Cognitive Processing in Monozygotic Twins Discordant for Chronic Fatigue Syndrome.

Twenty-one pairs of monozygotic twins discordant for chronic fatigue syndrome (CFS) and 21 matched healthy control (HC) subjects were assessed with 5 untimed tests and 5 timed tests from the computer-based NeuroCognitive Assessment Battery (R. K. Mahurin, 1993). Random effects regression showed no difference between CFS and healthy twins on any of the cognitive tests. Further, the twin groups did not differ from the HC group on any content-dependent measure. In contrast, both sets of twins performed worse than the HC group on all speed-dependent tests except Finger Tapping. Self-rated fatigue and dysphoric mood were only weakly correlated with cognitive performance. These data point toward a shared genetic trait related to information processing that is manifest in the CFS context. The findings have implications for differentiating genetic and acquired vulnerability in the symptomatic expression of the disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive complaints, depression, medical symptoms, and their association with neuropsychological functioning in HIV infection: A structural equation model analysis.

The main objective of this study was to use structural equation modeling (SEM) to clarify the relationship between subjective cognitive complaints and neuropsychological functioning in 160 adults with HIV infection. Participants completed questionnaires assessing cognitive complaints, symptoms of depression, and HIV-related medical symptoms. Neuropsychological tests included measures of attention, verbal fluency, psychomotor skills, learning, memory, and executive skills. SEM was used to test models of the relationships among cognitive complaints, mood, and medical symptoms with neuropsychological functioning. The model indicated that although depressed mood (β = 0.32, p     

Depression as a risk factor or prodromal feature for dementia? Findings in a population-based sample of Swedish twins.

This study tested whether history of depression is associated with an increased likelihood of dementia, and whether a first depressive episode earlier in life is associated with increased dementia risk, or whether only depressive episodes close in time to dementia onset are related to dementia. Depression information came from national hospital discharge registries, medical history, and medical records. Dementia was diagnosed clinically. In case–control results, individuals with recent registry-identified depression were 3.9 times more likely than those with no registry-identified depression history to have dementia, whereas registry-identified depression earlier in life was not associated with dementia risk. Each 1-year increase in time between depression onset and dementia onset or equivalent age decreased the likelihood of dementia by 8.4%. In co-twin control analyses, twins with prior depression were 3.0 times more likely to have dementia than their nondepressed twin partners, with a similar age of depression gradient. These findings suggest that after partially controlling for genetic influences, late-life depression for many individuals may be a prodrome rather than a risk factor for dementia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Medical evaluation of Persian Gulf veterans with fatigue and/or chemical sensitivity

The purpose of this study was to determine if Gulf War veterans with complaints of severe fatigue and/or chemical sensitivity (n = 72) fulfill case definitions for chronic fatigue syndrome (CFS) and/or multiple chemical sensitivity (MCS) and to compare the characteristics of those veterans who received a diagnosis of CFS (n = 24) to a group of non-veterans diagnosed with CFS (n = 95). Thirty-three veterans received a diagnosis of CFS with 14 having MCS concurrently; an additional six had MCS but did not fulfill a case definition for CFS. The group of fatigued veterans receiving a diagnosis of CFS was comprised of significantly fewer women and fewer Caucasians than the civilian group, and significantly fewer veterans reported a sudden onset to their illness. Veterans with CFS had a milder form of the illness than their civilian counterparts based on medical examiner assessment of the severity of the symptoms, reported days of reduced activity, and ability to work. Since CFS in veterans seems less severe than that seen in civilians, the prognosis for recovery of veterans with this disorder may be better.     

Up-regulation of integrin beta 3 expression by cyclic stretch in human umbilical endothelial cells

OBJECTIVE: Chronic fatigue syndrome (CFS) has been hypothesized to result from immune activation. We examined the role of serum markers of inflammation and immune activation among patients with CFS and in those with chronic fatigue (CF) not meeting the case definition. METHODS: Assays for soluble interleukin 2 (IL-2) receptor, IL-6, C-reactive protein, beta 2-microglobulin, and neopterin were performed in 153 fatigued patients in a referral clinic. Patients were classified according to whether they met criteria for CFS, reported onset of illness with a viral syndrome or had a temperature > 37.5 degrees C on examination. RESULTS: Compared to control subjects, mean concentrations of C-reactive protein, beta 2-microglobulin, and neopterin were higher in patients with CFS (p < or = 0.01) and CF (p < or = 0.01). Results did not distinguish CFS from CF. IL-6 was elevated among febrile patients compared to those without this finding (p < or = 0.001), but other consistent differences between patient subgroups were not observed. The presence of several markers was highly correlated (p < 0.01). CONCLUSION: Our findings that levels of several markers were significantly correlated points to a subset of patients with immune system activation. Whether this phenomenon reflects an intercurrent, transient, common condition, such as an upper respiratory infection, or is the result of an ongoing illness associated process is unknown. Overall, serum markers of inflammation and immune activation are of limited diagnostic usefulness in the evaluation of patients with CSF and CF.     

Attachment relationships in infant twins: the effect of co-twin presence during separation from mother

In this study the roles of the mother and the co-twin in inhibiting emotional arousal and reducing manifest distress of a twin who had been isolated in a modified strange situation were compared. The subjects were 15 children, each a member of a twin pair. The subjects were placed in a playroom under three conditions in the following order: (a) mother and twins present; (b) twins together, mother absent; (c) subject isolated from both co-twin and mother. The episodes in which all partners were together were alternated with brief separations. The subjects' distress was minimal when they were separated from the mother with the co-twin present. Upon reunion, stable social behavior was quickly restored. However, separation from the mother and co-twin produced a high level of distress for the subjects. When reunited, the isolated twin initiated physical contact with the mother, soliciting and receiving comfort from her. Furthermore, the distress of the isolated twin was transmitted to the co-twin who had remained with the mother during the isolation period. The nonisolated twin also solicited comfort from the mother. The presence of the co-twin during the reunion following isolation had little effect in reducing the subject twin's distress.     

Cognitive performance in a high-functioning community-dwelling elderly population

BACKGROUND: The purpose of this study was to examine the role of demographic factors as predictors of cognitive performance in a high-functioning, community-dwelling elderly population. METHODS: The study cohort consisted of 1,192 community-dwelling subjects, who were selected to represent the highest third of an elderly population with respect to physical and cognitive functioning. A neuropsychological battery, including 5 cognitive performance subtests (confrontation naming, delayed recognition span, similarities, figure-copying, and incidental delayed recall) was administered to the subjects in their homes. RESULTS: A summary measure of the 5 neuropsychological subtest scores, the total cognitive score, arrayed the study group across a broad range of difficulty, creating a near-normal distribution. Education, income, and race had statistically significant associations with the total score and the individual subtests. The effect of education was the most striking finding, explaining 30% of the variance in the total score. Education was most strongly related to the abstraction (partial R2 = .11) subtest, and least related to the memory subtests, delayed recognition (R2 = .02) and delayed recall (R2 = .01). CONCLUSIONS: Demographic factors are important predictors of cognitive performance in this high-functioning cohort. Education had the strongest influence on overall cognitive performance, and particularly notable associations with subtests that depended upon the use of previously learned materials. Longitudinal follow-up, now underway, will help to determine whether high levels of education help to maintain cognitive performance with age.     

The relationship between sexual abuse and mild traumatic brain injury

It remains unclear why some individuals with mild traumatic brain injury (MTBI) complain of cognitive deficits many months after the injury. Given neuropathological changes associated with prolonged stress, such as occurs with repeated sexual abuse (SA), it seems possible that individuals who experienced SA might be predisposed to greater deficits after MTBI. Four groups of subjects were administered measures of cognitive and emotional functioning. These groups were those with MTBI (n = 10), those with a history of SA (n = 10), those with both MTBI and SA (n = 10), and normal control (NC) subjects (n = 10). Compared to the NC subjects, those with MTBI demonstrated deficits in working memory, those with SA demonstrated deficits in executive functioning, and those with both MTBI and SA demonstrated the greatest number of deficits which were in working memory, executive functioning and memory. Tests of anxiety, depression and post-traumatic stress disorder, while demonstrating significant symptoms in all clinical groups, did not correlate with the neuropsychological tests that differentiated the groups.     

Liveborn twin with intrauterine death of one twin: report of two cases

Twin pregnancies carry a greater mortality and morbidity rate than singleton pregnancies. In case of an intrauterine fetal death (IUFD), the risk of mortality and morbidity of the surviving twin is increased. The pathogenesis is usually due to twin to twin transfusion. The donor twin is hypovolemic, anemic and often shows a growth retardation or even severe enough to cause an IUFD. The recipient twin is hypervolemic, polycythemic and weighs more than its co-twin. In this paper we reported two cases of liveborn twin complicated by an IUFD of its co-twin. Both cases were monochorionic twins. The first case was born at 29 weeks and 6 days of gestation, a male infant weighed 1054 g. His co-twin was stillborn and weighed 722 g. At birth the surviving infant showed respiratory distress syndrome (RDS), anemia and bilateral periventricular echogenicity (PVE). The second case was a female infant with a gestational age of 26 weeks and 2 days and weighed 850 g. Her stillborn co-twin weighed 804 g. Both twins showed signs of hydrops, and the liveborn infant had RDS, marked anemia (Hb 6 g/dl) and hypoalbuminemia. We will discuss the possible pathogenesis in our cases and also review some literature.     

Attention and verbal learning in patients with chronic fatigue syndrome

Former neuropsychological studies with Chronic Fatigue Syndrome (CFS) patients evaluated a broad range of cognitive functions. Several, but not all, reported subtle attentional and memory impairments suggesting possible mild cerebral involvement. In this study, a battery of attentional tests and a verbal memory task were administered to 20 CFS patients and 22 healthy controls (HC) in order to clarify the specific nature of attention and memory impairment in these patients. The results provide evidence for attentional dysfunction in patients with CFS as compared to HC. CFS patients performed more poorly on a span test measuring attentional capacity and working memory. Speeded attentional tasks with a more complex element of memory scanning and divided attention seem to be a sensitive measure of reduced attentional capacity in these patients. Focused attention, defined as the ability to attend to a single stimulus while ignoring irrelevant stimuli, appears not to be impaired. CFS patients were poorer on recall of verbal information across learning trials, and poor performance on delayed recall may be due to poor initial learning and not only to a retrieval failure.     

Neuropsychological impairment from acute low-level exposure to carbon monoxide

OBJECTIVE: To investigate the effects of acute low-level exposure to carbon monoxide on higher cognitive functions in healthy humans. DESIGN: An empirical study of the effects of low-level exposure to carbon monoxide on higher cognitive functions in young healthy volunteers and a matched nonexposed control group. SETTING: A dormitory at the Hebrew University campus in Jerusalem, Israel. PARTICIPANTS: Forty-five student volunteers who were exposed to carbon monoxide from residential kerosene stoves for 1.5 to 2.5 hours (air carbon monoxide concentrations of 17-100 ppm; mean +/- SD, 61 +/- 24 ppm) served as the experimental group and 47 nonexposed students served as the control group. MAIN OUTCOME MEASURES: A battery of neuropsychological tests was administered to each participant including digit span, the revised Wechsler Memory Scale for verbal and figural memory, Trail-Making Test parts A and B, digit symbol, block design, and the Rey Auditory Verbal Learning Test. RESULTS: Venous blood carboxyhemoglobin (Hbco) levels in participants of the study group ranged from 0.01 to 0.11 (mean +/- SD, 0.04 +/- 0.03) and correlated with air carbon monoxide concentrations (r = 0.39; P = .01). The experimental group scored significantly lower than controls on the following tests: digit span forward (P = .02), short-term (P = .008) and long-term semantic memory (P = .008), digit symbol (P = .004), block design (P = .009), recall of figural memory (P = .02), and Trail-Making part A (P = .04). No significant differences were found between the experimental and control groups in other tests. CONCLUSIONS: The lower scores on neuropsychological tests indicate dysfunctions in memory, new learning ability, attention and concentration, tracking skills, visuomotor skills, abstract thinking, and visuospatial planing and processing. These dysfunctions correspond with previous reports of carbon monoxide neurotoxic effects in patients with moderate carbon monoxide poisoning. Low-level exposure to carbon monoxide results in impairment of higher cognitive functions. Neuropsychological testing appears to be sensitive in the detection of subtle neurologic dysfunctions resulting from carbon monoxide poisoning.     

A cotwin control study and a twin study of reflection-impulsivity in children.

Examined the modifiability and heritability of reflection-impulsivity as measured by Matching Familiar Figures. A co-twin control study of 3 pairs of 4-yr-old identical twins was conducted to study the modifiability of the trait. The heritability of the trait was investigated by a twin study of 54 pairs of 3- to 6-yr-old twins. The co-twin study suggests little modifiability of reflection-impulsivity, and the twin study suggests that some of the resistance to change may be due to genetic factors. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive impairment in chronic alcoholics: Some cause for optimism.

Even after they cease drinking, many alcoholics show continued impairment of cognitive functioning on both intelligence and neuropsychological tests, with deficits being apparent in visual perception, learning and memory, and the use of problem-solving strategies. Neuropsychological investigations have suggested that these deficits reflect premature aging, a direct dose response relationship, or localized brain damage. However, studies have shown that a considerable recovery of cognitive functioning occurs, most dramatically after drinking cessation and more slowly thereafter. Tasks that require novel, complex, and rapid information processing require longer to recover, and persistent impairments in visual-spatial abilities, abstraction and problem solving, and short-term memory are common, particularly in older alcoholics. Practical applications of this research are discussed in terms of the possibility of reducing cognitive dysfunction and improving treatment outcome in alcoholics. (72 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Occult ectopic ACTH secretion due to recurrent lung carcinoid: long-term control of hypercortisolism by continuous subcutaneous infusion of octreotide

OBJECTIVES: Patients with chronic fatigue syndrome complain of physical and mental fatigue that is worsened by exertion. It was predicted that the cognitive and motor responses to vigorous exercise in patients with chronic fatigue syndrome would differ from those in depressed and healthy controls. METHODS: Ten patients with chronic fatigue syndrome, 10 with depressive illness, and 10 healthy controls completed cognitive and muscle strength testing before and after a treadmill exercise test. Measures of cardiovascular functioning and perceived effort, fatigue, and mood were taken during each stage of testing. RESULTS: Depressed patients performed worst on cognitive tests at baseline. During the treadmill test, patients with chronic fatigue syndrome had higher ratings of perceived effort and fatigue than both control groups, whereas patients with depression reported lower mood. After exertion, patients with chronic fatigue syndrome showed a greater decrease than healthy controls on everyday tests of focused (p=0.02) and sustained (p=0.001) attention, as well as greater deterioration than depressed patients on the focused attention task (p=0.03). No between group differences were found in cardiovascular or symptom measures taken during the cognitive testing. CONCLUSIONS: Patients with chronic fatigue syndrome show a specific sensitivity to the effects of exertion on effortful cognitive functioning. This occurs despite subjective and objective evidence of effort allocation in chronic fatigue syndrome, suggesting that patients have reduced working memory capacity, or a greater demand to monitor cognitive processes, or both. Further insight into the pathophysiology of the core complaints in chronic fatigue syndrome is likely to be realised by studying the effects of exercise on other aspects of everyday functioning.     

Longitudinal deficits to attention, executive, and working memory in subtypes of mild cognitive impairment.

Objective: Mild cognitive impairment (MCI) has emerged as a classification for a prodromal phase of cognitive decline that may precede the emergence of Alzheimer's disease (AD). Recent research suggests that attention, executive, and working memory deficits may appear much earlier in the progression of AD than traditionally conceptualized, and may be more consistently associated with the later development of AD than memory processing deficits. The present study longitudinally tracked attention, executive and working memory functions in subtypes of MCI. Method: In a longitudinal study, 52 amnestic MCI (a-MCI), 29 nonamnestic MCI (na-MCI), and 25 age- and education-matched controls undertook neuropsychological assessment of visual and verbal memory, attentional processing, executive functioning, working memory capacity, and semantic language at 10 month intervals. Results: Analysis by repeated measures ANOVA indicate that the a-MCI and na-MCI groups displayed a decline in simple sustained attention (ηp2 = .054) with a significant decline on a task of divided attention (ηp2 = .053) being evident in the a-MCI group. Stable deficits were found on other measures of attention, working memory and executive function in the a-MCI and na-MCI groups. The a-MCI group displayed stable impairments to visual and verbal memory. Conclusions: The results indicate that a-MCI and na-MCI display a stable pattern of deficits to attention, working memory, and executive function. The decline in simple sustained attention in a-MCI and n-MCI groups and to divided attention in a-MCI may be early indicators of possible transition to dementia from MCI. However, further research is required to determine this. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Neuropsychological functioning in posttraumatic stress disorder and alcohol abuse.

Studies have shown differences in neuropsychological functioning between groups with posttraumatic stress disorder (PTSD) and control participants. Because individuals with PTSD often have a history of comorbid alcohol abuse, the extent to which an alcohol confound is responsible for these differences remains a concern. The current study compares neuropsychological testing scores in 4 groups of veterans with and without PTSD (PTSD+ and PTSD-, respectively) and with and without a history of alcohol abuse (ETOH+ and ETOH-, respectively): n for PTSD+/ETOH- = 30, n for PTSD+/ETOH- = 37, n for PTSD-/ETOH+ = 30, and n for PTSD-/ETOH- = 31. Results showed that PTSD, when alcohol, educational level, vocabulary, and depression are controlled for, was associated with decreased verbal memory, attention, and processing speed performance. Alcohol abuse history was associated with decreased visual memory performance. By controlling for alcohol and depression, the authors can more conclusively demonstrate that verbal memory and attention differences are associated with PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The heritability of cognitive functioning in very old adults: Evidence from Danish twins aged 75 years and older.

Heritable influences on cognitive functioning were investigated in a sample of 403 pairs of like-sex Danish twins aged 75 years and older. Twins completed the Mini-Mental State Examination and 3 other cognitive tests. Genetic factors accounted for 26–54% of the variance on these measures, with the balance being due to environmental factors that create differences rather than similarities among reared-together relatives. Deleting twins with severe cognitive impairment had little effect on the results, indicating that the heritability of cognitive functioning was not due entirely to genes affecting dementia. Neither age nor gender moderated twin similarity, and differential social contact could not account for correlation differences between monozygotic and dizygotic twins. These results replicate G. E. McClearn et al.'s (1997) study in indicating substantial genetic influences on late-life cognitive functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MR imaging of the inner ear and cerebellopontine angle: comparison of three-dimensional and two-dimensional sequences

OBJECTIVE: To determine the presence of chronic traumatic brain injury in professional soccer players. METHODS: Fifty-three active professional soccer players from several professional Dutch soccer clubs were compared with a control group of 27 elite noncontact sport athletes. All participants underwent neuropsychological examination. The main outcome measures were neuropsychological tests proven to be sensitive to cognitive changes incurred during contact and collision sports. RESULTS: The professional soccer players exhibited impaired performances in memory, planning, and visuoperceptual processing when compared with control subjects. Among professional soccer players, performance on memory, planning, and visuoperceptual tasks were inversely related to the number of concussions incurred in soccer and the frequency of "heading" the ball. Performance on neuropsychological testing also varied according to field position, with forward and defensive players exhibiting more impairment. CONCLUSION: Participation in professional soccer may affect adversely some aspects of cognitive functioning (i.e., memory, planning, and visuoperceptual processing).     

Finding the self in metacognitive evaluations: Metamemory and agency in nondemented elders.

Objective: Metacognitive methodologies are used to examine the integrity of self-referential processing in healthy adults and have been implemented to study disorders of the self-concept in neurologic and psychiatric populations. However, the extent to which metacognitive evaluations assess a uniquely self-evaluative capacity that cannot be explained fully by primary cognitive functions, demographics, or mood is not clear. The objective of the current study was to examine whether metamemory and a metacognitive test of agency shared a self-referential association that would not be explained by cognition, demographics, or mood. Method: Thirty-eight nondemented older adults (Mini Mental State Examination [MMSE] ≥24 and mean age = 68.13) participated in metacognitive testing and completed cognitive testing and mood questionnaires. Bivariate correlations were used to evaluate the association between metamemory and agency, and to determine the cognitive (memory, attention, and executive functioning), demographic (age and education), and mood (anxiety and depression) correlates of each. Correlates of metamemory and agency were then entered into linear regression models to determine whether any association between metacognitive measures remained. Results: Metamemory was associated with agency judgments (n = 27), specifically those on self-controlled rather than computer-controlled trials (r = .41, p = .03). Regression results supported a role for agency in predicting metamemory, above and beyond memory and education (β = .39, p = .034). Metamemory was also an independent predictor of agency judgments (β = .36, p = .049). Conclusions: The interrelation between metamemory and agency judgments suggests that metacognitive testing captures an important aspect of self-referential processing not otherwise assessed in a standard cognitive evaluation and may provide unique information about self-evaluative capacities in clinical populations. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The independent influence of apathy and depression on cognitive functioning in Parkinson's disease.

Objective: The purpose of the present study was to examine the independent influence of symptoms of depression and apathy, two of the most common neuropsychiatric symptoms in Parkinson's disease (PD), on executive functioning and memory in PD patients using measures designed to discriminate between these symptoms. Method: Participants included 68 nondemented, idiopathic PD patients, ages 56–82 years. The Apathy Evaluation Scale—Self-Rating and select items of the Beck Depression Inventory II were used to assess symptoms of apathy and depression, respectively. Cognitive function was assessed using the Wisconsin Card Sorting Test and Hopkins Verbal Learning Test—Revised. Correlations and hierarchical regressions were conducted to investigate the relationships between apathy, depression, and cognitive function. Hierarchical regression analyses were conducted to evaluate the degree of influence of depression and apathy on cognitive function. Results: Results revealed that symptoms of apathy, but not depression, were significantly and negatively associated with executive functioning. Immediate memory was significantly and negatively associated with both apathy and depression. However, apathy accounted for additional variance in memory performance after controlling for depression at a level approaching significance. Conclusions: Apathy is not only associated with cognitive impairment, but also with impaired daily functioning, caregiver burden and distress, medication noncompliance, and increased mortality. Differentiating apathy and depression, understanding their unique effects, and appropriately identifying apathy symptoms in patients have robust implications for the development of neuropsychological models of these effects in PD as well as practical implications in guiding improvements to patient care and enhancing quality of life in patients and caregivers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)