Alzheimer's disease and senile dementia of Alzheimer type. A comparative study

Diagnosing dementia: do we get it right?

To find out whether the diagnosis of dementia agreed with findings at necropsy a detailed assessment of 27 elderly patients (mean age 82 (range 70-94] presenting with dementia was conducted at a combined department of geriatric medicine and psychiatry for the elderly. On the basis of the results the cause of the dementia was diagnosed clinically. Neuropathological examinations were performed after death. The clinical diagnosis made during life was not supported by the findings at necropsy in 11 cases. Alzheimer's disease was overdiagnosed in life (13 cases, of which only six were confirmed at necropsy). Although the clinical investigation was limited by availability of resources, neither cranial computed tomography nor the Hachinski score helped to distinguish between multi-infarct dementia and Alzheimer's disease in this age group. This study confirms the value of neuropathological studies in the precise diagnosis of dementia.

Accuracy in the clinical diagnosis of parkinsonian syndromes

This review of Parkinson's disease and related disorders emphasizes the difficulties of distinguishing between variants of the parkinsonian syndrome. Characteristic clinical features may remain absent for many months, but accuracy of diagnosis may be improved by considering certain presenting symptoms and signs. The main characteristics of various parkinsonian syndromes are reviewed and their major distinguishing features are emphasized. Future improvement in the precision of clinical diagnosis, especially early in the course of parkinsonian syndromes, will depend on selecting out patients with Parkinson's disease using positive diagnostic criteria.

Metabolic changes in Alzheimer's disease

Patients with Alzheimer's disease (AD) and matched controls fasted for 24 hours, and serial glucose, pyruvate, lactate, beta-hydroxybutyrate, acetoacetate, insulin, and glucagon levels were measured. Patients with AD showed a glucose insulin correlation pattern over the 24 hours that differed from the control group. These differences may be secondary to weight loss or to other metabolic or nutritional factors affecting the AD patients.

EEG in the differential diagnosis between Alzheimer's disease and vascular dementia

Demented patients with Alzheimer's disease (AD) (n = 67), multi-infarct dementia (MID) (n = 77) and probable vascular dementia (PVD) (n = 45) were studied with electroencephalography (EEG). All patients underwent a routine EEG examination and quantitative EEG was recorded from 14 patients with AD, 20 with MID, and 12 with PVD. The patient groups did not differ in regard to sex, age, education, or degree of dementia. Diffuse abnormality of EEG increased in AD, while driving response to photic stimulation and the mean frequency of background activity decreased in all groups with increasing degree of dementia. In quantitative EEG, the percentage of alpha power decreased and those of theta and delta power increased relative to the degree of dementia. Focal abnormalities, and irritative (spikes and/or sharp waves) and slow wave paroxysms were more common in MID than in AD. Patients with different types of dementia did not differ significantly in regard to diffuse abnormality, occurrence of driving response, mean background frequency, or parameters of quantitative EEG. The mean frequency of background activity and the degree of diffuse abnormality correlated with central and cortical atrophy, white matter low attenuation seen on computed tomography, and with neuropsychological findings.

The economic costs of Alzheimer's disease

This paper estimates the economic costs of Alzheimer's Disease to individuals and to society, based on review of published Alzheimer's Disease-related research. The analysis is derived from epidemiological projections and cost information for the United States population in 1983. Estimated costs include both direct medical care and social support costs, as well as indirect costs, such as support services provided by family or volunteers, and the value of lost economic productivity in Alzheimer's Disease patients. Mid-range estimates of net annual expected costs for an Alzheimer's Disease patient, excluding the value of lost productivity, are $18,517 in the first year and $17,643 in subsequent years, with direct medical and social services comprising about half of these costs. Under base case assumptions, the total cost of disease per patient in 1983, was $48,544 to $493,277, depending upon patient's age at disease onset. The estimated present value of total net costs to society for all persons first diagnosed with Alzheimer's Disease in 1983 was $27.9-31.2 billion. Development of a public or private insurance market for the economic burdens of Alzheimer's Disease would fill some of the gaps in the current US system of financing long-term chronic disease care.

Alzheimer's disease: maintenance of neuronal and synaptic densities in frontal cortical layers II and III

Neuronal loss and alterations of the cortical neuropil were previously described on necropsic material from patients with senile dementia of the Alzheimer type, and the results compared to age-matched case controls. In frontal cortex biopsic material from our patients with Alzheimer's disease, the numerical densities of neurons and synapses were not significantly different from controls, indicating that changes in the highest cognitive functions might not depend on a generalized loss of neurons and synapses and that quantitative morphological differences may exist between Alzheimer's disease and senile dementia of the Alzheimer type.

Serum amyloid A protein, albumin and prealbumin in Alzheimer's disease and in demented patients with Down's syndrome

The concentrations of serum amyloid A (SAA) protein, albumin and prealbumin were measured in 22 patients with Alzheimer's disease (AD), in 21 demented patients with Down's syndrome (DS), and in age-matched control subjects for both groups in a 2-year follow-up study. The concentration of SAA was initially elevated in 9 of 22 (41%) patients with AD and in 8 of 21 (38%) patients with DS. After 2-years, 10 of 12 (83%) AD patients and 11 of 14 (79%) DS patients had elevated SAA levels but with fluctuation of the values. None of the controls revealed increase in the SAA level. The concentration of SAA did not correlate with the duration of AD or AD-like process although the highest values were found in cachectic AD patients confined to bed. Although neoplasm or infection were not diagnosed, the presence of occult neoplasm or subclinical infection as a cause of SAA elevation, especially in the DS group susceptible to infection, could not be excluded. Moreover, the fluctuation of SAA values in DS seems likely to be associated with an infection. Albumin and prealbumin levels were decreased in both AD and DS; the prealbumin levels in AD was lower than that in DS.

Epidemiology of clinically diagnosed Alzheimer's disease

This report reviews the current status of descriptive and analytic epidemiology of clinically diagnosed Alzheimer's disease (AD). Since AD can be diagnosed with certainty only at autopsy, currently available epidemiological data are based on a presumed clinical diagnosis. Current data indicate that AD represents a major health problem, at least in the developed countries. The prevalence ratio for AD ranges between 1.9 and 5.8 cases per 100 population aged 65 and over. Moreover, its prevalence is likely to increase in the next twenty years as a consequence of current demographic trends. The prevalence ratio for AD increases steeply with age and is higher in females. Incidence rates show a similar pattern, suggesting that AD should not be subdivided in a presenile and a senile form based on age of onset alone. Annual incidence rates of 2.4 cases per 100,000 population between ages 40 and 60, and 127 cases per 100,000 population after age 60 have been reported. Several case-control studies show that the occurrence of either dementia or Down's syndrome in other family members, advanced age of the mother at subject's birth, and head injury are possible risk factors.

The neuropathology of Alzheimer's disease: a review with pathogenetic, aetiological and therapeutic considerations

The neuropathology of Alzheimer's disease is reviewed in this paper emphasizing the morphological and morphometric changes that occur in the disease and their relationship to age and ageing. From this, a new hypothesis of pathogenesis is presented which accounts for the pattern of neuronal damage in Alzheimer's disease. This is that the pathogenesis of Alzheimer's disease begins with a leakage of a neurotoxin through a defective cortical blood brain barrier. This incites development of the senile plaque and later, via a retrograde transport of the same (or different) factors, intracellular neurofibrillary tangle formation and death of neurones within areas of cortex affected by plaques and in subcortical areas such as nucleus basalis of Meynert, locus caeruleus and dorsal raphe nuclei, all of which project to these same areas of cortex. Evidence consistent with this hypothesis is presented and the aetiological and therapeutic implications are discussed.

A longitudinal EEG study of mild senile dementia of Alzheimer type: changes at 1 year and at 2.5 years

This longitudinal study of resting EEGs compared patients with senile dementia of Alzheimer type (SDAT) and healthy controls at 3 times of testing over a 2.5 year period. Measures included the mean EEG frequency as well as the percentage of power in alpha, beta, theta, and delta frequency bands obtained from power spectral analysis. The values from occipital to vertex derivations were averaged for the left and right hemispheres. In healthy older adults delta increased, and both beta and mean frequency decreased over the study period; there was no significant change in theta or alpha. In the SDAT group, all 5 EEG measures changed significantly; there were increases in delta and theta, and decreases in beta, alpha and mean frequency. Theta percentage power distinguished between all 4 stages of dementia (control, mild, moderate and severe). Other EEG measures discriminated only at certain stages. In the mild stage of SDAT theta, beta and mean frequency were already different from control values. In the moderate stage, these differences persisted, and alpha became different. Delta was the last to change, and in the present small sample of those with severe SDAT the difference had not yet reached significance.

Alzheimer's disease: clinical features, pathogenesis, and treatment

Alzheimer's disease is an insidious degenerative disease of the brain and is the leading cause of dementia in the U.S. Numerous etiologies have been postulated, including a large body of evidence suggesting a slow viral infection, possibly in genetically predisposed individuals, but this remains to be proven. Differential diagnosis is based primarily on exclusion of other treatable forms of dementia. Neurochemical studies suggest a cholinergic deficit; thus primary emphasis in treatment has been directed at enhancing cholinergic activity. Choline and lecithin supplementation generally has been ineffective. Results with physostigmine are encouraging and further studies with this drug prototype are needed. Physostigmine's clinical usefulness is limited, however, due to peripheral side effects and its short duration of action. Other pharmacological approaches, such as naloxone, neural metabolic enhancers, stimulants, and vasopressin analogs, have been investigated. The clinical features and pathology of the disease are reviewed.

Dopamine-beta-hydroxylase and acetylcholinesterase activities of cerebrospinal fluid in Alzheimer's disease

Recent neurochemical studies have indicated that in Alzheimer's disease there is disturbance of the cholinergic metabolism of the brain. Defects in other transmitter systems have also been suggested. As a marker of noradrenergic metabolism of the central nervous system, we measured dopamine-beta-hydroxylase (EC. 1.14.17.1) activity in cerebrospinal fluid (CSF) from 60 Alzheimer patients and 20 controls of the same age and sex. Dopamine-beta-hydroxylase activities of the CSF from Alzheimer patients did not differ significantly from those for the controls. The dopamine-beta-hydroxylase activities were not correlated with severity of dementia. As reported previously, the activity of a cholinergic marker, acetylcholinesterase (EC 3.1.1.7), was reduced in the CSF of Alzheimer patients. Interestingly, dopamine-beta-hydroxylase activities were correlated with acetylcholinesterase activities both in Alzheimer patients and control group.

Primary dementias: epidemiological and sociomedical aspects

An epidemiological survey of primary dementia syndromes was conducted in the city of Bra (26287 residents) in the Piedmont region. All the patients for whom a diagnosis of senile dementia had already been recorded together with the cases coming to light as a result of a questionary circulated to general practitioners and neuropsychiatrists were subjected to a broad battery of neuropsychological tests. The prevalence rate proved to be 255 (+/- 61) per 100 000 of the population and 2028 (+/- 476) per 100 000 of the over 65s. Close attention was paid to dements living in nursing facilities. Factors favoring institutionalisation were: advanced age, severe motor impairment and female sex. No correlation between severity or dementia and institutionalisation was found.

Diagnosis and epidemiology of Parkinson's disease

The diagnosis of Parkinson's disease is purely a clinical diagnosis. The most common types of diagnostic error are a failure either to recognize the early, or unusual symptoms, or to differentiate other tremors and extrapyramidal syndromes from Parkinson's disease. The prevalence of Parkinson's disease is increasing. This has resulted from the reduction of the excess mortality by levodopa treatment. In the near future, there will be more older parkinsonian patients with a more prolonged duration of the disease.

Accuracy of clinical diagnosis in primary degenerative dementia: correlation with neuropathological findings

Neuropathological features and causes of death are presented in 27 deceased patients belonging to a prospective series of 71 hospitalised patients with primary degenerative dementia. The clinical criteria for primary degenerative dementia used in the present study were accurate enough to exclude patients with multi-infarct dementia. At necropsy, 82% of the cases had neuropathological changes of Alzheimer's disease. The clinical features of patients with other neuropathological changes are described. The most common immediate cause of death was bronchopneumonia which accounted for 59% of deaths in Alzheimer's disease.

Alzheimer's disease and senile dementia of Alzheimer type. A neuropsychological study

Neuropsychological performance was investigated in 36 presenile patients with Alzheimer's disease and 35 patients with senile dementia of Alzheimer type by using Luria's test methods. The most deteriorated performances in both groups were in memory, intellectual, higher visual and motor functions, and in orientation. The neuropsychological functions deteriorated gradually in the course of the disease process so that the shape of the performance profile was preserved. The progression of the disease seemed to be more rapid in senile patients but neuropsychologically there were no significant differences between Alzheimer's disease and senile dementia of Alzheimer type. They seemed to form a continuum of one disease. Luria's neuropsychological investigation turned out to be a useful method in the assessment of at least moderate to severe dementia.