bluuebunny/crossref_metadata_2025 huggingface dataset:
Does glutathione metabolism have a role in the defence of poplar against zinc excess?
Authors: Di Baccio Daniela , Kopriva Stanislav , Sebastiani Luca , Rennenberg Heinz
Published: June 2005

Transition metals such as zinc (Zn) are essential micronutrients for many physiological processes, but they become toxic at elevated levels. Zinc is one of the most abundant trace heavy metals present in agro‐ecosystems.

Populus spp. have been suggested as good candidates for using to study the removal and/or immobilization of environmental organic and inorganic pollutants. In order to understand the physiological and biochemical bases of this assumption for Zn, plants of Populus deltoides × P. nigra (P. × euramericana) were grown in hydroponics with different concentrations of Zn [1 µm (control), and 1, 5 and 10 mm] in the nutrient solution.

Shoot biomass decreased at 5 and 10 mm Zn, while the Zn content of young leaves increased progressively with increasing Zn concentration (1–10 mm). Total glutathione (GSH+GSSG) content was reduced with increasing Zn concentration, while the contribution of oxidized to total glutathione increased. Despite these observations, semiquantitative reverse transcription–polymerase chain reaction (RT–PCR) revealed that the gene expression of GSH reductase (GR, chloroplastic and cytosolic isoform) and γ‐glutamylcysteine synthetase (γ‐ECS) increased in young leaves of poplars treated with excess Zn.

We conclude that GSH synthesis, consumption and redox status play a central role in the response of poplars to high concentrations of Zn.
CFF thresholds: relation to macular pigment optical density
Authors: Hammond Billy R. , Wooten Billy R.
Published: June 2005

Purpose:  Only two small studies have evaluated the relation between individual differences in macular pigment (MP) levels and visual health prior to retinal disease. In this study, we assess the relation between MP and a general measure of visual health, the critical flicker fusion (CFF) threshold.

Methods:  A total of 134 subjects were assessed. CFF values were determined psychophysically using a 570 nm, circular 1‐degree test field centrally fixated. MP optical density was measured using flicker photometry and a 1‐degree circular 458 nm test field centrally fixated. Personal characteristics were determined by questionnaire.

Results:  Similar to past studies, we found a significant decline in CFF values with age (r = −0.56). There was a significant positive relationship (r = 0.30, p < 0.001) between MP density and CFF values that was independent of age.

Conclusions:  These results are consistent with a protective effect of MP on visual health across the lifespan.
The effect of apparent depth in pictorial images on accommodation
Authors: Busby Alan , Ciuffreda Kenneth J.
Published: June 2005

The purpose of this study was to investigate the effect of the apparent depth of pictorial images on accommodation. Steady‐state accommodation was assessed objectively while viewing eight pictorial stimuli containing varying degrees of monocular cues to depth. Sixteen young adult subjects were tested monocularly with accommodation either in the closed‐loop or open‐loop mode. Pictorial depth cues significantly influenced the mean level of accommodation under some of the open‐loop conditions in which blur feedback was rendered ineffective. For nearly all stimuli and viewing modes, the mean accommodative responses were biased in the perceptually‐appropriate direction, but they were larger in the open‐loop condition. Apparent depth cues did not significantly affect accommodation under closed‐loop viewing conditions, presumably because blur feedback markedly dampened any perceptually‐driven influences. Consistent with current models of accommodation, and several earlier studies, perceptually‐based accommodation had only a secondary effect on the overall accommodative response level under naturalistic viewing conditions, with blur dominating.
Effect of Vegetation Matrix on Animal Dispersal: Genetic Evidence from a Study of Endangered Skinks
Authors: BERRY OLIVER , TOCHER MANDY D. , GLEESON DIANNE M. , SARRE STEPHEN D.
Published: June 2005

Abstract:  Maintaining connectivity in fragmented landscapes is a key principle of biological conservation. Although corridors are a widely accepted approach to connecting populations, their merits are still debated, and they may be impractical in many situations. A focus on management of the vegetation matrix between populations has been advocated as an alternative way to deal with habitat fragmentation and has theoretical support. We combined microsatellite DNA and demographic data to provide an empirical account of how two forms of agricultural land use affect the connectivity of insular populations of an endangered skink in southern New Zealand. The grand skink (Oligosoma grande) lives in small populations (approximately 20 individuals) on rock outcrops separated from one another by 50–150 m of inhospitable matrix vegetation (either native tussock grassland or exotic pasture). Skinks typically dispersed short distances, and the nature of the matrix both quantitatively and qualitatively affected dispersal dynamics. Skink populations in pasture were significantly more genetically structured and had less genetic variation than similar populations in tussock, implying less dispersal between populations in pasture than tussock. Furthermore, although female‐biased dispersal was a feature of populations in tussock, no sex bias was evident in pasture. In addition, Bayesian individual‐based genetic assignment tests that incorporated prior mark‐recapture information revealed that some populations produced many emigrants but received few immigrants, whereas other populations were relatively insular. Patterns of dispersal and response to matrix vegetation were complex, and the causes of these patterns deserve attention in future studies of habitat fragmentation. Managing the vegetation matrix may be a practical way to connect animal populations in some situations.
Using Demographic Invariants to Detect Overharvested Bird Populations from Incomplete Data
Authors: NIEL COLIN , LEBRETON JEAN‐DOMINIQUE
Published: June 2005

Abstract: Conservation biology must be able to provide guidelines even when available data are incomplete, because data on rare and endangered species are usually limited. For instance, data on the effect of additional—human‐induced—sources of mortality on vertebrate populations, such as bycatch of seabirds by longline fisheries, are typically incomplete. The importance of an additional source of mortality can be evaluated by comparing it with the maximum annual growth rate of the species of concern, and various authors have attempted to determine the maximum growth rate from incomplete data. We developed a procedure we call the “demographic invariant method” (DIM). First we determined that the maximum growth rate per generation does not vary, by recalling that it is a dimensionless number primarily independent of body weight and also by empirically establishing its near constancy over a restricted set of bird species for which reliable demographic information was available. This first step provided an implicit function linking generation time and maximum annual growth rate, from which we obtained the maximum annual growth rate as a simple function of generation time. From several different ways of obtaining estimates of generation time, we derived in turn several ways to estimate the maximum annual growth rate of a bird species from incomplete demographic data set. We applied our approach to the Black‐footed Albatross(Phoebastria nigripes)and determined from incomplete data that longline fishery bycatch has a biologically significant impact on the growth potential of Black‐footed Albatross populations. Our method can be applied broadly to the conservation and management of harvested bird populations.
Using Distance from Putative Source Woodlots to Predict Occurrence of Forest Birds in Putative Sinks
Authors: NOL ERICA , FRANCIS CHARLES M. , BURKE DAWN M.
Published: June 2005

Abstract:  For some species of forest‐breeding birds, productivity is much higher in large forest fragments than in small forest fragments and is higher than the level needed to replace individuals within the fragment (sources). Thus large forest fragments potentially provide excess individuals to neighboring small fragments where productivity is much lower and not adequate for replacement (sinks). We used occurrence data and distances between putative sources and sinks for four species of forest birds with this pattern of demography in large and small forest fragments to predict occupancy in small fragments. For the Ovenbird ( Seiurus aurocapilla), Wood Thrush ( Hylocichla mustelina), Veery (Catharus fuscescens), and Rose‐breasted Grosbeak (Pheucticus ludovicianus), distance from large woodlots was a significant predictor of occurrence in small woodlots. Distance from large woodlots did not predict occupancy of Red‐eyed Vireos ( Vireo olivaceus), a species with no apparent difference in productivity in relation to fragment size. Neither vegetation features nor area of the small woodlots adequately explained patterns of occupancy for any species. These results suggest that maintenance of large, productive forest fragments benefit regional occurrence of forest‐breeding birds by providing individuals to neighboring small woodlots. Limited reproduction in these small woodlots means that they may act as a reservoir for excess individuals in the case of catastrophic events that result in vacancies in source woodlots. Conservation and sound forest management of small forests should be directed particularly toward those closer to large regional forests.
Mammal Conservation in Brazil
Authors: COSTA LEONORA PIRES , LEITE YURI LUIZ REIS , MENDES SÉRGIO LUCENA , DITCHFIELD ALBERT DAVID
Published: June 2005

Abstract: Brazil is the fifth largest country in the world and the first of the megadiversity countries, accounting for roughly 14% of the world's biota. It has the largest mammal diversity (more than 530 described species) with many yet to be discovered and cataloged. Very few sites have been adequately surveyed, and local lists are usually incomplete, which makes for knowledge gaps that hamper conservation and management initiatives and regional analyses. According to the Brazilian Institute for the Environment (IBAMA), 66 species are threatened, and the World Conservation Union lists 74. Primates, mostly Atlantic Forest endemics, are the most endangered group (40% of the threatened taxa). Carnivores and rodents are also notable members of the lists. Twenty‐nine percent of listed species are marine, 18% occur in the Atlantic Forest, 13% in the Pampas, 12% in the Cerrado, 11% in the Pantanal, 7% in the Amazon, and 6% in the Caatinga. Human‐induced habitat loss and fragmentation are major threats to land mammals in Brazil, and large‐ and medium‐sized mammals are hunted. The major threat to small mammals is the scarcity of basic scientific knowledge—taxonomy, systematics, distribution, and natural history. Aquatic mammals are threatened by commercial hunting, accidental netting, long‐line fisheries, chemical pollution, habitat degradation, tourism, and boat traffic. Mammal conservation has benefited from a number of recent initiatives by government and nongovernmental organizations, including legislation, nationwide initiatives to define priority areas for conservation, management plans for some threatened species, sustainable landscape planning, and new protected areas. Given the rate of habitat loss, a nationwide program of short‐ and long‐term field surveys and increased support for natural history collections is of particularly urgency. Progress has been made toward conserving Brazilian mammals in recent years, but threats are growing fast, and conservation science must keep growing to provide the wherewithal to minimize and remove these threats.
Challenges and Opportunities for Biodiversity Conservation in the Brazilian Atlantic Forest
Authors: TABARELLI MARCELO , PINTO LUIZ PAULO , SILVA JOSÉ M. C. , HIROTA MÁRCIA , BEDÊ LÚCIO
Published: June 2005

Abstract:  With endangered status and more than 8,000 endemic species, the Atlantic Forest is one of the world's 25 biodiversity hotspots.
Less than 100,000 km2 (about 7%) of the forest remains. In some areas of endemism, all that is left are immense archipelagos of tiny and widely separated forest fragments. In addition to habitat loss, other threats contributing to forest degradation include the harvesting of firewood, illegal logging, hunting, plant collecting, and invasion by alien species—all despite the legislation that exists for the forest's protection. More than 530 plants and animals occurring in the forest are now officially threatened, some at the biome level, some throughout Brazil, and some globally. Many species have not been recorded in any protected areas, indicating the need to rationalize and expand the parks system. Although conservation initiatives have increased in number and scale during the last two decades, they are still insufficient to guarantee the conservation of Atlantic Forest biodiversity. To avoid further deforestation and massive species loss in the Brazilian Atlantic Forest, the challenge is to integrate the diverse regulations, public policies, new opportunities, and incentive mechanisms for forest protection and restoration and the various independent projects and programs carried out by governments and nongovernmental organizations into a single and comprehensive strategy for establishing networks of sustainable landscapes throughout the region.
Conservation Alliances with Indigenous Peoples of the Amazon
Authors: SCHWARTZMAN STEPHAN , ZIMMERMAN BARBARA
Published: June 2005

Abstract:  Ongoing alliances between indigenous peoples and conservation organizations in the Brazilian Amazon have helped achieve the official recognition of ∼1 million km2 of indigenous lands. The future of Amazonian indigenous reserves is of strategic importance for the fate of biodiversity in the region. We examined the legislation governing resource use on indigenous lands and summarize the history of the Kayapo people's consolidation of their >100,000 km2 territory. Like many Amazonian indigenous peoples, the Kayapo have halted the expansion of the agricultural frontier on their lands but allow selective logging and gold mining. Prospects for long‐term conservation and sustainability in these lands depend on indigenous peoples' understandings of their resource base and on available economic alternatives. Although forest conservation is not guaranteed by either tenure security or indigenous knowledge, indigenous societies' relatively egalitarian common‐property resource management regimes—along with adequate incentives and long‐term partnerships with conservation organizations—can achieve this result. Successful initiatives include Conservation International's long‐term project with the A'ukre Kayapo village and incipient large‐scale territorial monitoring and control in the Kayapo territory, and the Instituto SocioAmbiental (ISA) 15‐year partnership with the peoples of the Xingu Indigenous Park, with projects centered on territorial monitoring and control, education, community organization, and economic alternatives. The recent agreement on ecological restoration of the Xingu River headwaters between ranchers and private companies, indigenous peoples, and environmentalists, brokered by ISA, marks the emergence of an indigenous and conservation alliance of sufficient cohesiveness and legitimacy to negotiate effectively at a regional scale.
Deforestation in Brazilian Amazonia: History, Rates, and Consequences
Authors: FEARNSIDE PHILIP M.
Published: June 2005

Abstract:  Brazil's Amazon forest remained largely intact until the “modern” era of deforestation began with the inauguration of the Transamazon Highway in 1970. Amazonian deforestation rates have trended upward since 1991, with clearing proceeding at a variable but rapid pace. Although Amazonian forests are cut for various reasons, cattle ranching predominates. The large and medium‐sized ranches account for about 70% of clearing activity. Profit from beef cattle is only one of the income sources that make deforestation profitable. Forest degradation results from logging, ground fires (facilitated by logging), and the effects of fragmentation and edge formation. Degradation contributes to forest loss. The impacts of deforestation include loss of biodiversity, reduced water cycling (and rainfall), and contributions to global warming. Strategies to slow deforestation include repression through licensing procedures, monitoring, and fines. The severity of penalties for deforestation needs to be sufficient to deter illegal clearing but not so great as to be unenforceable. Policy reform is also needed to address root causes of deforestation, including the role of clearing in establishing land claims.
Lessons from Fragmentation Research: Improving Management and Policy Guidelines for Biodiversity Conservation
Authors: TABARELLI MARCELLO , GASCON CLAUDE
Published: June 2005

Abstract:  Ideally, science should inform policy development in all areas of human endeavor. Nowhere is this truer than in the case of human land use and our impact on the natural environment. Unfortunately, little recent science has percolated into policy guidelines for tropical forest management in areas facing serious threats. To help science inform policy we present six guidelines, which have been empirically proven important, for the management of fragmented landscapes: (1) incorporate protection measures as part of development projects; (2) protect large areas and prevent the fragmentation of currently contiguous large patches of forest; (3) manage forest edges when creating forest patches; (4) protect gallery forests along waterways to connect isolated forest patches; (5) control the use of fire and the introduction of exotic plant species and limit the use of toxic chemicals in areas near forest patches; and (6) promote reforestation and forest cover in critical areas of landscapes. Straightforward linkages between science and policy formulation can result in simple, yet powerful, changes in land‐use patterns and have a concurrent positive effect on biodiversity and natural resources.
Conservation of the Biodiversity of Brazil's Inland Waters
Authors: AGOSTINHO ANGELO A. , THOMAZ SIDINEI M. , GOMES LUIZ C.
Published: June 2005

Abstract:  In terms of biodiversity, Brazilian inland waters are of enormous global significance for Algae (25% of the world's species), Porifera (Demospongiae, 33%), Rotifera (25%), Cladocera (Branchiopoda, 20%), and fishes (21%). Threatened freshwater species include 44 species of invertebrates (mostly Porifera) and 134 fishes (mostly Cyprinodontiformes, Rivulidae), primarily distributed in south and southeastern Brazil. Reasons for the declines in biodiversity in Brazilian inland waters include pollution and eutrophication, siltation, impoundments and flood control, fisheries, and species introductions. These problems are more conspicuous in the more‐developed regions. The majority of protected areas in Brazil have been created for terrestrial fauna and flora, but they also protect significant water bodies and wetlands. As a result, although very poorly documented, these areas are of great importance for aquatic species. A major and pressing challenge is the assessment of the freshwater biodiversity in protected areas and surveys to better understand the diversity and geography of freshwater species in Brazil. The concept of umbrella species (e.g., certain migratory fishes) would be beneficial for the protection of aquatic biodiversity and habitats. The conservation and improved management of river corridors and associated floodplains and the maintenance of their hydrological integrity is fundamental to preserving Brazil's freshwater biodiversity and the health of its aquatic resources.
Conservation of the Brazilian Cerrado
Authors: KLINK CARLOS A. , MACHADO RICARDO B.
Published: June 2005

Abstract:  The Cerrado is one of the world's biodiversity hotspots. In the last 35 years, more than 50% of its approximately 2 million km2 has been transformed into pasture and agricultural lands planted in cash crops. The Cerrado has the richest flora among the world's savannas (>7000 species) and high levels of endemism. Species richness of birds, fishes, reptiles, amphibians, and insects is equally high, whereas mammal diversity is relatively low. Deforestation rates have been higher in the Cerrado than in the Amazon rainforest, and conservation efforts have been modest: only 2.2% of its area is under legal protection. Numerous animal and plant species are threatened with extinction, and an estimated 20% of threatened and endemic species do not occur in protected areas. Soil erosion, the degradation of the diverse Cerrado vegetation formations, and the spread of exotic grasses are widespread and major threats. The use of fire for clearing land and to encourage new growth for pasture has also caused damage, even though the Cerrado is a fire‐adapted ecosystem. Ecosystem experiments and modeling show that change in land cover is altering the hydrology and affecting carbon stocks and fluxes. Cerrado agriculture is lucrative, and agricultural expansion is expected to continue, requiring improvements in and extension of the transportation infrastructure, which will affect not only the Cerrado but also the Amazon forest. Large‐scale landscape modification and threats to numerous species have led to renewed interest from various sectors in promoting the conservation of the Cerrado, particularly through strengthening and enlarging the system of protected areas and improving farming practices and thus the livelihoods of local communities.
Allocation of Patients to Conditions in Headache Clinical Trials: Randomization, Stratification, and Treatment Matching
Authors: Lipchik Gay L. , Nicholson Robert A. , Penzien Donald B.
Published: June 2005

Assuming control over the allocation of patients to treatment conditions is a fundamental element of any comparative clinical trial. There are three critical considerations investigators must balance in choosing an allocation scheme: reducing bias in patient allocation, producing balanced patient groups across treatment arms, and reducing the likelihood of errors attributable to chance variation. The authors review the principles of three key approaches to the allocation of patients to conditions within clinical trials, and their respective advantages with regard to these critical considerations. These allocation methods include randomization, stratification, and patient‐treatment matching. Randomization is fundamental to most clinical trials. Stratification is an advanced step in a systematic program of research investigating the efficacy and effectiveness of an intervention. If the trial has less than 100 per arm and there is a known prognostic factor, stratification is the best choice to ensure equal allocation across groups. Treatment matching (tailoring) attempts to match the most appropriate treatment to a specific patient based on a priori hypotheses. Two techniques used for exploring treatment matching are: patient typologies (patient profiling), and aptitude‐treatment interactions. Additional details pertaining to the rationale for selecting among these various approaches to patient allocation is provided, and their methodology is summarized with specific consideration for their application within clinical trials of headache treatment.
Outcome Measurement in Behavioral Headache Research: Headache Parameters and Psychosocial Outcomes
Authors: Andrasik Frank , Lipchik Gay L. , McCrory Douglas C. , Wittrock David A.
Published: June 2005

The experience of pain is complex and includes multiple dimensions or aspects, such as sensory and affective (among others). Headache includes not only pain, but also associated symptoms that can further diversify the relevant dimensions. Subjective ratings of head pain, sampled daily, have come to be regarded as the “gold standard” in behavioral headache research. Primary measures of headache include the attack frequency or headache days per month. Secondary measures of headache may include headache activity/index, headache duration, peak headache severity, and/or frequency of severe headaches per month. Secondary measures of disability and quality of life include Migraine Disability Assessment (MIDAS), Headache Impact Test (HIT), Headache Disability Inventory (HDI). Secondary nonheadache measures include medication consumption, psychiatric symptoms, stress and coping, treatment satisfaction and preference, side effects, and others. Researchers should include not only primary measures of headache, but also secondary measures, disability and quality of life, and nonheadache measures. All measures should be clearly defined and reported. A baseline period that is adequate for each measure needs inclusion and a minimum of 4 weeks is recommended for primary headache measures. Specific suggestions for future research directions are provided.
Future Directions in Behavioral Headache Research: Applications for an Evolving Health Care Environment
Authors: Penzien Donald B. , Rains Jeanetta C. , Lipchik Gay L. , Nicholson Robert A. , Lake Alvin E. , Hursey Karl G.
Published: June 2005

Three decades of research has produced effective behavioral treatments for migraine and tension‐type headache, yet the full fruition of this research has not been realized. Further development and dissemination of behavioral treatments is needed to impact the large numbers of those with headache who potentially could benefit from these interventions. At the same time, an evolving health care environment challenges researchers and providers to employ greater efficiency and innovation in managing all chronic disorders. Hopefully, the recently published clinical trials guidelines for behavioral headache research will serve as a catalyst for production of quality empiricism that, in turn, will generate enhanced behavioral strategies and will optimize health care resource utilization. This article describes 10 areas of critical needs and research priorities for behavioral headache research, including: replication and extension of seminal studies using improved methodology; analysis of barriers to implementation of behavioral treatments; development of referral and treatment algorithms; behavioral compliance facilitation with medical interventions; development of a headache self‐management model; integration of behavioral intervention within traditional medical practice; identification and management of comorbid psychopathology among headache patients; prevention of disease progression; analysis of behavioral therapeutic mechanisms, and development of innovative treatment formats and applications of information technologies.
Treating Early Versus Treating Mild: Timing of Migraine Prescription Medications Among Patients With Diagnosed Migraine
Authors: Foley Kathleen A. , Cady Roger , Martin Vincent , Adelman James , Diamond Merle , Bell Christopher F. , Dayno Jeffrey M. , Hu X. Henry
Published: June 2005

Introduction.—Although research suggests that early treatment of migraine headache when the pain is mild results in better outcomes for patients, many patients delay taking their acute‐migraine medication until their headaches are moderate or severe. Understanding when and why patients use their migraine medications is an important first step to improve migraine management.

Methods.—A prospective observational study, conducted at a major national retail pharmacy chain with stores across the United States between April 2001 and November 2002, enrolled men and women between 18 and 55 years of age with a physician diagnosis of migraine with or without aura. Baseline data on 690 patients included patient demographics, migraine history, medication use, tendency to avoid or delay treatment of a migraine attack, and reasons for delaying treatment. Reasons for delaying treatment were assessed via a checklist of nine potential reasons. In the follow‐up survey completed after treatment of the next migraine attack, patients reported the timing of medication use in relation to pain onset and the severity of the migraine headache at the time they took the medication.

Results.—Despite the severity of their typical migraine attacks, approximately 49% of the respondents answered, “yes” to the question, “Do you often avoid or delay taking your migraine medications when you start to experience a migraine attack?” The two most common rationales for avoiding or delaying treatment were “wanting to wait and see if it is really a migraine attack” (69%) followed by “only want to take medications if it is a severe attack” (46%). In the follow‐up survey, regardless of medication used, about 85% of patients did not treat their next migraine attack until the headache pain was moderate or severe, although 74% treated within 1 hour of pain onset.

Conclusion.—These results suggest that patients with migraine often delay their treatment until they have identified their attack as a migraine. In addition, while many patients treated their follow‐up headache early, they did not treat when the pain was mild. This suggests that there is an opportunity for physicians to educate their migraine patients on how to differentiate migraine from other headache types and about when and how to use their acute‐migraine medication.
Cortical Inhibition Is Reduced in Chronic and Episodic Migraine and Demonstrates a Spectrum of Illness
Authors: Aurora Sheena K. , Barrodale Patricia , Chronicle Edward P. , Mulleners Wim M.
Published: June 2005

Background.—The pathophysiological relationship between episodic migraine and chronic migraine is not fully understood. We aimed to examine transcranial magnetic stimulation (TMS) indices of cortical excitability in patients with episodic migraine (EM) and probable chronic migraine (PCM), and matched controls.

Methods.—Cortical excitability was assessed at baseline with two well‐established methods: phosphene thresholds (PT) and magnetic suppression of perceptual accuracy (MSPA) profiles. Five EM patients, five PCM patients, and five normal controls participated in the main study. In addition, two patients were reassessed after 30 days of treatment with topiramate.

Results.—Both PT and MPSA measures were consistent in indicating a continuum of excitability across the three groups: PCM patients had the highest excitability, followed by EM, then controls. In the two treated patients MPSA profiles appeared to normalize at a 100 mg dosage.

Conclusions.—Patients with PCM appear to be characterized by very high cortical excitability. This may contribute to their greatly increased attack frequency. TMS‐based methods will be important for future research examining the evolution of chronic migraine from episodic migraine over time.
Patients' Management of Migraine and Chronic Daily Headache: A Study of the Members of the Migraine Action Association (United Kingdom)
Authors: Peters Michele , Abu‐Saad Huda Huijer , Robbins Ian , Vydelingum Vasso , Dowson Andrew , Murphy Margaret
Published: June 2005

Background.—Many strategies are available to treat and prevent migraine and chronic daily headache (CDH). Broadly these strategies can be divided into four groups, including (i) health care consultations, (ii) medication and alternative remedies, (iii) general (acute and prophylactic) strategies, and (iv) social support.

Objective.—This study aimed to compare headache management between migraine (MO), migraine with aura (MA), and those with CDH over the last 12 months.

Design.—A postal questionnaire was sent to 887 members of the Migraine Action Association (MAA). The response rate was 60.5% (n = 537), and 438 questionnaires were included in the analysis. Migraine (n = 117) and MA (n = 239) patients were classed according to the International Headache Society (IHS). CDH (n = 82) was diagnosed when respondents had 15 or more headache days per month. Descriptive tests, analysis of variances (ANOVAs), χ2, and Kruskal‐Wallis tests were used for statistical analysis (P < .05).

Results.—The three groups did not differ in age, gender, ethnicity, level of education, and employment status. Significant differences in management strategies between the groups were found in the number of respondents who had consulted headache specialists (P= .002) and neurologists (P= .004), the number and types of acute medications (eg, triptans, P= .002), the use of antidepressants (P= .004), and some acute and prophylactic avoidance techniques. Although, no significant differences between the groups were found in the use of other health professionals (eg, GP), alternative health professionals, general acute management, and the use of social support, they all actively used these strategies.

Conclusions.—The respondents of this study were active users of management strategies that are based on a combination of health care consultations, medication and alternative remedies, general management, and social support. In comparison to previous findings, the respondents in this study frequently reported higher use of management strategies (such as the use of triptans), which may be related to this group of patients being better informed about headache management than those with headache within the general population. Thus, the findings may not be representative for the general population, but they give an indication of the influence and importance of headache‐related education carried out by patient organizations such as the MAA.
The Classification of Chronic Daily Headache in Adolescents—A Comparison Between the Second Edition of the International Classification of Headache Disorders and Alternative Diagnostic Criteria
Authors: Bigal Marcelo E. , Rapoport Alan M. , Tepper Stewart J. , Sheftell Fred D. , Lipton Richard B.
Published: June 2005

Objectives.—To compare the second edition of the International Classification of Headache Disorders (ICHD‐2) and the Silberstein‐Lipton (S‐L) criteria in the classification of adolescents with chronic daily headache (CDH).

Methods.—We reviewed the clinical records and the headache diaries of 170 adolescents (13 to 17 years) seen between 1998 and 2003 at a headache center. Relevant information was transferred to a standardized form that included operational criteria for the ICHD‐2. CDH subtypes were classified according the criteria proposed by S‐L into transformed migraine (TM) with (TM+) and without medication overuse (TM−), chronic tension‐type headache (CTTH), new daily persistent headache (NDPH), and hemicrania continua (HC).

Results.—From the 69 patients with TM− according the S‐L criteria, most (71%) could be classified as chronic migraine (CM), while a minority of patients required a combination of diagnosis, mainly migraine and CTTH (14.4%). Of the patients with TM+, just 39.6% met the criteria for probable CM (PCM) with probable medication overuse (PMO). If instead of 15 migraine days per month, we considered 15 or more days of migraine or probable migraine, 84% of the subjects with TM− and 68.7% of those with TM+ could be classified. Of the 27 subjects classified as NDPH without medication overuse according to the S‐L system, the majority (51.2%) were also classified as NDPH according the ICHD‐2. Interestingly, three (11.1% of the subjects with NDPH without medication overuse) were classified as CM in the ICHD‐2 because these patients had an abrupt onset of 15 or more days of migraine per month. All patients with NDPH with medication overuse according to the S‐L criteria required a combination of diagnoses in the ICHD‐2. All subjects with CTTH received a single diagnosis in both classification systems.

Conclusions.—(i) Among adolescents with TM, the majority (58.1%) could be classified as CM, according to the ICHD‐2. These results were driven by TM without medication overuse. (ii) If the ICHD‐2 criteria for CM are revised to require 15 days of migraine or probable migraine, the proportion of patients with TM− who meet the criteria for CM increases from 71% to 84%; for TM+, the proportion with probable chronic migraine and PMO increases from 30% to 68%. (iii) About half of the patients with NDPH according to the S‐L criteria have too many migraine features to meet ICHD‐2 criteria for NDPH.
Atypical Headache After Prolonged Treatment With Nasal Continuous Positive Airway Pressure
Authors: Bernstein Allan L. , Cassidy John , Duchynski Robert , Eisenberg Stephen S.
Published: June 2005

We report a case of atraumatic pneumocephalus associated with prolonged use of nasal continuous positive airway pressure. Initial symptoms included headache, ataxia, vertigo, and a “gurgling” sensation in the head; and a CT image showed small air bubbles along the falx of cerebrum and adjacent to the temporal epidural spaces bilaterally. Although no evidence of cerebrospinal fluid (CSF) leak was either reported by the patient or found at initial clinical examination, subsequent nasal discharge tested positive for β2‐transferrin, a finding consistent with CSF leak in the paranasal sinus region or through the cribriform plate. To try to prevent infection from an open communication between the paranasal sinuses and intracranial structures, an attempt should be made to localize the anatomic defect.
Gaze Deviation from Contralateral Pseudoperiodic Lateralized Epileptiform Discharges (PLEDs)
Authors: Kaplan Peter W.
Published: June 2005

Summary:  Pseudoperiodic lateralized epileptiform discharges (PLEDs) usually produce “negative” neurologic findings. This contrasts with seizures which typically induce cortical activation with “positive” clinical manifestations. Gaze preference may arise from ipsilateral frontal eye fields (FEFs) damage because of the unopposed action of an intact contralateral FEF. Epileptic nystagmus (EN) and gaze deviation (GD) can also occur with focal temporo‐parieto‐occipital or hemispheric seizures in awake or obtunded patients.

A patient with old right frontal and parieto‐temporal cerebral infarctions manifested leftward gaze preference and deviation (without nystagmus) while alert and talking. Digitized EEG demonstrated PLEDs at ∼1 Hz over the right fronto‐central region, without electrographic seizures.

This report illustrates that PLEDs without seizures may excite frontal regions proximate to the FEFs to produce contraversive gaze preference in an awake patient, and discusses putative mechanisms. Gaze deviation, in this case, was the principal clinical feature of PLEDs.
Short‐term Effects of Kainic Acid on CA1 Hippocampal Interneurons Differentially Vulnerable to Excitotoxicity
Authors: Sanon Nathalie , Carmant Lionel , Emond Martine , Congar Patrice , Lacaille Jean‐Claude
Published: June 2005

Summary:  Purpose: We sought to identify the inhibitory interneurons of the rat hippocampal CA1 region selectively vulnerable in the kainic acid (KA) model of temporal lobe epilepsy and to determine whether their selective vulnerability could be due to differential short‐term KA effects.

Methods: We quantified vulnerable interneurons in stratum oriens‐alveus (O/A) by using immunohistochemistry for glutamic acid decarboxylase (GAD), parvalbumin (PV), and somatostatin (SS) after KA injections in rats, and then compared in normal slices the effects of KA on interneurons either in O/A (vulnerable to KA) or in strata radiatum and lacunosum‐moleculare (R/LM) (resistant to KA) by using whole‐cell recording and calcium imaging.

Results: GAD‐, PV‐ and SS‐positive cells in O/A were decreased after KA treatment in P20 and P30 rats. Both short (1‐min) and long (10‐min) applications of KA produced similar tetrodotoxin (TTX)‐insensitive membrane depolarization and decrease in input resistance in O/A and R/LM interneurons. KA responses were antagonized by CNQX and GYKI52466, suggesting AMPA receptor activation. KA also generated a similar increase in intracellular Ca2+ in O/A and R/LM interneurons, which was antagonized by CNQX and GYKI52466.

Conclusions: The selective vulnerability of GAD‐, PV‐, and SS‐immunopositive O/A interneurons in the KA model may not arise from cell‐specific short‐term membrane effects or calcium responses induced by KA, but from other glutamate receptor‐mediated excitotoxic processes.
Periventricular White Matter Flumazenil Binding and Postoperative Outcome in Hippocampal Sclerosis
Authors: Hammers Alexander , Koepp Matthias J. , Brooks David J. , Duncan John S.
Published: June 2005

Summary:  Purpose: In patients with hippocampal sclerosis (HS), anterior temporal lobe resection offers the possibility of a long‐lasting suppression of seizures in two thirds of patients. White matter (WM) [11C]flumazenil volume of distribution (FMZ‐Vd) reflects the number of neuronal cell bodies in WM. Our objective was to correlate WM FMZ‐Vd in patients with unilateral HS and postsurgical outcome.

Methods: We performed [11C]FMZ‐PET in 15 patients with refractory mesial temporal lobe epilepsy (mTLE) and a quantitative MRI diagnosis of unilateral HS subsequently histologically verified in all cases. Median follow‐up was 7 years (range, 6–9 years). Metabolite‐corrected arterial plasma input functions and spectral analysis were used to generate parametric images of [11C]FMZ‐Vd. Statistical parametric mapping (SPM99) with explicit masking was used to investigate the entire brain volume including WM.

Results: Eight patients had Engel class IA outcome (completely seizure free since surgery), and seven were not seizure free. Comparison of seizure‐free patients with those who continued to have seizures after surgery revealed areas of increased FMZ binding around the posterior horns of the ipsilateral (z = 3.7) and contralateral (z = 2.7) ventricles in those with suboptimal outcomes.

Conclusions: Preoperative [11C]FMZ‐PET can detect periventricular increases of WM FMZ binding, implying heterotopic neurons in WM, in patients with mTLE. The presence of such increases correlates with a poorer outcome.
Computerized Motion Analysis of Videotaped Neonatal Seizures of Epileptic Origin
Authors: Karayiannis Nicolaos B. , Tao Guozhi , Xiong Yaohua , Sami Abdul , Varughese Bindu , Frost James D. , Wise Merrill S. , Mizrahi Eli M.
Published: June 2005

Summary: Purpose:The main objective of this research is the development of automated video processing and analysis procedures aimed at the recognition and characterization of the types of neonatal seizures. The long‐term goal of this research is the integration of these computational procedures into the development of a stand‐alone automated system that could be used as a supplement in the neonatal intensive care unit (NICU) to provide 24‐h per day noninvasive monitoring of infants at risk for seizures.

Methods:We developed and evaluated a variety of computational tools and procedures that may be used to carry out the three essential tasks involved in the development of a seizure recognition and characterization system: the extraction of quantitative motion information from video recordings of neonatal seizures in the form of motion‐strength and motor‐activity signals, the selection of quantitative features that convey some unique behavioral characteristics of neonatal seizures, and the training of artificial neural networks to distinguish neonatal seizures from random infant behaviors and to differentiate between myoclonic and focal clonic seizures.

Results:The methods were tested on a set of 240 video recordings of 43 patients exhibiting myoclonic seizures (80 cases), focal clonic seizures (80 cases), and random infant movements (80 cases). The outcome of the experiments verified that optical‐ flow methods are promising computational tools for quantifying neonatal seizures from video recordings in the form of motion‐strength signals. The experimental results also verified that the robust motion trackers developed in this study outperformed considerably the motion trackers based on predictive block matching in terms of both reliability and accuracy. The quantitative features selected from motion‐strength and motor‐activity signals constitute a satisfactory representation of neonatal seizures and random infant movements and seem to be complementary. Such features lead to trained neural networks that exhibit performance levels exceeding the initial goals of this study, the sensitivity goal being ≥80% and the specificity goal being ≥90%.

Conclusions:The outcome of this experimental study provides strong evidence that it is feasible to develop an automated system for the recognition and characterization of the types of neonatal seizures based on video recordings. This will be accomplished by enhancing the accuracy and improving the reliability of the computational tools and methods developed during the course of the study outlined here.
In Vivo Modulatory Action of Extracellular Glutamate on the Anticonvulsant Effects of Hippocampal Dopamine and Serotonin
Authors: Clinckers Ralph , Gheuens Sarah , Smolders Ilse , Meurs Alfred , Ebinger Guy , Michotte Yvette
Published: June 2005

Summary:  Purpose: Our recent work (Clinckers et al., J Neurochem 2004;89:834–43) demonstrated that intrahippocampal perfusion of 2 nM dopamine or serotonin via a microdialysis probe offered complete protection against focal pilocarpine‐induced limbic seizures and did not influence basal extracellular hippocampal glutamate levels. Ten nanomolar dopamine or serotonin perfusion, however, worsened seizures and was accompanied by significant extracellular glutamate increases to ∼200%. The significance of these glutamate elevations in seizure generation remains unclear. The present microdialysis study investigated the modulatory role of extracellular hippocampal glutamate levels in these monoaminergic protective and proconvulsant effects.

Methods: A first group of male Wistar albino rats was perfused intrahippocampally for 240 min with 6.25 μM glutamate alone to increase extracellular levels by 200%. Other animals were perfused with anticonvulsant concentrations of monoamines throughout the experiments while receiving continuous coperfusions of 6.25 μM glutamate either before, during, and after (240 min) or only after (100 min) pilocarpine perfusion (40 min). Rats were scored for epileptic behavior, and the mean scores were compared with those of the control group. Microdialysates were analyzed for monoamine and glutamate content with microbore liquid chromatography.

Results: No convulsions occurred during glutamate perfusion alone. When monoamines and glutamate were coperfused before pilocarpine administration, the anticonvulsant effect of the monoamines was lost. Glutamate addition after pilocarpine administration did not affect monoaminergic seizure protection.

Conclusions: These results indicate that extracellular glutamate increases per se do not necessarily induce seizures but that they can modulate the anticonvulsant effects exerted by hippocampal monoamines.