Neurological illnesses associated with Florida red tide (Karenia brevis) blooms.

Human respiratory and gastrointestinal illnesses can result from exposures to brevetoxins originating from coastal Florida red tide blooms, comprising the marine alga Karenia brevis (K. brevis). Only limited research on the extent of human health risks and illness costs due to K. brevis blooms has been undertaken to date. Because brevetoxins are known neurotoxins that are able to cross the blood-brain barrier, it is possible that exposure to brevetoxins may be associated with neurological illnesses. This study explored whether K. brevis blooms may be associated with increases in the numbers of emergency department visits for neurological illness. An exposure-response framework was applied to test the effects of K. brevis blooms on human health, using secondary data from diverse sources. After controlling for resident population, seasonal and annual effects, significant increases in emergency department visits were found specifically for headache (ICD-9 784.0) as a primary diagnosis during proximate coastal K. brevis blooms. In particular, an increased risk for older residents (≥55 years) was identified in the coastal communities of six southwest Florida counties during K. brevis bloom events. The incidence of headache associated with K. brevis blooms showed a small but increasing association with K. brevis cell densities. Rough estimates of the costs of this illness were developed for hypothetical bloom occurrences.

An Updated Review of Ciguatera Fish Poisoning: Clinical, Epidemiological, Environmental, and Public Health Management.

Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world. It causes substantial human health, social, and economic impacts. The illness produces a complex array of gastrointestinal, neurological and neuropsychological, and cardiovascular symptoms, which may last days, weeks, or months. This paper is a general review of CFP including the human health effects of exposure to ciguatoxins (CTXs), diagnosis, human pathophysiology of CFP, treatment, detection of CTXs in fish, epidemiology of the illness, global dimensions, prevention, future directions, and recommendations for clinicians and patients. It updates and expands upon the previous review of CFP published by Friedman et al. (2008) and addresses new insights and relevant emerging global themes such as climate and environmental change, international market issues, and socioeconomic impacts of CFP. It also provides a proposed universal case definition for CFP designed to account for the variability in symptom presentation across different geographic regions. Information that is important but unchanged since the previous review has been reiterated. This article is intended for a broad audience, including resource and fishery managers, commercial and recreational fishers, public health officials, medical professionals, and other interested parties.

Course of cognitive decline in hematopoietic stem cell transplantation: a within-subjects design.

This study examined the course of clinically significant cognitive change in hematopoietic stem cell transplant (HSCT), using a Reliable Change Index (RCI). Neuropsychological evaluations were administered to 117 patients before HSCT. Thirty-three received subsequent evaluations 6 and 28 weeks later. Of 117 patients, 39% were classified as impaired before HSCT. Of the 33 receiving subsequent evaluations, 47% showed reliable decline at 6-weeks; of these, 33% showed reliable decline again at 28-weeks. Mood and QOL did not account for declines. Verbal learning, psychomotor speed, and executive function showed greatest vulnerability to pre-HSCT impairment, and verbal learning showed greatest likelihood of further, subsequent decline. In conclusion, a subgroup of patients showed cognitive impairment before HSCT, indicating that factors other than HSCT contributed to cognitive deficits. Another subgroup showed further decline after HSCT. This study demonstrated the utility of the RCI in describing cognitive change in HSCT patients.

Ciguatera fish poisoning: treatment, prevention and management.

Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world, and it causes substantial physical and functional impact. It produces a myriad of gastrointestinal, neurologic and/or cardiovascular symptoms which last days to weeks, or even months. Although there are reports of symptom amelioration with some interventions (e.g. IV mannitol), the appropriate treatment for CFP remains unclear to many physicians. We review the literature on the treatments for CFP, including randomized controlled studies and anecdotal reports. The article is intended to clarify treatment options, and provide information about management and prevention of CFP, for emergency room physicians, poison control information providers, other health care providers, and patients.

Neuropsychological effects of third ventricle tumor surgery.

OBJECTIVE: This study assessed the neuropsychological outcome of patients after surgical treatment for third ventricle brain tumors. Neuropsychological consequences of surgical intervention can have a major impact on patients' quality of life and therefore have important implications for treatment planning. METHODS: A retrospective analysis of 33 patients' neuropsychological data was performed. All patients received a comprehensive neuropsychological evaluation after treatment for a primary brain tumor in the third ventricular region. Twenty-six patients underwent surgery, 14 via the transcallosal approach and 12 via a subfrontal, left transcortical, right pterional, or infratentorial supracerebellar approach. Seven patients were not treated by surgical intervention. RESULTS: There was a significantly elevated frequency of cognitive impairment relative to normative values in memory, executive functioning, and fine manual speed and dexterity. There were no differences in mean neuropsychological scores between patients who underwent surgery and those who did not. There were no differences in mean performance on the basis of surgical approach, tumor infiltration, or history of cranial irradiation. Repeated measures data available for two patients revealed memory impairment before and after surgery, and one patient experienced major improvement after surgery on a measure of mental flexibility and problem solving. CONCLUSION: Patients with third ventricle tumors are at risk for developing impairments in memory, executive function, and fine manual speed and dexterity, which are domains associated with frontal subcortical functions. In the current study, different types of treatment were not associated with differential cognitive sequelae, and surgical intervention did not account for cognitive deficits.

Neuropsychological study of ciguatera fish poisoning: a longitudinal case-control study.

PURPOSE: The purpose of the study was to evaluate the neuropsychological effects of ciguatera fish poisoning (CFP). METHOD: In a longitudinal matched cohort study, 12 CFP cases and 12 matched friend-controls received baseline neuropsychological evaluations within one month after intoxication and follow-up evaluations approximately six months after baseline. RESULTS: Only one case received intravenous mannitol treatment, which occurred 10 or more days after intoxication. At baseline and follow-up evaluations, there were no statistically significant differences between CFP cases and controls on cognitive measures. At baseline, however, CFP cases endorsed significantly greater subjective toxicity symptoms (e.g. fatigue, tingling sensations) and greater anxiety symptoms than controls. Follow-up evaluations suggested resolution of all symptoms after six months. Subsequent analyses, in which data from this study were pooled with data from an earlier pilot study, supported these results. CONCLUSION: Untreated ciguatera was associated acutely with significant subjective neurotoxicity symptoms and anxiety which were transient, but not with objectively measured cognitive changes. Future investigation with a larger sample size is warranted.

Neurobehavioral effects of harmful algal bloom (HAB) toxins: a critical review.

Human exposure to naturally occurring marine toxins has been associated with a range of neurobehavioral abnormalities. The toxins are produced by harmful algal blooms (HABs) and are typically contracted through seafood consumption. The primary target of many of the HAB toxins is the neurologic system, and the neurobehavioral symptoms associated with the HAB illnesses have influenced public health policy. The HAB-related illnesses most frequently linked to neuropsychological disturbance are Amnesic Shellfish Poisoning, Ciguatera Fish Poisoning, and Possible Estuarine Associated Syndrome, which is associated with exposure to the Pfiesteria piscicida organism. Although the neurophysiologic mechanisms underlying many of the HAB illnesses have been well delineated, the literature examining the neuropsychological impairments is unclear and needs to be defined. This review is intended to introduce an emerging area of study linking HAB illnesses with neuropsychological changes.

Neuropsychological effects of third ventricle tumor surgery.

OBJECTIVE: This study assessed the neuropsychological outcome of patients after surgical treatment for third ventricle brain tumors. Neuropsychological consequences of surgical intervention can have a major impact on patients' quality of life and therefore have important implications for treatment planning. METHODS: A retrospective analysis of 33 patients' neuropsychological data was performed. All patients received a comprehensive neuropsychological evaluation after treatment for a primary brain tumor in the third ventricular region. Twenty-six patients underwent surgery, 14 via the transcallosal approach and 12 via a subfrontal, left transcortical, right pterional, or infratentorial supracerebellar approach. Seven patients were not treated by surgical intervention. RESULTS: There was a significantly elevated frequency of cognitive impairment relative to normative values in memory, executive functioning, and fine manual speed and dexterity. There were no differences in mean neuropsychological scores between patients who underwent surgery and those who did not. There were no differences in mean performance on the basis of surgical approach, tumor infiltration, or history of cranial irradiation. Repeated measures data available for two patients revealed memory impairment before and after surgery, and one patient experienced major improvement after surgery on a measure of mental flexibility and problem solving. CONCLUSION: Patients with third ventricle tumors are at risk for developing impairments in memory, executive function, and fine manual speed and dexterity, which are domains associated with frontal subcortical functions. In the current study, different types of treatment were not associated with differential cognitive sequelae, and surgical intervention did not account for cognitive deficits.

Hopkins Verbal Learning Test-Revised: norms for elderly African Americans.

The Hopkins Verbal Learning Test-Revised (HVLT-R) is a memory test commonly used in neuropsychological evaluations, but for which there are currently no normative data for elderly African Americans. The current study examined the influence of demographic characteristics on HVLT-R performance measures in a community-dwelling sample of 237 African American older adults (60-84 years). Age, gender, and education accounted for moderate amounts of variance in HVLT-R performance. Based on these results, normative tables for HVLT-R scores, stratified by age and with score adjustments for education and gender, are provided.