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Adequate fluid intake is critical for survival. While adults are at liberty to drink fluids as wanted, children and infants are dependent upon caregivers for food and fluid. Children are at greater risk for dehydration than adults due to their higher surface-to-mass ratio. Additionally, children have different thirst sensitivities and body cooling mechanisms than adults. Children differ from adults in total body water content, and boys and girls differ in body water content with maturation. Research in young adults shows that mild dehydration corresponding to only 1% to 2% of body weight loss can lead to significant impairment in cognitive function. Dehydration in infants is associated with confusion, irritability, and lethargy; in children, it may produce decrements in cognitive performance.
Regional cerebral blood flow (rCBF) was measured using positron emission tomography (PET) in patients with Machado-Joseph disease (Joseph disease), hereditary OPCA of Menzel type (Menzel type), and in normal control subjects in order to investigate relationship between cognitive function and rCBF in 2 subgroups of hereditary spinocerebellar degeneration (SCD). Though absolute rCBF in the cerebellar hemisphere and pons was significantly low in each of 2 subgroups of SCD compared to the control group, no difference was seen between 2 subgroups of SCD in these regions. In addition, absolute rCBF in the cerebral cortices did not show significant difference among all groups. However, when the rCBF data was normalized to the occipital cortex for relative rCBF, in the patient group with Menzel type, relative rCBF in the thalamus was significantly low value compared to the control group and relative rCBF in the frontal, temporal, and parietal cortex, especially in the frontal, was significantly low value compared to the patient group with Joseph disease. Moreover, clinically cognitive impairments were seen in patients of Menzel type, but not in patients of Joseph disease. These findings suggest that the measurement of rCBF by PET is useful for the understanding of the pathophysiology of hereditary SCD subgroups as well as for the differential diagnosis of these diseases.
Thinner containing 60-70% toluene is a neurotoxic mixture, which is widely used as an aromatic industrial solvent. This product has been shown to cause functional and structural changes in the central nervous system. Thinner generates reactive oxygen species and the toxic effects relating to these reactants. We have investigated the effect of exposure to high concentrations (3000 ppm) of thinner for 45 days (1 h/day) on cognitive function and the levels of neural cell adhesion molecules (NCAM) and lipid peroxidation products in the hippocampus, cortex and cerebellum of rats. Thinner exposure caused a significant increase in lipid peroxidation products (malondialdehyde and 4-hydroxyalkenals) in all brain regions. Levels of NCAM 140 and NCAM 180 kDa were significantly decreased in the hippocampus and cortex of the thinner-exposed group. Furthermore, thinner-exposed rats showed cognitive deficits in passive avoidance and Morris water maze tasks. These cognitive deficits may be due to both elevated oxidative stress and changes in synaptic plasticity. Almost all studied parameters were reversed in animals which were allowed to recover from thinner inhalation, suggesting that the effects of exposure to thinner, at least for 1 h/day for 45 days, are reversible.
BACKGROUND: The clinical efficacy of chronic deep brain stimulation in the treatment of parkinsonian patients with severe levodopa-related motor adverse effects has been repeatedly shown. Bilateral subthalamic nucleus (STN) stimulation has been shown to present an advantage over pallidal stimulation as it induces a higher antiakinetic effect and has positive effects on all parkinsonian symptoms. The morbidity of such surgery is usually considered to be very low. However, few studies have extensively examined the effects of chronic STN stimulation on cognitive function. OBJECTIVE: The aim of the present study was to assess the effects of chronic bilateral STN stimulation on performance in an extensive battery of neuropsychological tests, three months and one year after surgery. METHODS: Nine patients with Parkinson's disease were selected for STN electrodes implantation. They underwent a neuropsychological evaluation at one month before and at three months after surgery. Six of them were examined again at one year after surgery. RESULTS: Before surgery, no patient showed cognitive decline. At three months after surgery, no modification was observed for most tasks. The information processing speed tended to improve. There was a significant reduction of the performance in a delayed free recall test and a trend toward a significant reduction of categorial word fluency. At one year after surgery, most task measures did not change. Slight impairment was observed for tasks evaluating executive function. Examination of individual results showed that some patients (30% at 3 months after surgery) showed an overall cognitive decline. Behavioural changes were also observed in 4 patients with overall cognitive decline in one of them. CONCLUSION: In general, STN deep brain stimulation can be considered as a significant contribution to the treatment of severe Parkinson's disease However, in some patients it can induce overall cognitive decline or behavioural changes.
Because prenatal exposure to polychlorinated biphenyls (PCBs) and related contaminants has been associated with reduced birth weight, neonatal behavioral anomalies, and poorer recognition memory in infants born to women who have consumed Lake Michigan sports fish, 236 children, previously evaluated for PCB-related deficits in infancy, were assessed at 4 years of age. Prenatal exposure (indicated by umbilical cord serum PCB level) predicted poorer short-term memory function on both verbal and quantitative tests in a dose-dependent fashion. These effects cannot be attributed to a broad range of potential confounding variables, the impact of which was evaluated statistically. Although much larger quantities of PCBs are transferred postnatally via lactation than prenatally across the placenta, exposure from nursing was unrelated to cognitive performance. The data demonstrate the continuation of a toxic impact received in utero and observed initially during infancy on a dimension of cognitive functioning fundamental to learning.
This review is concerned with the psychosocial functioning and the quality of life in patients with pituitary insufficiency who are receiving conventional hormone replacement therapy. The possible negative effects of pituitary surgery, treatment with irradiation, and suboptimal replacement regimens with hormones other than growth hormone on mood, behaviour and cognitive functioning are discussed. The influence of growth hormone deficiency per se, and the outcome of growth hormone therapy in adult patients are addressed in detail. A possible mechanism for a direct effect of growth hormone on the brain is presented.
The Sickness Impact Profile (SIP) and the Wechsler Memory Scale--Revised (WMS-R) were administered to a small sample of end-stage renal failure patients. The memory test successfully discriminated between patients who were rated by their nurses to be well adjusted or poorly adjusted to dialysis treatment. It is concluded that this instrument may be useful in investigating cognitive function in this patient population.
INTRODUCTION: In a prospective study 29 patients fulfilled the criteria of Whiplash-Associated Disorders grade III in the Quebec classification. MATERIAL AND METHODS: One month postinjury, computerized neuropsychological tests, a clinical interview and the symptom checklist SCL-90-R were administered. Three whiplash scales were extrapolated from SCL-90-R: pain, subjective cognitive difficulties and sleep disorders. SCL-90-R was repeated 6 months later. RESULTS: One month after the accident, 85% of the patients had resumed work. Subjective cognitive disturbances, however, were frequent but unrelated to test performances, which were within the normal range. Patients reporting stressful life events unrelated to the injury had more symptoms and elevated levels of distress on all SCL-90-R syndrome scales. At follow-up their distress was unchanged, and subjective cognitive function had deteriorated. CONCLUSION: Stressful life events unrelated to the accident and a high level of distress 1 month postinjury may augment the risk of "late whiplash syndrome". Reassessment 3-6 weeks postinjury as recommended by the Quebec Task Force should include assessment of complicating social factors and a psychological symptom checklist.
Coffin-Lowry syndrome (CLS) is an X-linked disorder associated with mental retardation, distinctive facies and hands, hypotonia, and skeletal abnormalities. The syndrome results from mutations in the RSK2 gene located in Xp22.2. Although the syndrome has been elucidated clinically, few, if any, studies have focused on the cognitive deficits of the affected males or carrier females. The subjects of the present study were selected from two African-American families who have the same missense mutation (C340T) in RSK2. The subjects included six affected males, seven carrier females, three normal males and three non-carrier (normal) females. Normal family members served as contrast/comparison cohorts to control for socio-economic, sociocultural and genetic variables which would impinge on intellectual abilities. Analysis of cognitive function, as measured by the Stanford-Binet Intelligence Scale, 4th edn, demonstrated a distinct hierarchy of abilities from normal to carrier to affected patients. The mean composite IQs of the cohorts were 90.8, 65.0 and 43.2 for normal, carrier and affected individuals, respectively. These findings lend support to the clinical concept of negative intellectual effects in carriers of certain X-linked mental retardation conditions. X-inactivation studies showed that carrier females had mild to significant skewing. Normal females in the family did not demonstrate skewing. The correlation coefficient between IQ and X-inactivation status among carriers was not significant.
Teratological investigations have demonstrated that agents that are relatively harmless to the mother may have significant negative consequences to the fetus. Among these agents, prenatal alcohol, nicotine or cannabis exposure have been related to adverse offspring outcomes. Although there is a relatively extensive body of literature that has focused upon birth and behavioral outcomes in newborns and infants after prenatal exposure to maternal smoking, drinking and, to a lesser extent, cannabis use, information on neurobehavioral and cognitive teratogenic findings beyond these early ages is still quite limited. Furthermore, most studies have focused on prenatal exposure to heavy levels of smoking, drinking or cannabis use. Few recent studies have paid attention to low or moderate levels of exposure to these substances. This review endeavors to provide an overview of such studies, and includes animal findings and potential mechanisms that may explain the mostly subtle effects found on neurobehavioral and cognitive outcomes. It is concluded that prenatal exposure to either maternal smoking, alcohol or cannabis use is related to some common neurobehavioral and cognitive outcomes, including symptoms of ADHD (inattention, impulsivity), increased externalizing behavior, decreased general cognitive functioning, and deficits in learning and memory tasks.
Apolipoprotein E (APOE) has been associated with a variety of late-life neuropsychiatric disorders, including geriatric depression. This study determined whether APOE genotypes affect vulnerability to geriatric depression. We also tested the effect of the presence of the APOE epsilon4 (APOE4) allele on age of onset, suicide attempt history and cognitive function in geriatric depressed patients. We genotyped APOE in 111 elderly inpatients diagnosed as having major depression and 144 normal controls. The depressed patients were evaluated at baseline using the Hamilton Rating Scale for Depression and the Mini-Mental State Examination (MMSE) after admission. Age of onset of depression and suicide attempt history in the depressed group were evaluated by interview and medical record. We found no association between APOE genotypes and geriatric depression (p = 0.342) or APOE4 status and age of onset of depression (p = 0.281). However, compared with depressed subjects lacking the APOE epsilon4 allele, depressed subjects who were also APOE4 carriers showed significantly lower MMSE scores (p = 0.021) and an increased suicide attempt history (p = 0.012). The APOE genotype may contribute to cognitive performance and suicidality in geriatric depression, rather than being a specific risk factor for the disorder.
During the standardization of the Wechsler Adult Intelligence Scale (3rd ed.; WAIS-III) and the Wechsler Memory Scale (3rd ed.; WMS-III) the participants in the normative study completed both scales. This "co-norming" methodology set the stage for full integration of the 2 tests and the development of an expanded structure of cognitive functioning. Until now, however, the WAIS-III and WMS-III had not been examined together in a factor analytic study. This article presents a series of confirmatory factor analyses to determine the joint WAIS-III and WMS-III factor structure. Using a structural equation modeling approach, a 6-factor model that included verbal, perceptual, processing speed, working memory, auditory memory, and visual memory constructs provided the best model fit to the data. Allowing select subtests to load simultaneously on 2 factors improved model fit and indicated that some subtests are multifaceted. The results were then replicated in a large cross-validation sample (N = 858).
Transcranial magnetic stimulation (TMS) can be triggered and thereby allows the reversible manipulation of cortical information processing. A magnetic field is induced by a coil which produces a current which has an excitatory or inhibitory effect on the underlying cortex. Triggered TMS has been used to assess the visual system and lately the method was also applied to higher cognitive functions. The method has good spatial and temporal resolution and it can be combined with other neuroscience and experimental psychological methods. We provide an overview on TMS research and present the results of a study. Possible applications and limitations of the method are discussed with respect to basic research as well as diagnostic and therapeutic implications.
PRIMARY OBJECTIVE: Given that poor effort may have a profound impact upon the results of neuropsychological assessment, it is of critical importance that assessment of effort is incorporated into the interpretation of a patient's neuropsychological profile. The current study examines the relationship between head injury severity (as measured by length of post-traumatic amnesia) and level of cognitive functioning in patients passing or failing a test of effort (Test of Malingered Memory). RESEARCH DESIGN: A cross-sectional correlational design was employed in a consecutive cohort of 78 persons with ongoing compensation claims. METHODS AND PROCEDURES: Head injury severity was assessed by duration of post-traumatic amnesia. All participants received a clinical interview followed by neuropsychological assessment. MAIN OUTCOMES AND RESULTS: A systematic and interpretable negative correlation between head injury severity and intellectual and memory functioning was demonstrated in persons passing the test of effort. However, in persons failing the test of effort no such relationships were demonstrated. CONCLUSIONS: The implications for the interpretation of neuropsychological test data are discussed. It is strongly recommend that valid interpretation of neuropsychological assessment data should include consideration of at least one test of effort.
RATIONALE: It is traditionally assumed that under normal conditions the brain is well supplied with glucose, its basic fuel. However, given the limited stores of glucose in the brain and its dependence on a continual peripheral supply of glucose, it was considered whether the availability of glucose, and the ability to efficiently utilise glucose, affects cognitive functioning. OBJECTIVE: There is increasing evidence that the provision of blood glucose influences memory. To date, the impact of blood glucose on non-memory task performance has received little attention. The present study investigated whether the performance of non-memory tasks was susceptible to the level of blood glucose. Two studies are reported in which the influence of a glucose containing drink on six cognitive tests was considered. RESULTS: The consumption of a glucose containing drink resulted in faster performance on the Porteus Maze and greater Verbal Fluency. Higher levels of blood glucose on arrival at the laboratory were associated with better performance on the Water Jars test. With both the Porteus Maze and Block Design tests, after taking a glucose drink, poor performance was associated with blood glucose that remained at higher levels. CONCLUSION: It was suggested that we should consider two physiological mechanisms, firstly, that an equilibrium develops between plasma and brain glucose, such that those with higher levels of blood glucose could be expected to have higher levels of brain glucose and secondly, whether there are individual differences in the efficiency with which glucose is taken from the blood; those with poor glucose control perform some cognitive tasks more poorly.