Search results for "current"
showing 10 items of 2224 documents
Suppression of the cardiac electric field artifact from the heart action evoked potential
2006
The study of heart action-related brain potentials is strongly disrupted by the presence of an inherent cardiac electric artifact. The hypothesis is presented that most of the electric current coupled to the cardiac field surrounds the skull and flows through the scalp tissue without crossing the cranial cavity. This pseudo two-dimensional conduction model contrasts with the volumetric conduction of the brain electrical activity, and this property is exploited to cancel the cardiac electric artifact. QRS loop vector-cardiographic projections on saggital planes were recorded in 11 healthy subjects in the head and neck areas. Comparative analysis of the projection eccentricities, estimated by…
Editor's Note: Relates to: ‘Familial hypercholesterolaemia is underdiagnosed and undertreated in the general population: guidance for clinicians to p…
2020
Aims The first aim was to critically evaluate the extent to which familial hypercholesterolaemia (FH) is underdiagnosed and undertreated. The second aim was to provide guidance for screening and treatment of FH, in order to prevent coronary heart disease (CHD). Methods and results Of the theoretical estimated prevalence of 1/500 for heterozygous FH, <1% are diagnosed in most countries. Recently, direct screening in a Northern European general population diagnosed approximately 1/200 with heterozygous FH. All reported studies document failure to achieve recommended LDL cholesterol targets in a large proportion of individuals with FH, and up to 13-fold increased risk of CHD. Based on prevalen…
FISH screening of aneuploidies in preimplantation embryos to improve IVF outcome
2005
Preimplantation genetic diagnosis (PGD) has transformed the approach to the infertility patient in the IVF setting. Although the principal applications of PGD have been to prevent the transmission of sex-linked diseases, in time and with growing knowledge of the chromosomal abnormalities observed in preimplantation embryos, its applications have widened. Nowadays, apart from its implications in the prevention of transmission of chromosomal and genetic abnormalities, PGD is being used with increased frequency to improve the IVF outcome in patients with advanced maternal age (or =38 years of age), recurrent miscarriage (or =2 miscarriages), recurrent IVF failure (or =3 failed IVF attempts) an…
Incidence, age at onset, and potential reasons of malignant transformation in recurrent respiratory papillomatosis patients: 20 years experience
2005
Forty-two patients with recurrent respiratory papillomatosis (RRP) were accepted into a multicenter prospective study in 1983 to 1990, treated with alfa-IFN 3 MU/m 2 3 times a week and then followed-up until August 1, 2003. All the patients who had disease progression with pulmonary spread were characterized by insufficient response to IFN-therapy and detection of HPV type 11. Five patients (4/5 smokers) presented malignant transformation in lungs or nasopharynx (mean RRP duration was 27.2 +/- 8 years from RRP onset and 14.6 +/- 6.3 years from pulmonary spread until malignant transformation) with persistent RRP in larynx. The results of long-term follow-up in RRP patients with HPV 11 underl…
Increased Neural Activity in Mesostriatal Regions after Prefrontal Transcranial Direct Current Stimulation and L-DOPA Administration
2019
Dopamine dysfunction is associated with a wide range of neuropsychiatric disorders commonly treated pharmacologically or invasively. Recent studies provide evidence for a nonpharmacological and noninvasive alternative that allows similar manipulation of the dopaminergic system: transcranial direct current stimulation (tDCS). In rodents, tDCS has been shown to increase neural activity in subcortical parts of the dopaminergic system, and recent studies in humans provide evidence that tDCS over prefrontal regions induces striatal dopamine release and affects reward-related behavior. Based on these findings, we used fMRI in healthy human participants and measured the fractional amplitude of low…
The development of a Spanish language version of the Worn Out scale of the General Well-Being Questionnaire (GWBQ).
2006
The paper describes the development of a short Spanish-language version of the General Well-Being Questionnaire (GWBQ; Cox & Gotts, 1987), based on the 12 items of its Worn Out scale. Research has shown the English-version Worn Out scale to be sensitive to aspects of the design and management of work. This study aimed to test its cross-cultural consistency in a Spanish-language workplace context. The data were collected from a sample of 229 workers in Valencia (Spain). Confirmatory Factor Analyses showed the factorial validity, reliability, and concurrent validity of the new Spanish version to be adequate. The sensitivity of the new measure to safety behavior and the reporting of accide…
Reduced Threshold for Inhibitory Homeostatic Responses in Migraine Motor Cortex? A tDCS/TMS Study
2014
Background and Objective Neurophysiological studies in migraine have reported conflicting findings of either cortical hyper- or hypoexcitability. In migraine with aura (MwA) patients, we recently documented an inhibitory response to suprathreshold, high-frequency repetitive transcranial magnetic stimulation (hf-rTMS) trains applied to the primary motor cortex, which is in contrast with the facilitatory response observed in the healthy subjects. The aim of the present study was to support the hypothesis that in migraine, because of a condition of basal increased cortical responsivity, inhibitory homeostatic-like mechanisms of cortical excitability could be induced by high magnitude stimulati…
Visual cortex hyperexcitability in migraine in response to sound-induced flash illusions
2015
Objective: Sound-induced flash illusions depend on visual cortical excitability. In this study, we explored whether sound-induced flash illusions are perceived differently in migraine, a condition associated with pathologic cortical hyperexcitability. Methods: Sound-induced flash illusions were examined in 59 migraine patients (mean age = 32 ± 16 years; 36 females), 32 without aura and 27 with aura, and in 24 healthy controls (mean age = 42 ± 17 years; 16 females). Patients were studied during attacks and interictally. Visual stimuli (flashes) accompanied by sounds (beeps) were presented in different combinations: a single flash with multiple beeps was given to induce the perception of mult…
Effects of transcranial direct current stimulation of the primary sensory cortex on somatosensory perception.
2011
Background: Transcranial direct current stimulation (tDCS) is able to modify cortical excitability and activity in humans. Objective: The aim of the present study was to analyze the effects of tDCS of the primary sensory cortex (SI) on thermal and mechanical perception, assessed by quantitative sensory testing (QST). Methods: The comprehensive QST protocol encompassing thermal and mechanical detection and pain thresholds as devised by the German Research Network on Neuropathic Pain (DFNS) was applied to skin areas innervated by the radial and median nerve of 12 healthy subjects, who were examined before and after each tDCS stimulation type. Anodal, cathodal, and sham tDCS was applied at a 1…
Brief depression among patients in general practice
1994
Depression with substantial psychosocial impairment, but not qualifying as depressive disorder according to the standard diagnostic manuals, is frequent among primary care patients. Recurrent brief depression (RBD) is a diagnostic category intended to identify a major proportion of this group of patients. The WHO study on "Psychological Problems in Primary Health Care" was used as a vehicle to estimate the proportion of patients with this diagnosis and to evaluate the validity of this diagnosis as well as of alternative concepts of brief depression with multiple episodes. This study applies a two-stage sampling scheme; 300 patients also underwent an additional interview tailored for variant…