Electrical injury and lightning injury: a review of their mechanisms and neuropsychological, psychiatric, and neurological sequelae.

Exposure to electrical current via industrial or residential accidents or lightning strikes is a serious and growing concern in today's medical community. The sequelae that result are referred to as electrical injury (EI) or lightning injury (LI). The relevant principles in electricity are reviewed with particular attention given to their damaging capabilities on the body. Specific neuropsychological, psychiatric, and neurological signs and symptoms as well as objective measures of psychological and neuropsychological functioning and brain imaging in victims of EI and LI, are reviewed from past research. Important issues relevant to researchers in the field are discussed. Finally, the role that neuropsychology might play in this area is outlined.

Impairments of memory and learning in older adults exposed to polychlorinated biphenyls via consumption of Great Lakes fish.

An association between in utero polychlorinated biphenyl (PCB) exposure and impaired childhood intellectual functioning has been reported, but the potential impact of PCB exposure during adulthood on intellectual functioning has received little attention. We assessed the impact of PCBs and other fish-borne contaminants on intellectual functioning in older adults. The subjects were 49- to 86-year-old Michigan residents recruited from an existing cohort. Fish eaters ate > 24 lb of sport-caught Lake Michigan fish per year and non-fish eaters ate < 6 lb of Lake Michigan fish per year. A battery of cognitive tests including tests of memory and learning, executive function, and visual-spatial function was administered to 180 subjects (101 fish eaters and 79 non-fish eaters). Blood samples were analyzed for PCBs and 10 other contaminants. We evaluated cognitive outcomes using multiple regression. PCBs and dichlorodiphenyl dichloroethene (DDE) were markedly elevated in fish eaters. After controlling for potential confounders PCB, but not DDE, exposure was associated with lower scores on several measures of memory and learning. These included the Weschler Memory Scale verbal delayed recall (p = 0.001), the semantic cluster ratio (p = 0.006), and list A, trial 1 (p = 0.037), from the California Verbal Learning Test. In contrast, executive and visual-spatial function were not impaired by exposure to either PCBs or DDE. In conclusion, PCB exposure during adulthood was associated with impairments in memory and learning, whereas executive and visual-spatial function were unaffected. These results are consistent with previous research showing an association between in utero PCB exposure and impairments of memory during infancy and childhood.

Incremental validity of the MMPI-2 Content Scales: a preliminary study with brain-injured patients.

OBJECTIVE: To examine the usefulness of the MMPI-2 Content Scales among traumatic brain injury (TBI) patients. DESIGN: Hierarchical stepwise regression analyses with the SCL-90-R scales as the criterion variables were conducted to determine the incremental validity of the Content Scales beyond the information provided by the Clinical Scales. PARTICIPANTS: 27 persons with moderate to severe TBI who had been discharged to the community from inpatient rehabilitation between 6 months and 4 years before the beginning of the study. RESULTS: The Content Scales accounted for an additional 4% to 36% of the variance of SCL-90-R scales beyond that predicted by the Clinical Scales. CONCLUSIONS: Interpretation of the Content Scales may be particularly valuable with TBI patients, because they provide an additional avenue for the identification of distressing symptoms.

Practice effects, test-retest stability, and dual baseline assessments with the California Verbal Learning Test in an HIV sample.

Repeated neuropsychological assessments have been recently employed to investigate the natural course and effects of interventions in individuals with human immunodeficiency virus (HIV) infection. Important considerations when interpreting serial assessments are the roles of practice effects and test-retest reliability on follow-up performance. Although several statistical and methodological controls have been proposed for minimizing practice effects, they have not been empirically tested in HIV samples. Three groups (HIV+/symptomatic, HIV+/asymptomatic, HIV- "at risk" controls) were administered the California Verbal Learning Test (CVLT) twice with a brief test-retest interval. Significant practice effects were observed on six of the CVLT measures. Test-retest stability coefficients were reported. A third and fourth administration of the CVLT was conducted to observe the impact of the dual baseline assessment approach on test performance. Trend analyses indicated that the dual baseline approach is a viable method for minimizing practice effects. The dual baseline approach also lead to improvement in a number of the stability coefficients. Limitations and future directions are discussed.

Serial neuropsychological assessment with the National Institute of Mental Health (NIMH) AIDS Abbreviated Neuropsychological Battery.

The effect of repeated administration of the (NIMH) AIDS Abbreviated Neuropsychological Battery was evaluated in a group of "at risk" individuals who served as control subjects in a larger research project. Subjects' performance across five assessment points was evaluated by repeated measures analysis. Statistically significant trends were obtained on the California Verbal Learning Test, the Paced Auditory Serial Addition Task, and the State scale of the State-Trait Anxiety Inventory. No discernable trends were detected on the Vocabulary subtest of the Wechsler Adult Intelligence Scale-Revised, total time or errors on the Visual Search Task, the Hamilton Depression Rating Scale, or the Trait scale of the State-Trait Anxiety Inventory. The implications of these findings in both clinical and research settings are discussed.

Multiple chemical sensitivity: a review of the theoretical and research literature.

Multiple chemical sensitivity (MCS) is a term used to describe a disorder characterized by a vast array of somatic, cognitive, and affective symptoms, the cause of which is attributed to exposure to extremely low levels of a variety of chemicals. Upon examination of the patient with a diagnosis of MCS, objective physical findings and consistent laboratory abnormalities are typically nonexistent. The concept of MCS has ignited considerable controversy in the fields of toxicology, immunology, allergy, psychology, and neuropsychology. Central to the controversy is the disagreement over the extent to which the manifestation of MCS is mediated by psychological factors. Because of the large number of neuropsychological symptoms associated with a diagnosis of MCS, neuropsychologists are increasingly receiving referrats for the assessment of these patients. It is important, therefore, that neuropsychologists become aware of the variety of clinical issues that must be taken into account when assessing an individual with a diagnosis of MCS. The theoretical and research literature on individuals with a diagnosis of MCS is reviewed here.

Olfactory dysfunction discriminates probable Alzheimer's dementia from major depression: a cross-validation and extension.

The present study was conducted to cross-validate and extend the hypothesis that olfactory dysfunction could discriminate between groups of patients with Alzheimer's disease and major depression. Forty patients meeting the DSM-IV criteria for either Alzheimer's disease or major depression (20 per group) underwent assessment with the Pocket Smell Test (PST), a three-item screening measure of odor identification, and the Mini-Mental State Examination (MMSE). A PST score of < or = 1 (1 or 0 correct) discriminated between the groups with a hit rate of 97.5% (sensitivity = 95%, specificity = 100%). The optimal hit rate for the MMSE (< or =24) was less effective (hit rate = 90%, sensitivity = 80%, specificity = 100%). Age, gender, and education had minimal impact on the PST for both groups. Olfactory assessment continues to add to the diagnostic utility in the differential diagnosis of Alzheimer's disease versus major depression in elderly patients.

PCB congener profile in the serum of humans consuming Great Lakes fish.

The State of Michigan has a long history of research into human exposure to environmental contaminants through consumption of recreationally caught fish. A large cohort of Lake Michigan residents who eat fish (fish-eaters) and those who do not eat fish (nonfish-eaters) established in 1980 served as the basis for the congener-specific polychlorinated biphenyl (PCB) exposure evaluation reported here. In this paper we present the serum PCB congener profile for a subset of this cohort who were over 50 years of age. Serum samples were collected in 1993-1995 and were evaluated by a dual column capillary column gas chromatography procedure capable of detecting over 90 PCB congeners. This evaluation demonstrated significant PCB exposure in the fish-eaters (mean serum PCB of 14.26 ppb; n = 101). This elevated exposure allowed the establishment of a detailed profile of the PCB congeners found in humans exposed by this route. Twenty-two congeners of varying concentrations were the most prevalent and constituted over 95% of the total PCB present in most subjects. Four congeners, 138/163 (2,2',3,4,4',5-PCB/2,3,3',4', 5,6-PCB), 180 (2,2',3,4,4',5,5'-PCB), and 153 (2,2',4,4',5,5'-PCB), accounted for 55-64% of the total PCB load. Other congeners, some of toxicologic significance, were also detected by this analytical protocol. Nonfish-eaters had lower total serum PCB levels (mean = 4. 56; n = 78), but the same general pattern of PCB congeners was present. It was demonstrated that careful selection of a subset of prevalent PCB congeners could provide a cost-effective assessment of exposure without losing critical scientific information.

Motor function in aging Great Lakes fisheaters.

Exposure to contaminants in Great Lakes fish has been linked to impaired neuropsychological functioning in children, but neurological function of exposed adults has not been evaluated. This report describes a cross-sectional analysis of the effects of PCB/DDE exposure from contaminated fish on fine motor function in older adults. The subjects were 50-90-year-old Michigan residents who were members of a previously established study cohort. Fisheaters ate 24 lbs or more of sport-caught Lake Michigan fish/year at the time they were originally recruited in 1980-1982. Age- and sex-matched non-fisheaters ate 6 or fewer lbs/year. Outcome measures were scores on the Static Motor Steadiness Test (SMST) and Grooved Pegboard Test (GPT). PCB/DDE exposure was determined through serum analyses performed at the time of recruitment into the present study in 1993-1995. Because of the high correlation between serum PCB and DDE levels in this sample (Spearman r=0.64, P<0.0001), the effects of the two contaminants were assessed jointly using a single derived exposure variable=Low=both PCB and DDE at or below the medians of their respective distributions, intermediate=PCB and/or DDE in the third quartile, and high=PCB and/or DDE in the upper quartile. In unadjusted analyses, high exposure to PCBs/DDE was associated with significantly poorer performance on the GPT (P=0.03). However, in the multiple regression model, age and gender emerged as the most significant factors affecting GPT scores, and exposure to PCB/DDE was not significant. Performance on the SMST was not related to PCB/DDE exposure in initial unadjusted analyses, but performance with the dominant hand was marginally (P=0.052) associated with exposure in the final model. Scores on the SMST improved slightly as PCB/DDE exposure increased. A similar trend was not observed for the nondominant hand (P=0.46). These findings suggest that PCB/DDE exposure from Great Lakes fish has not significantly impaired hand steadiness or visual-motor coordination in this sample of older adults.

Longitudinal analysis of olfactory deficits in HIV infection.

The presence and degree of odor identification deficits in 55 HIV-infected (30 asymptomatic, 25 symptomatic) and 29 HIV-negative at-risk control volunteers were examined longitudinally using the University of Pennsylvania Smell Identification Test (UPSIT). Factors other than HIV infection that could account for olfactory loss (i.e., sinusitis or upper respiratory infection) were also considered by obtaining MRI scans of the nasal passages and information from an olfaction questionnaire. No differences were found among groups at the first administration of the UPSIT, with significant differences among groups emerging at the 1-year and 2-year follow-ups. The symptomatic group showed a significant decline in odor identification scores across time, while means for the asymptomatic and control groups remained stable. The presence of sinusitis or an upper respiratory infection appeared to have no effect on odor identification. The implications for these findings in relationship to cognitive decline in neurodegenerative diseases are discussed.

Neuropsychological assessment of an aging population of Great Lakes fisheaters.

Because of the decline in central nervous system function that occurs with age, older people may be at greater risk of neurological dysfunction following exposure to neurotoxic contaminants in the environment. This study was designed to assess the neuropsychological functioning of a group of 50-90-year-old fisheaters exposed to polychlorinated biphenyls (PCBs) through Great Lakes fish consumption, and a group of age- and sex-matched nonfisheaters selected from the Michigan Department of Public Health's established cohort of fisheaters and nonfisheaters. A neuropsychological assessment battery, demographic interview, and fish consumption questionnaire were developed and piloted on similarly aged men and women in the Lansing and Detroit, Michigan, areas. The assessment battery included tests of motor function, memory and learning, executive functions, and visual-spatial functions, and took approximately two hours to administer. Most of the tests included in the battery have been shown to be sensitive to subtle, age-related declines in cognitive and motor function. The demographic questionnaire included questions on a number of important control variables that could influence the neuropsychological end points that were assessed in the study. These included demographic background, alcohol consumption, tobacco use, prescription and nonprescription drug use, medical history (including psychiatric illnesses), employment history, and activity level. The fish consumption questionnaire asked about historical and current consumption of specific fish species from each of the Great Lakes and its tributaries and was based on the fish consumption advisories published in the 1992 Michigan Fishing Guide. The questionnaire also asked about consumption of wild game, fish preparation and cooking methods, serving size, and changes in fish consumption patterns over time. After each subject completed the neuropsychological assessment, demographic interview, and fish consumption questionnaire, a blood sample was collected for analysis of PCBs, dichloro diphenyl dichloroethene (DDE), and ten other contaminants frequently detected in Great Lakes fish. Subject recruitment for the study began in July 1993 and was completed in November 1995. The data will be analyzed in two steps: first, to assess differences in confounding variables between fisheaters and nonfisheaters; and secondly, to determine the independent effects of Great Lakes fish consumption, as well as serum PCB and DDE levels, on cognitive and motor function after controlling for all identified covariates. Three indices of PCB exposure-total PCBs, total ortho-substituted PCBs and total coplanar PCBs-will be assessed. These studies should shed light on three questions: 1) Does consumption of contaminated fish from the Great Lakes exacerbate or accelerate the normal age-related decline in cognitive and motor function? 2) Do serum PCB or DDE concentrations predict the degree of behavioral dysfunction? and 3) If PCB exposure is related to behavioral outcomes, which class of PCB congeners, ortho-substituted or coplanar, are responsible for the cognitive and motor deficits?

Methotrexate does not interfere with an appetitive Pavlovian conditioning task in Sprague-Dawley rats.

There has been considerable interest in developing an animal model of the neuropsychological toxicity of chemotherapeutic agents used in the treatment of patients with cancer, especially children, since these agents often cause significant, long-term neuropsychological deficits. Yanovski, Packer, Levine, Davidson, Micalizzi, D'Angio (13) recently proposed such a model based on their finding that methotrexate retarded the formation of aversive Pavlovian excitatory associations. The present experiment examined the generality of methotrexate induced cognitive impairments by testing rats in Appetitive Pavlovian Conditioning tasks and a Conditioned Taste Aversion paradigm. The results of our study revealed no impairment following methotrexate exposure on the Appetitive Pavlovian tasks or on the Taste Aversion task, relative to two control conditions. While there were a number of methodological differences between the present experiment and those conducted by Yanovski et al. (13), the present results question the robustness and generality of Yanovski's et al. (13) animal model.

Issues associated with repeated neuropsychological assessments.

Distinguishing practice effects from other factors in repeated neuropsychological assessments are discussed in the context of research studies and clinical/forensic assessments. Potential methodological procedures for reducing the impact of practice effects in research settings are outlined. In contrast, the potential clinical utility and interpretation of practice effects in clinical assessments and forensic evaluations are highlighted.

Practice effects with the NIMH AIDS abbreviated neuropsychological battery.

The degree of practice effects with the Brief NIMH Neuropsychological Battery for HIV Infection and AIDS is reported using a 7-10 day test-retest interval. The patient groups were asymptomatic and symptomatic of HIV while the control group was made up of "at risk" volunteers. Statistically significant practice effects were obtained on the California Verbal Learning Test, the Paced Auditory Serial Addition Task and the Visual Search Test among the infected individuals. The controls subjects demonstrated statistically significant practice effects on all of the neuropsychological tests. The implications of these findings in prospective studies are discussed.

The relationship of expectancies to outcome in stress management treatment of essential hypertension: results from the Joint USSR-USA Behavioral Hypertension Project.

Outcome expectancy and efficacy expectancy measures were made during the course of a cross-cultural comparison of thermal biofeedback and autogenic training as treatments for mild essential hypertension. There were no differences between groups at either pre- or posttreatment, and expectancy measures were not related to initial success or failure at the completion of treatment. However, both outcome and efficacy expectations were related to relapse over the three months immediately following the completion of treatment. Treatment failures had lower ratings for both outcome and efficacy expectations at the posttreatment assessment in comparison to treatment successes. Implications of these results are discussed.

Effects of repeated neuropsychological assessments.

The effects of repeated administrations of neuropsychological instruments were evaluated in a group of chronic cigarette smokers who served as control subjects in a larger research project. Subjects performance on 13 neuropsychological variables across four assessments was evaluated using trend analyses. Statistically significant results were obtained on the Logical and Figurai Memory Subtests of the Wechsler Memory Scale (Form I-Russell's Revision) Part B of the Trail Making Test and the Grooved Pegboard Test (preferred hand). Of the remaining seven variables the Speech Sounds Perception Test, the Seashore Rhythm Test and Simple Auditory Reaction Time were highly consistent across all four assessments. The implications of these findings in clinical practice and research settings are addressed.

A methodological review of "method skeptic" reports.

The literature purporting to demonstrate that clinical neuropsychology is of limited validity in the forensic setting is reviewed critically and alternative interpretations are discussed. The methodological, procedural, conceptual, data analytical and survey/research design limitations are evaluated.

Alzheimer dementia: quantification of energy metabolism and mobile phosphoesters with P-31 NMR spectroscopy.

To determine whether high-energy phosphate metabolism and mobile phosphoester indexes of membrane metabolism are altered in Alzheimer disease and to help resolve some inconsistencies in the literature, brain phosphate metabolite concentrations and ratios were measured in 11 patients with mild to severe dementia of the probable Alzheimer type and 14 healthy subjects. Fully relaxed, spatially localized, phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy and proton (hydrogen-1) MR imaging were performed. No significant differences were found in the concentrations and relative ratios of phosphocreatine, nucleoside triphosphate, inorganic phosphate, phosphomonoester, and phosphodiesters in whole axial sections through the lateral cerebral ventricles of the brain that could not be accounted for by atrophy. There was no correlation between P-31 NMR indexes and the severity of dementia as assessed with neuropsychologic testing. High-energy phosphate and membrane metabolism, as detected in vivo with P-31 NMR spectroscopy in whole-brain sections, do not appear to play a major role in the disease process, except as a direct consequence of atrophy quantified with H-1 MR imaging.

Intraperitoneally injected cholecystokinin-octapeptide activates pica in rats.

Cholecystokinin-octapeptide (CCK-8) was injected intraperitoneally into rats to see if it could cause them to eat kaolin (clay)--a pica behavior which has been shown to indicate gastric distress. In the first study, a single large dose of CCK-8 (20 micrograms/kg) failed to produce pica. In the second study, 4 smaller doses of CCK-8 (8 micrograms/kg), 30 min apart, produced significant ingestion of kaolin compared to the baseline condition of vehicle injections. The pica was comparable to that observed in another group of rats given a toxic dose of LiCl (127 mg/kg, IP). It is concluded that intraperitoneal injections of CCK-8 can induce a state of gastric distress in the rat.

Personal and parental problem drinking: effects on problem-solving performance and self-appraisal.

This study examined the problem-solving performances and self-appraisals of problem-solving ability of college-age subjects with and without parental history of problem drinking. Contrary to our predictions, children of problem drinkers (COPDs) were rated as somewhat more effective in their problem-solving skills than non-COPDs, undermining prevailing assumptions about offspring from alcoholic households. While this difference was not large and was qualified by other variables, subjects' own alcohol abuse did exert a detrimental effect on problem-solving performance, regardless of parental history of problem drinking. However, a different pattern was evident for problem-solving self-appraisals. Alcohol-abusing non-COPDs saw themselves as effective problem-solvers while alcohol-abusing COPDs appraised themselves as poor problem-solvers. In addition, the self-appraisals of alcohol-abusing COPDs were consistent with objective ratings of solution effectiveness (i.e., they were both negative) while alcohol-abusing non-COPDs were overly positive in their appraisals, opposing the judgments of trained raters. This finding suggests that the relationship between personal alcohol abuse and self-appraised problem-solving abilities may differ as a function of parental history of problem drinking. Limitations on the generalizability of findings are addressed.