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Contingent negative variation in childhood migraine.

Adult migraineurs without aura have an increased amplitude of the Contingent Negative Variation (CNV) between attacks. Given the potential diagnostic importance of this finding and the difficulties associated with diagnosing migraine in childhood it seemed important to assess CNV in children suffering from this disorder. Ninety-seven children aged between 8 and 14 years were recruited. Forty-two suffered from migraine, 34 from tension-type headache. Twenty-one healthy controls were also studied. CNV was recorded from Fz, Cz and Pz referenced to linked earlobes during 20 trials consisting of two tones of moderate intensity with an interstimulus interval (ISI) of 4 sec and an intertrial interval (ITI) of 10 to 14 sec. The second tone of each trial required a button press. EOG was recorded from the left eye. The 10 CNV responses with the least EOG artefact were selected and averaged. Children with migraine had a highly significantly more negative mean CNV amplitude at all three electrode sites than children with tension-type headache and also a more pronounced Post-Imperative-Negative-Variation (PINV). Migrainous children differed from controls only at Cz (ISI). There was also a highly significant increase of mean CNV amplitude and PINV at all three electrode sites in the control group compared to the tension headache group.

Adolescent↗

Contingent negative variation indicates phasic arousal for externally cued unilateral eye blink in human subjects.

The contingent negative variation (CNV) as a slow cortical potential was used to investigate cortical processing of externally cued, voluntary unilateral eye blink. Probands blinked as a response within a modified two-stimulus reaction time paradigm. Reaction time and amplitudes of CNV were determined. The activity of the orbicularis oculi muscles (OO) was registered by surface electromyography (EMG). Probands who performed unilateral eye blinks with accurately inhibiting contralateral OO activity showed a significantly higher negativity of the early CNV component compared with the bilateral eye blink condition. This effect was confined to the beginning of unilateral blinking performance. It is suggested that the unilateral eye blink is a challenging motor task, initially requiring an increased cortically driven arousal and attention as revealed by increased early CNV components.

Adult↗

Interictal and postictal contingent negative variation in migraine without aura.

Cortical hyperexcitability is thought to explain the more enhanced contingent negative variation (CNV) amplitudes and impaired CNV habituation that have been found during the interictal period in migraine without aura. These CNV characteristics have been shown to normalize to the level of healthy controls during an attack. This study aimed to replicate the interictal findings, and additionally examine whether migraineurs show reduced CNV amplitudes during the postattack period. Of 12 patients with migraine without aura and their sex- and age-matched healthy controls, CNV characteristics were recorded once in an interictal period, once during the postattack period within 30 hours after an attack that was treated with sumatriptan, and once after an attack that was treated with habitual nonvasoactive medication (counterbalanced). The present results did not confirm the enhanced CNV early and late wave amplitudes or impaired habituation, and cortical hyperexcitability that have previously been reported in the interictal period in patients with migraine without aura. During the postattack period, a decrease in CNV early and late amplitudes was found but only after sumatriptan use. This reduction in CNV amplitudes was most prominent over the frontal cortex and could reflect cortical hypoexcitability, possibly related to a suppression of central catecholaminergic activity by sumatriptan.

Adult↗

Contingent negative variation and reaction time of physically-trained subjects in simple and discriminative tasks.

Contingent negative variations (CNV) were recorded during the S1-S2 interval of two simple and one discriminative task at Fz, Cz and Pz of 12 physically-trained college athletes and 12 non-trained students. The reaction time to S2 was also measured. The whole mean CNV amplitude average over the 2 sec S1-S2 interval and the segmented CNV amplitudes of the 250 msec epochs were submitted to 4-way ANOVA (physical training x task x electrode position x gender), while the mean reaction time was analyzed by 3-way ANOVA. The whole mean CNV amplitude and all the segmented CNV amplitudes were greater in the physically-trained group than in the non-trained group. In all tasks the mean reaction times of the physically-trained group were significantly shorter than those of the non-trained group. The main effect of gender was not statistically significant with respect to the CNV amplitudes and the mean reaction time. The increased CNV amplitude and the shortened reaction time of the physically-trained group were discussed in relation to the reported psychophysiological correlates of CNV. The present study shows that CNV provides a technique of possible value for assessing attention and motor preparation of workers engaged in vigilance tasks.

Adult↗

Measurement of light touch perception threshold by contingent negative variation.

An objective method developed to measure the threshold of light touch perception using contingent negative variation (CNV) is described. The light touch stimulus was a slight indentation of the skin produced through a displacement controlled stimulating probe (tip diameter of 2 mm). It was applied as the conditioning (S1) stimulus of the classical CNV paradigm of S1, S2, and R. To increase the CNV amplitude, the S2 stimulus was either a red or a yellow LED. The subjects were required to respond to only one of two by pressing a button. When the light touch stimulus was perceived, the CNV was recorded in all 19 healthy adult volunteers. In 14 of them, a systematic determination of the threshold of the ball of the thumb and index finger, thenar, hypothenar, face, shoulder, anterior thigh, foot dorsum and great toe ball, have been done. The thresholds of the light touch perception as defined by objective CNV measurement are very close to the results of the subjective psychophysiological determinations in normals. The amplitude of the averaged CNV (12 responses) started to decrease when stimulus intensity was reduced to the point that the subjects were able to perceive only a fraction of the presented touch stimuli. We believe, therefore, that the objective CNV determination of the light touch perception threshold is precise and sensitive enough to be used in research as well as in clinical applications.

Adult↗

Age differences in the contingent negative variation (CNV): reduced frontal activity in the elderly.

The effects of distraction on the contingent negative variation (CNV) were investigated in a group of 11 elderly (mean = 72.2 years) and a group of 12 young (mean = 23.3 years) subjects. Scalp electrical activity was recorded from midline sites at frontal, central, and parietal locations. Three experimental conditions included Recall, No Recall, and Control situations. In the Recall, or distraction condition, spoken consonant-vowel-consonant (CVC) letters were presented concurrently with the CNV signal interval and were recalled by the subjects after each trial. The No Recall condition was similar to the Recall task except that subjects were not required to repeat the CVSs. The Control condition presented a standard S1 - S2 CNV situation without CVCs. Amplitudes of the CNV, reaction times (RTs), and heart rate (HR) served as indices of distraction. The effects of distraction for both age groups indicated reduced CNVs, lengthened RTs, and elevated HRs. However, a significant age by electrode interaction revealed that while CNV amplitudes at central and parietal sites were comparable between age groups, amplitudes at the frontal placement were consistently reduced in the elderly compared to the young in all conditions. The finding of diminished frontal activity, as measured by the CNV, suggests a process of selective cortical aging and possible cellular loss which may be linked to performance deficits.

Adult↗

The contingent negative variation (CNV) to fear-related stimuli in acquisition and extinction.

Contingent Negative Variation (CNV) in anticipation of phobic and neutral slide material was recorded in Acquisition of a learned association between tone pitch and slide type, and in Extinction (following removal of slide presentation). In phobic volunteers, no clear CNV differentiation between 'phobic' and control condition was apparent in either Acquisition or Extinction. For Control subjects, a different pattern entirely has been demonstrated, with anticipation of the neutral condition giving rise to a larger CNV than anticipation of the 'phobic' condition (in Acquisition). In addition, Extinction led to a reversal of this CNV amplitude relationship, with the tone previously associated with the phobic slide producing a DC-shift which was larger than that following the tone previously paired with the neutral slide. The results are compatible with a dynamic model of CNV generation according to which CNV amplitude is positively related to an expectancy for reward or non-punishment but inversely related to an expectancy for punishment or non-reward.

Adult↗

Contingent negative variation in processes of expectancy, motor preparation and time estimation.

The contingent Negative Variation (CNV) was compared in four paradigms inducing distinct processes. All paradigms comprised empty intervals of 4 sec bounded by two 100 msec stimuli (S1 and S2) or by S1 and the response (a button press). In paradigm ID (Intensity Discrimination), the S1-S2 interval was followed, after another delay, by a choice response depending on the intensity of S2. In paradigm RT (Reaction Time), the S1-S2 interval was followed by a simple reaction time. In paradigm TP (Time Production), the subjects had to produce a response 4 sec after S1. In paradigm TR (Time Reproduction), the duration of the S1-S2 interval was estimated by the subjects and was to be reproduced after S2. Electrodes were placed on Cz, Fz and Pz in 12 human subjects. The largest CNVs were obtained in paradigm TR. Motor preparation before S2 had no effect on CNV amplitude. Discussion focuses upon the relations between CNV, temporal processes and activation.

Adolescent↗

Movement-related cortical potentials and contingent negative variation in olivopontocerebellar atrophy.

Movement-related cortical potentials (MRCPs) and contingent negative variation (CNV) were recorded in 8 cases of olivopontocerebellar atrophy (OPCA) and 8 age-matched healthy controls. The amplitude of the negative slope (NS') was smaller in the OPCA group than in the healthy control group. The amplitude of late CNV was smaller in OPCA group than in the healthy control group. These abnormalities in MRCPs and CNV were improved by intravenous infusion of thyrotropin releasing hormone.

Aged↗

[Contingent negative variations in headache in children].

The paper presents a study concerning contingent negative variation (CND) in period between the attacks in 29 children with migraine, in 26 cases with a headache of tension (HAT) and in 16 healthy children. The age of the children examined was 7-14 years. The role of the age factor was shown in dynamics of the behavioral and electrophysiological CND parameters. Differences of electrophysiological CND parameters in children with migraine, in children with HAT and in healthy children of the same age are discussed as well as the results of the complex clinical-neurophysiological estimation of the efficiency of the prophylactic therapy in groups. CND method was considered to be quite perspective for differential diagnosis of primary headache in children.

Adolescent↗

Contingent negative variation audiometry in children.

The aim of the present work was to establish whether contingent negative variation audiometry (CNV-A) is applicable to children. In a group of 23 children aged 5-7 years, only 10 generated clearly recognizable CNV when tested with the method successfully used in adults. When the procedure was modified by prolonging the S1-S2 interval and by introducing attractive slides to serve as the S2 stimulus and by adopting a slower repetition rate, 9 children randomly selected from the former group generated high-amplitude CNV (10.1 +/- 4 mu V). The CNV-A measurements involving a longer auditory stimulus (S1), lasting nearly to the beginning of S2, and an even slower repetition rate were equally successful in 18 children aged 3-5 years, who generated CNV with an average amplitude of about 9 mu V (range 5-15 mu V). We believe that the basic problem of successful CNV recording in children is to attract their attention to the signals of the CNV paradigm. The child's attentiveness decreases rapidly. The mean difference and the absolute mean difference between the subjective hearing threshold for white noise and the perception threshold for white noise as determined by CNV-A were as follows: 8.8 +/- 8 dB (both values) for the older group, and 3 +/- 10.4 and 8.6 +/- 6.5 dB, respectively, for the younger group. These differences are quite comparable to those obtained in adults. We therefore believe that CNV-A, used in combination with the behavioral method, provides a most reliable estimate of the child's hearing threshold in dubious situations.

Age Factors↗

Contingent negative variation and psychopathology: frontal-central distribution, and association with performance measures.

Central and frontal contingent negative variation (CNV) were studied in psychiatric patients - schizophrenics, nonschizophrenic psychotics, schizotypics, and neurotics (according to DSM III) - and in a normal control group. The early CNV components and postimperative negativity were significantly different in schizophrenic and in nonschizophrenic psychotics, in contrast with their scores on some attentional performance tests. Only the central CNV was significantly correlated with severity of diagnosis, but multivariate analyses indicated the importance of frontal CNV and postimperative negativity in this respect. Topographical characteristics of the CNV also seem indicative of severity of psychiatric disturbance. These results are integrated in a composite index for further study. The general trend showed a moderately high degree of shared variance of central CNV components and performance measures, but not in regard to the other CNV measures, with variation found across diagnostic groups. No significant associations were found between CNV measures and affective and social functioning, and with Eysenck's personality dimensions.

Adult↗

Neurophysiological study of 47, XYY and 47, XXY psychopaths: contingent negative variation, evoked potentials and motor nerve conduction.

Neurophysiological investigations-including sensory-evoked responses, contingent negative variation (CNV), and nerve conduction velocities-were done in 11 male polygonosomic patients and in comparison with a control group. Some significant data are reported pointing out differences which may be related to a hypovigil type (47, XYY) and a hypervigil type (47, XXY). The importance of the CNV and conduction velocity as an index of a constitutional minimal brain dysfunction is discussed.

Adult↗

Contingent negative variation in adults with Gilles de la Tourette syndrome.

Three deflections or waves of the Contingent Negative Variation (CNV): the Slow Negative Wave (SNW), the Terminal CNV (TCNV) and the Post Imperative Negative Variation (PINV) were studied in 18 adults with Gilles de la Tourette syndrome and in 15 controls. The patients showed a reduced SNW, a normal TCNV and an increased PINV. Moreover, at the right parietal region the patients demonstrated a decreased SNW, TCNV and PINV. The results are discussed in relation to behavioral and neuropsychological disturbances found in Gilles de la Tourette syndrome.

Adolescent↗

[Two phases of the contingent negative variation in humans: connection with motor and mental functions].

The question of dependence of the contingent negative variation (CNV) on the regulating mechanisms of motor and mental functions is not sufficiently studied. The tasks of the present work were: to investigate the dependence of the CNV early and late phases on the state of motor and mental functions in patients with Parkinson's disease (PD), and to elucidate the levodopa influence on the CNV parameters. 18 healthy subjects and 56 patients with PD were studied. In PD patients, significant reductions of amplitudes and squares of two CNV phases were observed. A negative correlation of the degree of coordinating muscle relationships disturbance with amplitudes of two CNV phases was found (p < 0.01). A positive interdependence between values of the both CNV phases and the state of mental functions was established, memory in particular (p < 0.05). After levodopa administration in PD patients, the early CNV phase did not significantly change, whereas the late CNV phase significantly increased (p < 0.05). Results of the investigation suggest an important role of the structures ensuring both direct motor control and mental functions in two CNV phases formation. A more obvious levodopa influence on the late CNV phase suggest participation of the basal ganglia efferent system in generation of the late CNV phase rather than in organization of the early CNV phase.

Aged↗

Preparatory visuo-motor cortical network of the contingent negative variation estimated by current density.

The present report studied the intracerebral current density of the contingent negative variation (CNV) during a visuo-manual task using the gap paradigm. The CNV is usually obtained during preparatory periods for perception and action. In this experiment right-hand responses were required. The CNV potential was obtained during the preparatory period from electrodes placed at 58 scalp sites. The CNV showed an early and a late phase. Scalp voltage and source current density maps showed that the early phase was focused on frontal midline sites. The late phase had two foci, one overlying the primary motor cortex and one over occipital sites. When analyzed by low-resolution tomography, the early phase of the CNV showed activations in the supplementary motor area (SMA), the anterior cingulate cortex (ACC), and some posterior areas. The late phase had anterior activations in the left prefrontal cortex, middle frontal cortex, primary motor cortex, ACC, and SMA; and several posterior activations including those in the medial occipital cortex, middle inferior occipital cortex, posterior cingulate cortex, and temporal and parietal areas. Results from the activated areas and their temporal dynamics during the preparatory period suggest that the ACC and the SMA areas recruit the action- and perception-related areas needed to process the expected subsequent imperative task.

Adolescent↗

Contingent negative variation (CNV) and erotic preference in self-declared homosexuals and in child sex offenders.

Contingent negative variation (CNV) was recorded bilaterally from central electrodes using a "match/mismatch" paradigm in (Study 1) samples of heterosexual men (N = 6), gay men (N = 10) and lesbian women (N = 14) and (Study 2) in samples of child sex offenders (N = 34) and heterosexual control men (N = 19). Sexual orientation was assessed using the Multidimensional Scale of Sexuality (MSS) and the Human Sexuality Questionnaire (HSQ). Separate CNV averages were formed for each condition of stimulation: for Study 1, slides of adult male and female nudes; for Study 2, slides of child, pubescent and adult male and female nudes. Penile plethysmographic (PPG) data were also obtained from 15 of the child sex offender sample while they viewed stimuli of the same categories as were used in the CNV recording. On the basis of their PPG responses to children, child sex offenders were classified as either "pedophiles" or "non-pedophiles". In Study 1 significant Group x Sex (of slide) and Group x Electrode interactions indicated that: (i) heterosexual men (but neither homosexual group) showed significantly larger CNVs to female than to male slides; (ii) both homosexual groups showed significantly asymmetrical (R > L) CNVs. In Study 2, controls showed significantly greater CNVs to adult females than to both adult males and female children. Child sex offenders showed no significant differences in CNV to male and female slides for any age. "Non-pedophiles" showed significantly larger CNVs to female adults than to female children, but "pedophiles" did not. It is concluded that CNV has promise as a measure of both deviant and non-deviant sexual preference.

Adolescent↗

Effects of disturbed sleep on contingent negative variation.

To understand better the pathophysiological aspects of disturbed sleep, six healthy male students underwent a series of sleep recordings. On the experimental night, subjects' sleep was disturbed, and the effects on contingent negative variation (CNV) were studied. Mean CNV amplitude decreased in magnitude in the Fz as well as Cz areas; the decrease in Fz-CNV tended to be greater in those subjects whose sleep was most disturbed. The decrease in amplitude of CNV appears to be a nonspecific phenomenon that occurs after any kind of disturbed sleep. Contingent negative variation is composed of two or more components with different spatiotemporal distribution. Depending on the placement of electrodes, the effect that disturbed sleep has on CNV will or will not be observed. The decreases in CNV amplitude were noted in the Fz and Cz areas. Other than subjective discomforts, psychometric measurements did not change significantly. Our data indicate, from the topographical and constructional analysis of CNVs, the possible involvement of the frontal lobe function after disturbed sleep.

Adult↗