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Biomedical subjects

W D Gerber

Publications and source records attributed to W D Gerber.

At least 19 recordsLinked to original sources
PubMed2006

Relationship between precipitating agents and neurophysiological abnormalities in migraine.

The particular mechanisms of migraine anticipation by different precipitating agents are still unknown. The contingent negative variation (CNV) was recorded in the premenstrual and ovulation phases of the cycle in both rest and stress conditions in 17 migraine and 15 healthy women. In migraineurs a significant increase of amplitude of the initial CNV component in the premenstrual phase compared with ovulation was observed. During both the ovulation and premenstrual phases both migraineurs and controls demonstrated a significant increase of the CNV amplitude on stress. The increase of the amplitude on stress in the premenstrual phase was more pronounced in migraineurs. This study shows that stress and menstrual cycle are associated with changes of the initial CNV amplitude, probably indicating a higher probability of migraine attacks.

Adult↗
PubMed2002

[Treatment of idiopathic headache in childhood - recommendations of the German Migraine and Headache Society (DMKG)].

According to the principles of evidence-based medicine, the controlled studies on the treatment of idiopathic headache in childhood have been analysed and compiled to treatment recommendations. For the acute treatment of migraine attacks or tension-type headache, ibuprofen (10 mg per kg body weight) or acetaminophen (15 mg per kg body weight) are recommended with highest evidence, intranasal sumatriptan (10 to 20 mg) can be given as second choice. For the prophylaxis of migraine, betablockers (propranolol and metoprolol), flunarizine, and valproic acid are recommended. Flunarizine is the drug of first choice in the treatment of migraine-related disorders. No controlled studies are available for the treatment of further headache types. First line methods for the non-drug treatment of headache in childhood are relaxation therapies, biofeedback, and specific training schedules.

Acetaminophen↗
PubMed2001

Non-linear electroencephalogram dynamics in patients with spontaneous nocturnal migraine attacks.

The present study was conducted to examine non-linear electroencephalogram (EEG) measures during the development of a spontaneous migraine attack. We investigated the sleep EEG of five patients with migraine without aura in the pain-free interval and at the onset of a nocturnal attack. Sleep EEG recordings were analysed using the method of global dimensional complexity compared to conventional sleep scoring techniques. We found no divergence between classical sleep architecture and the estimated dimensional course nor any relevant short-term changes related to the onset of headache. There was, however, a loss of dimensional complexity in the first two non-rapid eye movement sleep states in the migraine night, with statistical significance during the second sleep cycle. For the first time, these results provide evidence of a global dimension decrease that is related to cortical network changes during a migraine attack.

Electroencephalography↗
PubMed2001

Polysomnographic findings in nights preceding a migraine attack.

Sleep recordings were performed in eight patients to analyse sleep alterations preceding migraine attacks. Polysomnographic recordings from nights before an attack were compared with nights without following migraine. We analysed standard sleep parameters and electroencephalogram (EEG) power spectra. The main findings preceding migraine attacks were a significant decrease in the number of arousals, a decrease in rapid eye movement (REM) density, a significant decrease of beta power in the slow wave sleep, and a decrease of alpha power during the first REM period. The results suggest a decrease in cortical activation during sleep preceding migraine attacks. According to the models of sleep regulation, alterations in the function of aminergic or cholinergic brainstem nuclei have to be discussed.

Electroencephalography↗
PubMed2001

Contingent negative variation and attentional performance in humans.

The relation between a paper-pencil test of sustained attention (d2-letter cancellation test, d2-LCT) and the contingent negative variation (CNV) as a cortical slow potential was calculated in 23 healthy undergraduate students. Both d2-LCT and CNV reflect selective, focussed attention. There was a Pearson correlation coefficient of r = -0.670 between the early component of the CNV and the number of checked letters in d2-LCT, indicating significant differences in early CNV between low and high performance in d2-LCT. The results showed a linear relationship between paper-pencil registered attentional properties and the cortically recorded early component of CNV.

Adult↗
PubMed2000

Migraine in childhood--are periodically occurring migraine attacks related to dynamic changes of cortical information processing?

Amplitudes and habituation of contingent negative variation (CNV) were analyzed in relation to spontaneously occurring migraine attacks in ten children suffering from migraine without aura. Recording took place during feedback training and instrumental conditioning of slow brain potentials. Both the amplitude of the early CNV component and its habituation deficit increase during the 5 days prior to a migraine attack, with maximum abnormalities the day before the ictal episode. Abrupt reduction of the amplitude and normalization of the CNV habituation were observed during the attack. This study provides evidence for neurophysiological periodicity in young migraineurs and emphasizes that the time relative to the migraine attacks must be considered in studies of juvenile migraine during the headache-free period.

Cerebral Cortex↗
PubMed2000

Ten novel BRCA1 and BRCA2 mutations in breast and/or ovarian cancer families from northern Germany.

Germline mutations in the BRCA1 and BRCA2 gene account for the majority of high-risk breast/ovarian cancer families. We have screened such families from Northern Germany by using DHPLC analysis and subsequent direct sequencing techniques. In ten families we identified six novel BRCA1 and 4 novel BRCA2 mutations comprising four frame shift mutations, one nonsense and one splice site mutation in the BRCA1 gene as well as three frameshift mutations and one nonsense mutation in the BRCA2 gene. Our analysis contributes to the further characterisation of the mutational spectrum of BRCA1 and BRCA2.

Adult↗
PubMed2000

Neurofeedback--the significance of reinforcement and the search for an appropriate strategy for the success of self-regulation.

Nine healthy children took part in five sessions of feedback and instrumental conditioning of slow cortical potentials (SCPs). The feedback conditions (the relation between the feedback signal and amplitude of SCP) were inverted after two sessions. Neither the children nor the therapists were aware of this change. The adjustment of the children to the new feedback setting and the self-regulation strategies employed were investigated. The results were as follows: (a) Healthy children achieved control over cortical negativity within two sessions. (b) The change of feedback conditions worsened the regulation abilities, which then improved again within the following three sessions. (c) After the first two sessions, the participants were able to describe strategies that were successful during different phases of self-regulation. (d) Following the change in the feedback conditions, the children reevaluated the way they influenced their SCPs. However, they did not alter the cognitive or behavioral strategies. The study demonstrated that positive and negative reinforcement and the knowledge of results are more important for successful self-regulation than the search for effective strategies. The relevance of these findings is discussed.

Autonomic Nervous System↗
PubMed2000

Reliability and stability of contingent negative variation.

Reliability parameters of a test indicate the stability (and quality) of the test itself. Reliability coefficients greater than 0.70 suggest an attribute as being sufficiently stable over time to be characterized as a trait. Reliability parameters of contingent negative variation (CNV) amplitudes in 27 healthy individuals were determined using a test-retest design. CNV was recorded at Cz, with an interstimulus interval of 3 s, on 2 separate occasions: initial session and 10 days later. Correlation coefficients between the 2 recording sessions were 0.675 for the total-CNV (tCNV), 0.855 for the early component (iCNV), 0.631 for the late component (lCNV), and 0.420 for the post-imperative negative variation (PINV). Statistical retest parameters for Spearman Brown were 0.806 for tCNV, 0.922 for iCNV, 0.774 for lCNV, and 0.655 for PINV. The iCNV, more than the other parameters, remained stable over the period of 10 days. It is suggested that the described standardized CNV recording procedure ensures reproducible and stable results in healthy subjects.

Adult↗
PubMed2000

Self-regulation of slow cortical potentials in children with migraine: an exploratory study.

Migraine patients are characterized by increased amplitudes of slow cortical potentials (SCPs), representing pronounced excitability of cortical networks. The present study investigated the efficiency of biofeedback training of SCPs in young migraineurs. Ten children suffering from migraine without aura participated in 10 feedback sessions. They were compared with 10 healthy children for regulation abilities of cortical negativity and with 10 migraineurs from the waiting list for clinical efficacy. During the first two sessions, the migraine children were characterised by lacking ability to control cortical negativity, especially during transfer trials, compared with healthy controls. However, there was no difference following 10 sessions of training. Feedback training was accompanied by significant reduction of cortical excitability. This was probably responsible for the clinical efficacy of the training; a significant reduction of days with migraine and other headache parameters was observed. It is suggested that normalization of the threshold regulation of cortical excitability during feedback training may result in clinical improvement.

Analysis of Variance↗
PubMed2000

Are the periodic changes of neurophysiological parameters during the pain-free interval in migraine related to abnormal orienting activity?

OBJECTIVE AND METHODS: Migraine patients are characterized by increased amplitude and reduced habituation of contingent negative variation (CNV). Furthermore, the CNV underlies periodic changes during the pain-free interval, being maximal before attack. The periodicity of CNV is related to periodic changes in habituation, probably due to variation of orienting activity during the pain-free interval. CNV and orienting response (OR) were studied in 20 females suffering from migraine without aura and in 12 matched healthy females. The neurophysiological recordings in the group of patients were performed 1-4 days before and 4 days after a migraine attack. The amplitudes and habituation of early and late components and total CNV were calculated. The OR was assessed using the habituation of the skin conductance response (SCR) and alpha blocking (AB). The non-parametric tests were employed for statistical analysis. RESULTS: There were no differences between the two groups for habituation of all CNV components and of SCR following an attack. However, the habituation of AB was significantly reduced in migraine. Before attack we observed a significantly reduced habituation of the early and total CNV and of the AB compared to controls and recordings performed after an attack. The habituation of the late component and of SCR remained unchanged. CONCLUSIONS: The abnormal habituation could be explained by the periodic changes of physiological parameters during the pain-free interval. The impaired habituation of early CNV in migraine is associated with increased orienting activity seen only in the central component (AB) of OR.

Adult↗
PubMed2000

Slow cortical potentials in migraine families.

Amplitude and habituation of event-related potentials are abnormal in migraine. We investigated 43 migraine and 41 healthy families to evaluate the influences of age, sex and familial contribution on the variance of amplitude and habituation of the contingent negative variation (CNV). Analysis of individual differences in relation to the CNV habituation was performed. The study demonstrated that habituation of the early CNV component characterizes migraine considerably better than the CNV amplitudes. Habituation, however, is strongly influenced by age. Migraine adults and children generally showed reduced habituation. Surprisingly, more than 30% of the healthy adults demonstrated a marked loss of habituation. The reduced CNV habituation represented a high sensitivity but low specificity to migraine, especially in children. CNV amplitude and habituation parameters revealed a considerable familial contribution associated with migraine. No familial influence on either morphology or habituation of the CNV in healthy families or between healthy members of migraine families was observed. The low specificity and familial transmission of CNV parameters in members of migraine families suggest that increased amplitudes and reduced habituation of CNV do not constitute a primary risk factor for migraine, but rather represent a predisposition. Genetic components probably affect variation of the CNV amplitude and habituation.

Adolescent↗
PubMed2000

[Prediction of verbal and numerical comprehension in patients with cochlear implants].

BACKGROUND: Cognitive abilities determine the outcome of cochlear implantation. Neuropsychological tests of intellectual, memory, attentional and emotional functions were applied pre-operatively in 33 deaf patients receiving a cochlear implant. The outcome of verbal and numerical comprehension was measured in a subgroup of 14 patients post-operatively and correlated with pre-operative neuropsychological performance. METHODS: Neuropsychological performance was recorded using standardized tests for intellectual abilities (abbreviated Wechsler Adult Intelligence Scale [WAIS], crystallized intelligence scale), memory performance (Benton Visual Retention Test), attentional functions (d2 letter-cancellation-test), reaction time (Vienna Reaction Test) and emotional state (personality inventories). Verbal and numerical comprehension was measured post-operatively following adaptation of the speech processor. Performance and comprehension data were correlated. RESULTS: Cognitive performance parameters did not differ significantly from those of a healthy group. There was a correlation of r = +0.65 between numerical comprehension and the "mosaic-test", a subtest of the WAIS and of r = +0.78 between numerical comprehension and the crystallized intelligence scale. CONCLUSIONS: Pre-operative cognitive parameters may predict the outcome of cochlear implants.

Adolescent↗
PubMed2000

Contingent negative variation as indicator of duration of migraine disease.

Amplitudes of early wave contingent negative variation (iCNV) reveal significant differences between migraine patients and healthy controls, indicating a lack of habituation and pronounced attentional functions in migraine patients. CNV amplitudes were recorded in 20 migraine patients. The CNV amplitudes were Pearson correlated with the individual duration of the migraine disease. Only iCNV correlates inversely with the duration (r = -.544). The data show an influence of duration of migraine disease on iCNV amplitudes. It is suggested that iCNV is an indicator of chronicity in persistent migraine.

Adult↗
PubMed1999

Migraine--evidence for a disturbance of cerebral maturation in man?

The contingent negative variation (CNV), a slow cortical potential between two defined stimuli, was used to record the effect of age in 162 migraine patients and 320 healthy controls aged between 8 and 59 years. The early component (iCNV) and habituation slope of 32 GO-trials are presented. There were no significant differences between healthy controls and migraine patients in iCNV amplitudes or habituation slope up to the age of 19 years. In the age groups from 20-59 years the healthy controls showed a significantly reduced iCNV compared with migraine patients and healthy controls below 20 years of age. While the habituation slope increased in healthy controls, there was no habituation of iCNV in migraine patients. It is suggested that reduced iCNV amplitudes in healthy controls indicate a state of cerebral maturation. This maturation effect is missing in adult migraine patients, leading to pronounced attentional effort in these patients.

Adolescent↗
PubMed1999

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↗