Apolipoprotein E, angiotensin-converting enzyme and kaUikrein gene polymorphisms and the risk of Alzheimer s disease and vascular dementia. J. Neural Transm., 113, 1499-1509. 

Degenerative Dementias. Far and away, the most common dementias in the United States are of the degenerative type. These result from gradual deterioration of the brain and include Alzheimer s disease (AD). AD accounts for about 60% of dementias. Vascular dementia, another degenerative dementia, is the second most common form and accounts for another 10%. 

The cause of Alzheimer s disease is unknown, but genetic factors clearly play a role. One clue supporting this view is provided by the observation that individuals with Down syndrome, a common cause of mental retardation, frequently develop a dementia similar to Alzheimer s disease during early adulthood. Vascular dementia, which is also called multi-infarct dementia, results from the accumulation of tiny strokes. Individually, these strokes or infarcts are too small to cause any noticeable problem, but as they accumulate, they produce deficits similar to Alzheimer s disease. Other neurological diseases such as Parkinson s disease, Pick s disease, and Huntington s disease cause slow deterioration of the brain that ultimately leads to a degenerative dementia. 

The majority of dementias including Alzheimer s disease and vascular dementia are not reversible. However, treatments to protect the brain can theoretically slow the deterioration of these illnesses. 

In controlled trials, all of these treatments provided mixed results at best. A few patients seemed to benefit, but most did not. In retrospect, this is probably because patients with many different types of dementia were lumped together in these older stndies. We now believe that these treatments provided no benefit to the Alzheimer s disease patient bnt may have helped those with vascular dementia. 

As noted earlier, cognition-enhancing medications are most helpful during the early and moderate stages of dementia. These medications proved effective for both Alzheimer s disease and vascular dementia it s unknown whether they are helpful for other dementias. 

Bar, K. J., Franke, S., Wenda, B., Muller, S., Kientsch-Engel, R., Stein, G., and Sauer, H. (2002). Pentosidine and N(epsilon)-(carboxymethyl)-lysine in Alzheimer s disease and vascular dementia. Neurobiol. Aging 24, 333-338. 

Newman SC The prevalence of depression in Alzheimer s disease and vascular dementia in a population sample. J Affect Disord 52 169-176, 1999 Nibuya M, Rydelek-Fitzgerald L, Russell DS, et al Induction of BDNE and trkB by electroconvulsive seizure regional regulation and role of CREB. Soc Neurosci 24 1312, 1994... 

Donepezil is currently approved by the U.S. Food and Drug Administration (FDA) only for the treatment of mild to moderate Alzheimer s disease, but its efficacy also has been examined in other dementias, including moderate to severe Alzheimer s disease (Feldman et al. 2003 Gauthier et al. 2002), Parkinson s disease (Aarsland et al. 2002 Leroi et al. 2004 Ravina et al. 2005), and vascular dementia (Black et al. 2003 Wilkinson et al. 2003). Further study in these areas is needed. 

Alzheimer s disease however, studies have investigated its potential utility in vascular dementia (Erkinjuntti et al. 2002a) and advanced moderate Alzheimer s disease (Blesa et al. 2003). 

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