Clínica de la demencia con cuerpos de Lewy y evolución frente a la enfermedad de Alzheimer

Lewy body dementia (LBD) is a neurodegenerative disease with well-defined symptoms and established clinical criteria, characterized by the presence of cortical and subcortical dementia, accompanied by some characteristic features such as Parkinsonism, visual hallucinations and fluctuations in alertness and attention, as well as hypersensitivity to neuroleptics. Compared with Alzheimer's disease, LBD seems to have a more rapid clinical course and greater mortality. The differences with Alzheimer's disease may be more apparent in the initial stages of the disease but tend to disappear with disease progression. Because of the greater presence of neuropsychiatric symptoms and the higher degree of dependency in LBD, there is greater caregiver overload and probably greater resource use.     

Neuropsychological characteristics and diagnostic approach to Parkinsońs disease dementia and Lewy body dementia

When approaching the neurophysiological characteristics and diagnostic approach to Parkinson's disease dementia (PDD) and Lewy body dementia (LBD), the first idea that comes to mind is that both types of dementia fall within the group of subcortical dementias, with the practical implications that this observation entails. We should therefore leave our knowledge of Alzheimer's dementia and other cortical dementias to one side as, in most cases, these forms of dementia do not correspond clinically or diagnostically to subcortical dementias. Therefore, the clinical and therapeutic approach of PDD and LBD differs from that of cortical dementias in form, if not in essence.     

Tau gene mutations: dissecting the pathogenesis of FTDP-17

Tau is a microtubule-associated protein involved in microtubule assembly and stabilization. Abnormal filamentous tau deposits constitute a major defining characteristic of several neurodegenerative diseases, including Alzheimer's disease. Although the presence of tau pathology correlates with the symptoms of Alzheimer's disease, there was no genetic evidence linking tau to neurodegeneration until recently. However, since 1998, the identification of more than 25 mutations in the tau gene, associated with frontotemporal dementia and parkinsonism linked to chromosome 17, has demonstrated that tau dysfunction can lead to neurodegeneration and the development of clinical symptoms.     

Alzheimer's dementia: current data review

The review focuses on current data on Alzhemier's dementia, a clinical syndrom characterised with acquired deterioration of cognitive functioning and emotional capacities, which impaires everyday activity and quality of life. Alzheimer's dementia is the most common type of dementia in clinical surveys. The diagnosis of Alzheimer's dementia is primarily based on symptoms and signs and memory impairment is clinically most significant. Cholinesterase inhibitors -donepezil, rivastigmine and galantamine are considered to be the first line pharmacotherapy for mild to moderate Alzheimer's disease. Currently, no effective pharmacologic interventions have been researched enough to support their use in prevention of Alzheimer's dementia. Studies suggest that healthy lifestyle, ongoing education, regular physical activity, and cholesterol control, play a role in prevention of Alzheimer's dementia.     

Behavioural symptoms in patients with Alzheimer's disease and their association with cognitive impairment

Background  

Behavioural and psychological symptoms of dementia (BPSD) are non-cognitive symptoms commonly associated to Alzheimer's disease (AD). The characterization of the clinical profile of AD patients might help to better understand disease evolution and to improve diagnosis and treatment. Thus, the aim of the present study is to describe the clinical profile of AD patients, and to correlate the presence of BPSD with the severity of the disease.     

Características Neuropsicológicas y Aproximación Diagnóstica a la Demencia Parkinson y a la Demencia por Cuerpos de Lewy

When approaching the neurophysiological characteristics and diagnostic approach to Parkinson's disease dementia (PDD) and Lewy body dementia (LBD), the first idea that comes to mind is that both types of dementia fall within the group of subcortical dementias, with the practical implications that this observation entails. We should therefore leave our knowledge of Alzheimer's dementia and other cortical dementias to one side as, in most cases, these forms of dementia do not correspond clinically or diagnostically to subcortical dementias. Therefore, the clinical and therapeutic approach of PDD and LBD differs from that of cortical dementias in form, if not in essence.     

Serum and Cerebrospinal Fluid Levels of Transthyretin in Lewy Body Disorders with and without Dementia

Parkinson’s disease (PD) without (non-demented, PDND) and with dementia (PDD), and dementia with Lewy bodies (DLB) are subsumed under the umbrella term Lewy body disorders (LBD). The main component of the underlying pathologic substrate, i.e. Lewy bodies and Lewy neurites, is misfolded alpha-synuclein (Asyn), and - in particular in demented LBD patients - co-occurring misfolded amyloid-beta (Abeta). Lowered blood and cerebrospinal fluid (CSF) levels of transthyretin (TTR) - a clearance protein mainly produced in the liver and, autonomously, in the choroid plexus - are associated with Abeta accumulation in Alzheimer’s disease. In addition, a recent study suggests that TTR is involved in Asyn clearance. We measured TTR protein levels in serum and cerebrospinal fluid of 131 LBD patients (77 PDND, 26 PDD, and 28 DLB) and 72 controls, and compared TTR levels with demographic and clinical data as well as neurodegenerative markers in the CSF. Five single nucleotide polymorphisms of the TTR gene which are considered to influence the ability of the protein to carry its ligands were also analyzed. CSF TTR levels were significantly higher in LBD patients compared to controls. Post-hoc analysis demonstrated that this effect was driven by PDND patients. In addition, CSF TTR levels correlated negatively with CSF Abeta_1–42, total tau and phospho-tau levels. Serum TTR levels did not significantly differ among the studied groups. There were no relevant associations between TTR levels and genetic, demographic and clinical data, respectively. These results suggest an involvement of the clearance protein TTR in LBD pathophysiology, and should motivate to elucidate TTR-related mechanisms in LBD in more detail.     

Effects of alpha-synuclein immunization in a mouse model of Parkinson's disease

Abnormal folding of alpha-synuclein (alpha-syn) is thought to lead to neurodegeneration and the characteristic symptoms of Lewy body disease (LBD). Since previous studies suggest that immunization might be a potential therapy for Alzheimer's disease, we hypothesized that immunization with human (h)alpha-syn might have therapeutic effects in LBD. For this purpose, halpha-syn transgenic (tg) mice were vaccinated with halpha-syn. In mice that produced high relative affinity antibodies, there was decreased accumulation of aggregated halpha-syn in neuronal cell bodies and synapses that was associated with reduced neurodegeneration. Furthermore, antibodies produced by immunized mice recognized abnormal halpha-syn associated with the neuronal membrane and promoted the degradation of halpha-syn aggregates, probably via lysosomal pathways. Similar effects were observed with an exogenously applied FITC-tagged halpha-syn antibody. These results suggest that vaccination is effective in reducing neuronal accumulation of halpha-syn aggregates and that further development of this approach might have a potential role in the treatment of LBD.     

A familial case of Alzheimer's disease without tau pathology may be linked with chromosome 3 markers

Alzheimer's disease is the most common form of dementia that occurs in later years. The diagnosis is confirmed by the pathological findings of βA4-amyloid-containing neuritic plaques and neurofibrillary tangles, the former being present in sufficient quantity commensurate with age. Other forms of dementia are more difficult to diagnose clinically; their pathology is noted for the lack of plaques and tangles. A patient with a family history of dementia presented with the clinical signs of Alzheimer's disease which lasted for 13 years. At autopsy the brain tissue had βA4-amyloid-containing neuritic plaques, but no neurofibrillary tangles (i.e., the tissue was negative for staining with the tau antibody). Genetic analysis of DNA from family members revealed no linkage with chromosome 17 markers, indicating that this was not frontotemporal dementia. However, there was linkage with chromosome 3 markers. Thus, this form of Alzheimer's disease with a pathology of plaques only is linked with markers on chromosome 3. Electronic Publication     

CCK receptors and human neurological disease

Cholecystokinin (CCK) receptor binding was measured in postmortem brain tissue of patients with Alzheimer's dementia, Huntington's chorea, and neurologically healthy matched controls. CCK binding was significantly reduced inthe basal ganglia and cerebral cortex of Huntington's patients, but was normal in the temporal and cingulate cortex of patients with Alzheimer's disease. These findings indicate that CCK receptor loss is unique to specific neurodegenerative disease(s), and that CCK may be involved in the symptoms of Huntington's disease but is not implicated in the neuropathology of Alzheimer's dementia.     

Neuroleptic drugs in dementia: benefits and harm

Neuroleptic (antipsychotic) drugs are often used to treat psychiatric symptoms frequently seen in dementia, but their use is controversial. We present a new meta-analysis to assess the efficacy of these drugs for the treatment of psychiatric symptoms in Alzheimer's disease, and discuss the more limited evidence for their potential benefits in other dementias. We recommend that these treatments be limited to the short-term treatment of psychiatric symptoms associated with serious distress or risk.     

In-vivo proton MR-spectroscopy of the human brain: assessment of N-acetylaspartate (NAA) reduction as a marker for neurodegeneration

Summary.  Proton magnetic resonance spectroscopy (¹H-MRS) is a non-invasive method to investigate changes in brain metabolite composition in different cerebral diseases. We performed proton spectroscopy in patients with dementia of the Alzheimer's type (AD) and in patients with motor neuron disease (MND) with the aim to detect the specific metabolic pattern for these neurodegenerative disorders. In the MND group we found a significant reduction of NAA/tCr metabolite ratios in the motor cortex, which correlates with the disease severity and the clinical lateralization of neurological symptoms and further decreases in the time course of the disease. In AD patients a reduction of NAA/tCr was observed in the medial temporal lobe. Since NAA is exclusively expressed in neurons as shown by immunohistochemical studies, reduced NAA levels suggest neuronal loss or dysfunction in the observed regions. The observed regional metabolic alterations reflect the neuronal basis of the characteristic neurological symptoms in AD (dementia) and MND (muscular palsy) and mirrors the disease progress over time. Received June 29, 2001 Accepted August 6, 2001 Published online August 9, 2002     

Substantial sulfatide deficiency and ceramide elevation in very early Alzheimer's disease: potential role in disease pathogenesis

In addition to pathology in the gray matter, there are also abnormalities in the white matter in Alzheimer's disease (AD). Sulfatide species are a class of myelin-specific sphingolipids and are involved in certain diseases of the central nervous system. To assess whether sulfatide content in gray and white matter in human subjects is associated with both the presence of Alzheimer's disease (AD) pathology as well as the stage of dementia, we analyzed the sulfatide content of brain tissue lipid extracts by electrospray ionization mass spectrometry from 22 subjects whose cognitive status at time of death varied from no dementia to very severe dementia. All subjects with dementia had AD pathology. The results demonstrate that: (i) sulfatides were depleted up to 93% in gray matter and up to 58% in white matter from all examined brain regions from AD subjects with very mild dementia, whereas all other major classes of lipid (except plasmalogen) in these subjects were not altered in comparison to those from age-matched subjects with no dementia; (ii) there was no apparent deficiency in the biosynthesis of sulfatides in very mild AD subjects as characterized by the examination of galactocerebroside sulfotransferase activities in post-mortem brain tissues; (iii) the content of ceramides (a class of potential degradation products of sulfatides) was elevated more than three-fold in white matter and peaked at the stage of very mild dementia. The findings demonstrate that a marked decrease in sulfatides is associated with AD pathology even in subjects with very mild dementia and that these changes may be linked with early events in the pathological process of AD.     

Neuropathological, clinical and molecular pathology in female fragile X premutation carriers with and without FXTAS

Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder associated with premutation alleles of the fragile X mental retardation 1 (FMR1) gene. Approximately 40% of older male premutation carriers, and a smaller proportion of females, are affected by FXTAS; due to the lower penetrance the characterization of the disorder in females is much less detailed. Core clinical features of FXTAS include intention tremor, cerebellar gait ataxia and frequently parkinsonism, autonomic dysfunction and cognitive deficits progressing to dementia in up to 50% of males. In this study, we report the clinical, molecular and neuropathological findings of eight female premutation carriers. Significantly, four of these women had dementia; of the four, three had FXTAS plus dementia. Post-mortem examination showed the presence of intranuclear inclusions in all eight cases, which included one asymptomatic premutation carrier who died from cancer. Among the four subjects with dementia, three had sufficient number of cortical amyloid plaques and neurofibrillary tangles to make Alzheimer's disease a highly likely cause of dementia and a fourth case had dementia with cortical Lewy bodies. Dementia appears to be more common than originally reported in females with FXTAS. Although further studies are required, our observation suggests that in a portion of FXTAS cases there is Alzheimer pathology and perhaps a synergistic effect on the progression of the disease may occur.     

Predementia Alzheimer's disease. Benefits of early diagnosis

Given population aging and the rise in the number of persons with Alzheimer's disease, measures that aim not only to delay but also to prevent the development of this disease are increasingly required. Advances in the diagnosis of Alzheimer's disease support the need for a review of current clinical standards for mild cognitive impairment and provide new goals in the early treatment of this disease. The current diagnostic process should be refocussed toward the pathological substrate of this disease rather than symptoms in order to initiate therapeutic measures as soon as possible without waiting for clinical manifestations to appear. Such an approach is essential in patients with greater cognitive reserve, in whom the lesions are usually more severe at diagnosis and treatment is less effective. To identify disease-modifying therapies to delay the onset of the clinical symptoms of Alzheimer's disease in cognitively intact persons at high risk, biomarkers for this disease must be validated. A single biomarker is unlikely to provide the required diagnostic accuracy and therefore a multimodal approach, incorporating biochemical, neuropathological and anatomical and metabolic neuroimaging methods, should be employed. To optimize the results of drugs under investigation, a combination of biomarkers should be used to select appropriate participants in the earliest phases of the disease, and disease progression should be followed-up. Early diagnosis might clarify essential questions in the care of patients with Alzheimer's disease, such as the possibility of distinguishing among various subtypes, thus encouraging the development of optimal treatments for each. The ultimate goal is to develop disease-modifying treatments that could be initiated early, while patients are asymptomatic or only minimally symptomatic, to maintain their quality of life.     

Muscarinic Cholinergic Receptor Subtypes in Hippocampus in Human Cognitive Disorders

Total muscarinic receptor levels, the levels of the subtypes exhibiting high and low affinity for pirenzepine, and the high- and low-affinity agonist states of the receptor were investigated in hippocampal tissue obtained at autopsy from mentally normal individuals and the following pathological groups: Alzheimer's disease, Parkinson's disease, Down's syndrome, alcoholic dementia, Huntington's chorea, and motor-neurone disease. A moderate decrease in the density of both high-affinity pirenzepine and high-affinity agonist subtypes was found in Alzheimer's disease, whereas a trend towards an increase in the overall muscarinic receptor density was apparent in the parkinsonian patients without dementia, mainly due to an increase in the low-affinity agonist state; the differences between the Alzheimer's disease and nondemented parkinsonian cases were highly significant. As previously reported, the levels of both choline acetyltransferase and acetylcholinesterase were markedly reduced in both Alzheimer's disease and Parkinson's disease--with a greater loss of both enzymes in the demented subgroup of parkinsonian patients. Activities of the cholinergic enzymes were also extensively reduced in Down's syndrome, accompanied by a loss of high-affinity pirenzepine binding. There were no significant receptor or enzyme alterations in the other groups studied. These observations suggest that in the human brain, extensive degeneration of cholinergic axons to the hippocampus, as indicated by a loss of cholinergic enzymes, is not necessarily accompanied by extensive muscarinic receptor abnormalities (as might be expected if a major subpopulation were presynaptic). Moreover, the opposite changes in muscarinic binding in Parkinson's and Alzheimer's diseases may be related to the greater severity of dementia in the latter disease.     

Changes in life-quality, a possible symptom of dementia development

Dementia is a chronic and irreversible brain impairment characterised by significant cognitive deficits. Severe symptoms of the aforesaid disease interfere with normal life functions and daily activities. Dementia usually develops with advancing age, i.e. after the age of 85, and when it develops in people younger than age 65, it is referred to as early onset dementia. This paper presents a 53-year-old male patient. Provisional diagnosis was established while further diagnostic workup included psycho-diagnostic assessment, neurological exam, and brain CT Such workup confirmed the development of dementia, i.e. early-onset Alzheimer's disease accompanied by depressed mood with impaired vision.     

The role of protein ubiquitination in neurodegenerative disease.

Ubiquitin immunocytochemistry with an antiserum which reacts with ubiquitin-protein conjugates demonstrates the presence of ubiquitinated proteins in filamentous inclusions found in neurones in the major human neurodegenerative diseases, i.e. Alzheimer's disease, diffuse Lewy body disease, motor neurone disease. Ubiquitin immunohistochemistry has revolutionized the neuropathological diagnosis of dementia showing that diffuse Lewy body disease is not, as previously supposed, a rare cause of dementia. The filamentous inclusions in neurones in the human neurodegenerative diseases can be divided into at least two types based on recent immunocytochemical studies. We have shown that a ubiquitin-carboxyl terminal hydrolase is present in Lewy bodies but not in neurofibrillary tangles in Alzheimer's disease. This observation is significant since it indicates that molecular pathological mechanisms in neurones in diffuse Lewy body disease are fundamentally different to Alzheimer's disease. Ubiquitin-protein conjugates are also found in vacuoles in areas of granulovacuolar degeneration in hippocampal neurones in Alzheimer's disease and in granulovacuoles in neurones of scrapie infected mouse brain. These locations suggest that ubiquitinated protein are present in the lysosome-related system of neurones. We have recently shown that ubiquitin-protein conjugates are indeed enriched some 12-fold in the lysosomes of normal fibroblasts and lymphocytes.     

Pharmacological therapy in Alzheimer's disease. Current clinical practice in The Netherlands

Pharmacological therapy in Alzheimer's disease. Current clinical practice in The Netherlands. Dementia affects 195,000 patients of 65 years and older in The Netherlands currently. Rivastigmine and galantamine, both cholinesterase inhibitors, and memantine, an NMDA (N-methyl-D-aspartate) antagonist, are licensed for the treatment of AD. In clinical practice, these drugs have limited effects on cognitive and other symptoms of dementia. We describe the practical care of some patients treated with these drugs and discuss the pros and cons of pharmacotherapy in AD. Extensive knowledge of the drugs, other treatment options and of dementia are necessary for good clinical practice in the treatment of these patients and the counselling of their caregivers.