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Frontal lobe lesions and cognitive function in craniopharyngioma survivors.

We performed neuropsychological testing using the Luria-Nebraska Neuropsychological Battery, computed tomography, and magnetic resonance imaging (MRI) in four patients one to 15 years after surgery and radiation therapy for childhood craniopharyngioma. Of three patients with impairment of frontal lobe-mediated cognitive function, two had extensive areas of prolonged spin-lattice and spin-spin relaxation times in the frontal lobes demonstrated by MRI, and one had a lipid accumulation in the anterior horn of the right lateral ventricle and beneath a burrhole defect in the skull. One patient with minimal cognitive dysfunction had no abnormality in imaging studies. We believe assessment of neuropsychological status is an important aspect of the evaluation of children with craniopharyngioma. We have found the Luria-Nebraska Neuropsychological Battery and MRI to be particularly useful in this evaluation.

Adolescent↗

Sex hormones and cognitive functioning in men.

Blood and saliva samples were obtained from 117 healthy young men, following which radioimmunoassays were used to determine the serum concentrations of testosterone (Tser), 5 alpha-dihydrotestosterone (DHT), and the level of free testosterone (Tsal) in the saliva. The cognitive functioning was determined by five spatial and six verbal ipsative test scores, reflecting intra-individual variance in the performance of these tasks, independent of the person's general level of achievement. Within the normal physiological range of androgen levels--especially Tser and to a lesser extent DHT and Tsal--showed a significantly positive correlation with measures of spatial ability and field dependence-independence and a significantly negative correlation with measures of verbal production.

Adult↗

Cigarette smoking: effects on cognitive functions and drug-induced parkinsonism in chronic schizophrenia.

Epidemiological studies suggest an apparent protective effect of cigarette smoking on the risk of Parkinson's disease. There is also a report suggesting that patients with Parkinson's disease who smoke are less likely to develop dementia. I investigated the relationship of smoking to the severity of cognitive functions and presence of drug-induced parkinsonism in a group of 111 neuroleptic-treated chronic institutionalized schizophrenic patients. Patients who smoked had significantly less cognitive impairment (p < .02) and a lower prevalence of drug-induced Parkinsonism (p < .02) compared to nonsmokers. These findings suggest that cigarette smoking may protect against the development of dementia and drug-induced Parkinsonism in schizophrenia.

Adult↗

A psychopharmacological perspective of cognitive functions. I. Theoretical overview and methodological considerations.

Memory is not a unitary process. Rather it is comprised of several psychobiologically distinct elements which may be selectively affected by drugs or by disease processes. An understanding of these distinctions allows a greater appreciation of normal and altered cognitive functioning. In this article, we review several different conceptual approaches to memory and underscore certain methodological issues that are particularly important in studying the psychopharmacology of memory.

Animals↗

Event-related neuronal responses in the human strio-pallido-thalamic system. II. Cognitive functions.

Multiunit activity was recorded from the strio-pallido-thalamic system in the same parkinsonian patients (as described in the previous paper) who bore gold electrodes for diagnosis and therapy. The patients voluntarily participated in various tasks designed to study neuronal correlates of cognitive functions: "odd-omissions," "short-term memory," "cued bimodal," "assessment," and "dual-stage delayed response" tasks. Preparatory-related activities were found in multiunits reacting to sensory cues. In a few multiunits these activities depended upon the specific features of the stimuli that were anticipated for evaluation. The most striking characteristic of stimulus-related activity was the suppression of the multiunit responses when the stimuli become behaviourally meaningless. The hypothesis of action programming is discussed: the loop, including the cortex, neostriatum, pallidum and appropriate parts of the thalamus, is involved in the selection of actions, thus providing the organization of sequential behaviour.

Adult↗

Diseases and impairments as risk factors for onset of disability in the older population in England and Wales: findings from the Medical Research Council Cognitive Function and Ageing Study.

BACKGROUND: This paper reports the association between self-reported diseases and impairments and 2-year onset of disability in a prospective study of people aged 65 years or older in five urban and rural centers in England and Wales (Medical Research Council Cognitive Function and Ageing Study; MRC-CFAS). METHODS: We initially reviewed risk factors for onset of disability in 35 prospective studies of functional decline in older people published in 1998-2001. In the present study, disability was defined as requiring help from another person at least several times a week and was assessed by dependency in activities of daily living. Polytomous and bivariate logistic regression models were fitted for onset of disability and mortality among those nondisabled at baseline (n=7913), adjusting for age, sex, and sociodemography. RESULTS: Among prevalent conditions, arthritis (population-attributable risk 11.4%) and cognitive impairment indicated by a Mini-Mental State Examination score of <or=21 (population-attributable risk 6.8%) were powerful predictors of incident disability. Baseline cognitive impairment, stroke, treated diabetes, chronic airways obstruction, coronary heart disease, and treated hypertension were significantly associated with both incident disability and mortality, whereas Parkinson's disease, eyesight problems, and arthritis were statistically significant disabling conditions not associated with mortality. Stroke, heart attack, cognitive impairment, eyesight problems, and hearing problems were newly occurring conditions significantly associated with onset of disability. CONCLUSIONS: Cognitive impairment, arthritis, followed by stroke, and problems with vision have major impact on population disability at older ages. Both prevalent and incident conditions must be considered as risk factors to accurately assess potential benefits from prevention.

Aged↗

The effects of chronic administration of hydrocortisone on cognitive function in normal male volunteers.

RATIONALE: Corticosteroids are elevated in certain neuropsychiatric disorders and this may contribute to the neuropsychological impairments reported in these disorders. OBJECTIVE: To examine the effects of hydrocortisone on learning, memory and executive function. METHODS: Hydrocortisone 20 mg was administered twice daily for 10 days to normal male volunteers in a randomized, placebo control, crossover, within-subject design. Learning, memory and executive function were measured using selected subtests from the Cambridge Neuropsychological Test Automated Battery. RESULTS: Hydrocortisone caused impairments of visuo-spatial memory. These included increased within search errors and impaired use of strategies on the spatial working memory subtest. In addition, administration of hydrocortisone was associated with more errors in the paired associate learning subtest, although no effect was found on the Tower of London. Hydrocortisone speeded response latencies in certain tests (pattern and spatial recognition memory). CONCLUSION: These results indicate that chronic administration of hydrocortisone leads to deficits in certain tests of cognitive function sensitive to frontal lobe dysfunction and may contribute to the cognitive impairment reported in certain neuropsychiatric disorders.

Adult↗

On electromyographic (EMG) gradients and movement-related brain activity: significance for motor control, cognitive functions, and certain psychopathologies.

Electromyographic (EMG) voltage that rises continuously during motor performance or mental activity and falls precipitately at the end is known as an EMG gradient. Our review is based on 55 studies of EMG gradients, which were published during the period 1937-1994. The extremely wide diversity of situations yielding EMG gradients suggests the possibility that these gradients may be universal accompaniments of organized goal-directed behavioral sequences, overt and covert. Motor tasks and cognitive tasks (without any requirements for motor output) were found to have this in common: they both produced EMG gradients. EMG gradients were not observed during simple, repetitive exercises. On the efferent side, we propose a dual model for the production of EMG gradients, which is based on empirical findings. This model is discussed in relation to current views on central and peripheral neural control of muscle contractions, and on the electrical properties of extrafusal and intrafusal muscle fibers, with particular reference to surface electromyography. The complex relations between EMG gradient steepness and mental effort seemed well represented by the dual model, which was also useful in the interpretation of certain EMG gradients that were found in patients with anxiety disorders, tension-type headaches, and auditory hallucinations, respectively. On the afferent side, drawing on data from human and animal studies, we consider the evidence for movement-related brain activity generated by proprioceptive input, in relation to different types of feedback to the central nervous system during tasks that produce EMG gradients. On electromyographic (EMG) gradients and movement-related brain activity: significance for motor control, cognitive functions, and certain psychopathologies.

Brain↗

Steroid hormones and cognitive functioning in aging men: a mini-review.

The decrease in testosterone (T) production in aging men has been well documented. Because the majority of circulating estradiol (E2) in men arises through aromatization of T, levels of E2 decrease as well with increasing age. It is also clear that some proportion of men develop impairments in aspects of cognition, particularly in explicit memory and language abilities with normal aging. Although there is a paucity of studies that have attempted to determine whether the decline in the endocrine and cognitive changes in older men are related, findings from the extant literature provide some support for the notion that estrogen is important for aspects of memory in aging men, just as it is in women, whereas T helps to maintain visuospatial abilities. More definitive conclusions on the relationship between the sex hormones and specific cognitive functions in men await more careful investigation in this area in the future.

Aged↗

Cerebral vascular transit time in Alzheimer's disease and Korsakoff's psychosis and its relation to cognitive function.

The cerebral vascular transit time of 17 patients with pre-senile dementia of the Alzheimer type (ATD), nine abstinent patients with alcoholic Korsakoff's psychosis (KOR), and ten age-matched controls was determined by the bolus intravenous injection of pertechnetate. A gamma camera was used to estimate the median transit time (MTT) of the radioactive bolus in a planar (non-tomographic) projection normal to the vertex. The spread of the bolus arriving at the aortic arch was measured independently by a single external detector over the chest, and correction made for the transit time of this input function in calculating the net MTT for the head. Both ATD and KOR groups showed lengthened net MTTs, compatible with reduced cerebral blood flow, and which were correlated with reduced cognitive function. It is concluded that the method employed gives a simple, inexpensive estimate of function-related blood flow to the brain in pre-senile dementia.

Aged↗

Effects of lovastatin and pravastatin on cognitive function in military aircrew.

BACKGROUND: As evidence has accumulated for the role of HMG-CoA reductase inhibitors in the primary prevention of coronary artery disease, younger individuals with no other co-morbid conditions will be increasingly exposed to these agents. Some HMG-CoA reductase inhibitors have been reported to cause impairment of daytime cognitive processes that have the potential to directly impact the ability of pilots and other aircrew to perform. These studies suggested that there might be cognitive effects of these medications that would argue against their routine use in populations whose activities required high, sustained levels of cognitive performance. The objective of this study is to establish the effects of pravastatin and lovastatin on aircrew daytime cognitive function using tests that are correlated with actual cockpit tasks and inflight performance. METHODS: Military aircrew with hypercholesterolemia were enrolled in the study and assigned to lovastatin, pravastatin or placebo groups. Baseline cognitive and vigilance testing was performed with computerized test instruments. Following a 4-wk treatment period, subjects were retested on both cognitive and vigilance tasks. RESULTS: Laboratory studies confirmed that both medications were effective in lowering cholesterol. No major treatment-related side effects were encountered. Cognitive performance was not affected by either active treatment, and was not different from that of the placebo group. CONCLUSIONS: The tested medications did not have significant effects on performance as measured by two computerized performance tests. The data suggest that neither medication has significant effects on flight-related performance.

Adult↗

Cognitive functions in low-grade gliomas: disease and treatment effects.

BACKGROUND: The role of radiotherapy and chemotherapy in the treatment of low-grade gliomas (LGG) is controversial regarding their effect on survival and the development of neurotoxicity. The few published studies examining adverse treatment effects on cognition revealed conflicting results. OBJECTIVE: To assess cognitive functioning in LGG patients who received conformal radiation therapy (RT), chemotherapy, or no treatment. DESIGN: 40 LGG patients participated in the study; 16 patients had RT +/- chemotherapy, and 24 patients had no treatment. All patients underwent a neuropsychological evaluation. APOE genotype was obtained in 36 patients who were classified in two groups based on the presence or absence of at least one apolipoprotein E small je, Ukrainian-4 (APOE small je, Ukrainian-4) allele. RESULTS: Treated LGG patients had lower scores than untreated patients on several cognitive domains; patients who completed treatment at intervals greater than 3 years and had long disease duration had significantly lower scores on the Non-Verbal Memory domain. Antiepileptic polytherapy, treatment history, and disease duration jointly contributed to low Psychomotor domain scores. 62% of treated patients showed white matter confluence on MRI, whereas only 9% of the untreated patients had such changes. Preliminary comparisons between APOE small je, Ukrainian-4 carriers (n = 9) and non-carriers (n = 27) on cognitive domain scores revealed no statistically significant differences, but APOE small je, Ukrainian-4 carriers had lower mean scores on the Verbal Memory domain than did non-small je, Ukrainian-4 carriers. CONCLUSIONS: RT +/- chemotherapy, disease duration, and antiepileptic treatment contributed to mild cognitive difficulties in LGG patients.

Adult↗

Comparison of psychologic and cognitive functions after general or regional anesthesia.

The behavior of 105 patients randomly assigned to receive either general or regional anesthesia and who underwent one of three types of surgery (hysterectomy, prostatectomy, or joint replacement) was assessed before, immediately after, and 3 mo after surgery. Psychologic status was assessed by the Sickness Impact Profile, the SCL-90-R, and a Metamemory Questionnaire. Cognitive functioning was measured by a battery of ten psychomotor, memory, and skilled performance tasks. Physical health was scored by the ASA classification of physical status, a health index, postoperative complications ratings, and a self-rated measure of the patient's health. There were cognitive differences across surgery groups due to age and gender variability among the patients; however, the type of anesthesia produced no difference in behavior. Both the physical and mental health indices showed improvement from the preoperative to the postoperative periods. General anesthesia appears to pose no risk to mental function and recovery beyond that associated with regional anesthesia and surgery.

Adult↗

Curry consumption and cognitive function in the elderly.

Curcumin, from the curry spice turmeric, has been shown to possess potent antioxidant and antiinflammatory properties and to reduce beta-amyloid and plaque burden in experimental studies, but epidemiologic evidence is lacking. The authors investigated the association between usual curry consumption level and cognitive function in elderly Asians. In a population-based cohort (n = 1,010) of nondemented elderly Asian subjects aged 60-93 years in 2003, the authors compared Mini-Mental State Examination (MMSE) scores for three categories of regular curry consumption, taking into account known sociodemographic, health, and behavioral correlates of MMSE performance. Those who consumed curry "occasionally" and "often or very often" had significantly better MMSE scores than did subjects who "never or rarely" consumed curry. The authors reported tentative evidence of better cognitive performance from curry consumption in nondemented elderly Asians, which should be confirmed in future studies.

Aged↗

Alpha-1-antichymotrypsin polymorphism in schizophrenia: frequency, age at onset and cognitive function.

A common polymorphism in the alpha1-antichymotrypsin (ACT) gene is associated with Alzheimer's disease. ACT is also a trophic factor in the hippocampal neurons. In order to examine if the ACT gene plays a role in the pathogenesis of schizophrenic disorders, patients (n = 175) and control subjects (n = 114) were genotyped for ACT. We also investigated the relationship between genotypes and patients' cognitive function as evaluated by the Clinical Dementia Rating Scale and the Mini-Mental State Examination. The results demonstrated no association between schizophrenia and/or cognitive deficit in schizophrenia and ACT polymorphism. The data suggest that the ACT gene is not of major importance for the genesis of schizophrenia. Further studies measuring ACT expression as messenger RNA or serum ACT level may help to exclude the role of ACT in the pathogenesis of schizophrenia.

Adult↗

Systemic administration of Congo red does not improve motor or cognitive function in R6/2 mice.

Huntington's disease (HD) is a progressive neurodegenerative disorder for which there is no treatment. Prior to the onset of symptoms, abnormal protein aggregates (inclusions) are found in neurons in humans and R6/2 mice. It has been suggested that the progression of HD can be slowed or prevented by disruption of the aggregation process. In agreement with this, it has been reported that systemic treatment of R6/2 mice with Congo red caused a reduction in numbers of striatal inclusions and an improvement in motor symptoms and survival [Sanchez, I., Mahlke, C., Yuan, J., 2003. Pivotal role of oligomerization in expanded polyglutamine neurodegenerative disorders. Nature 421, 373-379]. Here we attempted to replicate this study. We extended the experiment to include measurement of the effects of Congo red on cognitive function in R6/2 mice. Congo red treatment failed to ameliorate either motor or cognitive deficits in R6/2 mice. We suggest that this is due to the inability of Congo red to cross the blood-brain barrier. Since it does not improve the behavioural deterioration that is a key feature of HD, Congo red is unlikely to be useful as a therapy for HD.

Animals↗

Subjective memory impairment, cognitive function and depression--a community study in older Koreans.

Correlates of subjective memory impairment (SMI) were investigated using data from a community study of 1,204 individuals aged 65 or over in an urban and rural area of South Korea. SMI and depression were ascertained from the Geriatric Mental State Schedule and cognitive function from the Korean version of the Mini-Mental State Examination (MMSE-K). 686 participants had also completed the MMSE-K two years earlier. SMI was present in 22% of the sample and was associated with depression and lower MMSE-K scores. Depression and SMI were most strongly associated in the presence of cognitive impairment. SMI was weakly associated with previous cognitive decline and was not associated with APOE e4. SMI and cognitive impairment were most strongly associated in urban residents, particularly rural-to-urban migrants.

Aged↗

Multiple, single-dose naltrexone administrations fail to effect overall cognitive functioning and plasma cortisol in individuals with probable Alzheimer's disease.

A double-blind placebo-controlled study was conducted in 10 individuals with probable Alzheimer's disease to assess the effects of varying doses of Naltrexone (0, 25, 50 and 100 mg) on cognitive functioning and on plasma cortisol. Each individual participated in four separate sessions at least three days apart. Naltrexone was found to improve performance in only one of the six psychometric tasks employed (Token Test). However, enhancement of Token Test performance was limited to the 25 mg Naltrexone dose and was mainly the result of an improvement on the part of the two most severely impaired patients. In contrast to the previous reports of elevations of plasma cortisol following administration of opiate antagonists to younger, non-demented subjects, Naltrexone administration failed to produce any significant increase in plasma cortisol in Alzheimer's patients.

Aged↗