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J Gallinat

Publications and source records attributed to J Gallinat.

At least 19 recordsLinked to original sources
PubMed2003

Panic attacks, spike-wave activity, and limbic dysfunction. A case report.

INTRODUCTION: Several lines of evidence indicate that an increased neuronal excitability of the corpus amygdaloideum and hippocampus may be one pathophysiological condition of panic attacks. METHODS: In this report, we will describe the case of a 54-year-old female patient with a depressive syndrome who first experienced very rapid atypical panic attacks with dizziness, trance-like and distorted optical perception, but without clear epileptic symptoms. RESULTS: Several EEG recordings showed temporal sharp-waves and spike-wave patterns. Magnetic resonance imaging (MRI) revealed a hypodense area near left mesial temporal structures. Brain imaging with SPECT showed a hypoperfusion of the basal temporal cortical structures on the left side. Treatment with antidepressants had no effect, but the addition of valproic acid led to an attenuation of the panic attacks and epileptic potentials on the EEG. DISCUSSION: A clinical trial using anti-epileptics could be successful in patients not responding to antidepressants or in the presence of epileptiform EEG activity. In this article, we will review the literature concerning the complex relationship between panic attacks and ictal activity of limbic structures and discuss the difficult diagnostic classification of atypical cases.

Anticonvulsants↗
PubMed2002

Comparison of the amplitude/intensity function of the auditory evoked N1m and N1 components.

This study compared the intensity dependence of the auditory evoked N1 and N1m components in 10 healthy subjects. The evoked responses were recorded simultaneously at 33 channels for the auditory evoked potentials (AEP) and with a 37-channel magnetometer for the auditory evoked fields (AEF). They were satisfactorily modeled by a tangential and a radial dipole per hemisphere for the N1 component and a tangential dipole in the left hemisphere for the N1m component. The tangential dipoles showed different dipole characteristics. The amplitude of the AEP rose significantly with increasing stimulus intensity whereas the amplitudes of the AEF tended to plateau between the highest intensities. The magnetic dipole shifted to the surface of the skull with higher stimulus intensity whereas the electric tangential dipole moved to the center of the skull. The latencies decreased with increasing stimulus intensity.

Adult↗
PubMed2001

Reduced event-related current density in the anterior cingulate cortex in schizophrenia.

There is good evidence from neuroanatomic postmortem and functional imaging studies that dysfunction of the anterior cingulate cortex plays a prominent role in the pathophysiology of schizophrenia. So far, no electrophysiological localization study has been performed to investigate this deficit. We investigated 18 drug-free schizophrenic patients and 25 normal subjects with an auditory choice reaction task and measured event-related activity with 19 electrodes. Estimation of the current source density distribution in Talairach space was performed with low-resolution electromagnetic tomography (LORETA). In normals, we could differentiate between an early event-related potential peak of the N1 (90-100 ms) and a later N1 peak (120-130 ms). Subsequent current-density LORETA analysis in Talairach space showed increased activity in the auditory cortex area during the first N1 peak and increased activity in the anterior cingulate gyrus during the second N1 peak. No activation difference was observed in the auditory cortex between normals and patients with schizophrenia. However, schizophrenics showed significantly less anterior cingulate gyrus activation and slowed reaction times. Our results confirm previous findings of an electrical source in the anterior cingulate and an anterior cingulate dysfunction in schizophrenics. Our data also suggest that anterior cingulate function in schizophrenics is disturbed at a relatively early time point in the information-processing stream (100-140 ms poststimulus).

Adult↗
PubMed2001

P300 and symptom improvement in schizophrenia.

RATIONALE: A reduced amplitude of the auditory evoked P300 was interpreted as a trait marker of schizophrenia but reports about correlations between schizophrenic psychopathology and P300 amplitude indicate also a state character. OBJECTIVES: To shed light upon these trait and state aspects a longitudinal study was performed to investigate the influence of symptom improvement and atypical neuroleptics on the amplitudes of the P300 and their subcomponents. METHODS: P300 was recorded in 17 schizophrenic patients before and after 4 weeks under either clozapine or olanzapine in a double-blind controlled design. For comparison, 17 age- and sex-matched healthy subjects were investigated. Parietal and frontal P300 subcomponents were investigated separately using dipole source analysis. RESULTS: Schizophrenic patients had smaller parietal (temporo-basal dipole) but not frontal subcomponent amplitudes (temporo-superior dipole) than controls. For the whole sample subcomponent amplitudes did not change over 4 weeks despite clinical improvement but patients with a pronounced improvement of the PANSS positive score showed a slight enhancement of both subcomponents. This was not significant when the P300 amplitude was measured at a single electrode (Pz). No significant difference between clozapine and olanzapine concerning effects on P300 amplitudes were observed. CONCLUSIONS: The results indicate that P300 subcomponents are modulated by changes of positive but not by changes of negative symptoms or different neuroleptics. This result was obvious for P300 subcomponents but not for Pz electrode measurement, which may be due to a higher reliability of the dipole source activity. The results can be integrated into a hypothetical model containing two pathophysiological subgroups of schizophrenia.

Adult↗
PubMed2001

Event-related potentials. Do they reflect central serotonergic neurotransmission and do they predict clinical response to serotonin agonists?

The increasing knowledge concerning anatomical structures and cellular processes underlying event-related potentials (ERP) as well as methodological advances in ERP data analysis (e.g. dipole source analysis) begin to bridge the gap between ERP and neurochemical aspects. Reliable indicators of the serotonin system are urgently needed because of its role in pathophysiology and as target of pharmacotherapeutic interventions in psychiatric disorders. Converging arguments from preclinical and clinical studies support the hypothesis that the loudness dependence of the auditory evoked N1/P2-response (LDAEP) is regulated by the level of central serotonergic neurotransmission. Dipole source analysis represents an important methodological advance in this context, because the two N1/P2-subcomponents, generated by the primary and secondary auditory cortex known to be differentially innervated by serotonergic fibers, can be separated. A pronounced LDAEP of primary auditory cortices is supposed to reflect low central serotonergic neurotransmission, and vice versa. LDAEP is a parameter with potential clinical value since subgroups of patients with a serotonergic dysfunction can be identified and can be treated more specifically. In depressed patients, a significant relationship between strong LDAEP, indicating low serotonergic function, and a favorable response to SSRI has been found. Additionally, there is evidence from several studies with patients with affective disorders implicating a strong LDAEP as a predictor of favorable response to a preventive lithium treatment.

Arousal↗
PubMed2001

P300 and LORETA: comparison of normal subjects and schizophrenic patients.

It was the aim of the present study 1) to investigate how many cortical activity maxima of scalp-recorded P300 are detected by Low Resolution Electromagentic Tomography (LORETA) when analyses are performed with high time-resolution, 2) to see if the resulting LORETA-solution is in accordance with intracortical recordings as reported by others and 3) to compare the given pattern of cortical activation maxima in the P300-timeframe between schizophrenic patients and normal controls. Current density analysis was performed in 3-D Talairach space with high time resolution i.e. in 6 ms steps. This was done during an auditory choice reaction paradigm separately for normal subjects and schizophrenic patients with subsequent group comparisons. In normal subjects, a sequence of at least seven cortical activation maxima was found between 240-420ms poststimulus: the prefrontal cortex, anterior or medial cingulum, posterior cingulum, parietal cortex, temporal lobe, prefrontal cortex, medial or anterior cingulum. Within the given limits of spatial resolution, this sequential maxima distribution largely met the expectations from reports on intracranial recordings and functional neuroimaging studies. However, localization accuracy was higher near the central midline than at lateral aspects of the brain. Schizophrenic patients less activated their cortex in a widespread area mainly in the left hemisphere including the prefrontal cortex, posterior cingulum and the temporal lobe. From these analyses and comparsions with intracranial recordings as reported by others, it is concluded that LORETA correctly localizes P300-related cortical activity maxima on the basis of 19 electrodes except for lateral cortical aspects which is most likely an edge-phenomenon. The data further suggest that the P300-deficit in schizophrenics involves an extended cortical network of the left hemisphere at several steps in time during the information processing stream.

Adult↗
PubMed2000

Digitized analysis of abnormal hand-motor performance in schizophrenic patients.

Many studies have shown a high prevalence of discrete neuromotor disturbances in schizophrenic patients. It was hypothesized that these disturbances are lateralized and reflect a neurodevelopmental disorder underlying schizophrenia. A new method for assessing subtle motor dysfunction and hemispheric asymmetries is the registration of hand movements with a digitizing tablet. Using this method, we studied hand-motor dysfunction and its lateralization in schizophrenics, as compared with healthy controls. All subjects (27 schizophrenic patients, 13 of them without neuroleptic medication, the others under neuroleptics; 31 healthy controls) drew super-imposed concentric circles. We computed kinematic parameters reflecting velocity and automatization to quantify neurological soft signs (NSS). The patients had significant impairments of regularity of repetitive hand movements, as compared with the healthy controls (F> or =5.35; p< or =0.024(*)). Comparing differences of left- and right-hand performance between patients and controls, we found longer stroke duration (F=(15,98); p=0.000***) and decreased automatization (F=18,14; p=0.000***), especially on the left side in schizophrenic patients. Measuring hand movements with a digitizing tablet is a sensitive method for assessing subtle motor dysfunction in schizophrenic patients, not reflected in the scores of clinical scales. Our findings show NSS in schizophrenic patients, independently of neuroleptics. Further, the hypothesis of lateralization of cerebral structures generating NSS towards the right hemisphere in schizophrenia is supported.

Adult↗
PubMed2000

Loudness dependence of auditory evoked potentials in obsessive-compulsive disorder: a pilot study.

In recent years it has been suggested that a serotonergic dysfunction is involved in the pathogenesis of obsessive-compulsive disorder (OCD). The loudness dependence of auditory evoked potentials (AEPs) is one of the best validated indicators of the activity of the serotonin system in humans. To explore the validity of the hypothesis of a serotonergic dysfunction in OCD, the loudness dependence of AEPs of 22 medication-free OCD patients were compared with those of 22 age- and gender-matched healthy subjects. Auditory evoked N1/P2 activity to tones of increasing intensity was studied using dipole source analysis. Contrary to the hypothesis, OCD patients and healthy controls did not differ in their LDAEPs of the tangential dipole in particular, located in the primary auditory cortex and closely related to central serotonergic activity. Furthermore, no significant correlation was found between the severity of obsessive-compulsive or depressive symptoms and the loudness dependence of AEPs. These findings do not support the hypothesis of a serotonergic dysfunction in OCD patients.

Adult↗
PubMed2000

The loudness dependency of the auditory evoked N1/P2-component as a predictor of the acute SSRI response in depression.

RATIONALE: A serotonergic dysfunction is supposed to play a pathogenetic role in depression, but there is a considerable number of non-responders in the acute treatment of depression with serotonergic agents like SSRI. Thus, an indicator of central serotonergic activity could lead to a more specific pharmacological treatment of depression. In animal and human data there is a growing amount of evidence that a strong loudness dependency of late auditory evoked potentials (LDAEP) is an indicator of low serotonergic activity and vice versa. OBJECTIVE: In 29 depressive inpatients (DSM-III-R diagnosis 296.x in 28 patients, 300.4 in one patient), the hypothesis was tested that a strong LDAEP prior to treatment can predict a better clinical outcome under SSRI treatment over 4 weeks. RESULTS: Patients with a strong pre-treatment LDAEP had a significantly greater decrease of depressive symptoms (Hamilton Scale for Depression) after 4 weeks than patients with a flat LDAEP. Significantly more responders fell into the group with a high LDAEP. Contrary to what might be expected, a second recording in a subsample of 19 patients after 4 weeks of treatment failed to show changes in the LDAEP. CONCLUSION: Our finding confirms the hypothesis that a strong LDAEP, indicating a low serotonergic activity, is related to a favorable response to acute SSRI treatment in depression. The LDAEP is a promising tool for the prediction of response to serotonin agonists in depression and it seems to be of clinical importance.

Acoustic Stimulation↗
PubMed2000

Association analysis of GABAAbeta2 and gamma2 gene polymorphisms with event-related prefrontal activity in man.

Gamma-aminobutyric acid (GABA)A-receptors play a crucial role in the generation of electroencephalogram (EEG) oscillations and evoked potentials (ERPs). The present association study was designed to test whether EEG and ERPs are modulated by genetic variations of the human GABAA beta2 (GABRB2) and gamma2 (GABRG2) genes on chromosome 5q33. The genotypes of two nucleotide substitution polymorphisms of the GABRB2 and GABRG2 genes were assessed in 95 psychiatrically healthy subjects of German descent. Neurophysiological phenotyping was performed with four factorized EEG/ERP parameters: EEG activation, anterior and posterior EEG synchronization, and event-related activity (N100/ P200-complex). No genotypic association was found for the GABRB2 nucleotide exchange polymorphism with any electrophysiological parameter. A significant association was found between the genotype of the intronic GABRG2 G-->A nucleotide exchange and the event-related N100/P200 (ANOVA: F=3.81; df=2; P=0.026). A comparison of homozygous subjects carrying either the G/G or A/A genotype of the GABRG2 polymorphism consistently revealed an even stronger difference in the effect-size (ANOVA: F=11.13; df=1; P=0.002). Post hoc analysis of this association with current density analysis in three-dimensional neuroanatomic Talairach space-time showed a reduction in the event-related signal power after 120 ms in the right dorsolateral prefrontal cortex. Taking into account the risk of false-positive association findings attributable to multiple testing, our results encourage further replication studies to examine the phenotype-genotype relationship of GABRG2 gene variants and event-related prefrontal activity.

Adult↗
PubMed2000

Dipole localization of P300 and normal aging.

At present, our understanding of how normal aging affects in vivo brain function is rudimentary. Therefore, the aim of the present study was to investigate age effects on auditory P300 topography. A recently developed dipole source model for P300 distinguishes overlapping P300 subcomponents and enhances reliability as well as validity of the measurement. 67 healthy subjects were examined using the P300 dipole model in addition to the scalp data measurement. The results show that P300 subcomponents reflect functionally different processes concerning age changes of P300 activities. Temporo-parietal P300 is smaller in older subjects, whereas frontal P300 is not attenuated. Age affected both P300 subcomponents' latencies. Therefore, the functionally different alteration of P300 subcomponents might be the reason for P300 topography changes with the P300 maximum more frontally in older age.

Acoustic Stimulation↗
PubMed2000

Clinical and biological findings in a case with 48-hour bipolar ultrarapid cycling before and during valproate treatment.

BACKGROUND: The rare cases of patients with 48-hour ultrarapid cycling allow close investigation of mood cycles in affective disorders, because rhythmic changes in psychopathologic state and biological parameters happen very precisely. METHOD: A 67-year-old white man who had experienced bipolar 48-hour ultrarapid cycling (DSM-IV 296.80) for several years was studied without any medication and then again studied 4 weeks later during treatment with valproate (1800 mg/day). RESULTS: Objective and self ratings revealed pronounced manic states 1 day and depressed states the following day, which were found to be accompanied by rhythmic fluctuations in behavior and electroencephalographic parameters, blood cortisol and growth hormone levels (both elevated on depressive days), and urinary metanephrine (dopamine metabolite) and norepinephrine levels (both elevated on manic days). Using single photon emission computed tomography, regional blood flow in the left thalamus was lower than in the right thalamus on the manic day, while symmetric perfusion of the thalamus was found on the depressive day. Under valproate treatment, the patient remitted completely, and significant rhythmic changes in most of the biological parameters were no longer detectable. CONCLUSION: The biological findings in this patient with bipolar 48-hour ultrarapid cycling, which correspond to those in other types of affective disorders, suggest that disturbances in the diencephalon-pituitary axis may be especially correlated to pathologic changes of mood.

Aged↗
PubMed2000

Is the EEG helpful in diagnosing and monitoring lithium intoxication? A case report and review of the literature.

Lithium is potentially toxic to the central nervous system. Clinical lithium neurotoxicity may appear at any time during therapy and may go unrecognized. Failure to appreciate this fact leads to delays in diagnosis and treatment, placing the patient at risk of permanent neurological damage or death. In spite of a largely clinical diagnosis of lithium intoxication, the EEG provides an objective criterion of intoxication. We report a case of lithium intoxication with neurotoxic symptoms associated with marked EEG changes despite moderate lithium serum levels. In contrast to the interindividually varying EEG changes under uncomplicated lithium therapy, pathological EEG findings are the rule in the case of intoxication. Several reports evince a closer relationship between neurotoxic symptoms with EEG changes than with serum levels of lithium. This is of clinical interest with respect to intoxication under therapeutic lithium serum levels, since the EEG is the only examination indicating an intoxication. In patients with intoxication, the phenomenon of long-lasting EEG changes after discontinuation of lithium is discussed with respect to neuronal storing of lithium and persisting neurological disturbances.

Aged↗
PubMed1999

P300 subcomponents reflect different aspects of psychopathology in schizophrenia.

BACKGROUND: The aim of the study was to investigate abnormalities of P300 subcomponents in schizophrenic patients as well as relationships between these subcomponents and positive versus negative schizophrenic symptoms. METHODS: Nineteen schizophrenic patients and 19 healthy controls were tested with an auditory event-related potential oddball paradigm designed to elicit the P300. The P300 data were analyzed by separating P300 subcomponents with a recently developed dipole source model. RESULTS: Compared to healthy controls, schizophrenic patients showed reduced P300 amplitudes of the temporo-basal dipoles, corresponding mainly to P3b. Positive symptoms of the Positive and Negative Syndrome Scale correlated positively with the temporo-basal but not with temporo-superior dipole P300 activities, whereas negative symptoms correlated positively with the temporo-superior but not with temporo-basal dipole activities. CONCLUSIONS: The P300 subcomponents separated with the dipole model are affected in a different manner by positive versus negative symptoms. Furthermore, the positive correlation between the severity of psychopathology and the P300 amplitudes of the different dipole activities appears to be a state-dependent effect, which has to be separated from the P300 amplitude reduction as a trait marker in schizophrenic patients.

Adult↗
PubMed1999

[Postoperative delirium: risk factors, prophylaxis and treatment].

After surgical operations delirium can occur as a serious and possible lethal complication in about 5-15% of patients. Additionally, risk factors such as old age, polymedication, organic and psychiatric diseases raise the incidence. After open-heart and orthopedic surgery more than half of the patients are affected. Delirium has negative effects on postoperative mobilization and reconvalescence and prolongs treatment on the ward. It is discussed in the literature that delirium may induce dementia in older patients. The correction of metabolic and electrolyte imbalances, as well as the therapy of neurologic and psychiatric diseases, belongs to prophylactic treatment. Environmental conditions which facilitate reorientation of the patient after operation have beneficial effects. Some success has been achieved by using the nootropic substance piracetam as a prophylactic. In acute treatment, the butyrophenon-neuroleptic haloperidol is the drug of choice. In delirium caused by intoxication with anticholinergic agents, physostigmin is indicated. Benzodiazepines, clonidine and clomethiazole are used in particular for the treatment of withdrawal delirium.

Aged↗
PubMed1999

[Limbic ictus as a condition for anxiety attacks].

Episodes of anxiety have been reported to be the most common psychological symptoms in patients with partial seizures. They may occur before, during and after seizures and can also appear in isolation without any convulsive symptoms. The epileptic anxiety syndrome is strikingly similar to panic attacks, and panic disorder is an important differential diagnosis. The close relationship between epileptic seizures and panic attacks is of special interest for a better pathophysiological understanding of panic attacks. In the literature an epileptiform neuronal activity is discussed as a possible underlying mechanism for panic disorder. The finding that anxiety was the most common experiential phenomenon produced by electrical stimulation of amygdala and hippocampus with depth electrodes points in this direction. PET has demonstrated abnormalities of hippocampal structures during the nonpanic state of patients with panic disorder. In addition, some EEG studies have demonstrated a high incidence of epileptiform EEG patterns in patients with panic disorder with or without agoraphobia. This was the reason why several investigators proposed that a subset of panic attacks may be related to abnormal epileptiform neuronal activity in the limbic system. The size of this subset is difficult to determine because discharges in the depth of the limbic system often cannot be seen in the scalp EEG. Concerning the hypothetical pathophysiological mechanism of panic disorder therapeutic measures were taken with antiepileptic agents. The best results were obtained for valproic acid. It seems to be reasonable to make a therapeutic trial with antiepileptic medication after nonresponse to standard pharmacotherapy.

Anxiety Disorders↗
PubMed1999

[Piracetam in anesthesia for prevention of postoperative delirium].

Delirium is a serious postoperative complication after general anaesthesia. The incidence is estimated to be about 10-15%. In the case of additional risk factors, such as old age, previously existing cerebral-vasculous and psychic deficiencies, and anaesthesia of long duration the incidence is much higher. Delirium impairs postoperative mobilisation and convalescence of the patient, can lead to a longer hospital stay and is associated with higher mortality rates. In a series of clinical studies it could be shown that the perioperative administration of the nootropic piracetam led to a shorter recovery period after anaesthesia and had a favourable influence on the delirious symptoms. Especially patients with risk factors for postoperative delirium profited from prophylactic application of piracetam. The success of this medication can be explained by a protective influence of the substance on central neurons against hypoxia, ischemia and intoxication, all of which are discussed as possible causes for postoperative delirium. Next to the pathogenetic mechanisms of postoperative delirium, the mode of action of piracetam is shown in a review and a summary of references on the clinical use in anaesthesia is given.

Anesthesia, General↗