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Migraine is the most common neurological disorder, and contributes to disability and large healthcare costs in the United States and the world. The treatment of migraine until recently has focused on medications, both abortive and prophylactic, but treatment of chronic migraine has been revolutionized with the introduction of botulinum toxin injection therapy. In this review, we explore the current understanding of migraine pathophysiology, and the evolution of the use of botulinum toxin therapy including proposed pathophysiological mechanisms through animal data. We also discuss the similarities and differences between three injection techniques. [ABSTRACT FROM AUTHOR]

Background: Haff disease is a syndrome of myalgia and rhabdomyolysis that occurs after eating cooked seafood. Methods: For this descriptive analytical article, a literature search identified the scientific articles on Haff disease and/or rhabdomyolysis after eating cooked seafood in the United States and China. Analysis of those articles focused on identifying the seafood vectors of Haff disease, describing the most commonly recurring clinical and laboratory manifestations of Haff disease, and comparing the Haff disease toxidrome with other similar seafood-borne toxidromes. Statistically significant differences were determined using unpaired t tests and Fisher exact tests. Results: Twenty-nine confirmed cases of Haff disease were identified in the United States, and 60 cases were identified in China during 1984-2014. Most of the US cases followed consumption of buffalo fish, and most of the Chinese cases followed consumption of freshwater pomfret. However, Haff disease also followed consumption of the same species of boiled crayfish (Procambarus clarkii) in the United States (n=9) and China (n=6). US patients with crayfish-transmitted Haff disease reported significantly more nausea with and without vomiting, chest pain, body and back pain, dyspnea, and diaphoresis than the Chinese patients and were more frequently misdiagnosed as having myocardial infarctions. Conclusion: The bioaccumulation of a new, heat-stable freshwater and/or brackish/saltwater algal toxin, similar to palytoxin but primarily myotoxic and not neurotoxic, is suspected of causing Haff disease. At present, only the rapid identification of the seafood vectors of Haff disease will limit disease outbreaks and prevent further cases. [ABSTRACT FROM AUTHOR]

Fish and other seafood may contain organic mercury but also beneficial nutrients such as n-3 polyunsaturated fatty acids. We endeavored to study whether maternal fish consumption during pregnancy harms or benefits fetal brain development. We examined associations of maternal fish intake during pregnancy and maternal hair mercury at delivery with infant cognition among 135 mother-infant pairs in Project Viva, a prospective U.S. pregnancy and child cohort study. We assessed infant cognition by the percent novelty preference on visual recognition memory (VRM) testing at 6 months of age. Mothers consumed an average of 1.2 fish servings per week during the second trimester. Mean maternal hair mercury was 0.55 ppm, with 10% of samples > 1.2 ppm. Mean VRM score was 59.8 (range, 10.9-92.5). After adjusting for participant characteristics using linear regression, higher fish intake was associated with higher infant cognition. This association strengthened after adjustment for hair mercury level: For each additional weekly fish serving, offspring VRM score was 4.0 points higher [95% confidence interval (CI), 1.3 to 6.7]. However, an increase of 1 ppm in mercury was associated with a decrement in VRM score of 7.5 (95% CI, -13.7 to -1.2) points. VRM scores were highest among infants of women who consumed > 2 weekly fish servings but had mercury levels ≤ 1.2 ppm. Higher fish consumption in pregnancy was associated with better infant cognition, but higher mercury levels were associated with lower cognition. Women should continue to eat fish during pregnancy but choose varieties with lower mercury contamination. [ABSTRACT FROM AUTHOR]

Botulinum toxin (BoNT) is a neurotoxin produced by the Clostridium botulinum bacteria. Among seven different isoforms, only BoNT-A and BoNT-B are commercially used. Currently, botulinum toxin has been indicated by the U.S. Food and Drug Administration in several disorders, among others: chronic migraine, hyperhidrosis, urinary incontinence from detrusor overactivity, or cosmetics. However, there are numerous promising reports based on off-label BTX usage, indicating its potential effectiveness in other diseases, which remains unknown to many. Among them, dermatological conditions, such as rosacea, annal fissure, Raynaud phenomenon, hypertrophic scars and keloids, and also hidradenitis suppurativa, are currently being investigated. This article aims to provide a comprehensive update on the off-label use of botulinum toxin in dermatology, based on an analysis and summary of the published literature.

YouTube is a common source of medical information for patients. This is the first study to assess the reliability and educational value of YouTube videos on neurotoxin procedures. YouTube.com was searched on June 15, 2020 using the keyword "Botox" or "neurotoxin." A total of 100 videos were reviewed. Sixty-one videos met the inclusion criteria and were included in the final analysis. Video characteristics were noted, and a score was assigned to each video using the Journal of the American Medical Association (JAMA) benchmark criteria and the Global Quality Score (GQS) to measure source reliability and educational value, respectively. A total of 61 videos that met the inclusion criteria had an average length of 589 seconds (9 minutes and 49 seconds), 210,673 views, 5,295 likes, 318 dislikes, and 478 comments. A total of 30 videos (49%) were posted with an intention to educate patients while 31 videos (51%) were posted with the intention to detail a personal experience with neurotoxin. Patient education videos were significantly more reliable ( P JAMA < 0.001) and had more educational value ( P GQS  < 0.001) but were less popular than "personal experience videos." Personal-experience videos posted by patients had higher popularity, more likes and comments, yet lower scores on reliability and education. Patients will continue to seek educational material online, and clinicians should utilize this information to help primarily educate patients with standardized and accurate information about their treatment. KEY POINTS: · Question: Are YouTube videos pertaining to neurotoxin reliable and contain useful information to educate patients to make informed decisions about their neurotoxin treatment?. · Findings: Roughly half of videos reviewed were vlogs (video logs), which were of low quality and educational value, but were more popular compared with videos that were intended to educate patients on neurotoxin treatment.. · Meaning: Patients who use YouTube as a source of information about neurotoxin treatment may be misled with inaccurate and unreliable information. Physicians must be aware of these findings to properly educate patients with standardized and accurate information about their treatment.., Competing Interests: None., (Thieme. All rights reserved.)

This document completes the biennial review and republication of the lists of biological agents and toxins regulated by the U.S. Department of Health and Human Services (HHS), as well as those biological agents and toxins regulated by both HHS and the U.S. Department of Agriculture (USDA). Because USDA has chosen to no longer regulate ten biological agents and toxins which HHS still believes have the potential to pose a severe threat to public health and safety, we have moved those ten biological agents and toxins from the overlap select agents and toxins section to the HHS select agents and toxins section of the select agent regulations. In a companion document published in this issue of the Federal Register, the USDA has established corresponding final rules regarding the select agents and toxins regulated only by the USDA, as well as those overlap select agents and toxins regulated by both agencies.

Substance abuse among older adults has received little attention in the past, presumably because this population has traditionally accounted for only a small percentage of the drug abuse problem in the United States. The aging of the baby boomer generation (born 1946-1964), however, will soon swell the ranks of older adults and dramatically alter the demography of American society. Several observations suggest that this expansion will likely be accompanied by a precipitous increase in the abuse of drugs, including prescription medications and illicit substances, among older adults. While it is now evident that the brain changes continuously across life, how drugs of abuse interact with these age-related changes remains unclear. The dynamic nature of brain function, however, suggests that substance abuse during older age may augment the risks and require unique considerations for diagnosis and treatment. In addition to describing current and projected prevalence estimates of substance abuse among older adults, the present review discusses how aging affects brain systems involved in drug abuse, and explores the potential impact of drug abuse on the aging brain. Future directions for substance abuse research among older adults will also be considered.

Background: Lead is neurotoxic; yet, whether cognitive decline in older persons is associated with lead exposure is unknown. We studied whether lead exposure biomarkers are associated with cognitive test scores, as well as the modifying effects of age on the lead-cognition relationship., Methods: Lead exposure biomarkers and Mini-Mental Status Exam (MMSE) scores were measured among subjects in the Normative Aging Study. Multiple linear and logistic regression analyses were performed to examine the cross-sectional association of these 2 variables., Results: We found an odds ratio (OR) of 2.1 for MMSE <24 with an increase from the lowest to the highest quartile of patella lead levels (95% confidence interval [CI] = 1.1 to 4.1). From the lowest to the highest quartile of blood lead the OR for low MMSE was 3.4 (CI = 1.6 to 6.2). There was an interaction between lead biomarkers and age. Among subjects in the lowest quartile of patella lead levels, MMSE score decreased by 0.03 points per year (CI = -0.07 to 0.005), whereas in the highest quartile, MMSE score decreased by 0.13 points per year (CI = -0.19 to -0.07). Similar interactions were found between blood lead levels and age., Conclusions: Increased levels of lead in bone and blood are inversely associated with cognitive performance among older men. Lead exposure might accelerate age-associated cognitive decline.

Antisocial behavior persists as a preeminent public policy issue in the United States. A more critical assessment of both the policies and the programs designed to address this problem is necessary, and new risk factors for antisocial behavior need to be investigated. Sufficient evidence exists to hypothesize that exposure to neurotoxins may be a risk factor for antisocial behavior. Neurotoxins such as lead have been demonstrated to affect the cognitive development of children, and impaired cognition is accepted as a risk factor for antisocial behavior. Little consideration has been given, however, to the possible link between neurotoxins and human behavior. This paper presents a biologically and socially plausible justification for this association, reviews the supporting evidence, and emphasizes the need for additional investigation of the phenomenon. Elucidation of this risk factor may lead to new strategies for preventing or mitigating antisocial behaviors among youth and adults.

Research to identify adverse effects in humans chronically exposed to neurotoxic substances in the workplace or environment typically assesses people at one point in time in a cross-sectional study. The most widely used strategy employs performance measures taken from a single point in time and compares these with either performance of a control group or established normative data. However, multiple comparison points of the same people on the same test allow the dissection of acute--from chronic--exposure effects, among other important questions. When performance measures are used from multiple points in time, within-subject deviations are examined. For either research design, the goal is to minimize the effects of practice and to obtain stable performance on a test. Demographic variables such as age, education, and cultural background or ethnicity influence performance on neurobehavioral tests. These variables may also influence the development of stable performance. Different populations may have different learning curves so that stable performance on a test is achieved with different amounts of practice. This is especially important when making comparisons across groups that may not have equivalent backgrounds. The performance of three groups, English-speaking adults, Spanish-speaking adolescents, and Spanish-speaking migrant adolescents, was examined. Each group completed a battery of neurobehavioral tests from the Behavioral Assessment and Research System (BARS) during four sessions. Repeated measures ANOVAs were used to investigate performance across time. Tests measuring motor performance produced stable performance from the first session. More complex tasks that involved attention and memory showed a practice effect across sessions.

Ample evidence demonstrates that many chemicals, at some concentration, affect the nervous system. Disastrous incidents resulting from food adulteration, medical experiments and pharmaceutical errors, and industrial and environmental exposures warn of the serious potential for neurotoxicants to affect human health. This article identifies the approximately 185 epidemiological behavioral neurotoxicology studies published through 1989 of extended workplace exposures to chemicals. Approximately 250 different tests have been administered to exposed workers in primarily cross sectional studies, and statistically significant decrements were reported in 43% of the approximately 1100 test/population administrations (virtually all 185 studies employed several of the 250 tests). In this research, 28 different chemicals as well as multiple chemical exposures have been studied. The most extensive findings are seen in research on carbon disulfide, lead, mercury, and multiple solvent exposures, although three or more independent studies also have been reported on workers exposed to styrene and organophosphates. Analyzing the consistent findings in these studies, they reveal a broad spectrum of cognitive, motor, and affective or personality changes. The most frequently reported functional deficits are in tests of intelligence, memory, spatial relations, coordination, and speed plus coordination. Individual behavioral measurement methods and significant test batteries that have been employed to assess changes in human nervous system functions to determine the degree of risk posed by new and established chemicals are described; two of those human behavioral test batteries are predicted to dominate research at the onset of the 1990's. There is a lack of parallelism between the human test methods found in these batteries and the US Environmental Protection Protection Agency (EPA) and Food and Drug Agency (FDA) guideline methods for pre-production screening of chemicals and food additives in animals, and it appears unlikely that the widely employed human and animal behavioral test batteries, as currently evaluated, could identify disease complexes newly suspected of having a chemical etiology.

A large proportion of compounds studied for their neurotoxic potential are at the same time suspected or proven carcinogens. This is demonstrated using the International Neurotoxicology Association (INA) Professional Interest Directory and publications from the field of neurotoxicology as examples. In addition to listing these compounds, the classification scheme used by the International Agency for Research on Cancer (IARC), the Commission of the European Communities (EC), the U.S. Environmental Protection Agency (EPA), the German MAK-Commission of the Deutsche Forschungsgemeinschaft (DGF) and the U.S. National Institute of Occupational Safety and Health (NIOSH) to make qualitative risk assessments is explained. Finally, a short initiation to quantitative risk assessment as performed by the US EPA and the World Health Organization (WHO) is given in order to put the reader into a position as to assess the cancer risk incurred by his/her co-workers and by himself.

Acetylethyltetramethyltetralin, a widely used synthetic fragance material, was found to cause neurotoxic effects in animals. 6-Methylcoumarin, another fragance material, was determined to be a photocontact allergen. Insufficient information on their usage, consumer exposure and likely hazard to human health under conditions of use impair regulatory decisions. FDA's ability to protect consumers against a health hazard is greatly influenced by the availability of such data.