bluuebunny/crossref_metadata_2025 huggingface dataset:
Research frontiers in null model analysis
Authors: Gotelli Nicholas J.
Published: March 2003

Null models are pattern‐generating models that deliberately exclude a mechanism of interest, and allow for randomization tests of ecological and biogeographic data. Although they have had a controversial history, null models are widely used as statistical tools by ecologists and biogeographers. Three active research fronts in null model analysis include biodiversity measures, species co‐occurrence patterns, and macroecology. In the analysis of biodiversity, ecologists have used random sampling procedures such as rarefaction to adjust for differences in abundance and sampling effort. In the analysis of species co‐occurrence and assembly rules, null models have been used to detect the signature of species interactions. However, controversy persists over the details of computer algorithms used for randomizing presence–absence matrices. Finally, in the newly emerging discipline of macroecology, null models can be used to identify constraining boundaries in bivariate scatterplots of variables such as body size, range size, and population density. Null models provide specificity and flexibility in data analysis that is often not possible with conventional statistical tests.
Kelp rafts in the Southern Ocean
Authors: Smith Stephen D. A.
Published: March 2003

Kelp rafts were surveyed during three summer traverses between Hobart and Macquarie Island (subAntarctic) to determine the potential for dispersal of kelp‐associated macroinvertebrates across the latitudes of 46–53°S. Rafts of Durvillaea antarctica dominated the sightings (94% of rafts) and extrapolations to the full Southern Ocean between these latitudes indicate a figure of over 70 million rafts afloat at any one time, 20 million of which support a holdfast, the habitat supporting the highest faunal diversity in attached kelp plants. In contrast, few, small rafts of Macrocystis pyrifera were observed. The potential for dispersal of fauna is presumed to be related to the species of kelp with which they are associated. Empirical studies of survival of animals while drifting at sea, and also on making land‐fall, are required to allow fuller interpretation of the significance of these findings.
Effects of drought on contrasting insect and plant species in the UK in the mid‐1990s
Authors: Morecroft M. D. , Bealey C. E. , Howells O. , Rennie S. , Woiwod I. P.
Published: March 2003

AbstractAimWe examined the effects of drought in the summer of 1995 and the subsequent year on contrasting species of plants, moths, butterflies and ground beetles. We tested whether population increases were associated with: (a) species of warm environments (b) species of dry environments (c) species with rapid reproduction (d) species with high rates of dispersal.

LocationThe study was conducted at Environmental Change Network (ECN) sites throughout Great Britain and Northern Ireland.

MethodsClimate monitoring, recording of plant species in permanent plots, transect walking for butterflies, light trapping for moths and pitfall trapping for carabid beetles were used.

ResultsThere was an overall increase in the number of species recorded in permanent vegetation plots between 1994 and 1996, principally among the annual and biennial vascular plants, probably as a result of gap colonization in grasslands. Most butterfly and moth species increased between 1994 and 1995. Among the butterflies, a southern distribution and high mobility were associated with species tending to increase throughout the period 1994–96, whereas declining species tended to have a northern distribution. A similar number of carabid beetle species increased as decreased in the period 1994–96; decreasing species tended to be associated with lower temperatures and wetter soils.

Conclusions

Current climate change scenarios indicate that the incidence of droughts in the United Kingdom will increase. A series of dry, hot summers could lead to a rapid change in the population of some species although others, including many plants, may be more resilient. This may lead to complex changes in ecosystems and needs to be considered in planning conservation strategies.
Pastoral management vs. land abandonment in Mediterranean uplands: impact on land snail communities
Authors: Labaune Corinne , Magnin Frédéric
Published: March 2003

The aim of the study was to assess the impact of a pastoral management chosen to limit the recent expansion of woodland on a Mediterranean mountain on land snail diversity. An additional aim was to acquire quantitative data that could be used to identify pasture environments from Holocene molluscan assemblages. The work was undertaken at the Luberon mountain, Provence, south of France. We used a stratified quantitative sampling scheme according to altitude and vegetation structure. A total of 80 sites were studied. Large species were collected within a 5 × 5‐m plot. Small species were extracted from litter and surface soil. A standard procedure for site description was used based on 35 environmental variables. Grazing pressure was estimated according to the impact of grazing on the herb layer. Correspondence analysis and canonical correspondence analysis were performed using canoco 4.0 software. The distribution of land snails is related to altitude and grazing intensity. Large patches of grazed grassland harbour open country and mountain snail species. Thermophilic open ground species are located in grazed grasslands at lower altitude. Shade‐loving species are present in ungrazed scrublands or in small clearings on the upper slopes. The lowest species richness, diversity and equitability are associated with large patches of grazed grassland, the presence of a continuous cover of short grass reinforcing this negative impact on snail diversity. Our study is consistent with similar works on land snails or other invertebrates but discordant with vegetation studies. A homogeneous grazed herb layer significantly reduces snail diversity and abundance. Heterogeneity seems to favour snail diversity both at the local and landscape scales. However, sheep grazing contributes to the expansion of suitable habitats for rare snail species.
Do human activities raise species richness? Contrasting patterns in United States plants and fishes
Authors: McKinney Michael L.
Published: March 2003

In a given area, human activities usually cause the extinction of native species and the establishment of non‐native species. A key conservation issue is whether non‐native establishment tends to outpace native species extinction to produce a net gain in species richness. To determine this, empirical data must be accumulated at various scales. I show that, within the United States, the number of established non‐native plant species per state does tend to outpace the number of extinct and threatened species per state. The net gain in plant species is strongly and positively correlated with human population density. Continuation of this trend predicts substantial gains in net plant species richness for all states in the United States as human population grows. This contrasts with freshwater fishes, where most states show a net loss of species diversity as extinct and threatened species exceed established non‐native species. Changes in fish diversity do not correlate strongly with human population or non‐native species but are largely driven by the decline of native fish species.
Distribution of vascular plant species richness and endemic richness along the Himalayan elevation gradient in Nepal
Authors: Vetaas Ole R. , Grytnes John‐Arvid
Published: March 2003

Aim Species richness and endemic richness vary along elevation gradients, but not necessarily in the same way. This study tests if the maxima in gamma diversity for flowering plants and the endemic subset of these plants are coherent or not.

Location The study was conducted in Nepal, between 1000 and 5000 m a.s.l.

Methods We used published data on distribution and elevational ranges of the Nepalese flora to interpolate presence between maximum and minimum elevations. Correlation, regression and graphical analyses were used to evaluate the diversity pattern between 1000 and 5000 m a.s.l.

Results The interval of maximum species endemic to Nepal or the Himalayas (3800–4200 m) is above the interval of maximum richness (1500–2500 m). The exact location of maximum species density is uncertain and its accuracy depends on ecologically sound estimates of area in the elevation zones. There is no positive statistically significant correlation between log‐area and richness (total or endemic). Total richness is positively correlated with log‐area‐adjusted, i.e. estimated area adjusted for the degree of topographic heterogeneity. The proportion of endemic species increases steadily from low to high elevations. The peak in endemism (c. 4000 m) corresponds to the start of a rapid decrease in species richness above 4000 m. This may relate to the last glacial maximum (equilibrium line at c. 4000 m) that penetrated down to 2500–3000 m. This dynamic hard boundary may have caused an increase in the extinction rate above 4000 m, and enhanced the probability of isolation and facilitated speciation of neoendemics, especially among genera with a high proportion of polyploids.

Main conclusions The results reject the idea of corresponding maxima in endemic species and species richness in the lowlands tentatively deduced from Stevens’ elevational Rapoport effect. They confirm predictions based on hard boundary theory, but hard‐boundaries should be viewed as dynamic rather than static when broad‐scale biogeographical patterns with a historical component are being interpreted.
Glacial refugia of temperate, Mediterranean and Ibero‐North African flora in south‐eastern Spain: new evidence from cave pollen at two Neanderthal man sites
Authors: Carrión José S. , Yll Errikarta I. , Walker Michael J. , Legaz Alfonso J. , Chaín Celia , López Antonio
Published: March 2003

Aim To locate glacial refugia of thermophilous plant species in Spain.

Location Two south‐eastern Spanish Neanderthal man sites in Murcia; namely, the inland Cueva Negra del Estrecho del Río Quípar and the coastal Sima de las Palomas del Cabezo Gordo.

Methods We use pollen found in cave sediments as a source of palaeobotanical and palaeoecological information. The findings are discussed with regard both to animal remains from both sites, and also to other refugia in south‐eastern Spain and elsewhere in the Iberian Peninsula.

Results Both sequences show persistence of abundant mesothermophilous trees during the last glacial stage, suggesting both localities were reservoirs of phytodiversity and woodland species. At both sites, deciduous and evergreen oaks are the most abundant components, followed by a wide variety of deciduous trees and sclerophyllous shrubs, including Ibero‐North African xerothermic scrub near the coast.

Conclusions Incomplete information underlies a common misapprehension that Iberian glacial refugia were confined to southernmost parts of the peninsula. A rather different picture of Quaternary refugia emerges from consideration of pollen sequences from caves (and other inputs such as macroscopic charcoal, spatial genetic structure of present‐day populations, faunal remains, and present‐day distribution of thermophilous species). This picture offers a view of numerous viable areas for woodland species in southern Spain, in addition to others in the mountain ranges, both in continental central Spain and those of northern Spain: these stretch from the Mediterranean coast of Catalonia to the westernmost extent of the Bay of Biscay.
A candidate gene study of F cell levels in sibling pairs using a joint linkage and association analysis
Authors: Garner Chad , Tatu Thanusak , Game Laurence , Cardon Lon R. , Spector Tim D. , Farrall Martin , Thein Swee Lay
Published: March 2003

Introduction Fetal haemoglobin (Hb F) and fetal cell (FC) levels in adults show considerable variation and the heritability of FC levels has been estimated to be 89% in the healthy European population; measured genotype analyses have shown the trait to be influenced by several genetic factors. In addition to the β‐globin gene complex on chromosome 11p, linkage analyses have reported loci affecting FC levels on chromosomes Xp22.2–p22.3 and 6q23.

Methods We have genotyped a sample of approximately 300 unselected, same sex, dizygotic twin pairs from the St. Thomas’ UK Adult Twin Register for markers in these three regions and carried out a linkage analysis of FC levels. We also used a new method to simultaneously test for linkage and allelic association, and association caused by population stratification or admixture.

Results There was no evidence for linkage of FC levels to chromosomes Xp22.2–p22.3 and 6q23. However, the β‐globin cluster was shown to be significantly linked and to be responsible for approximately one‐third of the additive genetic variance in FC levels in the sample.

Conclusions The report represents the first application of this method to a sample of nonsimulated data and demonstrates the effectiveness of the approach. Combined linkage and association analysis of the β‐globin complex showed a strong association between the XmnI‐Gγ site and FC levels and that the observed association is not an artifact of recent population admixture or stratification.
The impact of subsidies upon fisheries management and sustainability: the case of the North Atlantic
Authors: Munro Gordon , Sumaila Ussif R
Published: March 2003

This paper provides both an estimate and assessment of subsidies in fisheries in the North Atlantic. The subsidies are estimated, on the basis of data taken from an OECD study and the Sea Around US Project database, to be in the order of US$ 2.0–2.5 billion per year. The assessment of the impact of the subsidies upon resource management and sustainability requires an examination of the underlying economics of subsidies in fisheries. There is general agreement, to which we subscribe, that fisheries subsidies do great harm by exacerbating the problems arising from the ‘common pool’ aspects of capture fisheries. Many economists, however, believe it that, if the ‘common pool’ aspects of a fishery could be removed by, for example, establishing a full‐fledged property rights system, the negative impact of fisheries subsidies would prove to be trivial.

This paper demonstrates that the aforementioned comfortable belief is unfounded. Fisheries subsidies can be seriously damaging, even if the ‘common pool’ aspects of the fishery are removed. There is also a widely held belief among economists and government officials that subsidies used for vessel decommissioning schemes, far from being harmful, actually have a beneficial impact upon resource management and sustainability, or are at worst, neutral. About 20% of the fisheries subsidies in the North Atlantic are directed towards these purposes. In this paper, we argue that these seemingly beneficial subsides can, in fact, be highly negative in their impact.
On biological species, species concepts and individuation in the natural world
Authors: Mayden Richard L
Published: March 2003

I am a realist and argue that biological species exist in nature. I also argue that the validity of findings of the many disciplines within the natural sciences employing biological species in their endeavours of inquiry are unequivocally linked to the accuracy of the species used in experiments. Few scientists today see the fundamental importance of taxonomic and systematic studies in both addressing accuracy of diversity and the delineation of species diversity for other areas of science. The basic controversial issues in the debate revolve around opinions regarding the nature of species as either Individuals or Classes, confusion of Species as a taxonomic category and as entities in nature, the varied practitioners studying diversity, a general lack of a Lineage perspective and a gross chauvinistic perspective on the types of data worthy of exposing and delineating diversity. I argue that species in nature are Individuals and form Lineages. As Individuals, they cannot be defined but can only be diagnosed in time. The category Species is a Class with a definition. The difficulties realised by scientists studying biodiversity in ‘defining’ a species hinges upon the fact that as natural entities they cannot be defined. Recognizing and understanding the origins of characters in species is further complicated if one views species in nature as Classes and lacks an appreciation for the Lineage and the origin and retention of traits through time. This forms an interesting paradox that many scientists have fallen victim to wherein species are viewed as Classes (hence definable, but immutable) yet are used to understand the process of descent that involves lineages and Individuals! The pre‐Darwinian Class perspective of species, combined with a common chauvinistic perspective on characters ultimately delays progress and places a ‘glass ceiling’ on species diversity for planet Earth. One resolution to the species and species concept issue is to view the concepts in a hierarchical manner of primary (theoretical) and secondary (operational) concepts. Interestingly, the issue of Individuals versus Classes for naturally occurring entities is much more widespread and exists in many other scientific fields. Thus, a hierarchical perspective of having a primary, nonoperational concept for natural entities and multiple operational concepts serving as ‘tools’ for discovering natural things consistent with the primary concept is a heuristic methodology that is applicable to the advancement of many areas of science.
Behaviour: an important diagnostic tool for Lake Malawi cichlids
Authors: Stauffer Jay R , McKaye Kenneth R , Konings Ad F
Published: March 2003

Historically, the cichlid fishes of Lake Malawi, which probably represent one of the best examples of rapid radiation of vertebrates, have been diagnosed with morphological and genetic data. Many of the populations once thought to be conspecific have been hypothesized to be separate species based on behavioural data. The use of behavioural data, as expressed in mate choice based on colour patterns or bower shapes, has been successfully used to diagnose both rock‐dwelling and sand‐dwelling cichlid species. Additionally, a combination of bower shapes and courtship patterns have been used as synapomorphies to diagnose genera within the Lake Malawi cichlid flock. It is concluded that taxonomists need to include behavioural data with morphological and genetic databases to diagnose species and to determine the phylogenetic relationships within this diverse assemblage of fishes.
Attention impairment in recently diagnosed multiple sclerosis
Authors: Dujardin K. , Donze A.C. , Hautecoeur P.
Published: March 2003

Patients with multiple sclerosis (MS) experience cognitive disorders which can occur early in the course of the disease. The present study tried to investigate attention abilities of MS patients at the early stage of the disease. Three attention modalities (sustained, simple and complex focused attention) were evaluated. The results show that MS patients at the early stage of the disease presented attentional dysfunction only when the cognitive load of the attention task was high and when controlled information processing was required. This suggests that MS patients probably suffer from a processing resources deficit without modification of the attentional mechanisms.
PET study of striatal fluorodopa uptake and dopamine D2 receptor binding in a patient with juvenile parkinsonism
Authors: Tanji H. , Nagasawa H. , Araki T. , Onodera J. , Takase S. , Itoh M. , Itoyama Y.
Published: March 2003

We studied pre‐synaptic and post‐synaptic function in the striatum of a patient with juvenile parkinsonism (JP) using positron emission tomography (PET). [18F]6‐fluorodopa (18FDOPA), 11C‐YM‐09151‐2 and [18F]fluoro‐2‐deoxy‐D‐glucose (18FDG) were used to measure fluorodopa uptake, dopamine D2 receptor binding and glucose metabolism, respectively. In this patient, 18FDOPA accumulation was decreased markedly in the caudate nucleus and the putamen bilaterally. In the images of 11C‐YM‐09151‐2 and 18FDG in contrast, no conspicuous changes were observed in the striatum. Thus our PET studies using 18FDOPA, 11C‐YM‐09151‐2 and 18FDG provide a useful approach for assisting the diagnosis of JP, because the present findings are different from the results in patients with dopa‐responsive dystonia and hereditary progressive dystonia with marked diurnal fluctuation. Furthermore, our findings are of particular interest in relation to the pathogenesis of JP.
Neuropeptides in headache
Authors: Edvinsson Lars , Goadsby Peter J.
Published: March 2003

The cerebral circulation is innervated by sympathetic, parasympathetic and sensory nerves which store a considerable number of neurotransmitters. The role of these have been evaluated in primary headaches. A clear association between head pain and the release of calcitonin gene‐related peptide (CGRP) was demonstrated. In cluster headache and in a case of chronic paroxysmal headache there was in addition release of vasoactive intestinal peptide (VIP) which was associated with the facial symptoms (nasal congestion, rhinorrhea). In parallel with sumatriptan treatment head pain subsided and neuropeptide release normalised. These data show the involvement of sensory and parasympathetic mechanisms in the pathophysiology of primary headaches.
Early clinical experience with subcutaneous naratriptan in the acute treatment of migraine: a dose‐ranging study
Authors: Dahlöf Carl , Hogenhuis Leon , Olesen Jes , Petit Henri , Ribbat Jacques , Schoenen Jean , Boswell Diane , Fuseau Eliane , Hassani Habib , Winter Paul
Published: March 2003

Naratriptan is a novel, potent agonist at the 5HT1B/1D receptor. A total of 335 migraine patients were treated in this randomized, double‐blind, placebo‐controlled, dose‐ranging, in‐clinic study, to evaluate the efficacy, safety and tolerability of five doses of subcutaneous (sc) naratriptan (0.5, 1, 2.5, 5 or 10 mg) in comparison with sc sumatriptan (6 mg) and placebo in the acute treatment of a moderate/severe migraine attack. Headache relief [reduction of headache severity from moderate or severe (grade 2/3) to mild or none (grade 1/0)] at 1 and 2 h after each dose, was reported by a statistically significantly higher proportion of patients for all doses of sc naratriptan and sc sumatriptan (6 mg) than for placebo. The percentages of patients with headache relief at 2 h post‐dose were: naratriptan (0.5 mg) 65%, (1 mg) 75%, (2.5 mg) 83%, (5 mg) 94% and (10 mg) 91%; sumatriptan (6 mg) 89%; placebo 41%, (P < 0.005). The earliest report of a statistically significant difference compared with placebo for the times assessed was with sc naratriptan (10 mg) at 10 min post‐dose (P= 0.023). The percentages of patients reporting adverse events were dose‐related; sc naratriptan (0.5 mg) 33%, (1 mg) 29%, (2.5 mg) 43%, (5 mg) 59% and (10 mg) 71%; sc sumatriptan 53%; placebo 22%. There were no clinically significant changes in electrocardiogram (ECG), vital signs or laboratory parameters. Systemic exposure increased proportionally to the dose, the absorption of sc naratriptan was rapid (tmax= 10 min) and the half‐life was 5 h. In conclusion, sc naratriptan was an effective and well‐tolerated acute treatment for migraine.
Variables linked to psychotic symptoms in Alzheimer's disease
Authors: Della Sala Sergio , Francescani Andrea , Muggia Silvia , Spinnler Hans
Published: March 2003

This study is aimed at assessing the prevalence and feature sof psychotic symptoms in a sample of 180 patients with Alzheimer's disease (AD). Sixty‐four patients (35.5% of the sample) showed one or more psychotic symptoms. The presence of these symptoms correlated with the severity of the patients' cognitive impairment, as well as the patients' age at first assessement. Sex, duration of illness, education and familiar history for dementia were not significantly correlated with the psychotic symptoms. Hallucination was the most common symptom (24.4% of the whole sample), followed by delusion (18.3%) and misperceptin (11.1%). Visual hallucinations were more frequent than auditory, and, among delusions, persecutory and theft thems were largely prevailing. Misperceptions included television related phenomena and phantom boarder illusions. A follow‐up study of 37 patients demonstreated the association between the presence of psychotic symptoms and a steeper slop of cognitive deterioration.
Ergotamine/caffeine treatment of orthostatic hypotension in parkinsonism with autonomic failure
Authors: Dewey Richard B. , Rao Surendra D. , Holmburg Stephanie L. , Victor Ronald G.
Published: March 2003

Eight patients with parkinsonism who developed severe orthostatic sypotension, were treated with oral ergotamine/caffeine. Significant long‐term improvement in standing systolic blood pressure and symptoms of syncope and light‐headedness were observed in four of these patients. One patient in whom the drug was effective discontinued it because of nausea. Another lost benefit after 2 weeks of sucessful therapy. Significant supine systolic hypertension occureed in only one patient, which was easily managed by nifedipine given at night. Symptoms or signs of ergotism were not observed. Oral ergotamine/caffeine should be considered as a cost‐effective teratment for refactory orthostatic hypotension in carefully selected patients with parkinsonism.
Post‐stroke depression and functional recovery in a population‐based stroke register. The Finnstroke study
Authors: Kotila Mervi , Numminen Heikki , Waltimo Olli , Kaste Markku
Published: March 2003

Post‐stroke depression and functional outcome were examined in a population‐based stroke register active in four different districts (total population, 134804) in Finland. Five hundred and ninety four first time strokes were registered. Beck's depression inventory (BDI), with ten as the cutoff point for depression, was applied to 321 of 423 survivors after three months and to 311 of 390 survivors after 12 months. Functional outcome was measured with the Barthel Index (BI) and the Rankin Scale (RS). One hundred and fifty one of 321 (47.0%) and 147 of 311 (47.3%) patients were depressed after three and 12 months, respectively. Depression at three months was associated with poor functional outcome at the one‐year follow‐up (P= 0.001 for the BI and the RS). On the other hand, poor functional outcome at three months was associated with depression after one year (P= 0.004 and 0.002 for the BI and the RS, respectively). Patients who were depressed at three months were more often in institutional care between three and 12 months later than non‐depressed patients (P= 0.005). Post‐stroke depression is associated with poor functional recovery of patients. If depression were diagnosed and treated early, it might help patients to recover more completely and/or faster, which could save community healthcare resources by avoiding or shortening the time of institutional care or reducing the need for home care.
Bulbar myoclonus without palatal myoclonus. A hypothesis on pathophysiology
Authors: Dietrichs Espen , Heier Mona Skard , Faye‐Lund Hilde , Nakstad Per H
Published: March 2003

A 40‐year‐old woman with myoclonic contractions bilaterally in the infrahvoid neck muscles, especially in the left cricothyroid muscle, was presented and successfully treated with botulinum toxin injections. The patient had a wide, aberrant vessel curving into the left dorsolateral reticular formction of the medulla oblongata. Based on our observations, we propose that symptomatic bulbar and palatal myoclonus is caused by pathology in the dorsolateral reticular formation, and not by inferior olivary dysfunction as is currently thought.
High levels of IL‐10 secreting cells are present in blood in cerebrovascular diseases
Authors: Pelidou Sigliti‐Henrietta , Kostulas Nikolaos , Matusevicius Darius , Kivisäkk Pia , Kostulas Vasilios , Link Hans
Published: March 2003

Ischemic stroke is associated with altered systemic immune responses both early after the onset and in the recovery phase. Interleukin (IL)‐10, a Th2 related cytokine, has multiple effects on different cell types, including T and B lymphocytes, monocytes, neutrophis and mast cells. IL‐4 is another Th2 cytokine that inhibits the synthesis of pro‐inflammatory cytokines by Th1 clones. We used enzyme‐linked immunospot assays to detect and enumerate blood mononuclear cells (MNC) secreting IL‐10 and IL‐4 spontaneously as well as after stimulation with myelin basic protein (MBP), considered to be an autoantigen of possible pathogenic importance in, for example, multiple sclerosis, to evaluate the involvement of anti‐inflammatory cytokines in ischemic stroke. All patients with ischemic stroke and cerebral hemorghage had strongly elevated numbers of IL‐10 secreting blood MNC compared with healthy individuals. Numbers of MBP‐reactive IL‐10 secreting blood MNC were also elevated in a proportion of the patients with stroke and hemorrhage. Levels of IL‐4 secreting blood MNC did not differ in ischemic stroke versus healthy individuals. The anti‐inflammatory IL‐10 could play a pivotal role in ischemic stroke as well as cerebral hemorrhage.
Familial Guillain—Barré Syndrome
Authors: Wilmshurst Jo M. , Pohl Keith R.E. , Vaughan Robert W. , Hughes Richard A.C.
Published: March 2003

There are few reports of Guillain–Barré Syndrome (GBS) occurring in families. We have encountered a mother, who developed acute inflammatory demyelinating polyradiculoneuropathy at age 35 years, whose son developed the bulbar form of GBS 7 years later. Both shared HLA DR2.
Features of dural sinus thrombosis simulating pseudotumor cerebri
Authors: Leker Ronen R. , Steiner Israel
Published: March 2003

To characterize dural sinus thrombosis (DST) patients presenting with a syndrome simulating pseudotumor cerebri (PTC), medical records of patients initially diagnosed as having PTC between 1980 and 1995 were analysed. Inclusion criteria were intracranial hypertension (IH) and a normal initial computed tomography (CT) scan. All patients underwent angiography or magnetic resonance imaging (MRI) and magnetic resonance venography (MRV). Patients with IH secondary to a determined disorder were excluded from the study. Forty‐six patients were included, 12 patients had MRI/MRV or angiography findings compatible with DST and the remaining 34 patients had no vascular pathology on neuroimaging studies and were considered to have PTC. No clinical or auxiliary findings differed between the two groups except for younger age, which delineated the PTC patients. Two patients with DST died during the study. Both were agitated, had a relatively rapid course of symptom progression, and a CSF pressure of over 40 cm water. We conclude that DST can be identified in 26% of patients presenting with symptoms and signs typical of PTC. It may be impossible to differentiate between patients with and without DST if MRI/MRV or angiography are not performed in this scenario.
Changes in short‐term memory processes in patients with multiple sclerosis
Authors: Janculjak Davor , Mubrin Zdenko , Brzovic Zdravko , Brinar Vesna , Barac Bosko , Palic Josip , Spilich George
Published: March 2003

In this study we compared the performance of 39 multiple sclerosis (MS) patients with 28 age‐, sex‐ and education‐matched controls on both the Mini‐Mental State Examination, a global cognitive assessment tool, and the Sternberg Short‐Term memory scanning task, a standardized test of short‐term memory (STM) processes. While the STM span of our MS patients did not differ from that of our controls, STM scanning time of the MS group was reliably slower than that of the controls and a significat correlation was observed between STM scanning time and duration but not severity of illness. Our results suggest that processing stages other than the manipulation of data within the STM buffer are also affected by MS.
Supression of cardiac parasympathetic functions in patients with right hemispheric stroke
Authors: Erciyas Ali Haydar , Topalkara Kamil , Topaktas Suat , Akyüz Aytekin , Dener Sefik
Published: March 2003

Objectives: The aim of this study was to investigate the relationship between sympathetic and cardiac parasympathetic function and the side of the lesion in stroke patients. Methods: Thirty‐two patients with stroke and 29 healthy age‐matched control subjects were studied. Sympathetic skin responses (SSR) and RR interval variations (RRIV) during rest and deep breathing were recorded for the assessment of sympathetic and vagal parasympathetic function, respectively. Results: The mean SSR amplitude values in patients compared with controls were 337 ± 244 versus 1897 ± 848 (P < 0.0001) for right hemispheric lesions and 466 ± 398 versus 1873 ± 843 (P < 0.0001) for left hemispheric lesions. The mean SSR latencies in patients compared with controls were 1526 ± 163 versus 1395 ± 109 (P < 0.05) for right hemispheric lesions and 1490 ± 125 versus 1423 ± 112 (P < 0.05) for left hemispheric lesions. RRIV (during deep breathing)/RRIV (at rest) ratios in patients compared with controls were 1.20 ± 0.25 versus 1.84 ± 0.52 (P < 0.0001), and 1.55 ± 0.88 versus 1.84 ± 0.52 (P < 0.05) for right and left hemispheric lesions, respectively. Conclusion: Supression of vagal parasympathetic activity was more apparent in stroke patients with right hemispheric lesions in our series. Therefore, the right hemisphere seems to have a greater effect upon parasympathetic activity.
The diversity of seizures related to alcohol use. A study of consecutive patients
Authors: Bråthen Geir , Brodtkorb Eylert , Helde Grethe , Sand Trond , Bovim Gunnar
Published: March 2003

The aim of the sudy was to investigate the influence of hazardous alcohol drinking on the occurrence of epileptic seizures, the semiology of such seizures, and the extent of the problem. A consecutive sample of 142 acute seizure patients (78 male and 64 female, mean age 46 (16–79) years) was studied. Control groups were 185 consecutive sciatica patients and 254 healthy individuals. Subjects with a hazardous alcohol drinking level were identified by a score>8 in the Alcohol Use Disorders Identification Test (AUDIT). Seizures in AUDIT‐positive individuals occurring withing 72 h of the last drink were considered to be related to alcohol withdrawal. Generalized or partial onset seizures were classified on the basis of history, electroencephalographic (EEG) and neuroradiological findings. Thirty‐five percent of seizure patients were AUDIT‐positive, whereas conversely 27% were abstainers. Two‐thirds of AUDIT‐positive seizure patients met the criteria for withdrawal seizures. Indications of partial onset seizures were found in 25 (51%) of AUDIT‐positive patients, all secondarily generalized seizures. Sixty percent of generalized onset sizure patients were AUDIT‐positive. In conclusion, seizure patients included significantly more AUDIT‐positive subjects, as well as abstainers, than healthy Norwegian controls and consecutive sciatica patients from our hospital. Partial onset seizures are more frequent among hazardous drinkers than hitherto recognized. A generalized onset seizure in adults warrants a high suspicion of alcohol as a provoking factor. Routine screening of acute seizure admission with the Alcohol Use Disorders Identification Test is recommended.
Neutralizing and binding anti‐interferon‐β (IFN‐β) antibodies. A comparison between IFN‐β‐1a and IFN‐β‐1b treatment in multiple sclerosis
Authors: Kivisäkk P. , Alm G. V. , Fredrikson S. , Link H.
Published: March 2003

Interferon‐β (IFN‐β) is currently the most commonly used treatment of relapsing–remitting multiple sclerosis (MS). At the time of this study, two preparations of IFN‐β were available, IFN‐β‐1a (Avonex™) and IFN‐β‐1b (Betaferon®), which both can elicit an immune response with the development of anti‐IFN‐β antibodies. Direct comparisons between these two preparations regarding antibody frequencies have, however, been difficult to perform, because two different analysis methods measuring partly different biological effects of IFN‐β have been employed. In the present study, binding and neutralizing anti‐IFN‐β‐1a and ‐1b antibodies were detected in parallel by an independent, well‐acknowledged, interferon research laboratory using an immunoassay and a cytopathic virus inhibition assay. Five per cent of patients treated with IFN‐β‐1a intramuscularly
(n = 20) had neutralizing antibodies (NABs) compared with 44% of patients treated with IFN‐β‐1b subcutaneously
(n = 48). A high degree of cross‐reactivity between neutralizing anti‐IFN‐β‐1a and ‐1b antibodies was observed. No effect of NABs on clinical outcome could be detected in this limited material. Binding anti‐IFN‐β antibodies were observed in 20% of IFN‐β‐1a treated patients compared with 81% of patients treated with IFN‐β‐1b. Only one of 17 patients examined (6%) had detectable titres of binding anti‐IFN‐β‐1b antibodies in the cerebrospinal fluid (CSF) . These data are the first using identical methodology to show that IFN‐β‐1a gives rise to fewer NABs than IFN‐β‐1b at recommended treatment schedules.
Interictal hippocampal benzodiazepine receptors in temporal lobe epilepsy: comparison with coregistered hippocampal metabolism and volumetry
Authors: Szelies B. , Weber‐Luxenburger G. , Mielke R. , Pawlik G. , Kessler J. , Pietrzyk U. , Bauer B. , Heiss W.‐D.
Published: March 2003

The significance of benzodiazepine receptor (BZR) concentration in comparison with hippocampal metabolism and volumetry was assessed in 14 patients diagnosed with temporal lobe epilepsy (TLE) without hippocampal signal change on T2‐weighted magnetic resonance imaging (MRI) scans. Focus lateralization was achieved by clinical, electroencephalographic and neuropsychological examinations. Three‐dimensional positron emission tomography (PET) and MRI scans were coregistered for determination of hippocampal 11C‐flumazenil (FMZ) binding, normalized to average cortical values for
glucose metabolism (rCMRglc) and volume. The hippocampi were individually outlined on T1‐weighted MRI. Volumes of interest (VOI) were used for calculation of asymmetries between clinically affected and unaffected sides. Eleven out of 14 TLE patients presented a significant reduction in hippocampal volume. In nine of these 11 patients hippocampal FMZ binding and in seven cases hippocampal CMRglc was also reduced. In two patients without hippocampal volume asymmetry FMZ binding was markedly reduced in the mesial temporal lobe appropriately to the clinically diagnosed side. In our study volumetry is therefore the most sensitive tool for the detection of hippocampal abnormality in TLE. However, in cases without hippocampal atrophy the reduction of FMZ may indicate functional impairment of BZR before neuronal loss becomes evident. Our results emphasize the complementary nature of these tests in TLE patients.
Statistical maps of cerebral blood flow deficits in Alzheimer’s disease
Authors: Johannsen P. , Jakobsen J. , Gjedde A.
Published: March 2003

Images of cerebral blood flow or metabolism are useful as adjunct to the differential diagnosis of cortical dementia. The aim of this study was to create statistical objective voxel maps of significant differences in regional cerebral blood flow between patients with Alzheimer’s disease and age‐matched healthy volunteers. Maps of significantly reduced cerebral blood flow were created based on a spatially normalized distribution of cerebral blood flow, measured with O‐15‐water and positron emission tomography in 16 Alzheimer’s patients, compared to 16 healthy age‐matched volunteers. After spatial normalization of voxel counts, the t‐statistic of the cerebral blood flow deficit was determined from the local voxel‐SDs. In the patients, significant reduction (P < 0.05) of the flow distribution was present in regions near the hippocampus, extending rostrally to the temporo–parietal region in both hemispheres, including the medial parietal cortex plus smaller frontal areas. The maximum reduction occurred in the left tapetum/hippocampus (53%, P = 0.061). In conclusion, statistical maps of cerebral blood flow deficits objectively reveal the location of deficits, identifying areas that are difficult to identify by subjective visual inspection of conventional sections of cerebral blood flow maps. This is particularly well illustrated by the pronounced flow reduction of the medial parietal cortices.
Chlamydia pneumoniae‐associated ADEM
Authors: Heick A. , Skriver E.
Published: March 2003

Inflammatory demyelinating diseases are a common cause of neurologic disability in young adults, and usually the cause is unknown. We describe a case of acute disseminated encephalomyelitis (ADEM) associated with Chlamydia pneumoniae infection. An 18‐year‐old previously healthy women, with a one‐week history of coryzal illness, was admitted because of progressive headache, dizziness, and a left‐sided hemiparesis. MR imaging of the brain and brainstem showed typical signs of ADEM. The diagnosis was established by PCR Chlamydia pneumoniae DNA positivity in a tracheal swab and by increasing titres of Chlamydia IgM antibody. The patient was treated with doxycycline and steroids and recovered completely. Apart from therapeutic implications, this case may contribute to our understanding of demyelinating diseases of the central nervous system.
Current evidence for the use of botulinum toxin type A in the management of children with cerebral palsy: a systematic review
Authors: Boyd R. N. , Hays R. M.
Published: March 2003

Management of children with cerebral palsy (CP) is the focus of considerable resources in many countries, so that evaluation of the efficacy for new and established treatments is imperative. Botulinum toxin type A (BTX‐A) is a relatively new method of spasticity management in children with cerebral palsy. It has been the focus of extensive research since its application to cerebral palsy 10 years ago. In a systematic review relating to the management of the lower limb in cerebral palsy 156 papers were identified. These were categorized according to Sackett and the World Health Organisation International Classification of Impairments, Disabilities and Handicaps model. We identified 10 randomized trials evaluating the use of BTX‐A in the lower limb in children with cerebral palsy in a systematic review. A meta‐analysis showed the pooled risk difference between BTX‐A and placebo in three trials was 0.25 (95% CI 0.13, 0.37) and 0.23 (95% CI −0.06, 0.53) for two trials of BTX‐A and casting using the physicians rating scale. These represent moderate treatment effects that are dosage‐dependent. Outcomes were also compared for function in five studies. The type of evidence for BTX‐A was graded by each treatment indication and directions for future research were then drawn from the available evidence.
Botulinum toxin type A injections in the spastic upper extremity of children with hemiplegia: child characteristics that predict a positive outcome
Authors: Fehlings D. , Rang M. , Glazier J. , Steele C.
Published: March 2003

Evidence is increasing to suggest that botulinum toxin type A (BTX‐A) plays a role in the management of upper extremity spasticity in the paediatric population. However, little information is available on the clinical characteristics of the child that predict a response to this intervention. Our research group previously published a randomized controlled trial demonstrating that BTX‐A injection improves function of the upper extremity of children with spastic hemiplegia. In the present paper, we evaluate the child characteristics that predict a positive response to the BTX‐A injections in the randomized treatment group. The treatment group was divided into positive functional responders and nonresponders using a cut score of a change of 10 points on the Quality of Upper Extremity Skills Test (QUEST). A two‐way analysis of variance procedure was done comparing the following baseline characteristics: function as scored on the QUEST and the Pediatric Evaluation of Disability Inventory (PEDI) self‐care domain, grip strength, upper extremity spasticity and age. Grip strength was significantly higher in responders with a P‐value of 0.001. Young age approached significance with a P‐value of 0.05. Correlation of change scores on the QUEST with baseline characteristics in the treatment group yielded similar results. BTX‐A causes a reduction in spasticity and strength; we postulate that if the hand is weak initially, BTX‐A can decrease hand function. Two case reports are presented that highlight the importance of grip strength and age.
Primary stroke prevention
Authors: De Freitas G. R. , Bogousslavsky J.
Published: March 2003

Stroke is one of the leading causes of death and disability worldwide. Although important advances in therapeutic approaches have been made, treatment is still far from satisfactory. Thus, major efforts should be made on stroke prevention. We present evidence‐based recommendations for primary stroke prevention. Changes to modifiable risk factors, the role of drugs and surgery are discussed. New markers may help identification of subjects at high risk.
Gabapentin in painful HIV‐related neuropathy: a report of 19 patients, preliminary observations
Authors: La Spina I. , Porazzi D. , Maggiolo F. , Bottura P. , Suter F.
Published: March 2003

The objective of this study was to assess the efficacy and safety of Gabapentin as the sole analgesic in patients with HIV‐related painful neuropathy. Nineteen patients with HIV‐related painful neuropathy were administered Gabapentin. Efficacy was evaluated with two 100‐mm Visual Analogue Scales (VAS) (0: no symptom; 100: worst symptom), rating pain and interference of pain with sleep, performed at baseline and monthly intervals. Main Pain VAS score decreased from a baseline of 55.7 ± 19.1 mm to a final 14.7 ± 18.6 mm (anovaP = 0.0001) and mean Sleep Interference VAS score decreased from a baseline of 60.4 ± 31.9 mm to a final 15.5 ± 27.7 mm (anovaP = 0.0001). Gabapentin provided significant pain relief in our patients with HIV‐associated painful sensory neuropathy.
Costs, quality of life and disease severity in multiple sclerosis: a cross‐sectional study in Sweden
Authors: Henriksson F. , Fredrikson S. , Masterman T. , Jönsson B.
Published: March 2003

This study assessed the cost to society of multiple sclerosis (MS) in Sweden in 1998. The cost‐of‐illness method, based on the human capital theory, was used as the theoretical framework. The study used a cross‐sectional approach, in which resource utilization data and quality‐of‐life data (utilities) were collected at a single time point. The total cost of MS was estimated at 4868 MSEK, or 586 MEUR, giving an annual cost of 442 500 SEK, or 53 250 EUR, per patient (1USD = 9.73 SEK, 1 EUR = 8.31 SEK, as of 21 September 2000). Direct costs accounted for about 67% of total cost, and they were dominated by the cost of personal assistants and drugs. Indirect costs (loss of production) accounted for about 33% of total costs. To these economic costs, intangible costs of 2702 MSEK (325 MEUR) should be added as well. Direct, indirect and informal care costs all rose significantly with increased disability and were higher during a relapse. Quality of life declined substantially with increased disability and was lower during a relapse. Multiple sclerosis was found to be associated with much higher costs to society than has been ascertained by former studies. The study also revealed a strong correlation between severity of the disease and quality of life. These results are crucial for further studies on the cost‐effectiveness of new treatments aimed at preventing relapses and reducing progression of the disease.