Effects of a significant-other observer on neuropsychological test performance.

The present study examined the effects of a third-party observer on neuropsychological test performance in a sample of 30 university students seeking evaluation for learning disability. A significant-other (defined as a parent, sibling, close friend, spouse, or partner) observed portions of a neuropsychological testing session. Subjects were administered a battery of tests, including seven repeatable measures, chosen to assess diverse neuropsychological functions. In the presence of an observer, performance deficits were found on tests of attention, speed of information processing, and verbal fluency. An observer had no effect on tests of cognitive flexibility or motor speed. Our results suggest that the validity of test results may be compromised by the presence of an observer.

Neuropsychological functions in idiopathic occipital lobe epilepsy.

PURPOSE: Despite the benign prognoses of idiopathic partial epilepsies, particularly regarding the response of seizures to treatment, some evidence now exists that patients with such disorders may have subtle neuropsychological deficits. This study was designed to investigate several modalities of neuropsychological functioning in a group of 21 patients, ranging from 6 to 14 years of age, with idiopathic occipital lobe epilepsy (IOLE). The case patients were compared with 21 healthy controls matched for age, sex, and socioeconomic status. METHODS: A battery of age-appropriate neuropsychological tests was administered individually to all the participants. Tests were chosen on the basis of age-appropriate norms, their ability to represent a wide variety of functional domains, and their appropriateness in a cross-cultural setting. The tests were selected to measure functioning in six domains: intellectual functioning, attention, memory, academic achievement, visual-motor functioning, and executive functioning; some were further subdivided by their verbal-versus-visual modality of functioning. RESULTS: The results revealed no significant difference in basic neurophysiological functions between the patient and control groups, although the case patients' performance scores were lower in attention (p < 0.01) and memory (p < 0.01), as well as in intellectual functioning (p <.05). CONCLUSIONS: The possibility of subtle cognitive deficits in IOLE patients should always be considered, though further studies are necessary to elaborate their precise and long-term effects.

Equivalence of the Color Trails Test and Trail Making Test in nonnative English-speakers.

The Color Trails Test (CTT) has been described as a culture-fair test of visual attention, graphomotor sequencing, and effortful executive processing abilities relative to the Trail Making Test (TMT). In this study, the equivalence of the TMT and the CTT among a group of 64 bilingual Turkish university students was examined. No difference in performance on the CTT-1 and TMT Part A was found, suggesting functionally equivalent performance across both tasks. In contrast, the statistically significant differences in performance on CTT-2 and TMT Part B, as well as the interference indices for both tests, were interpreted as providing evidence for task nonequivalence of the CTT-2 and TMT Part B. Results have implications for both psychometric test development and clinical cultural neuropsychology.

Neuropsychological function in retired workers with previous long-term occupational exposure to solvents.

OBJECTIVES: It is plausible that neurodegenerative processes of aging might have a contributing role in the development of chronic effects of exposure to organic solvents. This study evaluated the risk for neuropsychological deficits among retired workers, relative to their histories of exposure to occupational solvents. METHODS: This cross sectional study evaluated retired male workers, 62-74 years of age, including 89 people with previous long-term occupational exposure to solvents (67 retired painters and 22 retired aerospace manufacturing workers), and 126 retired carpenters with relatively minimal previous exposure to solvents. Subjects completed a standardised neuropsychological evaluation and psychiatric interview, structured interviews for histories of occupational exposure and alcohol consumption, and questionnaires assessing neurological and depressive symptoms. RESULTS: By comparison with the carpenters, the painters on average reported greater cumulative alcohol consumption and had lower scores on the WAIS-R vocabulary subtest, usually presumed to reflect premorbid intellectual functioning. These findings, however, were not sufficient to account for the other study findings. Controlling for age, education, vocabulary score, and alcohol use, the painters had lower mean scores on test measures of motor, memory, and reasoning ability; and a subgroup of aerospace workers with moderate to high cumulative exposure to solvents (n = 8) had lower mean scores on measures of visuomotor speed, and motor, attention, memory, and reasoning ability. Subjects were more likely to have an increased number of relatively abnormal test scores (three or more outlier scores on 17 test measures) among both the painter group (odds ratio (OR), 3.1; 95% confidence interval (95% CI) 1.5 to 6.2) and the subgroup of aerospace workers with higher cumulative exposure (OR 5.6; 95% CI 1.0 to 38). The painters, but not the aerospace workers, reported significantly more neurological and depressive symptoms. CONCLUSIONS: The findings are consistent with residual central nervous system dysfunction from long-term exposure to organic solvents, persisting years after the end of exposure.

Neuropsychological assessment of executive functions.

This article discusses the neuropsychological assessment of executive functions with respect to relevant clinical issues. Although neural mechanisms of executive dysfunction are postulated to involve the frontal lobes, the vital contribution of nonfrontal brain regions to executive abilities cannot be underestimated. A comprehensive neuropsychological testing approach, supplemented with keen observation of behavior outside the formal testing setting, is imperative in the determination of executive dysfunction. The development of clinically useful psychometric instruments in assessing executive functions is central to the evaluation of cognitive capabilities of individuals with a wide range of neuropsychiatric disorders. The clinician must also be aware of the limitations of "frontal" tests and take these limitations into consideration when addressing issues of assessment.

WAIS-III Matrix Reasoning test performance in a mixed clinical sample.

This study examined the relationship between the Matrix Reasoning subtest (MRT) of the WAIS-III and a selected number of neuropsychological tests in a heterogeneous clinical sample of English-speaking American (n = 41), and non-English-speaking immigrant (n = 14) adults. A moderate association between the Halstead Category Test and the MRT (-.58) was found in the English-speaking sample. Multiple regression analysis revealed a significant association between measures of verbal abstract reasoning and verbal fluency, and performance on the MRT. Among the immigrant sample, the MRT was also found to be significantly associated with verbal fluency task performance, as well as with the Comprehensive Test of Nonverbal Intelligence. Correlational analyses therefore suggest a strong verbal mediation element in the MRT, and that labeling it a nonverbal task may be misleading.

Neurologic Manifestationsof HIV Infection Without AIDS:Follow-UP of a Cohortof Homosexual and Bisexual Men.

To identify neurological abnormalities in HIV infection, 159 HIV-seropositive men without AIDS and 76 seronegative controls underwent standardized general and neurological examinations, lumbar puncture (LP), neuropsychological (NP) assessment, and brain magnetic resonance (MR) imaging. History, physical, and laboratory evaluations were repeated every six months. NP tests (all subjects) and MR imaging (seropositives only) was repeated every 6-12 months; LP (seropositives only) was repeated yearly. Mean follow-up was 24.6 months. Neurological abnormalities, most related to hearing, were seen in 60 (38.2%) of 157 seropositives and 23 (30.3%) of 76 controls at baseline (p = NS). During follow-up, 43 (31.6%) of 136 seropositives had persistent hearing abnormalities compared to 9 (14.1%) of 64 seronegatives (p = 0.008). Seven HIV-seropositives developed peripheral neuropathy; this was more common among those with hearing abnormalities (p = 0.03). HIV-seropositives performed less well on NP tests than controls, but overall performance did not decline. Worsening brain atrophy by MR imaging or cerebrospinal fluid abnormalities are more common in HIV-seropositives than seronegatives and may share a common mechanism with peripheral neuropathy. Further study is needed to determine whether these abnormalities portend more serious neurological disease.

Neuropsychological and behavioral status of Chinese children with acyanotic congenital heart disease.

Thirty-nine children between the ages of 5 to 8 years (N = 27) and 9 to 14 years (N = 12) who were undergoing cardiac surgery for repair of ventricular or atrial septal defect and 39 controls matched for age, educational level and social class were administered the age-appropriate Chinese versions of the Wechsler Intelligence scales and the Halstead Reitan Neuropsychological test batteries. Parents completed the Achenbach Behavioral Rating Scale. Surgical subjects underwent extracorporeal circulation and hypotensive anesthesia. The intellectual development of children with heart disease was significantly lower than normal controls and showed particular impairment of complex integrative functions of the brain. Parents of surgical subjects also rated their children as having greater behavioral disturbance than did parents of healthy children. Acyanotic heart disease was found to both impact negatively neuropsychological and behavioral functioning.

Cognitive risk factors and neuropsychological performance in HIV infection.

Almost all investigations examining the effects of early HIV infection on neuropsychological functioning in homosexual males have excluded subjects with cognitive risk factors such as recreational drug use and head injury. While insuring that results reflect the influence of the virus on cognition, this selection bias limits the ability to generalize findings. Comprehensive neuropsychological evaluations were compared between two groups of homosexual males with a variety of cognitive risk factors. Subjects were 132 HIV seropositive males (108 CDC class II & III and 24 CDC class IVA & IVC2) and 65 HIV seronegative controls. Recreational drug use in the six months prior to exam was found to interact with HIV infection and was associated with selective areas of cognitive decline and a significantly worse overall neuropsychological performance. Although significantly lower functioning in the domains of Verbal Memory and Attention and Speed of Information processing was noted for subjects with CDC class IVA and IVC2 compared to seropositives with CDC class II & III, overall neuropsychological performance was similar in these two groups. At this early stage of HIV infection, we did not find indication of association between neuropsychological performance and decreased immunological status. A history of head injury and recent recreational drug use emerged as primary cognitive risk factors associated with decreased neuropsychological performance. As 50% of our HIV seropositive subjects reported active recreational drug use, this cognitive risk factor in particular may contribute to the appearance of HIV-related cognitive deficits during early stages of HIV infection.

Prospective cerebral MR study of HIV seropositive and seronegative men: correlation of MR findings with neurologic, neuropsychologic, and cerebrospinal fluid analysis.

PURPOSE: As part of a longitudinal study of human immunodeficiency virus type 1 (HIV) infection, we attempted to identify early cerebral MR findings that might correlate to clinical evidence of central nervous system involvement. METHODS: We studied 65 seropositive and 40 seronegative homosexual males using cranial MR, neurologic, immunologic, and neuropsychologic examinations. RESULTS: The incidence of mildly enlarged ventricles, sulci, and punctate areas of abnormal signal in both groups was similar in both groups. Diffuse, poorly defined areas of abnormal white matter signal were difficult to consistently identify in seropositives. Enlarged adenoidal lymphoid tissue was found in 30 (46%) of seropositives and 2 (5%) of seronegatives (P = .0001). The incidence of sinus inflammatory change was similar in the two groups. CONCLUSION: MR of intracranial contents is substantially normal in a non-AIDS HIV(+) population.

Neurologic syndrome in 25 workers from an aluminum smelting plant.

BACKGROUND: This article expands on an earlier series of three patients with a neurologic syndrome, who had all worked in an aluminum smelting plant. METHODS: Twenty-five symptomatic workers from the same plant were referred for a standardized evaluation, including completion of a health questionnaire, neurologic examination, and neuropsychologic evaluation. An exposure index was calculated for each worker based on level and duration of exposure in the potroom, where exposures were the greatest. This index was correlated with symptoms, signs, and neuropsychologic test scores. RESULTS: Twenty-two (88%) of the patients reported frequent loss of balance, and 21 (84%) reported memory loss. Neurologic examination revealed signs of incoordination in 21 (84%) of the patients. Neuropsychologic test results showed preservation in certain spheres of functioning, such as verbal IQ, with substantial impairment in others, particularly memory functioning. On memory tests, 70% to 75% showed mild or greater impairment. The majority (17 of 19 tested, or 89%) showed depression on the Minnesota Multiphasic Personality Inventory. The exposure index was significantly correlated with signs and symptoms of incoordination. CONCLUSIONS: This study and others in humans and animals support the existence of a syndrome characterized by incoordination, poor memory, impairment in abstract reasoning, and depression. Aluminum exposure in the potroom seems the most likely cause.

Electroencephalography during surgery with cardiopulmonary bypass and hypothermia.

After more than 30 yr of use, electroencephalographic (EEG) monitoring during cardiopulmonary bypass has not gained wide clinical acceptance. To assess its utility to predict central nervous system injury, two-channel recordings were made from 78 patients undergoing cardiopulmonary bypass and anesthetized with fentanyl/diazepam/enflurane. The perfusion regimen included the use of high pump flow, a bubble oxygenator, and no arterial tubing filter. Target values were 28-32 degrees C for the minimum rectal temperature, 60-80 mmHg for mean arterial pressure, and 20-25% for hematocrit. Eight descriptors of the Fourier power spectra of the EEG were calculated off-line, and outcome comparisons were made with the results from neuropsychological tests. Among 58 patients yielding complete data of acceptable quality, a statistically significant reduction in total power was observed from prebypass to postbypass, accompanied by an increase in the fractional power in the theta and beta frequency bands and in the spectral edge frequency. The shifts in total and theta power were weakly associated with short-term but not with long-term changes in neuropsychological scores. Nearly 40% of the patients' EEGs were corrupted with electrical noise at some time during bypass. In 15 patients selected for having high-quality recordings and no neuropsychological deficit, an extensive statistical analysis failed to reveal any consistent variation in the EEG descriptors with hypothermia. Under the conditions studied, it appears that for other than gross signal dropout, the strong background variability in the EEG makes it have little value for detecting harbingers of brain injury.

Central nervous system manifestations in human immunodeficiency virus infection without AIDS.

To characterize neurological and neuropsychological findings associated with human immunodeficiency virus type-I (HIV) infection, 77 seropositive homosexual or bisexual males with no or minor symptoms of HIV were compared prospectively to 44 HIV seronegative men by observers blinded to serological status of the subjects. Neurological symptoms and examination findings were not significantly different between seropositives and seronegatives except for cranial nerve findings, predominantly mild hearing impairment. Mean performance scores for a 15-test neuropsychological battery were within an unimpaired range for both groups, although for five tests, mean scores were significantly poorer in seropositives. After adjustment for vocabulary score, and demographic and psychosocial variables, the mean score of seropositives was significantly worse only for the Benton Visual Retention Test. Magnetic resonance (MR) images of brain were abnormal in 14 (27%) of 52 seropositives and one of 10 seronegatives (value was not significant). HIV was isolated from cerebrospinal fluid (CSF) in 31 (61%) of 51 seropositives. The only clinical or laboratory difference between CSF culture positives and negatives was a higher CSF immunoglobulin synthesis rate in the former subjects (medians of 10.3 versus 0.1 mg/day; p = 0.03). An additional 13 seropositive subjects had immunologic evidence of central nervous system HIV infection, defined by a serum-to-CSF HIV antibody ratio of less than 5.5. Intracranial abnormalities on MR imaging were associated with CSF immunologic responses to HIV. Nervous system involvement occurred in the vast majority of men with early HIV infection, but clinically significant impairment was uncommon.

Cognition and metacognition at extreme altitudes on Mount Everest.

The FACTRETRIEVAL2 test battery, which assesses both retrieval of general information from memory and metacognition about that retrieval, was administered to people before and after a recent expedition to Mount Everest and at extreme altitudes above 6,400 m (higher than any mountain in North America or Europe). The major findings were as follows: First, the same extreme altitudes already known to impair learning did not affect either accuracy or latency of retrieval, and this robustness of retrieval occurred for both recall and forced-choice recognition. Second, extreme altitude did affect metacognition: The climbers showed a decline in their feeling of knowing both while at extreme altitude and after returning to Kathmandu (i.e., both an effect and an aftereffect of extreme altitude). Third, extreme altitude had different effects than alcohol intoxication (previously assessed by Nelson. McSpadden, Fromme, & Marlatt, 1986). Alcohol intoxication affected retrieval without affecting metacognition, whereas extreme altitude affected metacognition without affecting retrieval; this different pattern for extreme altitude versus alcohol intoxication implies that (a) hypoxia does not always yield the same outcome as alcohol intoxication and (b) neither retrieval nor metacognition is strictly more sensitive than the other for detecting changes in independent variables.

Psychosis following styrene exposure: a case report of neuropsychological sequelae.

A patient with a significant history of substance abuse was exposed to styrene and other solvents in the workplace. He became acutely psychotic, experiencing visual hallucinations. The psychosis was controlled with neuroleptic medications and avoidance of solvent exposure, but he continued to show significant deficits in visual-spatial and memory abilities. These deficits cleared with time away from the workplace. The case is of interest in terms of neuropsychological sequelae of solvent exposure and potential interaction of solvents with alcohol and recreational drugs.

The relationship between the pediatric neurological examination and neuropsychological assessment measures for young children.

Children with some degree of neurological dysfunction have traditionally been assessed by means of pediatric neurological examinations and/or neuropsychological test batteries. The present study investigated the relationship between these two different assessment methods in a normal population of 129 kindergarten and second grade students. Results indicated that of the 396 correlations conducted for each grade, 18% of the kindergarten and 15% of the second grade sample correlations were significant at the .01 level. Given the relatively few positive correlations, and the fact that there were few consistent patterns within and across grade levels, it was concluded that these two assessment procedures measure different areas of functioning and constitute two separate components of a broad evaluation of the relationship between behavior and the adequacy of brain functions.

A randomized study of carbon dioxide management during hypothermic cardiopulmonary bypass.

Eighty-six patients undergoing coronary artery bypass graft (n = 63) or intracardiac (n = 23) surgery were randomly assigned with respect to the target value for PaCO2 during cardiopulmonary bypass. In 44 patients the target PaCO2 was 40 mmHg, measured at the standard electrode temperature of 37 degrees C, while in 42 patients the target PaCO2 was 40 mmHg, corrected to the patient's rectal temperature (lowest value reached: mean 30.1, SD 1.9 degrees C). Other salient features of bypass management include use of bubble oxygenators without arterial filtration, flows of 1.8-2.4 l.min-1.m-2, mean hematocrit of 23%, and mean arterial blood pressure of approximately 70 mmHg, achieved by infusion of phenylephrine or sodium nitroprusside. Neuropsychologic function was assessed with series of tests administered on the day prior to surgery, just before discharge from the hospital (mean 8.0, SD 5.8 days postoperatively, n = 82), and again 7 months later (mean 220.7, SD 54.4 days postoperatively, n = 75). The scores at 8 days showed wide variability and generalized impairment unrelated to the PaCO2 group or to hypotension during cardiopulmonary bypass. At 7 months no significant difference was observed in neuropsychologic performance between the PaCO2 groups. Regarding cardiac outcome, there were no significant differences between groups in the appearance of new Q-waves on the electrocardiogram, the postoperative creatine kinase-MB fraction, the need for inotropic or intraaortic balloon pump support, or the length of postoperative ventilation or intensive care unit stay. These findings support the hypothesis that CO2 management during cardiopulmonary bypass at moderate hypothermia has no clinically significant effect on either neurobehavioral or cardiac outcome.