bluuebunny/crossref_metadata_2025 huggingface dataset:
Intercomparison of volcanic gas monitoring methodologies performed on Vulcano Island, Italy
Authors: Aiuppa Alessandro , Burton Mike , Murè Filippo , Inguaggiato Salvatore
Published: January 2004

Volcanic gas emissions from fumaroles on the rim of La Fossa crater, Vulcano Island, Italy, were measured simultaneously using direct sampling (for H2O, CO2, total sulfur, HCl and HF), filter packs (for SO2, HCl, HF) and short‐path active‐mode FTIR measurements (for H2O, CO2, SO2, HCl and HF) in an intercomparison study in May 2002. The results show that Cl/F ratios were in good agreement between all three methods, and that FTIR and direct sampling determined comparable proportions of CO2 and H2O. Amounts of total S observed in direct sampling data were approximately double the amounts of SO2 measured with filter packs and FTIR. This difference could be attributed either to the fact FTIR and filter packs do not measure reduced sulfur species (e.g., H2S) or to sublimation of elemental S upon exit from the fumarole, after collection by direct sampling but before detection with FTIR and filter packs.
Three‐dimensional collisionless magnetic reconnection in the presence of a guide field
Authors: Pritchett P. L. , Coroniti F. V.
Published: January 2004

Previous investigations of collisionless magnetic reconnection in a standard Harris neutral sheet configuration have demonstrated the importance of the Hall term for producing near‐Alfvénic rates of reconnection and the existence of a very thin (∼c/ωpe) electron current layer and sharp density/pressure gradients on c/ωpi scales. The present work uses three‐dimensional (3‐D) particle‐in‐cell simulations with an open geometry to investigate the changes in the reconnection physics produced by a “guide field” component B0y of the magnetic field. With B0y ≲ B0, the nonlinear reconnection rate is not substantially modified from that for the Harris case. The properties of the reconnection fields and particle dynamics, however, are strongly altered. The familiar quadrupole By pattern is replaced by an enhancement of ∣By∣ between the separatrices. The enhanced parallel electric field and parallel electron velocity are confined to one pair of separatrix arms (which are positively charged), while the electron current peaks on the other pair (which are negatively charged). The ion outflow along the current sheet polarizes the separatrices, thereby creating large components of the in‐plane electric field. The electrons are accelerated to form a beam structure with parallel speed limited by the electron Alfvén speed. The beam‐dominated electron distribution produces some y‐dependent structures in E∥. For B0y ≫ B0, the reconnection rate is reduced by a factor of 2–3, and the parallel fields and velocities are somewhat smaller; the Hall current produced perturbations in By are considerably reduced.
Steady state slow shock inside the Earth's magnetosheath: To be or not to be? 2. Numerical three‐dimensional MHD modeling
Authors: Samsonov A. A. , Hubert Daniel
Published: January 2004

Large‐scale structures in the dayside terrestrial magnetosheath are studied in this paper. The question about existence of the steady state slow MHD shock in the inner magnetosheath is one of the principal theoretical and experimental problems which has not been solved yet. In part 1, the original observations have been revisited. In this part, the numerical results of the three‐dimensional MHD model are presented and discussed. It is shown that for the given observations the density enhancement identified previously as a slow mode transition region is explained by temporal variations of the magnetic field and density observed in the supersonic solar wind. There are three factors resulting in the density increase in the slow mode transition region: A density increase in the upstreamflow, a decrease of the IMF modulus, and a new IMF orientation which forms a quasi‐parallel bow shock in the subsolar region. We show that numerical solutions obtained by non‐stationary and stationary MHD models are significantly different for the same solar wind conditions. We discuss how the magnetopause motion may enlarge the observed variations of the magnetosheath density. Also we answer the question why the existed numerical MHD models do not predict the slow shock in the steady state solution and show how the magnetosheath flow may be organized without such shock.
Steady state slow shock inside the Earth's magnetosheath: To be or not to be? 1. The original observations revisited
Authors: Hubert D. , Samsonov A.
Published: January 2004

The original data that led to the slow mode transition (SMT) scenario for the diversion of the solar wind flow, in front of the dayside magnetoseath, are reexamined. It is shown that a number of SMT cases on the original list should be rejected because the corresponding solar wind data observed upstream from the magnetosheath display numerous density data gaps or have low time resolution inconsistent with accurate correlation study, or the SMT occurs between two successive crossings of the magnetopause. Therefore the SMT scenario is not established at a statistical level because of the limited number of well‐identified cases. Temporal variations of the interplanetary magnetic field (IMF) are shown to play a crucial role in the origin, duration and magnetic field topology of SMTs through the introduction of multiple time shifts in any correlations of magnetic field data obtained on two spacecraft whose distance in a plane perpendicular to the Sun‐Earth line is more than a few of tens Earth radius. These temporal IMF variations, correlated with solar wind density enhancements, induce a compressed magnetopause during SMT observations. The exogeneous nature of SMTs is established. Case studies reveal the different processes at the origin of the large enhancement of the density in SMTs with respect to the density upstream of the SMTs. These processes include: (1) an increase of the solar wind density, (2) variations in the density in the magnetosheath linked to increases of the Alfvén Mach number and to a new orientation of the IMF, and (3) a density gradient effect induced in the magnetosheath depletion layer by motion of the magnetopause. Other cases display proeminent density peaks linked to interplanetary magnetic field discontinuities imbedded in the SMTs. We also show that a previous analysis about stationarity of a SMT's front as well as of identification of slow modes propagating against the flow are not confirmed. The exogeneous scenario based on IMF and solar wind density variations for the origin and nature of the SMT phenomenon answers all the questions so far asked about this process.
Core ion interactions with BB ELF, lower hybrid, and Alfvén waves in the high‐latitude topside ionosphere
Authors: Burchill J. K. , Knudsen D. J. , Bock B. J. J. , Pfaff R. F. , Wallis D. D. , Clemmons J. H. , Bounds S. R. , Stenbaek‐Nielsen H.
Published: January 2004

We present simultaneous observations of ion distribution functions and plasma waves in the high‐latitude topside ionosphere (500–1000 km) near local midnight during substorm activation. Using a new instrument, the Suprathermal Ion Imager (SII), we are able to explore two‐dimensional ion distribution functions with unprecedented resolution in time (93 s−1) and energy, focusing on the lowest‐energy core (<1 eV) population and suprathermal extensions thereof. The GEODESIC sounding rocket flew through regions containing broadband extremely low frequency (BB ELF) waves, large‐amplitude Alfvén waves, and lower‐hybrid solitary structures (LHSS), all of which have been shown previously to correlate with ion heating. However, GEODESIC detected heating only in association with LHSS. Ion distributions in and near LHSS showed acceleration in the direction transverse to (TAI) with temperatures as high as 5–10 eV, appearing in regions 65 ± 25 m across. TAI were centered on much smaller structures (∼20 m across) of depleted plasma density and enhanced perpendicular electric fields from 0.1 to 10 kHz, consistent with observations from previous rocket flights. Also in agreement with previous findings, we find two distinct ion populations inside LHSS. The dominant population is composed of unheated, isotropic “core” Maxwellian ions having temperatures comparable to the surrounding ambient plasma, while roughly 10% of the plasma density corresponds to the TAI at pitch angles of 90 ± 5°. We argue that the TAI associated with LHSS is consistent with bulk heating of the core ions, and we describe two scenarios that can lead to the observed two‐temperature distributions. The BB ELF wave emissions were correlated with LHSS heating at short scales and anticorrelated with auroral electron precipitation at large scales. The GEODESIC instruments observed no large‐scale ion heating in association with BB ELF waves. Similarly, no ion heating was detected in the presence of large‐amplitude, short perpendicular wavelength Alfvén waves.
Temporal and spatial structures of flickering aurora derived from high‐speed imaging photometer observations at Syowa Station in the Antarctic
Authors: Sakanoi Kazuyo , Fukunishi H.
Published: January 2004

In order to investigate the generation mechanisms of flickering aurora, especially the physical processes producing its temporal and spatial structures, an advanced optical observation system called “a high‐speed imaging photometer system” was developed by Tohoku University in 1997. The high‐speed imaging photometer system consists of two sets of imaging photometer, which are used for measurements of the N2+ first negative emission (427.8 nm) and N2 first positive emission (∼660 nm) independently. Observations were carried out at Syowa Station (69.00° S, 39.58° E, −66.2° MLAT) in the Antarctic from April 24, 1998 to September 26, 1998. Dynamic spectra at two different wavelengths and clear temporal and spatial structures of flickering aurora at 427.8 nm are derived from these high‐speed imaging photometer data. The most important result in this study is that flickering auroral columns (or spots) remain in almost the same location during their lifetime and that these columns (or spots) do not propagate across the magnetic field lines. It is suggested that interference of electromagnetic ion cyclotron (EMIC) waves or inertial Alfvén waves (IAW) in the auroral acceleration region produce the observed characteristics of flickering aurora.
Thermal diffusivity measurements of porous methane hydrate and hydrate‐sediment mixtures
Authors: Kumar P. , Turner D. , Sloan E. D.
Published: January 2004

An experiment has been constructed to measure thermal diffusivity of methane hydrate and methane hydrate‐sand/sediment mixtures. Thermal diffusivities of porous methane hydrate (40% pore space filled with methane gas) and mixtures of methane hydrate with Platte Valley sand and Blake Ridge sediment have been measured between the temperature range 265 K and 281 K, at pressures between 4.35 and 7.65 MPa. Thermal diffusivities of porous methane hydrate ranged between 3.1 × 10−7and 3.3 × 10−7m2/s. Thermal diffusivity of 0.4 porosity methane hydrate was found to have inverse dependence on temperature, whereas the thermal diffusivity of methane hydrate‐sediment/sand mixtures has positive temperature dependence. Thermal diffusivity of methane hydrate‐sand/sediment mixtures increased with increasing hydrate volume fraction to a maximum between about 30 and 35 vol% in sand and between about 20 and 40 vol% in sediment. After the maxima, the thermal diffusivities decreased with increasing hydrate volume fraction.
On the influence of a surface coastal front on near‐inertial wind‐induced internal wave generation
Authors: Xing Jiuxing , Davies Alan M.
Published: January 2004

A numerical model is used to examine the wind‐induced near‐inertial internal waves in the coastal region in the presence of a surface front. Initial calculations with the front separating a well‐mixed coastal region from a stratified offshore area in an infinite sea domain showed that away from the front, surface inertial oscillations are dominant. Near the front on the positive vorticity side, superinertial internal waves are generated and propagate offshore in an analogous manner to that found when stratification intersected a coastal boundary. However, in the case of a coastal boundary, the no‐flow condition at the coast produced inertial oscillations at depth phase shifted by 180° from those at the surface. On the negative vorticity side of the front, internal waves at the subinertial frequency are trapped between the well‐mixed region and the front. Some inertial energy is found at depth in the frontal region. Although the large‐scale features of the distribution of inertial energy are independent of vertical eddy viscosity parameterization, its magnitude depends upon it. In the case of a stratified nearshore region and an offshore front, near‐inertial waves generated at the coast were trapped between the coastal boundary and the front, which results in a surface region of enhanced inertial energy. This gradually decreased with time as inertial energy diffused to depth. This timescale depended upon vertical eddy viscosity magnitude.
Impacts of land use/cover changes on surface climate over east Asia for extreme climate cases using RegCM2
Authors: Suh Myoung‐Seok , Lee Dong‐Kyou
Published: January 2004

Systematic biases were found in the National Center for Atmospheric Research Regional Climate Model (NCAR RegCM2) through the 10‐year east Asian summer simulations. In the simulations, positive and negative surface temperature biases of 2°–4°C occurred systematically over north China and Mongolia. The model also produced excessive precipitation over land but less precipitation over the southern ocean of the model domain. In this study, impacts of land cover changes (LCC) on the systematic biases were investigated through the cool/wet and warm/dry summer climate simulations using two types of land cover maps using RegCM2. One type was an NCAR land cover map, and the other was a current land cover map derived from satellite data. Simulated latent heat flux and wind speed increased noticeably over central and north China, where deciduous broad leaf trees have been replaced by mixed farm and irrigated crop. As a result, the systematic positive biases over central and north China were greatly reduced regardless of climate regimes. Cooling in central and north China resulted in a pressure gradient decrease between the east Asian continent and the Pacific Ocean. The decrease in pressure gradient suppressed northward transport of moisture from south China and the South China Sea. The change reduced not only excessive precipitation over north China and Mongolia but also less precipitation over south China. However, in LCC, precipitation increased in the Korean Peninsula and the Japan Islands, in particular, during July and August. As a result, LCC resulted in cooler and drier summer climate over north China, but cooler and wetter summer climate over the Korean Peninsula and the Japan Islands irrespective of climate regimes. In general, the impacts of LCC were relatively significant in the warm and dry summer.
Comprehensive laboratory measurements of biomass‐burning emissions: 2. First intercomparison of open‐path FTIR, PTR‐MS, and GC‐MS/FID/ECD
Authors: Christian T. J. , Kleiss B. , Yokelson R. J. , Holzinger R. , Crutzen P. J. , Hao W. M. , Shirai T. , Blake D. R.
Published: January 2004

Oxygenated volatile organic compounds (OVOC) can dominate atmospheric organic chemistry, but they are difficult to measure reliably at low levels in complex mixtures. Several techniques that have been used to speciate nonmethane organic compounds (NMOC) including OVOC were codeployed/intercompared in well‐mixed smoke generated by 47 fires in the U.S. Department of Agriculture Forest Service Fire Sciences Combustion Facility. The agreement between proton transfer reaction mass spectrometry (PTR‐MS) and open‐path Fourier transform infrared spectroscopy (OP‐FTIR) was excellent for methanol (PT/FT = 1.04 ± 0.118) and good on average for phenol (0.843 ± 0.845) and acetol (∼0.81). The sum of OP‐FTIR mixing ratios for acetic acid and glycolaldehyde agreed (within experimental uncertainty) with the PTR‐MS mixing ratios for protonated mass 61 (PT/FT = 1.17 ± 0.34), and the sum of OP‐FTIR mixing ratios for furan and isoprene agreed with the PTR‐MS mixing ratios for protonated mass 69 (PT/FT = 0.783 ± 0.465). The sum of OP‐FTIR mixing ratios for acetone and methylvinylether accounted for most of the PTR‐MS protonated mass 59 signal (PT/FT = 1.29 ± 0.81), suggesting that one of these compounds was underestimated by OP‐FTIR or that it failed to detect other compounds that could contribute at mass 59. Canister grab sampling followed by gas chromatography (GC) with mass spectrometry (MS), flame ionization detection (FID), and electron capture detection (ECD) analysis by two different groups agreed well with OP‐FTIR for ethylene, acetylene, and propylene. However, these propylene levels were below those observed by PTR‐MS (PT/FT = 2.33 ± 0.89). Good average agreement between PTR‐MS and GC was obtained for benzene and toluene. At mixing ratios above a few parts per billion the OP‐FTIR had advantages for measuring sticky compounds (e.g., ammonia and formic acid) or compounds with low proton affinity (e.g., hydrogen cyanide and formaldehyde). Even at these levels, only the PTR‐MS measured acetonitrile and acetaldehyde. Below a few ppbv only the PTR‐MS measured a variety of OVOC, but the possibility of fragmentation, interference, and sampling losses must be considered.
Upper atmosphere of Mars up to 120 km: Mars Global Surveyor accelerometer data analysis with the LMD general circulation model
Authors: Angelats i Coll M. , Forget F. , López‐Valverde M. A. , Read P. L. , Lewis S. R.
Published: January 2004

Mars Global Surveyor (MGS) aerobraking accelerometer density measurements are analyzed with the use of the general circulation model (GCM) at the Laboratoire de Météorologie Dynamique (LMD). MGS constant altitude density data are used, obtaining longitudinal wavelike structures at fixed local times which appear to be dominated by low zonal wave number harmonics. Comparisons with simulated data for different seasons and latitudinal bands at constant altitude are performed. Excellent agreement is obtained between the simulated and observational data for low latitudes, with accuracy in both mean and zonal structure. Higher latitudes show a reduction in agreement between GCM results and MGS data. Comparisons that result in good agreement with the observational data allow for the study of wave composition in the MGS data. In particular, the excellent agreement between the simulations and the data obtained at 115 km during areocentric longitude Ls ≈ 65° allows the extraction of the major contributors to the signature, with the eastward propagating diurnal waves of wave numbers one to three being the major players. Significant contributions are also obtained for eastward propagating semidiurnal waves of wave numbers two, three, and five and diurnal wave number five. A sensitivity study is performed to delineate the effects of the near‐IR tidal forcing of the upper atmosphere on the wave content at those heights. Simulations without this forcing yield reduced amplitudes for diurnal eastward propagating waves two and three along with a more latitudinally symmetric response for these two components as well as for diurnal eastward propagating wave number one.
Founder effects and stochastic dispersal at the continental scale of the fungal pathogen of bananas Mycosphaerella fijiensis
Authors: Rivas Gonzalo‐Galileo , Zapater Marie‐Françoise , Abadie Catherine , Carlier Jean
Published: January 2004

The worldwide destructive epidemic of the fungus Mycosphaerella fijiensis on banana started recently, spreading from South‐East Asia. The founder effects detected in the global population structure of M. fijiensis reflected rare migration events among continents through movements of infected plant material. The main objective of this work was to infer gene flow and dispersal processes of M. fijiensis at the continental scale from population structure analysis in recently invaded regions. Samples of isolates were collected from banana plantations in 13 countries in Latin America and the Caribbean and in Africa. The isolates were analysed using polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) and microsatellite molecular markers. The results indicate that a high level of genetic diversity was maintained at the plantation and the plant scales. The loci were at gametic equilibrium in most of the samples analysed, supporting the hypothesis of the existence of random‐mating populations of M. fijiensis, even at the plant scale. A low level of gene diversity was observed in some populations from the Africa and Latin America–Caribbean regions. Nearly half the populations analysed showed a significant deviation from mutation‐drift equilibrium with gene diversity excess. Finally, a high level of genetic differentiation was detected between populations from Africa (FST = 0.19) and from the Latin America–Caribbean region (FST = 0.30). These results show that founder effects accompanied the recent invasion of M. fijiensis in both regions, suggesting stochastic spread of the disease at the continental scale. This spread might be caused by either the limited dispersal of ascospores or by movements of infected plant material.
Medical Oophorectomy With and Without Estrogen Add‐Back Therapy in the Prevention of Migraine Headache
Authors: Martin Vincent , Wernke Suzanne , Mandell Karen , Zoma Willie , Bean Judy , Pinney Susan , Liu James , Ramadan Nabih , Rebar Robert
Published: January 2004

Objectives.—To determine the preventive benefit of “medical oophorectomy” and transdermal estradiol in women with migraine.

Background.—Epidemiological studies have demonstrated that declines in serum estrogen levels occurring during normal menstrual cycles can trigger headache in women with migraine. Prior to this study, no randomized controlled trials have evaluated whether minimizing these hormonal changes pharmacologically can prevent headache.

Methods.—Twenty‐one women with regular menstrual cycles and a diagnosis of migraine headache were enrolled. After a 2.5‐month placebo run‐in phase, all patients received a subcutaneous goserelin implant (a gonadotropin‐releasing hormone agonist) to induce a medical oophorectomy. One month later, while continuing goserelin, participants were randomized to receive a transdermal patch containing 100 μg of estradiol‐17β (gonadotropin‐releasing hormone agonist/estradiol group, n  =  9) or a placebo patch (gonadotropin‐releasing hormone agonist/placebo group, n  =  12) during a 2‐month treatment phase. The primary outcome measure was the headache index, which was defined as the mean of pain severity ratings (0 to 10 scale) recorded three times per day by daily diary. Secondary outcome measures included headache disability, headache severity, headache frequency, and the percentage of headaches with a pain severity rating of 7 or greater.

Results.—The headache index was significantly lower during the treatment period in the gonadotropin‐releasing hormone agonist/estradiol group than in the gonadotropin‐releasing hormone agonist/placebo group (P  =  .025). Similar improvements were observed in the gonadotropin‐releasing hormone agonist/estradiol group for all secondary outcome measures with the exception of headache frequency, which was unchanged between the groups. Within the gonadotropin‐releasing hormone agonist/estradiol group, there was a 33.7% reduction (95% confidence interval, −64.4 to −3.0) in the headache index during the treatment phase when compared with the placebo run‐in phase; no difference was seen between those phases within the gonadotropin‐releasing hormone agonist/placebo group.

Conclusions.—Minimization of hormonal fluctuations with gonadotropin‐releasing hormone agonist therapy alone is inadequate to prevent headache in women who are premenopausal with migraine. The addition of transdermal estradiol to existing gonadotropin‐releasing hormone agonist therapy provides a modest preventive benefit.
A Structural Representation of Migraine Diagnostic Criteria: The Experts' View
Authors: Nash Jane Gradwohl , Nash Justin M.
Published: January 2004

Objective.—To generate an empirically derived structural representation of migraine diagnostic criteria in a group of international headache experts using the Pathfinder network scaling algorithm in order to evaluate the validity of the migraine criteria used in the International Headache Society (IHS) classification system.

Background.—Because it is a disease entity that lacks objective defining markers, developing valid diagnostic criteria for migraine is a challenge. The IHS committee relied on expert consensus to develop their classification system in 1988. Expert consensus also was used to evaluate the validity of the IHS classification system, but further studies employing alternative methods still are needed.

Methods.—Headache experts representing the Executive Committee of the IHS and the Board of Directors of the American Headache Society analyzed 14 criteria (7 IHS and 7 non‐IHS) considered relevant in diagnosing migraine. Their ratings were submitted to the Pathfinder algorithm to generate a network structure reflecting the experts' conceptualization of migraine diagnostic criteria.

Results.—The expert network had 3 groupings: headache characteristics (eg, phonophobia, unilateral pain, throbbing pain), biological contributing factors (eg, family history, hormonal relationship, relief with sleep), and triggering factors (eg, worse with stress, food triggers). The IHS criteria were clustered together in the center portion of the network. A t test showed that each IHS criterion was closer conceptually to other IHS criteria than to non‐IHS criteria. Graph theory indices revealed that the most central criteria were unilateral pain, moderate/severe intensity, and nausea/vomiting.

Conclusion.—The structural representation of migraine diagnostic criteria from these international headache experts is consistent with the migraine diagnostic criteria set forth in the IHS classification system and thus provides further support for the validity of migraine criteria in the IHS system.
Health Care Utilization in Patients With Migraine: Demographics and Patterns of Care in the Ambulatory Setting
Authors: Gibbs Trevor S. , Fleischer Alan B. , Feldman Steven R. , Sam Maria C. , O'Donovan Cormac A.
Published: January 2004

Background.—Migraine affects people of all races and both sexes. Migraineurs suffer both financial losses and impaired quality of life. Recent progress in the treatment of migraine has not been made readily available to all who suffer the condition.

Objective.—To assess outpatient health care delivery patterns for migraine sufferers in the United States.

Methods.—National Ambulatory Medical Care Survey data from 1990 to 1998 was used to assess the demographics of patients seen with a diagnosis of migraine, the types of physicians they saw, and the medications used to treat migraine.

Results.—Women accounted for 79% of visits for migraines and whites for 91% of the visits. There was a dramatic increase in the number of migraine visits during the study period, from 9.4 visits per 1000 people in 1990 to 18 visits per 1000 in 1998. Primary care physicians saw the majority of patients (72.2%). Butalbital/aspirin/caffeine was the drug most commonly prescribed for migraine treatment, followed by acetaminophen/dichloralphenazone/isometheptene mucate, propranolol, and sumatriptan.

Conclusion.—Perhaps in part due to newer treatment options, the number of visits for the treatment of migraine doubled over the study interval. Even so, most patients with migraine continue to be treated with older and presumably less effective medications.
Internet‐Based Treatment of Headache: Does Telephone Contact Add Anything?
Authors: Andersson Gerhard , Lundström Per , Ström Lars
Published: January 2004

Objective.—To study the contribution of therapist‐initiated telephone contact in the treatment of recurrent headache via the Internet.

Background.—Internet‐based cognitive behavioral self‐help is a promising new venue for the treatment of recurrent headache. While cost‐effective, there are indications that this modality may be associated with high dropout rates.

Design and Methods.—The role of therapist‐initiated contact was investigated in a randomized controlled trial in which 44 self‐recruited headache sufferers were randomized to either a Web‐based self‐help program with e‐mail support or to a group receiving, in addition, weekly individual telephone calls. An additional 8 control subjects were recruited to receive similar treatment outside of the study.

Results.—Dropout rates were 29% in the telephone support group and 35% in the control group, suggesting that the telephone calls did not affect dropout. Results showed significant reductions in headache‐related disability, depression, maladaptive coping strategies, and perceived stress but little to indicate any superior performance in the Internet‐only group and little improvement in the headache index. In short, therapist‐initiated telephone calls did not influence the results.

Conclusions.—Internet‐based treatment for headache is not affected by minimal therapist‐initiated telephone contact.
Migraine Headaches and Sleep Disturbances in Children
Authors: Miller V.A. , Palermo T.M. , Powers S.W. , Scher M.S. , Hershey A.D.
Published: January 2004

Objective.—The aim of the present study was to investigate the prevalence of sleep disturbances in children with migraine headaches and to describe individual differences in sleep behaviors based on headache features (eg, frequency, duration, intensity).

Background.—A relationship between migraine headaches and sleep disturbances has been suggested in both children and adults, but there is a lack of research examining the relationship between specific headache features and the range of sleep behaviors in children.

Methods.—One hundred eighteen children, aged 2 to 12 years (mean, 9.1; standard deviation, 2.3) were evaluated for headaches at two pediatric neurology departments. Parents completed the Children's Sleep Habits Questionnaire and a standardized questionnaire regarding headache characteristics.

Results.—Parents reported a high rate of sleep disturbances in children, including sleeping too little (42%), bruxism (29%), child co‐sleeping with parents (25%), and snoring (23%). Children with migraine headaches experienced more sleep disturbances compared to published healthy control norms. After controlling for child demographics, we found that the frequency and duration of migraine headaches predicted specific sleep disturbances, including sleep anxiety, parasomnias, and bedtime resistance.

Conclusions.—Children with migraine headaches have a high prevalence of sleep disturbances. The direction of the relationship between headaches and sleep is unknown. Regardless, interventions targeting sleep habits may improve headache symptoms, and effective treatment of headaches in children may positively impact sleep.
Peripheral Neurostimulation for the Treatment of Chronic, Disabling Transformed Migraine
Authors: Popeney Charles A. , Aló Kenneth M.
Published: January 2004

Background.—Up to 5% of the general population suffers from transformed migraine. This study analyzes clinical responses of transformed migraine to cervical peripheral nerve stimulation.

Methods.—Headache frequency, severity, and disability (Migraine Disability Assessment [MIDAS] scores) were independently measured in an uncontrolled consecutive case series of 25 patients with transformed migraine implanted with C1 through C3 peripheral nerve stimulation. All patients met International Headache Society (IHS) criteria for episodic migraine, as well as suggested criteria for transformed migraine, and had been refractory to conventional treatment for at least 6 months. Responses to C1 through C3 peripheral nerve stimulation were recorded.

Results.—Prior to stimulation, all patients experienced severe disability (grade IV on the MIDAS) with 75.56 headache days (average severity, 9.32; average MIDAS score, 121) over a 3‐month period.

Following stimulation, 15 patients reported little or no disability (grade I), 1 reported mild disability (grade II), 4 reported moderate disability (grade III), and 5 continued with severe disability (grade IV), with 37.45 headache days (average severity, 5.72; average MIDAS score, 15). The average improvement in the MIDAS score was 88.7%, with all patients reporting their headaches well controlled after stimulation.

Conclusions.—These results raise the possibility that C1 through C3 peripheral nerve stimulation can help improve transformed migraine symptoms and disability. A controlled study is required to confirm these results.
Nα‐Methylhistamine Safety and Efficacy in Migraine Prophylaxis: Phase I and Phase II Studies
Authors: Millán‐Guerrero Rebeca O. , Pineda‐Lucatero Alicia G. , Hernández‐Benjamín Trujillo , Tene Carlos E. , Pacheco Mauro F.
Published: January 2004

Objective.—To study the therapeutic potential of the subcutaneous administration of Nα‐methylhistamine in migraine prophylaxis.

Background.—The histamine catabolite, Nα‐methylhistamine, possesses a selective affinity for H3 receptors. We consequently considered it viable to conduct a clinical pharmacological study to evaluate the safety and efficacy of this histaminergic H3 agonist in migraine prophylactic treatment, which specifically may inhibit the neurogenic edema response involved in migraine pathophysiology.

Methods.—Phase I.—In a clinical trial of 30 healthy volunteers, the effects of the subcutaneous administration of Nα‐methylhistamine and placebo were studied to assess undesirable symptomatic effects.

Phase II.—In a clinical open study, we evaluated the efficacy of Nα‐methylhistamine in reducing headache intensity, frequency, and duration; and in decreasing analgesic intake in 18 patients with migraine.

Results.—Phase I.—None of the variables studied showed significant differences (P>.05), and no secondary effects were observed at doses below 10 ng.

Phase II.—Nα‐methylhistamine, at doses of 1 to 3 ng, significantly reduced (P<.0001) the frequency, intensity, and duration of migraine attacks, as well as the need for rescue analgesics. However, at doses greater than 3 ng, patients experienced intense headache.

Conclusions.—The present study provides evidence of the safety and efficacy of Nα‐methylhistamine applied subcutaneously at doses of 1 to 3 ng twice a week.
Efficacy of Sumatriptan Nasal Spray in Recurrent Migrainous Headache: An Open Prospective Study
Authors: Carpay J. A. , Linssen W. H. J. P. , Koehler P. J. J. , Arends L. R. , Tiedink H. G. M.
Published: January 2004

Objective.—To evaluate the effectiveness of sumatriptan 20 mg via nasal spray and 100‐mg tablets in treating migrainous headache in patients without a concomitant migraine diagnosis.

Methods.—We prospectively investigated the efficacy of sumatriptan 20 mg via nasal spray and 100‐mg tablets in patients with a history of at least 5 moderate to severe headache attacks lasting 2 to 72 hours that consistently did not meet the International Headache Society (IHS) criteria for migraine or episodic tension‐type headache.

Results.—Nineteen headache attacks classifiable as migrainous disorder without aura (IHS 1.7) were evaluated in 13 patients using 20‐mg sumatriptan nasal spray within a 10‐week period. A 2‐point decrease in headache severity on a four‐point scale was achieved in 74% (95% confidence interval [CI], 50% to 89%) of the attacks within 2 hours. The pain‐free incidence (a reduction in headache severity from moderate or severe to none) was 37% (95% CI, 17% to 63%) after 2 hours. Ten patients completed the second part of the study, taking oral sumatriptan for 14 migrainous attacks: a 2‐point decrease in headache severity was achieved in 38% (95% CI, 13% to 71%) of the attacks within 2 hours and in 77% (95% CI, 48% to 92%) within 4 hours.

Conclusion.—This is the first prospective study to show that intranasal or oral sumatriptan may be effective in patients experiencing moderate to severe headache attacks which consistently do not fulfill the IHS criteria for migraine or episodic tension‐type headache.
Chiari‐Associated Exertional, Cough, and Sneeze Headache Responsive to Medical Therapy
Authors: Buzzi M. Gabriella , Formisano Rita , Colonnese Claudio , Pierelli Francesco
Published: January 2004

Benign exertional headache is coded as a separate entity within the International Headache Society's classification system, but the pathophysiological mechanisms underlying this clinical headache subtype are unknown and possibly are similar to those generating migraine.

Coexistence of migraine and benign exertional headache in the same patient is not unusual, and antimigraine pharmacologic treatments are often effective in both headache types. Regardless, optimal management mandates that the clinician exclude any intracranial or systemic disease that could mimic “primary” exertional headache. The same holds for primary headaches induced by coughing or sneezing; congenital malformations or neoplasms, particularly within the posterior fossa, are not rare in these patients. The neurologic examination may not be sufficiently sensitive to detect the offending lesion.

We describe a patient with migraine without aura and exertional secondary headache due to Chiari malformation type I whose headaches responded to treatment with propranolol and indomethacin.
Sumatriptan in Migraine With Unilateral Cranial Autonomic Symptoms: An Open Study
Authors: Barbanti Piero , Fabbrini Giovanni , Vanacore Nicola , Pesare Marina , Buzzi Maria Gabriella
Published: January 2004

Objective.—To investigate the response to sumatriptan in migraineurs with unilateral cranial autonomic symptoms such as lacrimation, eye redness, eyelid edema, nasal congestion, and rhinorrhea.

Background.—Given the potential large‐scale recruitment of peripheral neurovascular 5‐HT1B/1D receptors consequent to the activation of the trigeminal autonomic reflex in such patients, the presence of unilateral cranial autonomic symptoms may predict a positive response to sumatriptan.

Methods.—Seventy‐two consecutive migraineurs with unilateral cranial autonomic symptoms were given sumatriptan 50‐mg tablets to treat 1 migraine attack and were asked to record their clinical response to the drug at different time points. End points were pain‐relief and pain‐free response at 1 and 2 hours.

Results.—Pain relief was reported by 47 patients (65.3%) at 1 hour and by 59 (81.9%) at 2 hours. Pain‐free response was reported by 22 patients (30.6%) at 1 hour and by 44 (61.1%) at 2 hours. Responsiveness to sumatriptan did not correlate with the type or number of unilateral cranial autonomic symptoms, demographic characteristics, prophylactic treatments, use of contraceptives, or concomitant tension‐type headache.

Conclusions.—Migraineurs with unilateral cranial autonomic symptoms seem to respond to sumatriptan better than other migraineurs. The presence of unilateral cranial autonomic symptoms may predict a positive response to the triptans.
Nuclear factor‐kappaB as a molecular target for migraine therapy.
Authors: Reuter U , Chiarugi A , Bolay H , Moskowitz MA
Published: January 2004

Ann Neurol. 2002;51:507‐516.

Nitric oxide (NO) generated from inducible NO synthase (iNOS) participates in immune and inflammatory responses in many tissues. The NO donor glyceryl trinitrate (GTN) provokes delayed migraine attacks when infused into migraineurs and also causes iNOS expression and delayed inflammation within rodent dura mater. Sodium nitroprusside, an NO donor as well, also increases iNOS expression. Because inflammation and iNOS are potential therapeutic targets, we examined transcriptional regulation of iNOS following GTN infusion and the consequences of its inhibition within dura mater. We show that intravenous GTN increases NO production within macrophages. L‐N(6)‐(1‐iminoethyl)lysine, a selective iNOS inhibitor, attenuates the NO signal, emphasizing the importance of enzymatic activity to delayed NO production. iNOS expression is preceded by significant nuclear factor kappa B (NF‐kappaB) activity, as reflected by a reduction in the inhibitory protein‐kappa‐Balpha (IkappaBalpha) and activation of NF‐kappaB after GTN infusion. IkappaBalpha degradation, NF‐kappaB activation, and iNOS expression were attenuated by parthenolide (3mg/kg), the active constituent of feverfew, an anti‐inflammatory drug used for migraine treatment. These findings suggest that GTN promotes NF‐kappaB activity and inflammation with a time course consistent with migraine attacks in susceptible individuals. We conclude, based on results with this animal model, that blockade of NF‐kappaB activity provides a novel transcriptional target for the development of anti‐migraine drugs.

Comment: This paper suggesting the localization of NO production in dural macrophages as part of delayed inflammation may indicate proliferation and or recruitment of these cells in migraine. Could this also be a target for drug treatment? Specifically, is the genetic transcription that leads to nitric oxide generation such a target? To amend slightly the old advertising slogan, “when Michael Moskowitz talks, we all listen.” DSM and SJT
Drug overuse and rebound headache.
Authors: Silberstein SD , Liu D
Published: January 2004

Curr Pain Headache Rep. 2002;6:240‐247.

The overuse of acute medications in patients who are headache‐prone poses a great challenge to headache management. Medication overuse‐induced headache represents one of the most common iatrogenic disorders. It is the reason that most patients visit headache subspecialty clinics worldwide and often is the cause of an intractable or worsening headache in primary headache sufferers. The recent development of acute headache medications, especially the triptans, has provided increased migraine relief; however, the incidence of triptan‐overuse headache has also increased. Awareness of medication overuse‐induced headache and familiarity with the diagnosis and the treatment of this disorder are important to physicians who treat patients with headache.

Comment: Medication overuse headache is the bugaboo of most neurologists and headache specialists, and this review is by a master of that topic who provides clinical guidance for the condition's recognition and treatment. SJT

I would agree with Dr. Tepper. We need to scrutinize closely this group of patients to avoid replacing the “ergot abusers” of the past with the triptan overusers. Diener et al has proposed that patients should restrict triptan use to <12 attacks per month. DSM
Chronic headache: new advances in treatment strategies.
Authors: Lake AE , Saper JR
Published: January 2004

Neurology. 2002;59(5 suppl 2):S8‐S13.

Chronic daily headache (CDH) affects approximately 4 to 5% of the population and encompasses a number of different diagnoses, including transformed migraine, chronic tension‐type headache (TTH), new‐onset daily persistent headache, and hemicrania continua. Although the pathophysiology of CDH is still poorly understood, some research has suggested that each of the various subtypes of CDH may have a different pathogenesis. The goals of prophylactic therapy are to reduce the frequency, severity, and duration of headache attacks; to improve responsiveness to treatment of acute attacks; to improve function; and to reduce disability. However, opinions differ as to exactly which are the best and most appropriate outcome measures for prophylaxis. Several pharmacologic treatment options exist, including antidepressants, anticonvulsants, muscle relaxants, serotonin agonists, ergots, serotonin antagonists, antianxiety agents, and other miscellaneous drugs. Tizanidine, an alpha(2)‐adrenergic agonist, has recently emerged as a promising prophylactic adjunct for CDH, which implicates a central alpha(2)‐adrenergic mechanism as an important factor in the pathophysiology of CDH.

Comment: Drs. Lake and Saper provide a superb overview of frequent headache, and taken with Dr. Silberstein's article described above, the two reviews constitute the most up‐to‐date reviews on the subject. SJT
Complicated migraine and migraine variants.
Authors: Rothner AD
Published: January 2004

Curr Pain Headache Rep. 2002;6:233‐239.

This article reviews the less frequently encountered varieties of migraine. It is suggested that these disorders be approached by evaluating possible underlying etiologies before positively diagnosing migraine. This decreases the likelihood of “missing” structural or metabolic disorders. The classification, diagnostic evaluation, differential diagnosis, and treatment options of these disorders is reviewed and a selection of references appended for additional information.

Comment: Dr. Rothner is one of the most prominent pediatric neurology headache specialists in the country, and he sees a variety of atypical presentations of migraine. This is an excellent review of such presentations. SJT
Serotonin reuptake inhibitors for dizziness with psychiatric symptoms.
Authors: Staab JP , Ruckenstein MJ , Solomon D , Shepard NT
Published: January 2004

Arch Otolaryngol Head Neck Surg. 2002;128:554‐560.

OBJECTIVE: To investigate the efficacy and tolerability of selective serotonin reuptake inhibitors (SSRIs) for the treatment of patients with dizziness and major or minor psychiatric symptoms, with or without neurotologic illnesses. DESIGN: Review of 60 consecutive cases of patients with dizziness who were treated with an SSRI for at least 20 weeks during the 30‐month period from July 1998 to December 2000. SETTING: Tertiary care, multidisciplinary referral center. PATIENTS: Sixty men and women, aged 13 to 81 years, with (1) psychogenic dizziness, (2) dizziness due to a neurotologic condition, as well as significant psychiatric symptoms, or (3) idiopathic dizziness. INTERVENTIONS: Open‐label treatment with an SSRI titrated to 1 of 3 end points: optimal clinical benefit, intolerable adverse effects, or no therapeutic response. MAIN OUTCOME MEASURE: Change in dizziness and psychiatric symptoms measured by the 7‐point, clinician‐rated, Clinical Global Impressions‐Improvement Scale. RESULTS: Thirty‐eight (63%) of 60 patients in the intent‐to‐treat sample and 32 (84%) of 38 patients who completed treatment improved substantially. The response rates did not differ between patients with major psychiatric disorders and those with lesser psychiatric symptoms. Patients whose only diagnosis was a psychiatric disorder and those with coexisting peripheral vestibular conditions or migraine headaches fared better than patients with central nervous system deficits. Before being treated with an SSRI, two thirds of the study patients took meclizine hydrochloride and/or benzodiazepines, with minimal benefit. CONCLUSIONS: Treatment with SSRIs relieved dizziness in patients with major or minor psychiatric symptoms, including those with peripheral vestibular conditions and migraine headaches. Patients fared far better with SSRI treatment than with treatment with vestibular suppressants or benzodiazepines.

Comment: Migraineurs with vestibular symptoms are a challenging group to treat, especially given the labelling restrictions contraindicating triptans in patients with basilar migraine. How confident would most clinicians be in differentiating between these patient groups? DSM

I included this abstract because of the comment in the paper that those patients with migraine and dizziness did very well with SSRI treatment. This open‐label study suggests that a randomized, controlled study of SSRIs in patients with migrainous vertigo may be useful. SJT