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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To date, positron emission tomography (PET) has been the only technology for the quantitative imaging of the changes of regional cerebral glucose (rCMRGl) or oxygen metabolism and blood flow (rCBF) associated with psychophysical stimulation and with the performance of mental tasks. So far, the majority of studies performed in healthy subjects demonstrated activation patterns involving not only certain limbic structures, most of all hippocampus, amygdala, parahippocampus, and cingulate, but also temporal, parietal, and occipital association cortex, depending on the applied paradigm. Indeed, the closest correlation between regional metabolism and memory test scores was found in mesiotemporal structures during the performance of memory tasks. Metabolic or CBF studies also seem to indicate that memorizing strategies may differ among individuals. PET was repeatedly used to investigate metabolic and/or blood flow abnormalities in patients with various amnestic syndromes. In cases with uni- or bilateral lesions of mesiotemporal structures, caused by surgery, herpes simplex encephalitis, or permanent ischemic, anoxic, or toxic damage, disturbances of metabolism and blood flow typically extended far beyond the morphological defects detected by computed tomography or magnetic resonance. In acute transient global amnesia, CBF and metabolism were decreased bilaterally in the mesiotemporal lobes, where hypometabolism persisted for some time, while higher values were observed in thalamus and some cortical areas. Diencephalic lesions causing Korsakoff's syndrome were associated with decreased rCMRGl in the hippocampal formation, upper brainstem, cingulate, and thalamus. Discrete thalamic infarcts caused amnesia and metabolic depression in the morphologically intact ipsilateral thalamus and in various projection areas of the infarcted nuclei. In ischemic forebrain lesions, amnestic deficits could be related to involvement of the anterior cingulate and of basal cholinergic nuclei. A large number of pathologies are diffusely spread out in the brain and affect partially or predominantly structures in memory processing. This holds true especially in the various dementias where memory disturbances are a consistent and often leading feature. Notably, Alzheimer's disease can be distinguished from other dementias by its characteristic pattern of metabolic dysfunction, with the most prominent changes occurring in parietotemporal and frontal association cortex whose residual metabolism is related to the severity of the disease. Therefore, activation studies using paradigms involving memory functions enhance that typical pattern. Only in the activated state is metabolism of mesiotemporal structures significantly correlated with the performance in memory tests. Other dementias also affect some of the distributed memory networks, with Huntington's disease suggesting a role of the striatum in memory processing.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:PET correlates of normal and impaired memory functions. 156 50

Limited information is available regarding the relationship between elderly individuals and depression; but the clinician can anticipate problems in those who have had depression in the past, in those who are bereaved, in caretakers, and in patients with a number of other illnesses, including Alzheimer's disease, Parkinson's disease, Huntington's disease, stroke, alcoholism, and severe medical illness. Treatment may shorten the duration of the depression, limit long-term sequelae, and reduce the likelihood of suicide. More research with careful methodology would be helpful in clarifying directions for primary, secondary, and tertiary prevention.
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PMID:The prevention of major depression in the elderly. 157 73

The etiology of Alzheimer's disease (AD) is still unknown, and a definitive diagnosis of the disease can be determined only at autopsy or by brain biopsy. AD can be characterized by various structural changes, including cerebral cortical atrophy, neuronal loss, neuritic plaques, and neurofibrillary tangles. The primary defect involves reduced activity of choline acetyltransferase. Neurotransmitters, such as norepinephrine, serotonin, dopamine, and somatostatin, are also compromised. Treatment of AD requires maintenance of a consistent lifestyle and environment for the patient, as well as counseling and support for the patient's family. Medications, which have been effective in some patients, are primarily used to improve cognitive function and modify behavior. Cognitive medications such as tacrine hydrochloride and physostigmine have proven beneficial in some patients, while behavioral medications have been effective in the treatment of depression, aggression, agitation, and anxiety associated with AD. However, the side effect profile of each medication and its probable overall benefit to the individual patient should be evaluated before beginning therapy. Continued research in patients with AD is required to identify medications that will consistently ameliorate the memory loss associated with the disease.
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PMID:Current concepts in the treatment of Alzheimer's disease. 157 22

Physostigmine was originally isolated from the Calabar Bean, which was used for ordeal by poison in West Africa. The main alkaloid was isolated in 1864. It acts through inhibition of acetylcholinesterase, and has been of major importance in elucidating the kinetics and configuration of the enzyme. Physostigmine has been important for our understanding of neurohumoral chemical transmission, and in mapping the cholinergic nerves. It was the first antagonist to curare, and has been widely used for various therapeutic purposes. Today it has been largely replaced by more efficient and safe drugs. It is still used as an antidote to poisoning from various psychopharmacological drugs, and to treat postoperative somnolence and respiratory depression. It is considered a potent antidote to organophosphorous poisoning and is used experimentally to treat Alzheimer's disease.
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PMID:[Development of physostigmine from a poisonous plant to an antidote. One of the most important drugs in the development of modern medicine?]. 157 14

Brain computed tomography (CT) scans were performed in hospitalized geriatric patients with major depression (n = 45) or primary degenerative dementia (n = 21). Depressed patients with onset of illness at age 60 years or older (n = 32) had greater ventricular size than geriatric depressives with earlier age of illness onset (n = 13). CT parameters of late-onset depressives were comparable to those of patients with primary degenerative dementia. However, early-onset geriatric depressives had significantly smaller ventricles and less sulcal widening than demented patients. The findings suggest that late-onset depression may have a stronger association with neurological dementing disorders than early-onset depression.
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PMID:Brain computed tomography findings in geriatric depression and primary degenerative dementia. 158 38

The clinical neuropsychologic profiles of patients with Parkinson's disease and patients with SDAT show both overlap and dissociation. Speech, language, and certain memory skills are examples of dissociable differences, especially in the early stages of the disease. Furthermore the presence of depression, evidence of cognitive slowing, and absence of aphasia in patients with Parkinson's disease suggest prominent subcortical involvement. It is probably premature to categorize all of the cognitive changes in patients with Parkinson's disease as subcortical, however. Some skills, such as visuospatial and executive functions, are impaired in both disorders, and although the etiologic bases for task failure may differ for each, this issue remains open-ended. Another problem is that often the evidence for or against the cortical/subcortical distinction is insufficient and in some cases based on a single measure thought to be representative of a given cognitive domain. Most importantly there are few comparative studies that provide unequivocal support for making a cortical/subcortical distinction. Failure to equate for level of cognitive impairment or functional disability between dementias and strict adherence to cross-sectional study designs further compromise efforts to characterize each syndrome precisely. Whitehouse suggested that a prospective study of several different dementias studied in parallel, examining a wide range of cognitive skills, is required before the cortical/subcortical classification scheme can be validated. A critical component is an autopsy program to confirm diagnoses and provide clinicopathologic correlation. It is possible that the diverse nature of the cognitive impairment in patients with Parkinson's disease is not a methodologic artifact but reflects multiple disease subtypes. Ross, Mahler, and Cummings proposed three dementia syndromes in patients with Parkinson's disease: one that is relatively mild and meets the criteria for subcortical dementia, a second that is more severe and shows a wider range of cognitive impairment but is still neuropathologically distinct from SDAT, and a third severe dementia with both subcortical and cortical involvement that may reflect basal ganglia and Alzheimer-type pathology.
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PMID:Cognitive impairments in Parkinson's disease. 158 85

Sleep-wake rhythms are known to be altered in Alzheimer's disease (AD) and in unipolar depression. Other evidence suggests that the circadian rhythm in body temperature may be altered as well. Entrained circadian temperature rhythms were measured in healthy elderly men and women, as well as in men and women suffering from unipolar depression or mild AD, to examine this possibility. There were no differences in the temperature rhythm characteristics of subjects with depression or AD compared with healthy control subjects. However, gender differences were observed. Female control subjects showed a larger amplitude, higher peak temperature, and earlier acrophase relative to male control subjects. Also, the mesor of female AD subjects was higher than for male AD subjects. These results are discussed in the context of the widely varying subject populations used in other studies.
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PMID:Entrained body temperature rhythms are similar in mild Alzheimer's disease, geriatric onset depression, and normal aging. 159 Sep 13

It is common knowledge that the base of the demographic pyramide is turning upwards as a consequence of the constant growing of the elderly population. This phenomenon worries everybody from families to government agencies. As a consequence, neuroscientists have been asked to cooperate for a better understanding of the problem related with the aging of the nervous system. Essentially they try to better grasp the mechanism of aging and their deleterious effects on the brain and how to fight the diseases of the nervous system with particular affinity for the aged people. We know that brain goes through morphological and biochemical changes with the passing of the years; it loses weight, microscopic changes occur and the activity of many neurotransmitters diminishes. In this context it is strange that some people still argue against the enfeeblement of the mental faculties with aging. Of all diseases of the nervous system tormenting the aged, the most common are depression and dementia. Most cases of depression and some forms of dementia are treatable but Alzheimer's disease, which afflicts a considerable percentage of old people, leading to greater psychological decline and leaving doctors helpless to halt it's unavoidable progress, is certainly the most dreaded old age mental sickness. The etiology of Alzheimer's disease is unknown. Under these circumstances several possibilities are investigated: genetic, infectious and toxic. Lately, investigators have focused their attention on amyloid, constitutive substance of the senile plaques one of the characteristic structural changes of the diseased brain. Nowadays there are studies on the relation between amyloid and a protein considered to be its precursor which has been found outside the nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Brain aging and dementia]. 159 74

Changes in brain structure have been demonstrated in elderly patients suffering affective disorder. Enlarged ventricles are associated with cognitive impairment and higher mortality. Depressed subjects also may show a greater degree of cortical atrophy and subcortical white matter, and basal ganglia lesions seem to be commoner than in age-matched controls. The abnormalities demonstrated are not as severe as those found in degenerative dementias such as Alzheimer's disease, and at present there is no evidence to suggest they are progressive. There is a convincing association with vascular disease, although further neuropathologic correlates are needed. Functional imaging methods are just beginning to be applied to elderly populations and, in affective disorder, findings are similar to those in younger patient groups. The results from different groups vary due to technologic differences and the clinical heterogeneity of the patients studied. Depression, however, may be accompanied by decreased and mania by increased cerebral blood flow or metabolism. Evidence also appears to be mounting of a state-dependent frontostriatal dysfunction in depression. Challenges for the future include replicating such results using larger diagnostically homogeneous patient groups and differentiating the findings from those in other disorders such as schizophrenia and basal ganglia disorders.
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PMID:Imaging and affective disorder in the elderly. 160 Apr 77

This article reviews the syndromic concepts of depression and dementia and the concurrence of these common entities. In DAT, depression appears to be a reversible source of excess disability, amenable to pharmacologic as well as environmental interventions. In the vascular dementias, depression appears to be a specific complicating feature, in which localization of the lesion plays a significant role. The abulic state should not be mistaken for a depressive syndrome, although its presence should alert the clinician to evaluate for dementia and depression. Depression is especially prevalent in the subcortical dementias. Future studies using dynamic neuroimaging will help define the limits of this important concept. Reversible forms of dementia are much less common than previously suspected. The clinician's task is to identify causes of excess disability due to superimposed illnesses while avoiding diagnostic or therapeutic nihilism. The appropriate use of medication and the ongoing surveillance for adverse drug reactions are the foremost tasks of today's clinician treating the elderly patient.
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PMID:Depression, dementia, and reversible dementia. 160 Apr 79


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