bluuebunny/crossref_metadata_2025_split huggingface dataset:
EEG Correlates of Startle Reflex with Reactivity to Eye Opening in Psychiatric Disorders: Preliminary Results
Authors: Arikan Kemal , Boutros Nash N. , Bozhuyuk Erol , Poyraz B. Cagri , Savrun B. Mert , Bayar Reha , Gunduz Aysegul , Karaali-Savrun Feray , Yaman Mehmet 
Published: February 2012

Previous studies have shown alterations of eyeblink reflex in patients with various psychiatric disorders. It has previously been demonstrated by our group that EEG measures of the reactivity to eye opening could effectively predict patient-reported startle response in patients with acute stress reaction. In our present study, EEG spectral power analysis and eyeblink electrical startle responses were acquired from a total of 39 patients diagnosed with various psychiatric disorders: 7 patients with schizophrenia, 10 patients with major depressive disorder (MDD), 10 patients with panic disorder, 5 patients with posttraumatic stress disorder (PTSD) and 7 patients with generalized anxiety disorder (GAD). EEG percent power data of each frequency band (delta, theta, alpha, beta) obtained from the 19 leads under open or closed eyelid conditions were used to calculate the arithmetical difference between eyes-open and eyes-closed states as representative of “EEG reactivity to eye opening.” Data was analyzed separately for each diagnostic group. For all of the disorders, right-sided R2c (contralateral secondary component) latency was the single eyeblink startle measure that was found to be significantly correlated with EEG reactivity to eye opening. The correlation was most significant for right temporal theta frequency in schizophrenia, right temporal theta frequency in MDD, left central beta frequency in panic disorder, left parietotemporal delta frequency in PTSD and right occipital alpha frequency in GAD. Findings showed a newly identified pattern that has potential scientific and clinical value with respect to psychiatric medicine.
Event-Related Potentials in Psychiatry
Authors: Pogarell Oliver , Mulert Christoph , Hegerl Ulrich 
Published: February 2012

Electrophysiological assessments of psychiatric disorders have produced a number of promising, highly replicable findings and thus carry the potential of becoming clinically utilizable in the diagnostic or prognostic evaluation of psychopathological conditions. The procedures involved are rather complex technically and the interpretation of the findings require a combined neurophysiological and clinical expertise. On the other hand, electrophysiological techniques are in general non-invasive and relatively inexpensive, and neurophysiology laboratories are widely available in the clinical setting. Among these techniques, event-related potentials (ERPs) are of major interest in psychiatry, particularly since these tools can indicate cortical neuronal dysfunctions, which play a major role in various neuropsychiatric disorders.
Considerations of the Ischemic Basis and Therapy of Alzheimer Disease
Authors: Niedermeyer E. 
Published: February 2012

A recently presented concept of Alzheimer disease (AD) is based on a primarily ischemic (rather than degenerative) type of brain disease. Etiologically, this new concept is presumed to be related to the human upright gait along with individual predisposition. The proposed treatment—head-down therapy (HDT)—is the centerpoint of this presentation: a simple and generally accessible type of therapy, with monitoring by neuropsychological questioning, electroencephalography, and transcranial Doppler. As a treatment of AD (limited to stage 1), HDT is expected to be helpful. It is possible, however, that its prophylactic use may be of even greater importance.
Prediction of Clinical Response to Antidepressants in Patients with Depression: Neurophysiology in Clinical Practice
Authors: Pogarell Oliver , Juckel Georg , Norra Christine , Leicht Gregor , Karch Susanne , Schaaff Nadine , Folkerts Malte , Ibrahim Ahmad , Mulert Christoph , Hegerl Ulrich 
Published: February 2012

Brain monoaminergic neurotransmission is involved in the pathophysiology of various psychiatric disorders including depression. Reliable indicators of central monoaminergic activity might be helpful to specifically identify and differentiate dysfunctions in individual patients in order to selectively adjust medication and predict clinical response. In patients with depression, predictors of treatment response to serotonergic versus non-serotonergic (e.g., noradrenergic) antidepressants could be of considerable clinical relevance by avoiding unfavorable factors such as a prolonged duration of the disorder, risk of suicidality and therapy-resistance. Consequently, these tools might help to decrease direct and indirect costs of treatment. The loudness dependence of the N1/P2 component of auditory evoked potentials (LD) has been proposed as a noninvasive neurophysiological indicator of central serotonergic function. This review focuses on recent studies providing evidence for the validity of LD as an indirect serotonergic marker and highlights data on the clinical application in terms of prediction of treatment response in patients with depression.
Hand-Motor Dysfunction in Depression: Characteristics and Pharmacological Effects
Authors: Mergl Roland , Pogarell Oliver , Juckel Georg , Rihl Julian , Henkel Verena , Frodl Thomas , Müller-Siecheneder Florian , Karner Max , Tigges Peter , Schröter Andreas , Hegerl Ulrich 
Published: February 2012

Motor retardation is a relevant aspect of depression. Kinematic analysis of movements can be applied to explore which type of motor dysfunction is associated with depression and to examine motor side effects of antidepressants. Using this tool, we aimed to investigate fine motor performance in patients suffering from depression and to compare a selective noradrenaline re-uptake inhibitor (NARI) (reboxetine) and a selective serotonin reuptake inhibitor (SSRI) (citalopram) regarding motor side effects after 4 weeks of treatment. In the first study (I), we examined 37 depressed patients and 37 healthy subjects using a digitizing graphic tablet and kinematic analysis of handwriting and rapid drawing movements. Both groups were comparable regarding age, gender distribution, handedness (preponderance of right-handers) and educational level. In the second study (II), we examined different types of hand movements in 16 depressed patients receiving citalopram (flexible dosage) and 12 depressed patients treated with reboxetine (varying dosage) using the afore-mentioned methods. Both groups were comparable regarding age, gender, handedness and the baseline Hamilton Depression Rating Scale total score. I: Depressed patients performed drawing with significantly less regular velocity than controls (p < 0.001), but normal velocity. Handwriting of depressed patients was abnormally slow (p = 0.04). II: Reboxetine led to a significant improvement of repetitive drawing movements in depression. In contrast, citalopram had no pronounced effects on hand movements in depressed patients. I: Irregular patterns of velocity peaks in depressed patients point to basal ganglia dysfunction and/or deficient activity of the sensorimotor cortex and the supplementary motor area as possible substrates of hand-motor disturbances in depression. II: Computer-aided analysis of hand movements is a sensitive tool for the registration of differential pharmaceutical effects on hand-motor function in depression.
Influence of Anxiety on Electrophysiological Correlates of Response Inhibition Capacities in Alcoholism
Authors: Karch Susanne , Graz Christian , Jager Lorenz , Karamatskos Evangelos , Stammel Andreas , Flatz Wilhelm , Lutz Jürgen , Holtschmidt-Taschner Bettina , Genius Just , Leicht Gregor , Reiser Maximilian , Möller Hans-Jürgen , Hegerl Ulrich , Soyka Michael , Mulert Christoph 
Published: February 2012

Anxiety disorders are highly prevalent in patients with alcohol use disorder. The purpose of the present study was to examine the neural correlates of behavioral inhibition in alcohol-dependent patients (ICD-10: F 10.2), and in healthy controls and to determine the influence of anxiety on these processes. Therefore, behavioral responses (reaction times; error rates) and event-related potentials of 16 patients with alcohol dependence syndrome and 16 age-and gender-matched healthy controls were recorded while the participants performed an auditory go/no-go task. The patient group was stratified according to their self-rated trait anxiety (STAI) with scores above and below median. We hypothesized that patients suffering from alcohol dependence would show reduced no-go P3 amplitudes involved in response inhibition compared to healthy subjects. In patients with alcoholism and high trait anxiety the decline of no-go P3 amplitudes was expected to be less distinct. The estimation of effect size based on the reaction times of patients with high and low anxiety ratings revealed a cohen's d of 0.61 indicating a small effect. High trait anxiety ratings were also associated with slightly enhanced no-go P3 amplitudes in central brain regions (Mean no-go P3 amplitude at Cz: 10.43 μV) compared to patients with low anxiety scores (Mean 8.98 μV). The effect size (cohen's d) revealed a small effect. Using the Mann-Whitney-U-test for independent samples of the comparison of high- and low-anxious patients, however, did not reveal any significant differences concerning no-go P3 amplitudes. Patients with alcohol use disorder and healthy controls did not differ significantly with regard to reaction time, error rate and no-go P3 amplitudes. This study suggests that no-go P3 amplitudes in patients with alcohol use disorder might be affected to some degree by habitual anxiety. The results emphasize the importance of monitoring trait anxiety in studies regarding cognitive functions in subjects with alcohol use disorder.
Induced Gamma Activity and Event-Related Coherence in Schizophrenia
Authors: Bucci P. , Mucci A. , Merlotti E. , Volpe U. , Galderisi S. 
Published: February 2012

Evidence has been provided that high frequency oscillations within the gamma band reflect mechanisms of cortical integration. In the light of recently proposed pathophysiological models of schizophrenia, suggesting a disturbance of the functional connectivity within distributed neural networks, it has been hypothesized that abnormalities in the gamma band underlie perceptual and cognitive dysfunctions in patients with schizophrenia. In the present study we investigated evoked and induced 40-Hz gamma power as well as frontoparietal and frontotem-poral event-related coherence in patients with deficit and nondeficit schizophrenia and in matched healthy controls. In patients, correlations between gamma oscillations and psychopathological dimensions were also investigated. A reduction of both induced gamma power and event-related coherence was observed in patients with nondeficit schizophrenia, but not in those with deficit schizophrenia. Our findings support the hypothesis that deficit and nondeficit schizophrenia represent separate disease entities, suggesting the presence of a poor integration of the neuronal activity within distributed neural network only in the subgroup of schizophrenic patients without primary and persistent negative symptoms. Associations between an excess of gamma oscillations and psychopathological dimensions were observed, suggesting that abnormal thoughts, behaviors and perceptions might be related to the formation of inappropriate neural connections.
nCPAP Treatment of Obstructive Sleep Apnea Increases Slow Wave Sleep in Prefrontal EEG
Authors: Eskelinen Veera , Uibu Toomas , Himanen Sari-Leena 
Published: February 2012

According to standard sleep stage scoring, sleep EEG is studied from the central area of parietal lobes. However, slow wave sleep (SWS) has been found to be more powerful in frontal areas in healthy subjects. Obstructive sleep apnea syndrome (OSAS) patients often suffer from functional disturbances in prefrontal lobes. We studied the effects of nasal Continuous Positive Airway Pressure (nCPAP) treatment on sleep EEG, and especially on SWS, in left prefrontal and central locations in 12 mild to moderate OSAS patients. Sleep EEG was recorded by polysomnography before treatment and after a 3 month nCPAP treatment period. Recordings were classified into sleep stages. No difference was found in SWS by central sleep stage scoring after the nCPAP treatment period, but in the prefrontal lobe all night S3 sleep stage increased during treatment. Furthermore, prefrontal SWS increased in the second and decreased in the fourth NREM period. There was more SWS in prefrontal areas both before and after nCPAP treatment, and SWS increased significantly more in prefrontal than central areas during treatment. Regarding only central sleep stage scoring, nCPAP treatment did not increase SWS significantly. Frontopolar recording of sleep EEG is useful in addition to central recordings in order to better evaluate the results of nCPAP treatment.
Event-Related Desynchronization of Frontal-Midline Theta Rhythm during Preconscious Auditory Oddball Processing
Authors: Kawamata Masaru , Kirino Eiji , Inoue Reiichi , Arai Heii 
Published: February 2012

The goal of this study was to explore the frontal-mid-line theta rhythm (Fm theta) generation mechanism employing event-related desynchronization/synchronization (ERD/ERS) analysis in relation to task-irrelevant external stimuli. A dual paradigm was employed: a videogame and the simultaneous presentation of passive auditory oddball stimuli. We analyzed the data concerning ERD/ERS using both Fast Fourier Transformation (FFT) and wavelet transform (WT). In the FFT data, during the periods with appearance of Fm theta, apparent ERD of the theta band was observed at Fz and Cz. ERD when Fm theta was present was much more prominent than when Fm theta was absent. In the WT data, as in the FFT data, ERD was seen again, but in this case the ERD was preceded by ERS during both the periods with and without Fm theta. Furthermore, the WT analysis indicated that ERD was followed by ERS during the periods without Fm theta. However, during Fm theta, no apparent ERS following ERD was seen. In our study, Fm theta was desynchronized by the auditory stimuli that were independent of the video game task used to evoke the Fm theta. The ERD of Fm theta might be reflecting the mechanism of “positive suppression” to process external auditory stimuli automatically and preventing attentional resources from being unnecessarily allocated to those stimuli. Another possibility is that Fm theta induced by our dual paradigm may reflect information processing modeled by multi-item working memory requirements for playing the videogame and the simultaneous auditory processing using a memory trace. ERS in the WT data without Fm theta might indicate further processing of the auditory information free from “positive suppression” control reflected by Fm theta.
EEG Coherence for a Patient with Marchiafava-Bignami Disease
Authors: Fang Shih-Chin , Hsu Jung-Lung , Chen Wei-Hung 
Published: February 2012

We evaluated a 39-year-old chronic alcoholic man with acute multiple cognitive impairment and callosal lesion seen in MRI, diagnosed as Marchiafava-Bignami disease (MBD), using analysis of electroencephalography (EEG) coherence. Three EEG sessions were recorded in the first week, the second and eighth month after disease onset in the MBD patient. Inter-hemispheric coherence (IhC), parasagittal coherence (PsC) and spatially averaged coherence (SAC) were computed. The results were compared with normative data from 30 age-matched healthy subjects. Mean values for IhC, PsC and SAC were significantly decreased during the acute stage of the disease (P<0.01). The IhC values remained low (P<0.01), however, PsC and SAC values rebounded in follow-up study. The IhC and SAC values were lowest in the frontal region, consistent with the main pathological involvement in the anterior two-thirds of the corpus callosum and early involvement of frontal cortex. In conclusion, MBD may manifest as a cerebral-disconnection state, which can be quantified using EEG-coherence analysis. EEG-coherence may serve as a useful tool for MBD diagnosis and evaluation.
Midline Spikes
Authors: Yong T. , Chayasirisobhon S. , Yoshina J. S. , Tin S. N. , Tehrani K. , Skinner S. E. , Markus E. , Spurgeon B. D. , Gurbani S. 
Published: February 2012

Midline spikes are characterized by spike foci recorded at Cz, Fz, or Pz with amplitude ranging from 20 to 350 microvolts. Out of 7,929 EEGs performed at the Neurodiagnostics Laboratory, Kaiser Permanente Medical Center, Anaheim, California, between 1996 and 2006, 17 EEGs (0.21%) were identified as having interictal midline spikes with or without other epileptiform discharges. Eight EEGs showed midline spikes at Cz, 2 at Fz, 2 at Cz and Fz, 1 at Cz and C3, 1 at Cz, C3, and P3, 1 at Cz and F8, 1 at Cz and T4, and 1 at Cz with 2 Hz generalized spike and slow wave complex. Midline spikes were recorded in 10 males and 7 females. The age ranged from 4 days to 38-years-old with a mean age of 10.8 years. Twelve patients (70.6%) were children. Twelve patients (70.6%) had generalized tonic-clonic seizures and 5 had partial motor seizures. Of the 17 patients, 14 had no known causes, 1 had an agenesis of corpus callosum, 1 had a left frontal arteriovenous malformation, and 1 had a left frontal area stroke. We postulate that the mechanism for the genesis of midline spikes may be heterogeneous. Midline spikes may be triggered by thalamocortical network in a generalized tonic-clonic seizure, or may originate in the parasagittal cortex in a partial motor seizure.
Focal EEG Findings in Juvenile Absence Syndrome and the Effect of Antiepileptic Drugs
Authors: Tezer F. Irsel , Sahin Gurdal , Ciger Abdurrahman , Saygi Serap 
Published: February 2012

The presence of focal EEG abnormalities in juvenile absence syndrome (JAS) may cause it to be misdiagnosed as focal epilepsy. The purpose of our study was to determine the presence of focal EEG abnormalities in patients with JAS and to ascertain whether some clinical features or antiepileptic drugs (AEDs) have an effect on focality. Serial EEGs of 52 consecutive patients with JAS were retrospectively analyzed. The patients were divided into two groups according to whether they were treated with valproic acid and/or lamotrigine (VA-LTG) or not during the times of these EEG recordings. The relationship between the presence of EEG focality and the use of AEDs in addition to other risk factors was examined. Two or three consecutive EEGs (total 100) of the 52 patients were evaluated. Among these, the rates of focal EEG abnormalities were 18%, 36%, and 25% during the follow-up EEGs without AEDs (5/27) and first (16/45) and second EEGs (7/28) with AEDs, respectively. The last two EEGs showed a tendency towards a higher proportion of EEG focality in patients who received other AEDs (47%-45%) compared with those that received VA-LTG (13%-12%). The proportion of JAS patients with focal EEG findings in serial EEGs tended to decrease with an increasing rate of VA-LTG use. As a hypothetical explanation, changes in EEG focality may reflect the effect of AEDs other than VA and/or LTG, in addition to a developing hyperexcitable cortical area.
Auditory/Verbal Hallucinations, Speech Perception Neurocircuitry, and the Social Deafferentation Hypothesis
Authors: Hoffman Ralph E. 
Published: February 2012

Auditory/verbal hallucinations (AVHs) are comprised of spoken conversational speech seeming to arise from specific, nonself speakers. One hertz repetitive transcranial magnetic stimulation (rTMS) reduces excitability in the brain region stimulated. Studies utilizing 1-Hz rTMS delivered to the left temporoparietal cortex, a brain area critical to speech perception, have demonstrated statistically significant improvements in AVHs relative to sham simulation. A novel mechanism of AVHs is proposed whereby dramatic pre-psychotic social withdrawal prompts neuroplastic reorganization by the “social brain” to produce spurious social meaning via hallucinations of conversational speech. Preliminary evidence supporting this hypothesis includes a very high rate of social withdrawal emerging prior to the onset of frank psychosis in patients who develop schizophrenia and AVHs. Moreover, reduced AVHs elicited by temporoparietal 1-Hz rTMS are likely to reflect enhanced long-term depression. Some evidence suggests a loss of long-term depression following experimentally-induced deafferentation. Finally, abnormal cortico-cortical coupling is associated with AVHs and also is a common outcome of deafferentation. Auditory/verbal hallucinations (AVHs) of spoken speech or “voices” are reported by 60–80% of persons with schizophrenia at various times during the course of illness. 1 – 2 AVHs are associated with high levels of distress, 3 – 5 functional disability, 6 and can lead to violent acts. 7 , 8 Among patients with AVHs, these symptoms remain poorly or incompletely responsive to currently available treatments in approximately 25% of cases. 9 For patients with AVHs who do respond to antipsychotic drugs, there is a very high likelihood that these experiences will recur in subsequent episodes. 10 A more precise characterization of underlying pathophysiology may lead to more efficacious treatments.
Cortical Inhibition in Motor and Non-Motor Regions: A Combined TMS-EEG Study
Authors: Fitzgerald Paul B. , Daskalakis Zafiris J. , Hoy Kate , Farzan Faranak , Upton Daniel J. , Cooper Nicholas R. , Maller Jerome J. 
Published: February 2012

A number of studies using paired pulse transcranial magnetic stimulation (TMS) have demonstrated that cortical inhibition (CI) of the motor cortex can be recorded and also gauged through surface electromyography. However, recording CI from other brain regions that are more directly related with the pathophysiology of some neurologic and psychiatric disorders (e.g., dorsolateral prefrontal cortex (DLPFC) in schizophrenia) was previously fraught with technical difficulties. This study was therefore designed to examine, through a combination of TMS with EEG, whether CI could be measured directly from the motor cortex, DLPFC, and another non-motor region. To index CI, long interval cortical inhibition (LICI; a TMS paradigm) was used in the motor cortex and DLPFC in 14 healthy subjects, and in the parietal lobe in 5 of those subjects. In the motor cortex, LICI resulted in a significant suppression in mean cortical evoked activity on EEG (37.31 ± 47.51 %). In the DLPFC, LICI resulted in a significant suppression (32.45 ± 47.86 %) in mean cortical evoked activity and did not correlate with LICI in the motor cortex although they did not significantly differ. In the parietal lobe, LICI resulted in significant suppression (47.76 ± 44.70 %) in mean cortical evoked activity. In conclusion, CI in the dorsolateral prefrontal cortex, motor cortex and parietal cortex were similar at 120% of motor threshold. These data suggest that CI can be recorded by combining TMS with EEG and may facilitate future research attempting to ascertain the role of CI in the pathophysiology of several neurologic and psychiatric disorders.