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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuropsychological testing of elderly schizophrenic patients reveals that a significant portion of this population exhibit varying degrees of cognitive impairment. Since Alzheimer's disease is the most common cause of dementia in geriatric patients, we investigated whether the cognitive decline observed in schizophrenia is the result of degenerative changes analogous to those characteristic of Alzheimer's disease. For this purpose, the number and distribution of senile plaques and neurofibrillary tangles were mapped in the hippocampi of 10 cognitively impaired schizophrenic patients, 10 patients with Alzheimer's disease, and 10 patients with dementia not attributed to either schizophrenia or Alzheimer's disease. In Alzheimer's disease, degenerative changes invariably predominated in the CA1 subfield, subiculum, and proisocortex. By contrast, findings characteristic of Alzheimer's disease were virtually never observed in the hippocampi of schizophrenic and other cognitively impaired patients. In some patients with Alzheimer's disease, the presence of senile plaques in the molecular layer of the dentate gyrus suggested the existence of an underlying entorhinal cortex lesion. Similar dentate gyrus pathology was never found in any of the other patients. The authors conclude that cognitive impairment in schizophrenia is not the result of degenerative changes analogous to those found in Alzheimer's disease.
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PMID:A topographical study of senile plaques and neurofibrillary tangles in the hippocampi of patients with Alzheimer's disease and cognitively impaired patients with schizophrenia. 814 Jan 81

The question of whether and to what extent poor performance on the Wisconsin Card Sorting Test (WCST) in patients with schizophrenia can be improved with coaching has been controversial. We review relevant studies with particular reference to the following issues: (1) can improvement occur? (2) if improvement does occur, what is its significance? and (3) what is the association between performance and neurophysiology? The studies indicate that in patients with schizophrenia performance can frequently be improved, but usually remains in the abnormal range. Similar results for memory measures have been reported in patients with amnesias or dementias of known neurological origin. This suggests that simple dichotomies between neurologic and psychological explanations of cognitive impairment and potential amelioration of such impairment may be inadequate. Comparisons of the results of studies using the WCST as a clinical tool with binary cut-off scores to define normal and abnormal, as a measure of neuropsychological function along a continuum, and as an activation stimulus to probe neurophysiology suggest that absolute WCST scores may not always accurately gauge the functional integrity of neural systems dedicated to the task. This situation may arise because of individual differences in endowment and in the capacity for neuronal compensation, as well as measurement error. Given these issues, caution is advised in the interpretation of WCST scores, which are best understood as representing a final common cognitive pathway that can be the product of diverse psychological, physiological, and neuroanatomic mechanisms.
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PMID:Schizophrenia, training paradigms, and the Wisconsin Card Sorting Test redux. 819 66

To investigate a possible association between disordered water homeostasis and cognitive impairment in schizophrenia, neuropsychological tests were applied to 16 schizophrenic patients with severely deranged water homeostasis and to 16 matched schizophrenic controls. The patients with disordered water homeostasis tended to obtain poorer scores than the controls throughout, the differences being statistically significant for two of the tests (Wechsler Memory Scale Visual Reproduction and Trial Marking Test part A). These results were not ascribable to differences in the duration of the illness, premorbid IQ, medication, or electroconvulsive therapy received, or prominence of any particular symptoms. The results suggest the co-existence of disordered water homeostasis and cognitive impairment in a subset of schizophrenic patients.
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PMID:Disordered water homeostasis and cognitive impairment in schizophrenia. 829 91

Many followup studies have found that frontal leukotomy does not lead to marked changes in behavioral or cognitive functions in patients with chronic schizophrenia. However, these studies left open the issue of whether aging interacts with frontal lobe lesions in some way. This study examined 24 elderly schizophrenia patients who had experienced a bifrontal leukotomy and 48 subjects who were similar to the leukotomized patients in age, gender, chronicity, and overall severity of cognitive impairment. Clinical ratings of schizophrenic symptoms and cognitive deficits were obtained, as was a neuropsychological evaluation. Very few cognitive effects of leukotomy were noted, although clinically rated deficits in self-care were more severe in the leukotomized sample. These findings again suggest that the cognitive effects of frontal leukotomy procedures are limited and imply that aging does not interact substantially with leukotomy in patients with chronic schizophrenia.
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PMID:Leukotomy and aging in chronic schizophrenia: a followup study 40 years after psychosurgery. 830 23

The clinical features of patients who satisfy a variety of criteria for the negative syndrome can be arranged in five groups of phenomena: (a) poverty of thought and speech, (b) blunted affect, (c) decreased motor activity, (d) apathy and abolition, and (e) diminished interpersonal interaction. We have shown that depressed mood and depressive cognition are not related to the negative syndrome, but there is some overlap between the specific phenomena of depressive illness and negative symptoms in schizophrenia. Items measuring cognitive impairment have a moderate correlation with the negative syndrome, but the negative syndrome accounts for less than half of the variance of cognitive performance. These items that define the negative syndrome can be as reliably measured as depressive and positive symptoms.
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PMID:The composition of the negative syndrome of chronic schizophrenia. 833 Jan 5

There is accumulating evidence that impairment of neuropsychological and basic information processing abilities is an important feature of schizophrenia. Despite the size of this literature and persistent controversy on many specific points, there are several key reliable findings that are relevant to everyday clinical practice. First, impaired cognition is a fundamental aspect of the illness. It can be detected in nearly every case when appropriate controls are used and is often present from before the onset of major signs of the illness. Impairment of most functions is stable even in the face of clinical-symptomatic change. Thus, impairment is not an epiphenomenal feature of symptomatic state, although it is probably a good measure of the overall severity of the illness. In contrast to the perspective of many clinicians, the florid symptoms of schizophrenia are quite unlikely to be the cause of most cognitive deficits. Impairments of attention, memory, and problem solving appear to have particular neurobiologic significance. Although impairments of these functions are not diagnostic of schizophrenia, they are observed frequently and provide converging evidence that schizophrenia is fundamentally an illness of the brain and that cognitive impairment is a symptom domain in its own right, with as much importance for understanding and treating the disorder as positive or negative behavioral symptoms.
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PMID:Cognitive deficits in schizophrenia. 833 66

There have been many reports on the Event-Related Potentials (ERPs) abnormalities, especially P300 amplitudes reduction, in schizophrenic patients. However the relationships between P300 abnormalities and schizophrenic subtypes have not been clarified. This study aims to investigate the relationships in a relatively large number of drug free schizophrenics. Seventy three unmedicated schizophrenic patients (45 males, 28 females) who met the DSM-III-R criteria for schizophrenia were tested. Twenty seven of the schizophrenics were paranoid type according to the DSM-III-R, 23 were undifferentiated, 19 were disorganized, 2 catatonic and 2 residual. Seventy three healthy controls were age and gender matched to the patient group. All the ERPs were recorded during auditory odd ball task. Stimuli consists of 2 kHz and 1 kHz tone bursts, and the respective probabilities of the rare and frequent stimuli were 0.2 and 0.8. They were presented random order. The duration of each stimulus was 90 msec with rise and fall times of 10 msec, and the intensity was approximately 70 dB SPL for all the stimuli. The inter-stimulus intervals were 1.7 +/- 0.1 seconds. The subjects were instructed to count the numbers of rare tones. The scalp EEGs were recorded from Ag-AgCl electrodes at 16 sites that referred to linked earlobes. P300 amplitudes reduction [F (1,144) = 39.33, p < 0.001] and P300 latencies prolongation [F (1,144) = 12.41, p < 0.001] were found in schizophrenic group as a whole. Lower amplitude of P300 was observed at both right and left temporal sites in the subjects with undifferentiated type and disorganized type. Although in the subjects with paranoid type, the reduction was recognized at left temporal region, reduced amplitude was not seen at right temporal site. While no relationships between P300 amplitudes, the score of BPRS and SAPS were detected, in the patient with paranoid type, significant negative correlation between P300 amplitudes and SANS total scores was observed (r = -0.425, p = 0.03) at Pz site. These results were discussed with respect to cognitive impairment of schizophrenia.
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PMID:[Cognitive impairment in schizophrenic patients on event-related potentials component P300]. 837 57

In a study using a trial by trial version of the Stroop color naming task, we previously found that unmedicated patients with schizophrenia show a pattern of abnormal performance characterized by increased facilitation (speeding) of color-naming, color-congruent words but normal amounts of interference (slowing) of color-naming, color-incongruent words (Carter et al., 1992). Since a similar finding had recently been reported in patients with Parkinson's disease, we suggested that this finding was consistent with hypotheses about the neurobiological substrates of cognitive impairment that draw upon parallel patterns of cognitive performance in the two illnesses. We now report results from an enlarged group of unmedicated patients with schizophrenia that extend our original finding by allowing us to evaluate the role of illness subtype in abnormal performance on the Stroop task. We found that patients with the undifferentiated subtype of the disorder account for the increased Stroop facilitation effect. Patients with the paranoid subtype show their own pattern of abnormal performance, with normal amounts of facilitation and increased interference. These findings are consistent with the results of other studies which suggest that illness subtype is an important source of variability in studies of cognitive functioning in schizophrenia.
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PMID:Abnormal processing of irrelevant information in schizophrenia: the role of illness subtype. 841 15

After initial interviews with 20,291 adults in the National Institute of Mental Health Epidemiologic Catchment Area Program, we estimated prospective 1-year prevalence and service use rates of mental and addictive disorders in the US population. An annual prevalence rate of 28.1% was found for these disorders, composed of a 1-month point prevalence of 15.7% (at wave 1) and a 1-year incidence of new or recurrent disorders identified in 12.3% of the population at wave 2. During the 1-year follow-up period, 6.6% of the total sample developed one or more new disorders after being assessed as having no previous lifetime diagnosis at wave 1. An additional 5.7% of the population, with a history of some previous disorder at wave 1, had an acute relapse or suffered from a new disorder in 1 year. Irrespective of diagnosis, 14.7% of the US population in 1 year reported use of services in one or more component sectors of the de facto US mental and addictive service system. With some overlap between sectors, specialists in mental and addictive disorders provided treatment to 5.9% of the US population, 6.4% sought such services from general medical physicians, 3.0% sought these services from other human service professionals, and 4.1% turned to the voluntary support sector for such care. Of those persons with any disorder, only 28.5% (8.0 per 100 population) sought mental health/addictive services. Persons with specific disorders varied in the proportion who used services, from a high of more than 60% for somatization, schizophrenia, and bipolar disorders to a low of less than 25% for addictive disorders and severe cognitive impairment. Applications of these descriptive data to US health care system reform options are considered in the context of other variables that will determine national health policy.
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PMID:The de facto US mental and addictive disorders service system. Epidemiologic catchment area prospective 1-year prevalence rates of disorders and services. 842 58

The severe cognitive impairment that affects many of the elderly schizophrenic patients could represent the outcome of schizophrenia in old age for the very severe and chronically ill patients or may be the result of lengthy institutionalization and somatic treatment. Alternatively, it could be due to the presence of concurrent dementing disorders, such as Alzheimer's disease (AD) or multi-infarct dementia. Using an identical neuropathological protocol, brain specimens from schizophrenic patients who showed evidence of severe cognitive impairment were compared with 12 age-matched control cases and the same number of age-matched cases of neuropathologically confirmed patients with AD. Despite their relatively advanced age (mean age 77.1 years +/- 2.8), none of the schizophrenia cases showed sufficient degree of senile plaques and neurofibrillary tangle formations to confirm a diagnosis of AD. Other neurodegenerative disorders associated with dementia were also not identified. These studies suggest that alternative explanations need to be sought for the severe cognitive impairment commonly encountered in elderly schizophrenic patients.
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PMID:Severe cognitive impairment in elderly schizophrenic patients: a clinicopathological study. 847 78


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