Detection of early FXTAS motor symptoms using the CATSYS computerised neuromotor test battery.

Background: Carriers of the FMR1 premutation allele are at a significantly increased risk for a late-onset neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS). This disorder is distinct from fragile X syndrome (FXS) in its molecular aetiology and clinical presentation. The primary features of FXTAS are late-onset intention tremor and gait ataxia.

Behavioral, social, and affective factors associated with self-efficacy for self-management among people with epilepsy.

The purpose of the study described in this article was to evaluate the extent to which selected behavioral, social, and affective factors contribute to self-reported epilepsy self-efficacy. Participants completed three assessments 3 months apart, with only those completing both the first and second assessments included in this analysis. Self-efficacy scores at the second assessment were regressed on the behavioral, social, and affective characteristics ascertained at the first assessment.

The complexity of treatments for persons with epilepsy.

The purpose of this study was to describe the types of antiepileptic medication regimens and the types of actions required to take medications for a group of patients with epilepsy. The Epilepsy Medication and Treatment Complexity Index (EMTCI) was used to gather information about medications and treatments. The sample of 314 reported on 585 epilepsy medications.

Examination of the effect of the polymorphic CGG repeat in the FMR1 gene on cognitive performance.

A CGG repeat sequence located in the 5' untranslated region of the FMR1 gene is polymorphic with respect to size and stability of the repeat during parent-offspring transmission. When expanded to over 200 repeats, the gene is hypermethylated and silenced, leading to fragile X syndrome (FXS). Recently, alleles with large unmethylated repeat tracts (premutations) have been associated with ovarian failure and a late-onset tremor/ataxia syndrome, symptoms unrelated to FXS.

Project EASE: a study to test a psychosocial model of epilepsy medication managment.

The purpose of this study was to test a psychosocial model of medication self-management among people with epilepsy. This model was based primarily on social cognitive theory and included personal (self-efficacy, outcome expectations, goals, stigma, and depressive symptoms), social (social support), and provider (patient satisfaction and desire for control) variables. Participants for the study were enrolled at research sites in Atlanta, Georgia, and Boston, Massachusetts and completed computer-based assessments that included measures of the study variables listed above.

A computer-based reading test for use as an index of premorbid general intellectual level in North American English-speaking adults.

Brief tests of vocabulary or reading ability are often used as an index of general intellectual level to hypothesize deficits in patients, to establish comparability of comparison groups, and as a covariate of performance on other neuropsychological tests. We evaluated a new variant of a reading test for potential use in estimating premorbid general intellectual ability and implementation as a computerized-adaptive test. A total of 319 outpatients who participated in an epilepsy self-management study were tested on three occasions, completing the Wide-Range Achievement Test-3 (WRAT-3) Reading test at baseline and the NES3 Adult Reading Test (ART) at the 3-month follow-up.

Further standardization of some NES3 tests.

NES3 is a computer-based neurobehavioral testing system designed for use in investigating potential cognitive impairment. Data from NES3 tests employed in a study of epilepsy self-management were analyzed to estimate test-retest reliability for NES3 tests on a large sample and to estimate the effect of some common covariates of test performance. A total of 319 participants in an epilepsy self-management study were examined on three occasions (baseline, 3-month follow-up, and 6-month follow-up) with a set of psychological questionnaires and seven neuropsychological tests from NES3.

Continuing challenges for computer-based neuropsychological tests.

A number of issues critical to the development of computer-based neuropsychological testing systems that remain continuing challenges to their widespread use in occupational and environmental health are reviewed. Several computer-based neuropsychological testing systems have been developed over the last 20 years, and they have contributed substantially to the study of neurologic effects of a number of environmental exposures. However, many are no longer supported and do not run on contemporary personal computer operating systems.

Neurologic outcomes of toxic oil syndrome patients 18 years after the epidemic.

Toxic oil syndrome (TOS) resulted from consumption of rapeseed oil denatured with 2% aniline and affected more than 20,000 persons. Eighteen years after the epidemic, many patients continue to report neurologic symptoms that are difficult to evaluate using conventional techniques. We conducted an epidemiologic study to determine whether an exposure to toxic oil 18 years ago was associated with current adverse neurobehavioral effects.

The epilepsy medication and treatment complexity index: reliability and validity testing.

Medications are the most common treatment for epilepsy. Regimens vary from once per day dosing to several pills several times per day. More complex regimens have been associated with lower adherence rates.

The association of stigma with self-management and perceptions of health care among adults with epilepsy.

Objective: The purpose of this study was to examine the perception of stigma among adults with epilepsy including its association with epilepsy self-management and perceptions of health care.

Methods: Participants for the study were recruited from two epilepsy centers and a neurology clinic. Individuals agreeing to participate in the study were asked to complete three assessments each 3 months apart.

Neuropsychological screening for cognitive impairment using computer-assisted tasks.

The aim of this study was to validate a computer-assisted screening battery for classifying patients into two groups, those with and without cognitive impairment. Participants were all patients referred to the neuropsychology clinics at four VA medical centers during a 1-year period. Patients meeting the study inclusionary criteria (N = 252) were administered the Neurobehavioral Evaluation System-3 (NES3) computer-assisted battery.

Association between bone lead concentration and blood pressure among young adults.

Background: Occupational and environmental exposure to lead has been examined for its effect on blood pressure (BP) in adults with varying results. The present analyses assessed the association between bone lead concentration and BP in early adult life in persons exposed during childhood.

Methods: Study participants included young adult members of two cohorts with different past histories of lead exposure.

Neurobehavioral test performance in the third National Health and Nutrition Examination Survey.

The third National Health and Nutrition Examination Survey (NHANES III) contained three computerized neurobehavioral tests from the Neurobehavioral Evaluation System (NES): simple reaction time, symbol-digit substitution and serial digit learning. The neurobehavioral data that were collected came from a nationally representative sample of adults 20-59 years old. Performance on the tests was related to sex, age, education level, family income and race-ethnicity.

Health effects of long-term mercury exposure among chloralkali plant workers.

Background: Inorganic mercury is toxic to the nervous system, kidneys, and reproductive system. We studied the health effects of mercury exposure among former employees of a chloralkali plant that operated from 1955 to 1994 in Georgia.

Methods: Former plant workers and unexposed workers from nearby employers were studied.

Epidemiological case definitions of peripheral neuropathy: experience from two neurotoxicity studies.

Objective: The purpose of this investigation was to develop and apply case definitions of peripheral neuropathy (PN) derived from a set of individual measures of peripheral nerve function obtained in two epidemiological studies.

Methods: In the first study, retired workers of an industrial plant who were either previously exposed to mercury or not underwent a set of peripheral neurological tests. In the second study, persons living in an arsenic contaminated community in rural Georgia, USA, and unexposed comparison subjects were tested.

Relationships between quantitative measures and neurologist's clinical rating of tremor and standing steadiness in two epidemiological studies.

Objective: The purpose of the present investigation was to 1) compare a neurologist's physical examination (NPx) rating of severity of postural tremor to several summary measures derived from quantitative measurements of tremor and 2) compare a NPx rating of standing steadiness and related clinical findings to quantitative sway speed measurements.

Methods: Comparisons were performed on data obtained from two epidemiological field studies: 1) retired heavy industrial workers (n= 198, approximately half previously exposed to elemental mercury), and 2) small town residents (n=234, approximately 40% with environmental exposure to arsenic). A commercially available tremor measurement instrument was used in both studies.

Reliability of some tremor measurement outcome variables in field testing situations.

Objective: Many summary measures of data obtained from tremor measurement procedures are commonly reported. The reliability of many of these summary measures of tremor measurements made in field testing situations is unknown. The purpose of the present investigation was to assess the reliability of a number of summary measures produced by the software of a widely used, commercially available tremor measurement instrument using data collected in three field epidemiologic studies.

Validity of a computer-assisted neurobehavioral test battery in toxicant encephalopathy.

The computer-assisted Neurobehavioral Evaluation System 2 (NES2) test battery provides an efficient method of measuring neurobehavioral effects in epidemiological studies, and a newer computer-assisted battery, NES3, has been developed to assist in neuropsychological assessment. This study assesses the validity of some NES2 and NES3 tests in patients diagnosed with toxicant encephalopathy (TE) following exposure to lead or to mixed solvents. This information can be used to improve the interpretation of NES test results in research studies and clinical evaluations examining central nervous system function.

Neurological effects of environmental exposure to arsenic in dust and soil among humans.

Persons living in a small town in Georgia, USA, were studied because of known environmental exposure to arsenic-containing dust. To assess the effects of this exposure on the nervous system, a cross-sectional epidemiological study was performed. The health outcome assessments of the study were based on a priori selected clinical examination results and quantitative electrophysiologic and behavioral outcome measures.

Residual neurologic deficits 30 years after occupational exposure to elemental mercury.

A battery of tests of peripheral and central nervous system function was administered to 205 former workers of a large heavy industrial plant, 104 of whom were previously exposed to inorganic mercury. The mean age of those examined was 71 years. Exposed subjects had participated in a urine-mercury exposure monitoring program during the time of operation of a process that required the use of mercury and its subsequent clean-up.

Neurotoxicity in young adults 20 years after childhood exposure to lead: the Bunker Hill experience.

Objectives: An epidemiological study of young adults was conducted to determine whether environmental exposure to lead during childhood was associated with current adverse neurobehavioural effects.

Methods: The exposed group consisted of 281 young adults who had been exposed environmentally to lead as children and the unexposed referent group consisted of 287 age and sex frequency matched subjects. Information on demographics, past and current health, and past exposures to neurotoxicants, and responses to the Swedish Q16 questionnaire were collected by interview.

The sensitivity and specificity of tests for carpal tunnel syndrome vary with the comparison subjects.

The performance of a variety of common office-based clinical tests for detection of carpal tunnel syndrome (CTS) was assessed in 119 subjects with and without electrophysiological evidence of CTS. Symptoms compatible with CTS and electrophysiological tests positive for median mononeuropathy at the wrist were observed in 57 hands, symptoms compatible with CTS and normal electrophysiological test results were observed in 58 hands, and no symptoms compatible with CTS and normal electrophysiological test results were observed in 123 hands. For all the diagnostic tests studied, the proportion of subjects who had a false positive clinical test result was much higher in the electrophysiologically normal subjects who had CTS compatible hand symptoms than in the electrophysiologically normal subjects who were asymptomatic.

Tolerance of mefloquine by SwissAir trainee pilots.

Due to presumed adverse performance impact, a World Health Organization clause currently restricts the use of mefloquine malaria chemoprophylaxis in individuals requiring fine coordination and spatial discrimination. We conducted a double-blind, placebo-controlled, cross-over study to quantitatively assess the effects of mefloquine at steady state on performance in 23 trainee airline pilots. Flying performance was assessed using a flight simulator, psychomotor function was evaluated, sleep and wake cycles were monitored, and symptoms and moods were assessed using standardized questionnaires.