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PubMed1985

Experience-dependent recovery of cognitive functioning in young alcoholics.

Spontaneous recovery of some cognitive functioning in alcoholics after drinking has ceased has been convincingly demonstrated, but there have been no demonstrations of recovery that occurs primarily due to exposure of the alcoholic to specific environmental events. In the present study two groups of alcoholics began a 3-week series of tests sensitive to alcoholic cognitive dysfunction at different time lags after drinking ceased (1 week vs. at least 3 weeks). Each group received five administrations each of three tests. On two of the measures, comparisons between the initial testings administered at least three weeks apart revealed the expected pattern of improvement concommitant with the passage of time. On the Halstead-Reitan Trailmaking Test (Part B), initial test scores were equivalent, showing no time-dependent recovery. Instead, performance improved solely as a function of repeated task administration, thus demonstrating "experience-dependent" recovery. Initial levels of impairment and the extent of recovery were established using two non-alcoholic control groups. Since evidence has accrued that alcoholics' treatment outcome may relate to neuropsychological status, experience-dependent rehabilitation of cognitive functioning may improve success rates in alcoholism treatment.

Adult↗
PubMed1990

Cognitive functioning and symptomatology in chronic schizophrenia.

Chronic schizophrenic patients in a long stay hospital were found to have low levels of intelligence (mean IQ of 80), which was attributed to the effects of substantial intellectual deterioration on below average pre-morbid levels of functioning. Patients with the lowest IQ scores had the least severe positive symptoms but symptomatology was not related to age or extent of intellectual decline. Speed of functioning was relatively more impaired than level of intellectual functioning, with cognitive speed being more affected than motor speed. The severity of negative but not positive symptoms was significantly related to the severity of bradyphrenia (cognitive slowing), a result which would be consistent with the notion of a subcortical pathology in patients with Type II schizophrenia.

Adult↗
PubMed1988

Specialized cognitive function and reading achievement in hearing-impaired adolescents.

This study evaluated the performance of hearing-impaired adolescents on tests of specialized cognitive functioning and explored the linkage between cognitive profile and reading achievement. Other variables noted were mathematics achievement, speech production, etiology, and age of onset of hearing loss. Subjects were 62 severely-to-profoundly hearing-impaired students between 15 and 20 years of age, 31 "high readers" and 31 "low readers." Results indicated that, for this sample, cognitive function was below average for the verbal and sequential skills associated with the left hemisphere but above average for the "visuospatial" skills associated with the right hemisphere. Reading performance proved to be highly correlated with cognitive profile, as did mathematics performance and, to a lesser extent, speech and age of onset. Ramifications for instruction are discussed--in particular, development of strategies for using the right hemispheric cognitive strengths, as identified in this sample, to help overcome the deficits in "verbosequential" processing and reading achievement traditionally associated with hearing-impaired students.

Achievement↗
PubMed1992

The importance of comparative studies and ecological validity for understanding hippocampal structure and cognitive function.

Building from the premise that hippocampal cognitive function has been molded by natural selection under natural environmental conditions, it is argued that traditional laboratory studies likely do not reveal the richness and complexity of hippocampal function. Research on the role of the hippocampal formation in the navigational behavior of homing pigeons is offered as an example to illustrate the advantages of using an ecological approach to understand hippocampal function. It is further proposed that dissimilarities in hippocampal anatomy, physiology, and neurochemistry found between species reflect species differences in the range of functions served by the hippocampal formation, as well as possibly the molecular and cellular mechanisms that support such functions. These differences notwithstanding, it is suggested that, from an evolutionary perspective, the primary function of the hippocampal formation is a role in some aspect of spatial cognition. Dissimilarities in hippocampal structure and function among extant species are viewed as resulting from differences in evolutionary selective pressure and evolutionary history.

Animals↗
PubMed1990

[Diffuse bilateral periventricular hyperintensity of unknown origin on MRI spin-echo sequence. Cognitive function and regional cerebral blood flow].

Cognitive function and regional cerebral blood flow (rCBF) were studied in 26 patients (mean age 77.9) who showed bilaterally an ill-defined diffuse periventricular hyperintensity (PVH) on the magnetic resonance imaging (MRI) spin-echo sequence. Diffuse PVH was classified into two groups according to severity, group A (more severe) and group B (less severe); their cognitive impairment was classified into three stages, stage 1 (mildly impaired) through stage 3 (severely impaired). rCBF was assessed by single photon emission computed tomography (SPECT). The result showed that 6 of 7 MRI-group A patients were stage 3, but the stages of 19 group B patients varied. Five of 7 MRI-group A patients showed severe hypoperfusion, but rCBF of group B patients also varied. Nineteen patients had a hypertensive history, but only 10 patients complained of cerebrovascular incidents before admission. All 3 younger patients (one in his fifties and two in their sixties), however, showed hypertension, stepwise neurological deterioration as in Binswanger's disease. These results suggest that there might be various pathogenesis of diffuse bilateral PVH in the elderly and they are different from that of the classical "Binswanger's disease".

Aged↗
PubMed1992

Cognitive functions, epileptic syndromes and antiepileptic drugs.

Cognitive function of patients on monotherapy specific for their epileptic syndrome has been studied infrequently. We evaluated 7 patients with symptomatic localised epilepsies (SEL) on phenytoin aged 30 +/- 12 (mean +/- standard deviation) years, 8 with idiopathic generalised epilepsies on sodium valproate aged 18 +/- 4 years, 16 with SEL on carbamazepine aged 28 +/- 11 years, and 35 healthy controls aged 27 +/- 11 years. All subjects were of normal intelligence, educated appropriately to age, and led productive lives in the community. Two of the patients on carbamazepine and one on valproate had less than five partial, absence or myoclonic seizures monthly, the remaining were controlled. Carbamazepine serum concentrations were 12 +/- 5 micrograms/ml, phenytoin were 23 +/- 7, and valproate were 62 +/- 23 (mean +/- sd). Tests included immediate recall and recognition for pictures, Stroop test, delayed recall and recognition of pictures. Patients on phenytoin and valproate performed significantly worse than controls on immediate recall, and patients on carbamazepine performed significantly worse than controls in Stroop test (p < 0.01). The results indicate relatively minor effects of the epileptic syndromes and of phenytoin, carbamazepine and valproate on cognition of patients with controlled epilepsy leading productive lives in the community. We conclude that the cognitive deficit found in chronic epileptic patients on poly-therapeutic drug regimen must be multifactorial, and that future studies need to control for all possible variables in order to achieve meaningful results.

Adolescent↗
PubMed1986

Age differences in sensory and cognitive function in elderly Nepalese.

This paper describes age differences in sensory and cognitive function in a cross-sectional sample of 117 Nepalese men aged 50 to 88 years living in a traditional agrarian society. The prevalence of impairment of vision, hearing, vibration sensitivity, and cognitive function is progressively higher in successively older age categories in this society as it is in Western industrial societies. This has practical consequences for everyday life. Men with vision impairment are less likely to retain the esteemed social role of head of an extended household. Men with visual and hearing impairment leave their household compounds less frequently, have less frequent social contacts outside their households, and remain inactive a greater proportion of the time. In this technologically simple society without modern medical remedies, vision and hearing impairments are associated with social roles and daily activity patterns that foster economic and political dependence and social isolation.

Aged↗
PubMed1992

Epoetin and cognitive function.

The uremia of chronic renal failure (CRF) can alter brain electrophysiology and cognitive function, even in the well-dialyzed patient. The effect of uremia on brain function can be assessed by electrophysiologic techniques such as electroencephalogram (EEG), sensory-evoked potentials (EPs), and cognitive event-related potentials (ERPs), and through a series of neuropsychologic tests. Five tests have been used clinically to measure the speed and efficiency of cognitive functioning and include the following: Number Cancellation, Trailmaking Test, Symbol Digit Modalities Test, Rey Auditory Verbal Learning Test, and Controlled Oral Word Association Test. Test performance by patients with CRF is often below that of healthy controls. Auditory ERPs, a sensitive indicator of subtle changes in central nervous system (CNS) function in uremia, result in the generation of a P300 component wave that varies in amplitude and latency with patient variables such as attention and effort. Although dialysis tends to normalize P300 latencies, the waves remain somewhat prolonged in most patients. The anemia often observed in patients receiving chronic dialysis appears to aggravate uremic encephalopathy. This effect can be reversed when anemia is corrected following administration of recombinant human erythropoietin (epoetin). Improvement in P300 amplitudes, and, in some cases, decreases in P300 latencies correlated well with epoetin-induced increases in hematocrit levels. With the correction of anemia, that component of brain dysfunction not attributable to retention of uremic toxins can largely be reversed.

Anemia↗
PubMed1992

Toward an understanding of cognitive functioning in geriatric depression.

This paper addresses the questions of whether depression compromises cognition in the elderly and whether discernable patterns of cognitive performances could be differentiated between patients with severe depression and those with organic dementia. Published data on geriatric depression and cognitive functioning are divided in demonstrating a depression effect. Further examination and external validation by new data show that the depression effect on discrete cognitive tasks is (1) small, and (2) sensitive to the confounding of sampling and task variables. Future research must take these factors into account. Patterns of cognitive functioning in depression and dementia are different and can be differentiated using a variety of measures. This review finds the term pseudodementia inappropriate and misleading and recommends that it be abandoned.

Aged↗
PubMedDate not supplied

The effects of mild diastolic hypertension on the results of tests of cognitive function in adults 22 to 59 years of age.

OBJECTIVE: To test the hypothesis that mild diastolic hypertension (90 to 104 mm Hg) may induce asymptomatic impairment of cognitive function. DESIGN: Cross-sectional. SETTING: Community participants recruited to a university-based ambulatory care center. PARTICIPANTS: Three hundred twelve men and women with untreated essential hypertension and 47 normotensive subjects, 22 to 59 years of age. MEASUREMENTS AND MAIN RESULTS: Cognitive function tests measured reaction time to and accuracy in interpreting predetermined visual stimuli, the ability to acquire, reproduce, and change a set of arbitrary stimulus-response associations, and memory and learning of verbal information. These tests were selected to detect subtle differences in performances as opposed to differentiating neurologically normal persons from brain-damaged persons. After controlling for age, gender, and education, results showed that there was no significant difference between the normotensive and hypertensive subjects in two measures of reaction time to and four measures of accuracy in interpreting predetermined visual stimuli, in the measure of arbitrary stimulus-response associations, or in seven memory and learning variables. Although confidence intervals for the differences between means were wide, clinically significant differences were not likely to be present. Younger age was associated with faster reaction times, fewer errors, and better performance on memory and learning tasks, independent of diastolic blood pressure. CONCLUSIONS: The few detectable effects of untreated mild hypertension on cognitive function reported in the literature may be due to chance and are of questionable clinical significance.

Adult↗
PubMed1989

Impact of iron supplementation on cognitive functions in preschool and school-aged children: the Indian experience.

Four studies examined impacts of iron supplementation on school children of various ages and both sexes. The first study investigated impact of iron-folic acid supplements for 60 d on cognition in 94 boys and girls aged 5-8 y. Improvement in total scores of the anemics was significantly higher than the nonanemics in 7-8-y-old children only. The second study assessed impacts of supplementation on cognition in 14 pairs of 5-6-y-old anemic boys, with clear beneficial effects on cognitive function. The third study investigated effects of varying dosages of elemental iron on cognitive function in 48 boys aged 8-15 y, with different levels of improvement. The fourth study investigated impacts of iron supplementation on 163 anemic girls aged 8-15 y with treatment and evaluations at 4 and 8 mo, with significantly improved scores in cognitive function after the eighth month.

Adolescent↗
PubMed1992

Cognitive function--victim of disease or hostage to treatment?

In persons suffering from epilepsy, cognitive functioning may be compromised for various reasons, including--first and foremost--the learning and behavioral effects of the conditions causing the epilepsy. In addition, the epilepsy itself may cause changes in the nervous system through the metabolic and excitotoxic effects of the seizures and the neurotransmitter elements involved at the membrane level. The effect of the treatment modality, be it pharmacologic or surgical, may also play havoc with cognitive function. The neurobehavioral effects of antiepileptic drugs, although probably less important with the newer agents than in the past, must be considered, especially in polypharmacy, as recent reports have indicated. With increasing data, the effects of various surgical procedures on the cognitive elements of human behavior are becoming better recognized.

Anticonvulsants↗
PubMed1991

Reversed lateralization of cognitive functions in right handers. Exceptions to classical aphasiology.

Most current and past research on the cerebral organization of cognitive functions has presupposed certain specialized hemisphere operations. At least for right handers, language and praxis are to be organized in the left hemisphere, while affective prosody, configurational spatial capacity, and global attention are lateralized in the right hemisphere. Deviations from these presuppositions, as in crossed aphasics and perhaps left handers, are generally considered to be 'exceptions' and either to disprove the rules or to be irrelevant to the rule. We report 4 very 'exceptional' cases, right handers with almost entirely reversed lateralization of functions. Analysis of the intrahemispheric relationships between functions suggests that there may be a specific neurobiology to the interrelationships between and among cognitive functions, handedness, and the intrahemisphere localization of the function.

Adult↗
PubMedDate not supplied

Sensory-motor and cognitive functioning in children who have undergone bone marrow transplantation.

Sensory-motor and cognitive functioning was investigated in a group of 32 children treated with bone marrow transplantation (BMT), 1-6 years after treatment. Twenty-five of the patients had suffered from leukemia. The BMT procedure had involved a regimen of cytostatic drugs and, for leukemia patients, total body irradiation at a dose of 10 Gy, administered in one session. Cytostatic drugs and irradiation are known to be potentially neurotoxic, particularly when combined. The examination involved four neuropsychological tests of sensory-motor and cognitive functioning, as well as an age-appropriate intelligence test. For control the bone marrow donors (n = 32), siblings of the patients, were also investigated. A pronounced delay in motor development was found in four children, who had been treated with BMT including total body irradiation before 3 years of age. Patients between 3 and 11 years of age at BMT were at a slight disadvantage, compared to donors, on tasks involving perceptual and fine motor speed. In older patients no deficits were observed.

Adolescent↗
PubMed1991

Brain somatostatin: receptor-coupled transducing mechanisms and role in cognitive functions.

In recent years there has been an increased interest in understanding the role of somatostatin in the brain. This review summarizes the current knowledge of the anatomical distribution of somatostatin and its receptors, the receptor-coupling mechanisms and the somatostatinergic modulation of cognitive functions. Somatostatin is also highly concentrated in the extra-hypothalamic areas of the brain, including the frontal and parietal cortex and the hippocampus. At these locations somatostatin may play a fundamental role in the modulation of cognitive functions. Activation of somatostatin receptors in the brain results in an inhibition of adenylate cyclase enzyme activity, reduction in intracellular Ca2+ levels and hypopolarization of cells by inducing outward K+ currents. Biological studies on the effects of increased brain somatostatin showed a facilitation in learning behavioural tasks, while brain somatostatin depletion by cysteamine caused memory loss. These observations, along with the severe somatostatinergic neurotransmission impairment demonstrated in Alzheimer's patients, strongly suggest a fundamental role for somatostatin in the modulation of cognitive functions.

Animals↗
PubMed1989

Antiepileptic drugs, cognitive function, and behavior in children.

In conclusion, it should be repeated that behavioral and cognitive functions in children with epilepsy, as in adults, represent the outcome of multifactorial processes. However, interest has been growing in the role of anticonvulsant drugs as an important variable. Studies in adults have clearly shown the impact of these drugs on both cognitive function and behavior, and the beneficial effects of achieving monotherapy, especially with carbamazepine, have been noted. Extrapolation of these results to children would seem reasonable, and there is some evidence in the literature to support this conclusion. Data in children, however, are complicated by several confounding factors. These include the status of the child under investigation; for example, children with a pre-existing behavior disorder appear to be more susceptible to developing grossly disturbed behavior with medications such as phenobarbital, as opposed to those who at pretreatment assessment do not display abnormalities. Mentally retarded children may be another group specifically susceptible to developing problems with medications. The effect of the anticonvulsant drug on seizure frequency is a complicating variable in interpretation of many investigations: in some patients improvement of seizures leads to improved behavior, while in others the opposite occurs. In some children, behavior exacerbations appear to be provoked by the sudden cessation of seizures, which may occur, for example, in forced normalization associated with barbiturates or benzodiazepines. Serum level monitoring is often not possible in childhood studies because of ethical considerations, and interpreting pharmacokinetic interactions from mere knowledge of orally prescribed agents is hazardous.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticonvulsants↗
PubMed1992

[The effect of dihydroergocristine on cognitive functions and sleep in elderly subjects].

The aim of this study was to assess the effect induced by the dopamine agonist dihydroergocristine (DHEC, CAS 17479-19-5), whose memory-improving activity is well-known, on sleep pattern and cognitive function, and the possible relationship between them. Ten elderly volunteers were included in the study. Selected subjects had to be neither demented nor depressed, according to neuropsychodiagnostic criteria (SCAG < 30, Hachinski dementia score < or = 15, Hachinski ischemic score < 6, HRSD < or = 22). All subjects underwent a nightly polysomnographic evaluation during placebo, after single and long-term once-daily 6 mg DHEC administration. Cognitive function and attention were also assessed by the Randt memory test and WAIS digit-symbol subtest. DHEC caused a marked and significant increase in the acquisition subitem, and memory improvement was documented during DHEC treatment. A significant direct relationship between the effect of DHEC on REM sleep and memory test was also evidenced. Our results confirmed the role of REM sleep in the restoration of cognitive function.

Aged↗