Search results for "threshold"
showing 10 items of 688 documents
Olfactory Dysfunction After Head Injury
2008
Objective: To determine the incidence of olfactory dysfunction after head trauma using clinical and radiologic findings, quantitative assessment, and electro-physiologic methods. Participants: A total of 190 patients with head trauma of different severity (n = 32 with mild traumatic brain injury (TBI), n = 94 with signs of moderate TBI, and n = 64 with severe TBI) 6 to 32 months prior to the study. Design: Patients were selected retrospectively, surveyed by telephone (n = 190), and screened for olfactory function with Brief Smell Identification Test (n = 82). Those with olfactory dysfunction were assessed as outpatients using the Sniffin' Sticks (n = 19) and olfactory-evoked potential recor…
Pseudoradicular and radicular low-back pain--a disease continuum rather than different entities? Answers from quantitative sensory testing.
2006
To assess whether pseudoradicular low-back pain may be associated with subclinical sensory deficits in the distal extremity, we applied the quantitative sensory testing protocol of the German Research Network on Neuropathic Pain (DFNS) in 15 patients with pseudoradicular pain distribution. Sixteen age- and gender-matched healthy control subjects as well as 12 patients with radicular pain syndromes (L4-S1) were studied with the same protocol. Radicular pain was diagnosed using clinical criteria (pain radiation beyond the knee, motor-, sensory-, or reflex deficits, positive Lasegue's test). Z-score QST profiles revealed a selective loss of vibration detection, detection of v. Frey hair contac…
Increased visual cortical excitability in ecstasy users: a transcranial magnetic stimulation study
2003
To test the presence of abnormalities of visual cortical excitability in people using ecstasy as a recreational drug.Ecstasy users and control subjects underwent single pulse transcranial magnetic stimulation (TMS) of the occipital cortex. The phosphene threshold was analysed and compared in the two groups.Phosphene thresholds were significantly lower in ecstasy users compared with control subjects, and were correlated negatively with frequency of ecstasy use. Frequency of use was positively correlated with the presence of visual hallucinations. The phosphene threshold of subjects with hallucinations was significantly lower than that of subjects without hallucinations.The use of ecstasy as …
Transcranial direct current stimulation of the motor cortex induces distinct changes in thermal and mechanical sensory percepts
2009
Abstract Objective The aim of this single-blinded, complete crossover study was to evaluate the effects of tDCS on thermal and mechanical perception, as assessed by quantitative sensory testing (QST). Methods QST was performed upon the radial part of both hands of eight healthy subjects (3 female, 5 male, 25–41 years of age). These subjects were examined before and after cathodal, anodal or sham tDCS, applied in a random order. TDCS was administered for 15 min at a 1 mA current intensity, with the active electrode placed over the left primary motor cortex and the reference electrode above the right orbit. Results After cathodal tDCS, cold detection thresholds (CDT), mechanical detection thr…
Speech Perception: Phonological Neighborhood Effects on Word Recognition Persist Despite Semantic Sentence Context
2019
This study tested the hypothesis that two lexical properties, both phonological neighborhood density (ND) and neighborhood frequency (NF), influence the recognition of target words when preceded by either a semantically congruent or semantically neutral context. Our study is the first to test this hypothesis using a language other than English (i.e., Spanish). We used highly familiar bisyllabic nouns with medium-frequency occurrence as target words, and we expected recognition accuracy to increase as ND and NF decreased in both semanticallly congruent and semantically neutral sentences. We presented 48 undergraduate listeners with a set of 80 words, differing in ND and NF, within these two…
Sensitivity of laser-evoked potentials versus somatosensory evoked potentials in patients with multiple sclerosis
2003
Somatosensory evoked potentials (SEPs) play a less important role in the diagnosis of multiple sclerosis (MS) than visually evoked potentials. Since standard SEPs only reflect the dorsal column function, we now investigated spinothalamic tract function in patients with MS using laser-evoked potentials (LEPs).LEPs to thulium laser stimuli (3ms, 540 mJ, 5mm diameter) were recorded from 3 midline positions (Fz, Cz, Pz) in 20 patients with MS, and 6 patients with possible but unconfirmed MS. Peak latencies and peak-to-peak amplitude of the vertex potential negativity (N2) and positivity (P2) were evaluated and compared with normative values from 22 healthy control subjects. Median and tibial ne…
Cardiorespiratory and Neuromuscular Responses to Motocross Riding
2008
The aim of the present study was to examine physiological and neuromuscular responses during motocross riding at individual maximal speed together with the riding-induced changes in maximal isometric force production. Seven A-level (group A) and 5 hobby-class (group H) motocross-riders performed a 30-minute riding test on a motocross track and maximal muscle strength and oxygen uptake (VO2max) tests in a laboratory. During the riding the mean (+/-SD) VO2 reduced in group A from 86 +/- 10% to 69 +/- 6% of the maximum (P < 0.001), whereas in group H the corresponding reduction was from 94 +/- 25% to 82 +/- 20% (P < 0.05). This relative VO2 during the riding correlated with riding speed (r = 0…
Studies on adaptation to complete dentures. Part II: Oral stereognosis and tactile sensibility
1995
High oral perception is thought to contribute to poor adaptation to new dentures. The aim of this study was to evaluate the oral stereognosis and tactile sensibility in edentate subjects and relate these to patient age and capability of adaptation to new prostheses. A total of 67 patients were provided with new complete dentures 2-3 weeks before the experiment. In 54 subjects, the oral stereognosis was evaluated by 12 different test-pieces, which were placed unseen on the tongue and had to be recognized. In 38 patients, the oral tactile sensibility was determined in the premolar area using copper foils. The capability of adaptation was evaluated by a questionnaire. Denture retention was ass…
Tap water consumers differ from non-consumers in chlorine flavor acceptability but not sensitivity
2010
International audience; Unpleasant taste and especially chlorine flavor is one of the most common reasons advocated for choosing tap water alternatives as drinking water. As a consequence, the putative link between sensitivity to chlorine flavor and tap water consumption is an issue in drinking water habits studies. In the present study, we set out to examine such a link following a strategy in which we measured chlorine flavor perception at threshold and supra-threshold level for two groups of participants selected on their drinking water consumption habits. The first group included exclusive tap water consumers and the second group included exclusive bottled water consumers. In a first ex…
Tas1R1-Tas1R3 taste receptor variants in human fungiform papillae.
2009
International audience; Monosodium glutamate as well as metabotropic and ionotropic glutamate receptor agonists have been reported to be perceived as umami by humans. In spite of the fact that Tas1R1-Tas1R3 has been shown to mediate most of the glutamate taste sensation in mice other candidate receptors have been put forward for which a clear role in detection is still lacking. This work was aimed at investigating the molecular determinants underlying umami taste detection in humans. First, we show evidence supporting expression of Tas1R1 and Tas1R3 but not mGluRs in the fungiform papillae of several individuals. Next, we report a number of naturally occurring l-glutamate taste receptor var…