Clinical Neuroscience

[Synchronized, oscillatory brain activity in visual perception]


SEPTEMBER 30, 2008

Clinical Neuroscience - 2008;61(09-10)

[The present study investigates one of the most promising developments of the brain-mind question, namely the possible links between synchronized oscillatory brain activity and certain (visual) perceptual processes. Through a review of the relevant literature, the author introduces the reader to the most important theories of coherent perception (’binding‘), and makes an attempt to show how synchronization of EEG-registrable oscillatory activities from various frequency bands might explain binding. Finally, a number of clinical problems are also mentioned, regarding which the presented theoretical framework might deserve further consideration.]



Further articles in this publication

Clinical Neuroscience

[Hungarian Society of Neurology and Psychiatry]


Clinical Neuroscience

[Antiepileptic drugs as mood stabilizers: what did we learn from the epileptology?]


[Author summarizes the practical aspects of psychiatric application of mood stabilizing antiepileptic drugs. He observes how to transfer experiences taken from the “epileptological” practice into the psychiatric care of bipolar patients. He shortly demonstrates the relevant information on the mechanisms of action, controversies and possible clinical effects influenced by the seizure inhibiting effect of the concerning molecules. By the opinion of the author the clinical importance of pharmacokinetic parameters are underestimated in the psychiatric practice. Therefore - as an original approach in the literature - he summarizes the detailed clinical indications of serum level measurements of antiepileptic drugs applied in psychiatry as mood stabilizers. The therapeutic experiences in epilepsy added a lot of practices for the most effective dosing, building, tapering and exchange of the mood stabilizer antiepileptics. Drug interactions (appear among the psychotropic drugs or with the commonly used medicines). As in any chronic therapies the main condition of patient's compliance is the lacking or very mild presence of the applied therapy. The paper discusses the most frequently occurring and drug-specific side effects in table forms. Using the term of “relative therapeutic potential” the need of balance between the efficacy (influenced by the choice and dosing) and the tolerance are pointed. Rules of application can change significantly in special populations like in pregnancy, obesity, chronic diseases or in chronic comorbide states and in case of polytherapy. As for the special therapeutic effects, the experiences are not completed even in group of antiepileptics: we have larger and more favorable knowledge on the traditional drugs (carbamazepine and valproates) and on lamotrigine (from the newer generation) but promising but not enough information exists on the newest antiepileptic molecules. Further targeted studies are needed for the identification and positioning of antiepileptic drugs in the palette of mood stabilizing pharmacotherapy and for the definition of evidence based, individually tailored and lifelong applied highly effective combinations of the mood stabilizing pharmacotherapy containing antiepileptic agents.]

Clinical Neuroscience

[Editorial comment]


Clinical Neuroscience

[Paraneoplastic chronic demyelinating neuropathy and lambert-eaton myasthenic syndrome associated with multiple anti-neural antibodies and small-cell lung cancer]

RÓZSA Csilla, VINCENT Angela, ARÁNYI Zsuzsanna, KOVÁCS G. Gábor, KOMOLY Sámuel, ILLÉS Zsolt

[Lambert-Eaton myasthenic syndrome (LEMS) developed in a patient with presumed chronic inflammatory demyelinating polyneuropathy (CIDP) and negative chest CT. Since antibodies against both Hu and voltage-gated calcium channel (VGCC) were detected, repeated chest CT was performed, which eventually showed a pulmonary mass lesion. Biopsy revealed small cell lung cancer (SCLC) indicating the importance of repeated chest CT in LEMS even when an existing autoimmune-like disease and negative CT may suggest an autoimmune origin. This is the first report of paraneoplastic CIDP and LEMS associated with anti-Hu, anti-VGCC and SCLC.]

Clinical Neuroscience

[European Association of Young Neurologists and Trainees]


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Clinical Neuroscience

The yield of electroencephalography in syncope

NALBANTOGLU Mecbure, TAN Ozturk Ozlem

Introduction - Syncope is defined as a brief transient loss of consciousness due to cerebral hypoperfusion. Although the diagnosis of syncope is based on a thorough history and examination, electroencaphalography (EEG) is also an important investigational tool in the differential diagnosis in this group of patients. In this study we aimed to identify the diagnostic value of EEG in patients with syncope. Methods - We retrospectively examined EEG recordings of 288 patients with the diagnosis of syncope referred to the Cankiri State Hospital EEG laboratory, from January 2014 to January 2016. The EEG findings were classified into 6 groups as normal, epileptiform discharges (spike and sharp waves), generalized background slowing, focal slowing, hemispherical asymmetries, and low amplitude EEG tracing. The EEGs were separated according to gender and age. Results - Total of 288 patients were included in this study, 148 were females (51.4%) and 140 (48.6%) were males. Among all the EEG reports, 203 (70.5%) were normal, 8 of them (2.8%) showed generalized background slowing and 7 (2.4%) demonstrated focal slow waves. Epileptiform discharges occured among 13 patients (4.5%). Hemispherical asymmetries were detected in 10 patients (3.5%) and low amplitude EEG tracing in 47 patients (16.3%). There was no significant difference between age groups in EEG findings (p=0.3). Also no significant difference was detected in EEG results by gender (p=0.2). Discussion - Although the diagnosis of syncope, epilepsy and non-epileptic seizures is clinical diagnosis, EEG still remains additional method

Clinical Neuroscience

[EEG source localization using LORETA (Low Resolution Electromagnetic Tomography)]

PUSKÁS Szilvia

[Electroencephalography (EEG) has excellent temporal resolution, but the spatial resolution is poor. Different source localization methods exist to solve the so-called inverse problem, thus increasing the accuracy of spatial localization. This paper provides an overview of the history of source localization and the main categories of techniques are discussed. LORETA (Low Resolution Electromagnetic Tomography) is introduced in details: technical informations are discussed and localization properties of LORETA method are compared to other inverse solutions. Validation of the method with different imaging techniques is also discussed. This paper reviews several publications using LORETA both in healthy persons and persons with different neurological and psychiatric diseases. Finally future possible applications are discussed.]

Clinical Neuroscience

[Spectral, phase-synchronization, and graph theoretical EEG changes related to mental arithmetics]

BOHA Roland, TÓTH Brigitta, GAÁL Zsófia Anna, KARDOS Zsófia, FILE Bálint, MOLNÁR Márk

[During mental arithmetic operations working memory playsan important role, but there are only few studies in which anattempt was made to separate this effect from the process ofarithmetics per se. In this study the effects of arithmetic onthe EEG of young adults (14 participants, six of themwomen, mean age 21.57 years, SD: 2.62) was investigatedduring a subtraction task in the θ(4-8 Hz) frequency band.Besides the power density spectrum analysis phasesynchrony based on recently developed graph theoreticalmethods were used and strength of local connections (clustercoefficient; C) and global interconnectedness of network(characteristic path length; L) were determined. Before thearithmetic task passive viewing (control situation) and anumber recognition paradigms were used. During the arith-metic task compared to the control situation significantlyincreasing phase synchrony and C values were found. L wassignificantly shorter (F(2, 26)=818.77, p<0.0001) only dur-ing the arithmetic task: this fact and the former two resultsimply that the network topology shifted towards the “smallworld” direction. Our findings concerning regionaldifferences confirm those reported earlier in the literature:compared to the control condition significant task-relatedincrease was found in C values in the parietal areas [moreexplicitly in the left side, (F(1, 13)=7.2020, p=0.0188)],which probably corresponds to stronger local connectionsand more synchronized (sub)networks. During the task con-dition significantly increased θband power; (F(1,13)=7.9708, p=0.0144) and decreased L values werefound in the left frontal region compared to the right side(F(1, 13)=6.0734, p=0.0284), which can also be interpret-ed as an indicator of optimized network topology ofinformation processing.]

Clinical Neuroscience

[Analysis of mental arithmetic task by the “minimum spanning tree” method]

BOHA Roland, TÓTH Brigitta, KARDOS Zsófia, FILE Bálint, GAÁL Zsófia Anna, MOLNÁR Márk

[Goals - In the present study basic arithmetic induced rearrangements in functional connections of the brain were investigated by using graph theoretical analysis what becomes increasingly important both in theoretical neuroscience and also in clinical investigations. Research questions - During mental arithmetic operations (working) memory plays an important role, but there are only a few studies in which an attempt was made to separate this effect from the process of arithmetic operations themselves. The goal of our study was to separate the neural networks involved in cognitive functions. Methods - As an attempt to clarify this issue the graph-theoretical “minimal spanning tree” method was used for the analysis of EEG recorded during task performance. The effects of passive viewing, number recognition and mental arithmetic on PLI based minimal spanning trees (MST) were investigated on the EEG in young adults (adding task: 17 subjects; passive viewing and number recognition: 16 subjects) in the θ (4-8 Hz) frequency band. Results - Occipital task relevant synchronization was found by using the different methods, probably related to the effect of visual stimulation. With respect to diameter, eccentricity and fraction of leafs different task-related changes were found. Discussion - It was shown that the task related changes of various graph indices are capable to identify networks behind the various relevant dominant functions. Thus the “minimal spanning tree” method is suitable for the analysis of the reorganization of the brain with respect to cognitive functions.]

Clinical Neuroscience

Extreme delta brush EEG pattern in a case with anti-NMDA receptor encephalitis


Anti-N-methyl-D-aspartate receptor NMDA-R encephalitis is caused by antibodies against the NMDA-R and characterized by a severe encephalopathy with psychosis, epileptic seizures and autonomic disturbances. This disorder is often accompanied with malignancies, especially ovarian teratoma. Some patients’ EEGs show a different pattern similar to the waveforms of premature infants and this pattern is specifically named as extreme delta brush (EDB). We report a 24-year-old female having anti-NMDA receptor encephalitis and EDB patern.