Sensory Phenomenon Research Articles

Phenytoin, folic acid and gingival enlargement: Breaking myths.

Background:Epilepsy is described as a chronic neurological disorder characterized by recurrent seizures of cerebral origin, presenting with episodes of sensory, motor or autonomic phenomenon with or, without loss of consciousness. A recent meta-analysis of published and unpublished studies puts an overall prevalence rate of epilepsy in India at 5.59 per 1,000 populations. There have been studies that report clinical benefits of the use of folic acid as an adjuvant to the anti-epileptic therapy in the prevention of anti-epileptic drug induced gingival enlargement. However, studies conducted in the past have also reported precipitation of epileptic attacks in patients on folic acid adjuvant therapy due to fall in sera levels of phenytoin due to drug interactions. The study was planned to investigate the association of phenytoin induced gingival enlargement and sera levels of folic acid in epileptic patients on phenytoin therapy so as to justify the use of folic acid as a routine adjuvant to the usual anti-epileptic therapy to prevent this inevitable adverse effect without destabilizing the ongoing regimen leading to the precipitation of seizures in an otherwise stable patient (breakthrough seizures).Materials and Methods:A total of 100 patients between the ages 18 and 50 years were clinically diagnosed with epilepsy prior to the start of phenytoin therapy were included based on selection criteria and written informed consents were obtained. Assessment of serum folic acid levels and gingival enlargement was performed prior to the start of and after 1 year of phenytoin therapy.Statistical Analysis Used:The statistical analysis was carried out using t-test and the baseline serum folate levels and the serum folate levels obtained after 1 year of phenytoin therapy were correlated with the respective grades of gingival enlargement using Pearson's coefficient formula.Results:The results of the study confirmed a significant association between low serum folate levels with increasing severity as well as an early onset of phenytoin induced gingival enlargement.Conclusions:The results of the study suggest a higher incidence of gingival enlargement with an early onset and increased severity in phenytoin treated epileptic patients with a positive correlation with falling serum folic acid levels as the duration of the therapy increases.

SENSORY NEURONOPATHY; A CASE REPORT AND A REVIEW OF THE ROLE OF GANGLION NERVE BIOPSY IN DIAGNOSIS

Dorsal root ganglionopathies present with sensory ataxia, areflexia and asymmetrical positive and negative sensory phenomenon of both limb often with trigeminal involvement. There may be associated Adie's pupil1 Despite their...

Sensory and chemical interactions of food pairings (basmati rice, bacon and extra virgin olive oil) with banana

The aim of this study aimed to investigate food pairings as an important sensory phenomenon in order to determine how different components in the selected food pairings affect and interact with other components. Three novel food pairings (banana and bacon, banana and olive oil, and banana and rice) were selected. A conjoint approach utilising qualitative (organic volatile analysis and descriptive sensory analysis) and quantitative (comparable semi quantitative organic volatile analysis and affective sensory tests) methods of analysis n an attempt to elucidate the success or failure of selected food pairings. Free choice profiling (descriptive sensory analysis) data was analysed using Generalised Procrustes analysis. The correlation between volatile analysis and descriptive sensory analysis results were analysed using ANOVA partial least squared regression. Hedonic results were analysed using a Friedman rank sum test, while preference results were analysed using a Wilcoxon signed rank test. The food pairings of banana and bacon and banana and rice were found to be liked significantly more than banana and olive oil. The results of this study suggest that synergistic and/or antagonistic interactions between the volatile compounds in the foods influenced the hedonic ratings of these food pairings.

Experiencing Dalmatia: What Constitutes the Sensory Landscape Identity of the Dalmatia Region?

The article addresses the concept of landscape identity considered from a new perspective – a perspective of five fundamental human senses: sight, hearing, smell, touch and taste. Landscape identity is mostly understood as a phenomenon based on its distinguishable visual characteristics. However, human environment is a multisensory medium, rich in information from all fields of perception. Equally, a man is a multisensory being and experiences his environment with multiple senses. The underlying assumption is that human identification with places does not only arise from the interaction with their visual, but also with their auditory, olfactory, tactile, and even gustatory properties. As a research area, the Dalmatia region in Croatia has been chosen. By the content analysis method, applied on samples of lyric poems and promotional (mostly tourist) materials, the aim was to examine what features, visual and non-visual, the social conception of Dalmatian landscape is based on. The results show that landscape identity of Dalmatia, in terms of sensory perception, is rather diverse. Understanding landscape identity as a sensory multidimensional phenomenon opens many new questions and possibilities in the field of landscape theory and practice.

Modulation of proprioceptive feedback during functional electrical stimulation: an fMRI study

Functional electrical stimulation (FES) is sometimes used as a therapeutic modality in motor rehabilitation to augment voluntary motor drive to effect movement that would otherwise not be possible through voluntary activation alone. Effective motor rehabilitation should require that the central nervous system integrate efferent commands and appropriate afferent information to update the internal models of acquired skills. Here, we investigate whether FES-evoked (FES-ev) and FES-assisted (FES-as) movement are associated with the normal integration of motor commands and sensory feedback in a group of healthy participants during functional magnetic resonance imaging (fMRI). Sensory feedback was removed with a peripheral ischaemic nerve block while the participants performed voluntary (VOL), FES-ev or FES-as movement during fMRI. Before the peripheral nerve block, secondary somatosensory area (S2) activation was greater for the FES-ev and FES-as conditions than for the VOL condition. During the ischaemic nerve block, S2 activation was reduced for the FES-ev condition but not for FES-as and VOL conditions. The nerve block also reduced activation during FES in the primary somatosensory cortex and other motor areas including primary motor cortex, dorsal premotor cortex and supplementary motor area. In contrast, superior parietal lobule (area 7A) and precuneus activation was reduced as a consequence of the ischaemic nerve block in the VOL condition. These data suggest FES-related S2 activation is mainly a sensory phenomenon and does not reflect integration of sensory signals with motor commands.

Synesthésies, un monde sensoriel augmenté : phénoménologie et revue de la littérature

Synaesthetic people are probably more numerous than usually thought. This unique sensory phenomenon may concern up to 4% of the general population. Physicians are not very aware of synaesthesias because synaesthetes ignore themselves and most often consider this perceptive faculty as common and not pathological. We report in detail a grapheme-phoneme to colour developmental synaesthesia in a 54-year-old woman. The major contribution of research over the last two decades is also summarized.

Auditory Enhancement of Increments in Spectral Amplitude Stems from More Than One Source

A component of a test sound consisting of simultaneous pure tones perceptually "pops out" if the test sound is preceded by a copy of itself with that component attenuated. Although this "enhancement" effect was initially thought to be purely monaural, it is also observable when the test sound and the precursor sound are presented contralaterally (i.e., to opposite ears). In experiment 1, we assessed the magnitude of ipsilateral and contralateral enhancement as a function of the time interval between the precursor and test sounds (10, 100, or 600 ms). The test sound, randomly transposed in frequency from trial to trial, was followed by a probe tone, either matched or mismatched in frequency to the test sound component which was the target of enhancement. Listeners' ability to discriminate matched probes from mismatched probes was taken as an index of enhancement magnitude. The results showed that enhancement decays more rapidly for ipsilateral than for contralateral precursors, suggesting that ipsilateral enhancement and contralateral enhancement stem from at least partly different sources. It could be hypothesized that, in experiment 1, contralateral precursors were effective only because they provided attentional cues about the target tone frequency. In experiment 2, this hypothesis was tested by presenting the probe tone before the precursor sound rather than after the test sound. Although the probe tone was then serving as a frequency cue, contralateral precursors were again found to produce enhancement. This indicates that contralateral enhancement cannot be explained by cuing alone and is a genuine sensory phenomenon.

Synaesthetic Associations Decrease During Infancy

Early development is characterized by a period of exuberant neural connectivity followed by a retraction and reweighting of connections over the course of development. It has been proposed that this connectivity may facilitate arbitrary sensory experiences in infants that are unlike anything experienced by typical adults but are similar to the sensory experiences of adults with synaesthesia, a rare sensory phenomenon that has been associated with exuberant neural connectivity and that is characterized by strong arbitrary associations between different sensations. We provide the first evidence for this infant-synaesthesia hypothesis by showing that the presence of particular shapes influences color preferences in typical 2- and 3-month-olds, but not in 8-month-olds or adults. These results are consistent with the possibility that exuberant neural connectivity facilitates synaesthetic associations during infancy that are typically eliminated during development, but that a failure of the retraction process leads in rare cases to synaesthesia in adults.

Clinical characteristics and treatment of dystonia

Dystonia is defined as a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements, or abnormal postures. Its diagnosis is based on clinical characteristics. In dystonia, the pattern of abnormal posture or movement tends to be constant during the short term even if its severity fluctuates. This stereotypy often helps differentiate dystonia from psychogenic reaction. Dystonia may appear only during some specific task (task specificity) especially in its early phase, although it often becomes obscure during the long clinical course, resulting in persistent dystonic posture. Sensory trick or geste antagoniste means the change of severity triggered by some sensory input Overflow phenomenon is the activation of muscles unnecessary to a task, hampering purposeful movement. Symptoms tend to be milder in the morning, with large individual variation of its duration (morning benefit). Symptoms of dystonia may abruptly appear or disappear (flip-flop phenomenon). Cocontraction, believed as an essential feature of dystonia, reflects a loss of reciprocal inhibition of muscle activities, causing involuntary simultaneous contractions of agonists and antagonists. "Negative dystonia," still an unaccepted feature of dystonia, is defined as non-paretic loss of central driving of muscle activities necessary to a task. Apraxia of lid opening/closure, paretic form of hand dystonia, dropped head syndrome, camptocormia, Pisa syndrome, cervical dystonia with limited range of head movement, or mandibular dystonia without cocontractions of masticatory muscles, can be explained with this concept at least in a subset of cases. Treatment of dystonia includes medication, botulinum toxin injection, intrathecal baclofen, surgical intervention, acupuncture and other alternative therapies, rehabilitation, and psychotherapy. Oral medication is usually an adjunct to more potent therapeutic options except for some specific indications like dopa-responsive dystonia. Botulinum toxin is usually the treatment of choice for focal dystonia. Deep brain stimulation can be considered for both focal and non-focal phenotypes of dystonia.

COMT Val108/158Met genotype modulates human sensory gating

BackgroundThe catechol-O-methyltransferase (COMT) Val108/158Met polymorphism of the dopamine system is essential for prefrontal cortex processing capacity and efficiency. In addition, dopaminergic neurotransmission is also associated with the sensory gating phenomenon protecting the cerebral cortex from information overload. It is however unclear if COMT genotype as a predictor of prefrontal efficiency modulates sensory gating on the level of the auditory cortex, i.e. the gating of the auditory evoked P50 and N100 components. MethodsP50 and N100 gating and COMT Val108/158Met genotype were determined in 282 healthy subjects of German descent carefully screened for psychiatric or neurological disorders. ResultsA significant effect of the COMT genotype was observed for N100 gating (F=4.510, df=2, p=0.012) but not for P50 gating (F=0.376, df=2, p=0.687). Contrast analysis showed that Met/Met individuals had poorer N100 gating compared to Val/Met (F=−12.931, p=0.003) and the Val/Val individuals (F=−11.056, p=0.057). ConclusionThe results indicate that a high prefrontal efficiency as suggested by the COMT Met/Met genotype is associated with to a poor sensory gating of the N100 component. This would fit in a model where a high prefrontal processing capacity allows a pronounced afferent input of sensory information from the auditory cortex as reflected by a poor sensory gating. The more pronounced prefrontal contribution to the N100 compared to the P50 component may explain the exclusive genotype association with the N100 sensory gating. This preliminary model should be replicated and validated in future investigations.

At sanse smagen af tv-medieret mad [To sense the taste of TV-mediated food

How is it possible for a food programme to give me a sensory experience of taste, when the two most important senses – the actual smell and taste – are not in play? This is a sensory paradox that this article will examine. The argumentation is apparent in descriptions about the sensory phenomenon synaesthesia, which basically suggests that we can think about the senses as co-dependent. I will argue that food programmes use sensory strategies – that is synaesthetic strategies – in order to mediate a specific and sensory experience of taste. In light of this, I will analyse two Danish produced food programmes, “Spise med Price” (2008-2009) and “Du er hvad du spiser” (2005-2007), in order to establish a profound understanding of the food programmes’ sensory dramaturgical tools.

A Study on Bidirectional Detection Safety Equipment Mechanism for Casualty Accidents Protection of Railroad Workers and Motorcars

Workers maintaining at the railroad trackside may collide with the train since they cannot recognize the train approaching because of the sensory block phenomenon occurred due to their long hours of continued monotonous maintenance work. To reduce these casualty accidents of maintenance workers working at the trackside of railroad, we developed the wireless communication-based safety equipment for preventing accidents. The motor-cars for maintaining trackside facility have unique operational patterns suitable for urban environment. The several mechanism for developed safety equipment are represented in this paper.

Right Sensory Alien Hand Phenomenon from a Left Pontine Hemorrhage

BackgroundAcute onset of a sensory alien hand phenomenon has been observed only from a supratentorial lesion involving the non-dominant hand, mostly from a right posterior cerebral artery infarction. A single acute vascular lesion resulting in a dominant hand sensory alien hand syndrome has not been previously documented.Case ReportA 78-year old right-handed woman exhibited right sensory alien hand phenomenon from a left pontine hemorrhage. Disturbance of proprioceptive input and visuospatial perception are likely to play a role in manifesting the sign.ConclusionsDominant-hand sensory alien hand phenomenon may occur in an acute setting from a left pontine hemorrhage.

Sensory dominance in combinations of audio, visual and haptic stimuli

Participants presented with auditory, visual, or bi-sensory audio-visual stimuli in a speeded discrimination task, fail to respond to the auditory component of the bi-sensory trials significantly more often than they fail to respond to the visual component--a 'visual dominance' effect. The current study investigated further the sensory dominance phenomenon in all combinations of auditory, visual and haptic stimuli. We found a similar visual dominance effect also in bi-sensory trials of combined haptic-visual stimuli, but no bias towards either sensory modality in bi-sensory trials of haptic-auditory stimuli. When presented with tri-sensory trials of combined auditory-visual-haptic stimuli, participants made more errors of responding only to two corresponding sensory signals than errors of responding only to a single sensory modality, however, there were no biases towards either sensory modality (or sensory pairs) in the distribution of both types of errors (i.e. responding only to a single stimulus or to pairs of stimuli). These results suggest that while vision can dominate both the auditory and the haptic sensory modalities, it is limited to bi-sensory combinations in which the visual signal is combined with another single stimulus. However, in a tri-sensory combination when a visual signal is presented simultaneously with both the auditory and the haptic signals, the probability of missing two signals is much smaller than of missing only one signal and therefore the visual dominance disappears.

Comparison of Midlatency Auditory Sensory Gating at Short and Long Interstimulus Intervals

Rationale: Suppression of P50, N100 and P200 auditory evoked responses in a dual-click procedure is considered an index for the multistage sensory gating process. Whereas most studies use a protocol with long interstimulus intervals of 8–12 s between the stimuli pairs, there is also evidence that sensory gating occurs at much lower intervals. The aim of the study was to investigate whether a simple modified dual-click protocol with short interstimulus intervals elicts similar sensory gating ratios compared to the classic protocol. Methods: P50, N100 and P200 amplitudes and sensory gating ratios were measured in 23 healthy subjects with 2 different dual-click protocols in 1 session: (1) a simple oddball modified with short interstimulus intervals of about 2.8 s (ISI2), and (2), the classic used with long intervals of about 8 s (ISI8). Results: The amplitudes of the P50, N100 and P200 responses were mostly comparable and correlated between both protocols. Mean sensory gating ratios (ISI8/ISI2) were as follows: P50, 35.4/36.4%; N40P50, 36.1/39.9%; N100, 44.4/48.4%; P200, 46.8/43.3%; N100P200, 45.3/41.8%; all differences between protocols, p > 0.1. P50 ratio scores did not show a sufficient correlation between protocols [intraclass correlation coefficient (ICC) P50, 0.13; N40P50, 0.0] compared to N100 (ICC, 0.79), P200 (ICC, 0.6) and N100P200 (ICC, 0.61). Conclusion: Our results contradict the assumption that long interstimulus intervals of about 8 s are absolutely necessary to elicit a marked sensory gating phenomenon for P50, N100 and P200 auditory responses (at least when using a protocol with a simple attention task). However, because only healthy subjects were investigated, no prediction can be made for psychiatric patients, in whom neuronal processing may be different.

Toward a Biopsychomotor Conceptualization of Pain

Nearly 400 years ago, René Descartes proposed a model of pain perception that characterized pain as a purely physical phenomenon, devoid of psychologic influence. The characterization of pain as an exclusively sensory (or experiential) phenomenon continues to dominate current conceptualizations of pain. This paper advances the view that the exclusive focus on pain sensation or experience as the essential feature of the pain system has given rise to conceptual frameworks that are incomplete and flawed. It is argued that individuals with pain differ from individuals without pain not only in how they "feel" but they differ in how they "behave." Arguments are put forward advocating for a biopsychomotor conceptualization of pain where pain behaviors are construed as integral components of the pain system. The biopsychomotor model proposes that at least 3 partially independent behavioral subsystems are integral components of pain. These include communicative pain behaviors, protective pain behaviors, and social response behaviors. Evidence is reviewed suggesting that different dimensions of pain behavior are functionally distinct, and questions are raised about the nature of motor programs responsible for the elicitation and maintenance of different forms of pain behavior. Clinical and theoretical implications of a biopsychomotor conceptualization of pain are discussed.

Application of an electronic nose for measurements of boar taint in entire male pigs

An electronic nose based on ion mobility spectrometry was used for boar taint measurements of entire male pig samples varying in androstenone and skatole levels (0.09–0.88 μg/g fat and 0.01–0.26 μg/g fat, respectively). Sensory perceptible boar taint (especially boar odour) was found to be more related to androstenone than to skatole, whereas a rancid note was determined more related to skatole than to androstenone. Multivariate models implementing some generally prescribed cut-off limits for androstenone (0.50 μg/g) and skatole (0.21 μg/g) indicated that the e-nose could be used for ordering samples with respect to low and high levels of androstenone and skatole. Studying the direct relationships between e-nose data, sensory data, androstenone and skatole showed better predictivity of the chemical compounds (androstenone: r = −0.948, RMSEP = 0.309; skatole: r = −0.629, RMSEP = 0.069) than for single sensory descriptors (boar odour r = 0.409, RMSEP = 0.789). The results thus suggest that the e-nose technology based on ion mobility spectrometry as in the MGD-1 may have a potential for future rapid sorting of boars at the slaughter line. The study provides new knowledge of the applicability of ion mobility spectrometry for measuring boar taint and also confirms the challenge of measuring boar taint using chemically determined cut-off limits for a sensory perceptible phenomenon. Thus, future development should be more devoted to developing holistic approaches rather than focusing on the influence of single variables on boar taint.

Postherpetic Pain: More Than Sensory Neuralgia?: Table 1

To describe a series of older adult patients with postherpetic myofascial pain, a heretofore rarely described complication of herpes zoster. Case series. Outpatient older adult pain clinic. Five older adults are presented with myofascial pain that developed as a complication of herpes zoster. Pain duration at the time of presentation ranged from 4 months to 7 years. All patients reported functional impairment from pain despite oral analgesics. Myofascial pathology was diagnosed by the presence of taut bands and trigger points in the affected myotome. Upon successful treatment of the myofascial pain with nonpharmacologic modalities (e.g., physical therapy, trigger point injections, dry needling, and/or percutaneous electrical nerve stimulation), all patients reported symptomatic improvement, and four out of five were able to significantly reduce or discontinue their opioids. Postherpetic pain is traditionally conceptualized as a purely sensory phenomenon. Identification of the intrusion of a myofascial component may be worthwhile, both from the standpoint of enhanced pain relief and reduction in the need for oral analgesics. Formal exploration of this phenomenon is needed.

How important is lateral masking in visual search?

Five experiments are presented, providing empirical support of the hypothesis that the sensory phenomenon of lateral masking may explain many well-known visual search phenomena that are commonly assumed to be governed by cognitive attentional mechanisms. Experiment I showed that when the same visual arrays are used in visual search and in lateral masking experiments, the factors (1) number of distractors, (2) distractor density, and (3) search type (conjunction vs disjunction) have the same effect on search times as they have on lateral masking scores. Experiment II showed that when the number of distractors and eccentricity is kept constant in a search task, the effect of reducing density (which reduces the lateral masking potential of distractors on the target) is to strongly reduce the disjunction-conjunction difference. In experiment III, the lateral masking potential of distractors on a target was measured with arrays that typically yield asymmetric search times in visual search studies (a Q among Os vs. an O among Qs). The lateral masking scores showed the same asymmetry. Experiment IV was a visual search study with such asymmetric search arrays in which the number of distractors and eccentricity was kept constant, while manipulating density. Reducing density (i.e., reducing lateral masking) produced a strong reduction of the asymmetry effect. Finally in experiment V, we showed that the data from experiment IV cannot be explained due to a difference between a fine and a coarse grain attentional mechanism. Taken together with eye movement data and error scores from experiment II and with similar findings from the literature, these results suggest that the sensory mechanism of lateral masking could well be a very important (if not the main) factor causing many of the well-known effects that are traditionally attributed to higher level cognitive or attentional mechanisms in visual search.

Aquadynia. a manifestation of small fiber sensory neuropathy?

Aquadynia is a rare phenomenon of water‐induced pain through presumed neural mechanisms. We describe two women in whom bathing was regularly followed by pain in the lower limbs, as a unique symptom (case 1) and, respectively, in the clinical context of an axonal polyneuropathy (case 2). Case 1: A 71‐year‐old woman complained, by age 69, of pruritus and pinprick‐like pain in the extremities that lasted about 20 minutes following bathing. Neurological examination and electroneurography were negative, as well as investigations for systemic diseases. Quantitative sensory testing (QST) showed abnormal cold‐pain sensation. Treatment with gabapentin was not effective. Case 2: A 69‐year‐old woman affected with HCV‐related cryoglobulinemia had numbness and aquadynia in the distal lower limbs and restless legs syndrome, in the last few months. Neurological examination showed absent ankle jerks, and decreased touch and vibration sense in the feet. Electroneurography demonstrated an axonal neuropathy. Aquadynia likely represents a manifestation of small fiber neuropathy. It is unclear whether it has to be viewed as a primary sensory phenomenon similar to allodynia, or a type of noradrenergic pain primarily due to autonomic dysfunction. Alteration of QST in case 1, and the association with obvious features of sensory neuropathy in case 2, may favour the sensory hypothesis.