bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of anticonvulsant and nootropic effect of ondansetron in mice
Authors: Jain S , Agarwal NB , Mediratta PK , Sharma KK
Published: February 2012

The role of serotonin receptors have been implicated in various types of experimentally induced seizures. Ondansetron is a highly selective 5-hydroxytryptamine 3 (5-HT3) receptor antagonist used as antiemetic agent for chemotherapy-, and radiotherapy-induced nausea and vomiting. The present study was carried out to examine the effect of ondansetron on electroshock, pentylenetetrazole (PTZ)-induced seizures and cognitive functions in mice. Ondansetron was administered intraperitoneally (i.p.) at doses of 0.5, 1.0 and 2.0 mg/kg (single dose) to observe its effect on the increasing current electroshock seizure (ICES) test and PTZ-induced seizure test. In addition, a chronic study (21 days) was also performed to assess the effects of ondansetron on electroshock-induced convulsions and cognitive functions. The effect on cognition was assessed by elevated plus maze and passive avoidance paradigms. Phenytoin (25 mg/kg, i.p.) was used as a standard anticonvulsant drug and piracetam (200 mg/kg) was administered as a standard nootropic drug. The results were compared with an acute study, wherein it was found that the administration of ondansetron (1.0 and 2.0 mg/kg) significantly raised the seizure-threshold current as compared to control group in the ICES test. Similar results were observed after chronic administration of ondansetron. In PTZ test, ondansetron in all the three tested doses failed to show protective effect against PTZ-induced seizure test. Administration of ondansetron for 21 days significantly decreased the transfer latency (TL) and prolonged the step-down latency (SDL). The results of present study suggest the anticonvulsant and memory-enhancing effect of ondansetron in mice.
Patient dignity and its related factors in heart failure patients
Authors: Bagheri Hossein , Yaghmaei Farideh , Ashktorab Tahereh , Zayeri Farid
Published: February 2012

Maintenance and promotion of patient dignity is an ethical responsibility of healthcare workers. The aim of this study was to investigate patient dignity and related factors in patients with heart failure. In this qualitative study, 22 patients with heart failure were chosen by purposive sampling and semi-structured interviews were conducted until data saturation. Factors related to patient dignity were divided into two main categories: patient/care index and resources. Intrapersonal features (inherent characteristics and individual beliefs) and interpersonal interactions (communication, respect, enough information, privacy, and authority) were classified as components of the patient/care index category. Human resources (management and staff) and environmental resources (facilities and physical space) were classified as components of the resources category. The results will increase healthcare staff's understanding of patient dignity and its related factors, and provide information regarding the development of systems and processes that support patients in ways that are consistent with these values.
Comparing Objective Measures and Perceptions of Cognitive Learning in an ERP Simulation Game
Authors: Cronan Timothy Paul , Léger Pierre-Majorique , Robert Jacques , Babin Gilbert , Charland Patrick
Published: February 2012

Enterprise Resource Planning (ERP) systems have had a significant impact on business organizations. These large systems offer opportunities for companies regarding the integration and functionality of information technology systems; in effect, companies can realize a competitive advantage that is necessary in today’s global companies. However, effective training for the incorporation and use of these large-scale systems is difficult and challenging; improved strategies for effective training include the use of business simulations. The question of the effectiveness of training remains—“How do we measure learning?”. In a recent Simulation & Gaming article “Business Simulations and Cognitive Learning”, Anderson and Lawton (2009) focus on research associated with the assessment of cognitive learning in business simulations. They indicate that little progress has occurred in objectively assessing cognitive learning in simulations and call for research that might help determine whether simulations accomplish what they purport to achieve in terms of participant learning. In this research note, objective measures of learning are presented. The results of objective measures of learning are compared with those of self-assessed perceptions of learning in the context of an ERP business simulation game. Based on the comparisons of learning measures, self-assessed measure results were not different from those of objective measures; moreover, learning did occur.
Development of a fuzzy model for predicting ground vibration caused by rock blasting in surface mining
Authors: Ghasemi Ebrahim , Ataei Mohammad , Hashemolhosseini Hamid
Published: February 2012

Ground vibration is an integral part of the rock blasting process in surface mines, which may cause severe damages to structures and plants in the nearby environment. Therefore, its prediction plays an important role in the minimization of environmental impacts. The peak particle velocity (PPV) is an important predictor for ground vibration. In this paper, first a fuzzy logic model was developed to predict PPV based on collected data from blasting events in Sarcheshmeh copper mine, located in the southwest of Iran. The predictive fuzzy model was implemented on the fuzzy logic toolbox of MATLAB using the Mamdani algorithm. Then, the PPV was predicted by conventional empirical predictors used in blasting practice and also by multiple regression analysis. Finally, a comparative analysis between the results obtained by the fuzzy model and common vibration predictors was carried out. The results indicated the high predictive capacity of fuzzy model, which can be used as a reliable predictor of ground vibration for the studied mine.
Continuous crack modeling in piezoelectrically driven vibrations of an Euler–Bernoulli beam
Authors: Afshari Mana , Inman Daniel J
Published: February 2012

One of the main objectives of the structural health monitoring community is to continuously monitor the integrity of a structure by embedding sensors and actuators into the structure. A piezoelectrically driven beam is considered in the present work and the effect of the growth of a single crack on the vibratory characteristics of the beam is studied. It is shown that in order to combine the effect of a crack and the piezoceramic (PZT) actuator into the modeling, available formulations of the mode shapes of the cracked beam, such as modeling the beam as a bi-section connected with a rotational spring, are not applicable as they are not twice differentiable. A new formulation of the mode shapes of the cracked beam is introduced here by applying the Rayleigh–Ritz method. The effect of location and depth of the crack on the vibratory response of the beam is modeled through formulating the loss of energy due to the presence of the crack, which is approximated here as a massless rotational spring. It is shown that the proposed crack modeling provides a close approximation of the mode shapes of the cracked beam. This modeling approach is beneficial as it provides twice-differentiable mode shapes for the cracked beam and can be used as trial functions in the assumed mode approximations. Numerical analysis is also provided for various design parameters, such as crack depth and position and the location of the PZT patch.
A randomized, controlled trial of fingolimod (FTY720) in Japanese patients with multiple sclerosis
Authors: Saida T , Kikuchi S , Itoyama Y , Hao Q , Kurosawa T , Nagato K , Tang D , Zhang-Auberson L , Kira J
Published: February 2012

Background:

Fingolimod (FTY720) has previously shown clinical efficacy in phase II/III studies of predominantly Caucasian populations with multiple sclerosis (MS).

Objectives:

To report six-month efficacy and safety outcomes in Japanese patients with relapsing MS treated with fingolimod.

Methods:

In this double-blind, parallel-group, phase II study, 171 Japanese patients with relapsing MS were randomized to receive once-daily fingolimod 0.5 mg or 1.25 mg, or matching placebo for six months. The primary and secondary endpoints were the percentages of patients free from gadolinium (Gd)-enhanced lesions at months 3 and 6, and relapses over six months, respectively; safety outcomes were also assessed.

Results:

147 patients completed the study. Higher proportions of patients were free from Gd-enhanced lesions at months 3 and 6 with fingolimod (0.5 mg: 70%, p = 0.004; 1.25 mg: 86%, p < 0.001) than with placebo (40%). Odds ratios for the proportions of relapse-free patients over six months favoured fingolimod versus placebo but were not significant. Adverse events related to fingolimod included transient bradycardia and atrioventricular block at treatment initiation, and elevated liver enzyme levels.

Conclusions:

This study demonstrated the clinical efficacy of fingolimod for the first time in Japanese patients with MS, consistent with the established effects of fingolimod in Caucasian patients.
Bad to the Bone
Authors: Thoroughgood Christian N. , Tate Brian W. , Sawyer Katina B. , Jacobs Rick
Published: February 2012

Although destructive leader behavior is an increasingly popular area of study, little is known about its content or dimensionality at a broad level. In this study, an inventory of destructive behaviors was developed through inductive and deductive methods. Across multiple studies, three behavioral dimensions emerged and were used to create a measure of the construct. Results provide support for the instrument’s construct and criterion validity and its predictive validity over abusive supervision. The study highlights the progress and limitations of prior research, suggests directions for future studies, and provides a practically useful measure of destructive leader behavior in organizations.
Can Police Car Colored Flash Light Induce Electroencephalographic Discharges and Seizures?
Authors: Gadoth Natan , Vainstein Gabriel , Yoffe Vitali
Published: February 2012

Aim: To explore the epileptogenic potential of a newly introduced police car flash light device (930 Heliobe Lightbar).

Methods: A 930 Heliobe Lightbar was installed in the EEG laboratory. Thirty patients with known epilepsy, 30 subjects with chronic headache who were otherwise healthy and 15 healthy volunteers were examined.

Results: All the subjects signed an informed consent and underwent an EEG during which photostimulation was performed with the standard stroboscope and later with the Police lightbar. In all 75 examined the lightbar did not induce clinical or electrographic seizures. In a single patient with epilepsy the lightbar enhanced epileptiform activity induced by standard photic stimulation.

Conclusion: In this study the new Police lightbar was found to be non-epileptogenic.
Integrative Neuroscience: The Role of a Standardized Database
Authors: Gordon E. , Cooper N. , Rennie C. , Hermens D. , Williams L.M.
Published: February 2012

Most brain related databases bring together specialized information, with a growing number that include neuroimaging measures. This article outlines the potential use and insights from the first entirely standardized and centralized database, which integrates information from neuroimaging measures (EEG, event related potential (ERP), structural/functional MRI), arousal (skin conductance responses (SCR)s, heart rate, respiration), neuropsychological and personality tests, genomics and demographics: The Brain Resource International Database. It comprises data from over 2,000 “normative” subjects and a growing number of patients with neurological and psychiatric illnesses, acquired from over 50 laboratories (in the USA, United Kingdom, Holland, South Africa, Israel and Australia), all with identical equipment and experimental procedures.

Three primary goals of this database are to quantify individual differences in normative brain function, to compare an individual's performance to their database peers, and to provide a robust normative framework for clinical assessment and treatment prediction. We present three example demonstrations in relation to these goals. First, we show how consistent age differences may be quantified when large subject numbers are available, using EEG and ERP data from nearly 2,000 stringently screened normative subjects. Second, the use of a normalization technique provides a means to compare clinical subjects (50 ADHD subjects in this study) to the normative database with the effects of age and gender taken into account. Third, we show how a profile of EEG/ERP and autonomic measures potentially provides a means to predict treatment response in ADHD subjects. The example data consists of EEG under eyes open and eyes closed and ERP data for auditory oddball, working memory and Go-NoGo paradigms. Autonomic measures of skin conductance (tonic skin conductance level, SCL, and phasic skin conductance responses, SCRs) were acquired simultaneously with central EEG/ERP measures.

The findings show that the power of large samples, tested using standardized protocols, allows for the quantification of individual differences that can subsequently be used to control such variation and to enhance the sensitivity and specificity of comparisons between normative and clinical groups. In terms of broader significance, the combination of size and multidimensional measures tapping the brain's core cognitive competencies, may provide a normative and evidence-based framework for individually-based assessments in “Personalized Medicine.”
The Australian EEG Database
Authors: Hunter M. , Smith R. L. L. , Hyslop W. , Rosso O.A. , Gerlach R. , Rostas J. A. P. , Williams D.B. , Henskens F.
Published: February 2012

The Australian EEG Database is a web-based de-identified searchable database of 18,500 EEG records recorded at a regional public hospital over an 11-year period. Patients range in age from a premature infant born at 24 weeks gestation, through to people aged over 90 years. This paper will describe the history of the database, the range of patients represented in the database, and the nature of the text-based and digital data contained in the database. Preliminary results of the first two studies undertaken using the database are presented. Plans for sharing data from the Australian EEG database with researchers are discussed.

We anticipate that such data will be useful in not only helping to answer clinical questions but also in the field of mathematical modeling of the EEG.
Functional Connectivity between Hemispheres and Schizophrenic Symptoms: A Longitudinal Study of Interhemispheric EEG Coherence in Patients with Acute Exacerbations of Schizophrenia
Authors: Higashima Masato , Takeda Tsutomu , Kikuchi Mitsuru , Nagasawa Tatsuya , Koshino Yoshifumi
Published: February 2012

To clarify whether interhemispheric electroencephalogram (EEG) coherence reflecting functional connectivity between the two cerebral hemispheres can change in a symptom-dependent manner in schizophrenia, we measured resting EEG and symptom severity twice at an average interval of 32.7 days during the course of treatment in 15 patients hospitalized for acute exacerbations of schizophrenia. Symptom severity was estimated quantitatively by means of the Brief Psychiatric Rating Scale (BPRS). Correlation analysis showed that increases in the beta-band coherence for frontal electrode pairs during the treatment were associated with improvement in the total score and the score on the positive subscale of BPRS. This result suggests that functional disconnection between the left and right frontal lobes may be related to the generation of psychotic symptoms and can normalize following antipsychotic treatment.
Autoimmune Thyroid Encephalopathy Presenting with Epilepsia Partialis Continua
Authors: Aydin-Özemir Zeynep , Tüzün Erdem , Baykan Betül , Akman-Demir Gülşen , Özbey Neşe , Gürses Candan , Christadoss Premkumar , Gökyiğit Ayşen
Published: February 2012

We report the first case of an autoimmune thyroid encephalopathy presenting with multifocal motor status epilepticus. A 37-year-old female patient was admitted with multifocal motor seizures intractable to intravenous status epilepticus treatments, asymmetrical quadriparesis, truncal ataxia and continuous semi-rhythmical jerks. Pathological signal alterations were detected in both precentral cortices in MRI examination. Autoimmune thyroiditis was diagnosed after radiological examinations of the thyroid gland and thyroid function tests. Seizures promptly ceased following intravenous steroid treatment. Immunohistochemistry studies showed mild to moderate neuronal staining with the plasma and CSF samples. Remarkably, autoimmune thyroiditis may present with migrating focal motor status epilepticus. We recommend anti-thyroid antibody screening for multifocal motor status epilepticus cases of unspecified cause.
Event-Related Potential Measures of Visual Working Memory
Authors: Drew Trafton W. , McCollough Andrew W. , Vogel Edward K.
Published: February 2012

Visual working memory is a limited capacity system that temporarily maintains information about objects in the immediate visual environment. Psychophysical experiments have shown that most people are able to actively maintain 3 or 4 items in visual working memory at any point in time To better understand how this process works and why our working memory capacity is so limited, a variety of neurophysiological approaches have been employed. In recent years, there has been a surge of interest in understanding how visual information is maintained in working memory at the neural level. Single-cell research with non-human primates has shown that neuronal firing during the retention period reflects the information that is currently held in working memory. In humans, event-related potentials (ERPs) have been used to examine the maintenance of information in working memory. An event-related potential component, known as the negative slow wave (NSW), has been used to measure the maintenance of information in working memory “online” during a given trial. More recently, another ERP component, the contralateral delay activity (CDA) has been shown to be a fairly specific correlate of the current contents of working memory. This component is sensitive to an individual's working memory capacity and may provide a window into the operations of this central cognitive construct.
Error Detection, Correction, and Prevention in the Brain: A Brief Review of Data and Theories
Authors: van Veen V. , Carter C.S.
Published: February 2012

Errors during speeded response tasks are typically immediately followed by a large component in the event-related potential, the error-related negativity; various lines of research have suggested that this component is primarily generated by the anterior cingulate cortex. This error-related activity has generated a high level of interest and investigation by cognitive neuroscientists because of the importance of online action monitoring for theories of cognitive regulation. A subsequent component, the error positivity, has remained more elusive to date. In this review we will discuss some of the extensive research which has suggested that these components are related to performance monitoring, and, should performance be compromised, dynamically adjusting control processes. Furthermore, evidence from patients with mental illnesses, including schizophrenia and obsessive-compulsive disorder, suggests that such illnesses might be understood as resulting in part from disturbances in this action monitoring function.
From Amnesia to Dementia: ERP Studies of Memory and Language
Authors: Taylor Jason R. , Olichney John M.
Published: February 2012

Cognitive event-related potential (ERP) studies of memory and language impairments in amnesia and Alzheimer's disease (AD) are reviewed. Well-circumscribed lesions of the medial temporal lobe (MTL) or diencephalon causing an amnestic syndrome, an inability to encode and retrieve episodic memories beyond the brief duration of working memory, appear to produce altered plasticity of the late positive P600 component, but usually spare P300 and N400 components. The neuropathology of AD affects MTL and extends to neocortical association areas, causing deficits of episodic and semantic memory. In AD dementia, the P300, N400, and P600 all commonly show abnormalities. ERP studies of individuals with mild cognitive impairment may reveal neurophysiological changes prior to the emergence of clinical deficits, which could advance the early detection and diagnosis of AD.
Spatial-Temporal Current Source Correlations and Cortical Connectivity
Authors: Thatcher R.W. , Biver C.J. , North D.
Published: February 2012

The purpose of this study was to explore spatial-temporal correlations between 3-dimensional current density estimates using Low Resolution Electromagnetic Tomography (LORETA).

The electroencephalogram (EEG) was recorded from 19 scalp locations from 97 subjects. LORETA current density was computed for 2,394 gray matter pixels. The gray matter pixels were grouped into 33 left hemisphere and 33 right hemisphere regions of interest (ROIs) based on groupings of Brodmann areas. The average source current density in a given region of interest (ROI) was computed for each 2 second epoch of EEG and then a Pearson product correlation coefficient was computed over the time series of successive 2 second epochs of current density between all pairwise combinations of ROIs during the resting eyes-closed EEG session.

Rhythmic changes in source correlation as a function of distance were present in all regions of interest. Also, maximum correlations at certain frequencies were present independent of distance. The occipital regions exhibited the highest short distance correlations and the frontal regions exhibited the highest long distance correlations. In general, the right hemisphere exhibited higher intra-hemispheric source correlations than the left hemisphere especially in the temporal, parietal and occipital cortex. The strongest left vs. right hemisphere differences were In the alpha frequency band (8–12 Hz) and in the gamma frequency band (37–40 Hz).

The pattern of spatial frequencies in different cortical lobules is consistent with differences in neural packing density and the operation of ‘U’ shaped fiber systems. The general conclusions were: 1− the higher the packing density then the greater the intra-cortical connection contribution to LORETA source correlations, 2- spatial frequencies are primarily due to intra-cortical ’U” shaped fiber connections and long distance fiber connections, 3− posterior and temporal cortical intra-hemispheric coupling is generally stronger in the right hemisphere than in the left hemisphere.
Antiepileptic Drugs and Mood Stability
Authors: Amann Benedikt , Grunze Heinz , Vieta Eduard , Trimble Michael
Published: February 2012

This paper will discuss different definitions of the term “mood stabilizer” and highlight in detail the antiepileptic drugs carbamazepine, valproate and lamotrigine with respect to their relative strengths in stabilizing mood in bipolar patients. These drugs are heterogeneous in their mechanisms of action and in their efficacy to stabilize patients with epilepsy and the various mood states in bipolar disorder. Lamotrigine has obtained approval in several countries for the indication of preventing bipolar depressive episodes, which raises the question of differential efficacy of other antiepileptic drugs as mood stabilizers in the prevention of either depressive or hypo-/manic episodes. A Medline Search to 2006 was conducted for controlled acute and maintenance studies of the three scientifically and clinically most established antiepileptic drugs carbamazepine, valproate and lamotrigine. The medications discussed in this review only partly fulfill definitions of a mood stabilizer, and we suggest that future research should focus on combined treatment strategies.
QEEG Prognostic Value in Acute Stroke
Authors: Cuspineda E. , Machado C. , Galán L. , Aubert E. , Alvarez M. A. , Llopis F. , Portela L. , García M. , Manero J. M. , Ávila Y.
Published: February 2012

The objective of our study is to determine the predictive value of QEEG in patients suffering from an acute ischemic cerebral stroke. Twenty-eight patients were studied within the first 72 hours of clinical evolution of middle cerebral artery territory ischemic stroke. Thirty-seven QEEG recordings were obtained: 13 in the first 24 hours after cerebral stroke onset, 9 between 24–48 hours and 15 between 48–72 hours. Absolute Energies (AE) were the QEEG selected variables for statistical analysis: first, AE Z values were calculated using the Cuban QEEG norms, then the maximum and minimum AE Z values were selected within each frequency band and total power. The medians of the five neighboring Z values were also chosen. Regression models were estimated using the RANKIN scores as dependent variables and the selected QEEG variables as independent, then outcome predictions at hospital discharge and 3 months later were calculated. Percentages of concordance and errors between the estimated and real outcome scores were obtained.

Alpha and theta AE were the best predictor for short-term outcome and delta AE for long-term outcome. We conclude that QEEG performed within the first 72 hours of ischemic stroke might be a powerful tool predicting short-and long-term outcome.
Source Localization of Triphasic Waves: Implications for the Pathophysiological Mechanism
Authors: Kwon Oh-Young , Jung Ki-Young , Park Ki-Jong , Kang Joong-Koo , Shon Young-Min , Lee Il-Keun , Yum Myung-Kul
Published: February 2012

To investigate the current source location from the electroencephalograms (EEGs) of 12 patients who showed typical triphasic waves attributable to various causes, using the combination of a dipole source model and a distributed source model. The triphasic waves were explained by a single main dipole in 10 of the 12 patients, and 2 patients had two dipoles responsible for the triphasic waves. All the main dipoles had a radial orientation with respect to the frontal pole.

The current density of the triphasic waves was distributed mainly in the bilateral medial frontal regions along the cingulate cortices. These findings suggest that current sources located in the medial frontal area are crucial for generating triphasic waves. The source localization may be useful for elucidating the pathophysiologic mechanism of generalized non-epileptic EEG activities, such as triphasic waves.
Creutzfeldt-Jakob Disease Presenting as Hyperparathyroidism and Generalized Tonic Status Epilepticus
Authors: Karatas Hulya , Dericioglu Nese , Kursun Oguzhan , Saygi Serap
Published: February 2012

Creutzfeldt-Jakob disease is the most common disorder among the very rare human transmissible subacute spongiform encephalopathies. Sporadic, familial or iatrogenic forms of the disease can be seen. The common presentations of the disease include rapidly progressive cognitive decline, behavioral changes, visual disturbances and cerebellar dysfunction. Hyperparathyroidism and toxicity of lithium and bismuth have been reported to induce similar symptoms and EEG findings, leading to a Creutzfeldt-Jakob like syndrome. We report a very rare case of Creutzfeldt-Jakob disease presenting with hyperparathyroidism and generalized tonic status epilepticus.
Combining ERP and Structural MRI Information in First Episode Schizophrenia and Bipolar Disorder
Authors: McCarley Robert W. , Nakamura Motoaki , Shenton Martha E. , Salisbury Dean F.
Published: February 2012

The electrical activity in the electroencephalogram (EEG) and the event-related potentials extracted from the EEG provide the greatest temporal resolution for examining brain function. When coupled with the high spatial resolution of structural magnetic resonance imaging (sMRI), the combined techniques provide a powerful tool for neuroscience in the examination of brain abnormalities in major psychiatric illnesses. Over the last 20 years, our work has examined brain structure and function in schizophrenia. Both EEG and MRI measures have indicated profound abnormalities in schizophrenia within the temporal lobe, particularly marked over the left hemisphere. Our studies of patients first hospitalized due to psychosis revealed the early course of the disease to be characterized by progressive impairment and cortical gray matter reduction, most intense near the time of first hospitalization. Knowledge of those locations and brain signals affected early should help understand the basic physiological defect underlying this progression, with potential implications for new therapeutic interventions.
Sensory Gating: A Translational Effort from Basic to Clinical Science
Authors: Cromwell Howard C. , Mears Ryan P. , Wan Li , Boutros Nash N.
Published: February 2012

Sensory gating (SG) is a prevalent physiological process important for information filtering in complex systems. SG is evaluated by presenting repetitious stimuli and measuring the degree of neural inhibition that occurs. SG has been found to be impaired in several psychiatric disorders. Recent animal and human research has made great progress in the study of SG, and in this review we provide an overview of recent research on SG using different methods. Animal research has uncovered findings that suggest 1) SG is displayed by single neurons and can be similar to SG observed from scalp recordings in humans, 2) SG is found in numerous brain structures located in sensory, motor and limbic subregions, 3) SG can be significantly influenced by state changes of the organism, and 4) SG has a diverse pharmacological profile accented by a strong influence from nicotine receptor activation. Human research has addressed similar issues using deep electrode recordings of brain structures. These experiments have revealed that 1) SG can be found in cortical regions surrounding hippocampus, 2) the order of neural processing places hippocampal involvement during a later stage of sensory processing than originally thought, and 3) multiple subtypes of gating exist that could be dependent on different brain circuits and more or less influenced by alterations in organismal state. Animal and human research both have limitations. We emphasize the need for integrative approaches to understand the process and combine information between basic and clinical fields so that a more complete picture of SG will emerge.
Future Directions for Examining Semantic Memory in Schizophrenia Spectrum Disorders
Authors: Niznikiewicz M.
Published: February 2012

Language abnormalities in schizophrenia are regarded as a hallmark of the disease. Clinical investigations provided accurate descriptions of the different manifestations of abnormal language use, and behavioral studies suggested several mechanisms that might contribute to these abnormalities. This review focuses on semantic memory dysfunction and, primarily, on functional methodologies such as ERP and fMRI that provide more direct measures of abnormal neural mechanisms related to language use in schizophrenia. In addition, the review points to future directions of study of the areas that received little attention thus far and whose investigation might contribute to a more detailed understanding of semantic memory dysfunction in schizophrenia.
Building Meaning in Schizophrenia
Authors: Kuperberg Gina R.
Published: February 2012

The schizophrenia syndrome is clinically characterized by abnormal constructions of meaning during comprehension (delusions), perception (hallucinations), action (disorganized and non-goal-directed behavior) and language production (thought disorder). This article provides an overview of recent studies from our laboratory that have used event-related potentials and functional magnetic resonance imaging to elucidate abnormalities in temporal and spatial patterns of neural activity as meaning is built from language and real-world visual events in schizophrenia. Our findings support the hypothesis that automatic activity across semantic memory spreads further within a shorter period of time in thought-disordered patients, relative to non-thought-disordered patients and healthy controls. Neuroanatomically, increased activity to semantic associates is reflected by inappropriate recruitment of temporal cortices. In building meaning within sentences, the fine balance between semantic memory-based mechanisms and semantic-syntactic integration (dictating “who does what to whom”) is disrupted, such that comprehension is driven primarily by semantic memory-based processes. Neuroanatomically, this imbalance is reflected by preserved (and sometimes increased) activity within temporal and inferior prefrontal cortices, but abnormal modulation of dorsolateral prefrontal and parietal cortices. In building meaning across sentences (discourse), patients fail to immediately construct coherence links, but may show inappropriate recruitment of temporal and inferior prefrontal cortices to incoherent discourse, again reflecting inappropriate semantic memory-based processing (abnormal inferencing). Finally, these abnormalities may generalize to real-world visual event comprehension, where patients show reduced neural activity in determining relationships around goal-directed actions, and comprehension is again dominated by semantic memory-based mechanisms.
Long Term Effects of Left Frontal rTMS on EEG and ERPs in Patients with Depression
Authors: Spronk Desirée , Arns Martijn , Bootsma Aukje , van Ruth Rosalinde , Fitzgerald Paul B.
Published: February 2012

Repetitive transcranial magnetic stimulation (rTMS) treatment for depression has been under investigation in many controlled studies over the last 20 years. Little is known about the neurobiological action of rTMS in patients. We therefore investigated pre- and post-treatment effects on QEEG, ERP's and behavior (BDI and NEO-FFI).

rTMS treatment was applied in 8 subjects for an average of 21 sessions to the left Dorsolateral Prefrontal Cortex (left DLPFC). Clients were assessed on a QEEG and Oddball ERP evaluation pre- and post-treatment. Clients were stimulated over the left DLPFC with 10 Hz rTMS (100% MT). Furthermore, rTMS treatment was complimented by psychotherapy.

All subjects showed full remission within 20 sessions and there was a significant reduction in depressive symptomatology (BDI score) after 10 and 15 sessions and a clear decrease in the Neuroticism and an increase on the extraversion scale of the NEO-FFI personality questionnaire. Pre- and post-QEEG measurements did not reveal treatment specific effects, but only an indirect right frontal increase in delta power. On the other hand, ERP measures did reveal treatment specific effects by showing an increased positivity in the post-treatment ERP's specifically left frontal. The P2 amplitude demonstrated a significant left frontal increase in amplitude, whereas for the negative N1 and N2 a significant decrease in amplitude was observed.

The results of this pilot study demonstrate that rTMS can be a safe and efficacious treatment modality for depression. Furthermore, a specific left frontal increase in positivity for the ERP's was found (increased P2 and decreased N1 and N2 components) most likely related to the rTMS over the left DLPFC. Furthermore, there was no change in the alpha asymmetry lending support to the fact that frontal alpha asymmetry can be considered a trait marker for depression. The findings from this pilot study require future replication with larger sample sizes.
Differential Neurophysiological Effects of Magnetic Seizure Therapy (MST) and Electroconvulsive Shock (ECS) in Non-Human Primates
Authors: Cycowicz Yael M. , Luber Bruce , Spellman Timothy , Lisanby Sarah H.
Published: February 2012

Magnetic seizure therapy (MST) is under development as a means of reducing the side effects of electroconvulsive therapy (ECT) through enhanced control over patterns of seizure induction and spread. We previously reported that chronic treatment with MST resulted in less impairment in cognitive function than electroconvulsive shock (ECS) in a non-human primate model of convulsive therapy. Here we present quantitative analyses of ictal expression and post-ictal suppression following ECS, MST, and anesthesia-alone sham in the same model to test whether differential neurophysiological characteristics of the seizures could be identified. Rhesus monkeys received 4 weeks of daily treatment with ECS, MST, and anesthesia-alone sham in a counterbalanced order separated by a recovery period. Both ECS and MST were given bilaterally at 2.5 × seizure threshold. Neurophysiological characteristics were derived from two scalp EEG electrode recording sites during and immediately following the ictal period, and were compared to sham treatment. EEG power within four frequencies (delta, theta, alpha and beta) was calculated.

Our results support earlier findings from intracerebral electrode recordings demonstrating that MST- and ECS- induced seizures elicit differential patterns of EEG activation. Specifically, we found that ECS shows significantly more marked ictal expression, and more intense post-ictal suppression than MST in the theta, alpha, and beta frequency bands (Ps<.05). However, the ECS and MST were indistinguishable in the delta frequency band during both ictal and post-ictal periods. These results demonstrate that magnetic seizure induction can result in seizures that differ in some neurophysiological respects compared with ECS, but that these modalities share some aspects of seizure expression. The clinical significance of these similarities and differences awaits clinical correlation.
Nicotine and Attention: Event-Related Potential Investigations in Nonsmokers
Authors: Knott Verner , Shah Dhrasti , Fisher Derek , Millar Anne , Prise Stephanie , Scott Terri Lynn , Thompson Mackenzie
Published: February 2012

Research into the effects of nicotine and smoking on cognition has largely confirmed the subjective reports of smoking in smokers on mental functions, showing smoking abstinence to disrupt and smoking/nicotine to restore cognitive functioning. Evidence of performance improvements in nonsmokers has provided partial support for the absolute effects of nicotine on cognitive processes, which are independent of withdrawal relief, but the mechanisms underlying its pro-cognitive properties still remain elusive.

The attentional facilitation frequently reported with smoking/nicotine may be indirectly related to its diffuse arousal-enhancing actions, as evidenced by electroencephalographic (EEG) fast frequency power increments, or it may reflect nicotine's direct modulating effects on specific neural processes governing stimulus encoding, selection and rejection. Event-related potential (ERP) components extracted during the performance of cognitive tasks have proven to be sensitive to early pre-attentive and later attention-dependent processes that are not otherwise reflected in behavioral probes. To date, the majority of ERP studies have been conducted with smokers using passive non-task paradigms or relatively non-demanding “oddball” tasks. This paper will emphasize our recent ERP investigations with acute nicotine polacrilex (6 mg) administered to nonsmokers, and with a battery of ERP and behavioral performance paradigms focusing on intra- and inter-modal selective attention and distraction processes. These ERP findings of nicotine-augmented early attentional processing add support to the contention that nicotine may be be used by smokers as a “pharmacological tool” for tuning cognitive functions relating to the automatic and controlled aspects of sensory input detection and selection.
Use of Clinical Neurophysiology for the Selection of Medication in the Treatment of Major Depressive Disorder: The State of the Evidence
Authors: Leuchter Andrew F. , Cook Ian A. , Hunter Aimee , Korb Alex
Published: February 2012

Approximately 50% of patients with Major Depressive Disorder (MDD) respond to the first antidepressant medication prescribed, and fewer than one-third experience remission of symptoms. The most significant challenge in the management of MDD, therefore, is selection of the antidepressant medication that is most likely to lead to response or to remission for an individual patient. There is a growing body of evidence that certain clinical neurophysiologic techniques may be useful for selecting the medication that is most likely benefit each patient. Use of low resolution electromagnetic tomography (LORETA), loudness dependent auditory evoked potentials (LDAEP), and resting state quantitative electroencephalography (QEEG) in the clinical setting is increasingly supported by studies indicating that these techniques may help identify particular medications that are most likely to lead to response or remission. The current state of evidence supporting the use of each technique is reviewed.
Visual Dysfunction and Computational Sleep Depth Changes in Obstructive Sleep Apnea Syndrome
Authors: Saunamäki Tiia , Jehkonen Mervi , Huupponen Eero , Polo Olli , Himanen Sari-Leena
Published: February 2012

The aims of this study are to clarify whether patients with obstructive sleep apnea syndrome (OSAS) have a decline in verbally or visually-based cognitive abilities and whether the possible decline is related to particular sleep depth changes. In addition, the effect of continuous positive airway pressure (CPAP) on the possible changes is investigated. Fifteen OSAS patients and 15 healthy controls joined two full-night polysomnographies, including a computational measure of deep sleep percentage (DS%) bilaterally from the frontal, central and occipital channels, and a neuropsychological assessment. After a 6-month CPAP the patients underwent one more full-night polysomnography with computational DS% analysis and a neuropsychological assessment.

At the baseline, the OSAS patients had poorer performance in the Picture Completion, in the Digit Symbol and in copying the Rey-Osterrieth Complex Figure Test (ROCFT) compared to the controls. The patients also showed reduced DS% in all 6 electrographic (EEG) channels compared to controls. The patients had an inter-hemispheric difference showing less deep sleep in the right hemisphere than in the left hemisphere both frontopolarly and centrally, while the controls showed this inter-hemispheric difference only frontopolarly. After CPAP the patients still had poorer performance in the Picture Completion and in the ROCFT. The patients continued to show reduced DS% in all 3 channels of the right hemisphere and occipitally in the left hemisphere, also the inter-hemispheric difference frontopolarly and centrally remained. OSAS patients have mild visually based cognitive dysfunction and reduced amount of deep sleep in the right hemisphere even after CPAP.
EEG Abnormalities in Poikilothermia Suggesting Creutzfeldt-Jakob Disease
Authors: Bouwman N.A.M.G. , Verhagen W.I.M. , Meulstee J.
Published: February 2012

A 87-year-old woman was admitted with a rapidly progressive confusion, disorientation and myoclonus, all suggestive of sporadic Creutzfeldt-Jakob disease (sCJD). This diagnosis was initially strongly supported by the EEG, which showed slow background activity and triphasic waves, combined with the finding of an increased level of 14-3-3 protein in the cerebrospinal fluid. Remarkably, this patient had also developed hypothermia, which, after warming-up, resulted in alleviation of the mental disturbances and disappearance of myoclonus. Over time, the EEG abnormalities disappeared. She recovered clinically for which reason the diagnosis of sCJD had to be rejected; however, she kept the inability to maintain body temperature (poikilothermia). Therefore, in patients with the aforementioned symptoms body temperature should be measured and adequately managed. Our hypothesis is that she suffered from a misleading acquired encephalopathy with reversible EEG and laboratory features, mimicking sCJD. When laboratory findings suggest sCJD it remains very important to see whether or not these findings are compatible with the clinical observations.
Resolution of EEG Artifact during Continuous Renal Replacement Therapy: Case Report
Authors: Engel Jim , Graansma Clarence , Liu Tom
Published: February 2012

We describe an electrical EEG artifact seen during continuous renal replacement therapy (CRRT). This artifact was spiky waves that disappeared with grounding of the CRRT device allowing accurate interpretation of the EEG tracing.
Utilization of Below-the-Hairline EEG in Detecting Subclinical Seizures
Authors: Bubrick Ellen J. , Bromfield Edward B. , Dworetzky Barbara A.
Published: February 2012

Nonconvulsive status epilepticus (NCSE) is a serious condition commonly considered when evaluating a patient with altered mental status, and an electroencephalogram (EEG) is necessary for diagnosis. Neurology house staff often must make this diagnosis at times when no EEG technologist is available. We report our experience with abbreviated, emergency below-the-hairline EEGs (BTH-EEG) performed by neurology residents at our institution over a 1–1/2 year period.

We analyzed demographic and clinical data in relation to whether or not an ictal or periodic pattern was identified, and these results were compared to follow up EEGs. Thirty-nine studies were identified, ranging in duration from 3 min-13 hrs. Mean and median age of patients included was 53 (range 25–81yrs); 21 were female. Seven of 39 BTH-EEGs showed at least one electrographic seizure, 9 more showed periodic discharges. Follow-up EEGs showed electrographic seizures in 6 of 39 patients, including 3 of the 7 with ictal BTH-EEG, and an additional 3 whose BTH-EEGs showed periodic lateralized discharges but no organized seizures. All 7 patients with ictal BTH-EEGs survived to discharge, vs. 23 of the remaining 32.

We conclude that in selected cases, BTH-EEG is useful in detecting seizures and/or other epileptiform patterns. In our series, when NCSE was in question, the BTH-EEG showed these patterns 41% of the time. The BTH-EEG is a fast, non-invasive, inexpensive tool that may save valuable time, especially when no other viable option is immediately available. This technique may be applicable more broadly, not just limited to centers with neurology residents.
Changing Views of Basal Ganglia Circuits and Circuit Disorders
Authors: DeLong Mahlon , Wichmann Thomas
Published: February 2012

The basal ganglia (BG) have long been considered to play an important role in the control of movement and the pathophysiology of movement disorders, such as Parkinson's disease (PD). Studies over the past decades have considerably broadened this view, indicating that the BG participate in multiple, parallel, largely segregated, cortico-subcortical reentrant pathways involving motor, associative and limbic functions. Research has shown that dysfunction within individual circuits is associated not only with movement disorders, but also with neuropsychiatric disorders. Accordingly, a number of movement disorders and neuropsychiatric disorders such as obsessive compulsive disorder and Tourette's syndrome are viewed as “circuit disorders.” We here discuss the changes in our current understanding of the anatomic and functional organization of BG circuits and related circuit disorders.
Functional Imaging of Cognitive Impairment in Parkinson's Disease
Authors: Fitzpatrick T. , Mattis P. , Eidelberg D.
Published: February 2012

Parkinson's disease (PD) is known by most persons to be a neurodegenerative disorder that affects one's motor skills. However, the disease is also characterized by the less recognized cognitive symptoms, including deficits in executive functioning, as well as mood and behavioral problems, which are just as disabling and distressing as the motor symptoms. Imaging methods such as positron emission tomography (PET) have recently enhanced our understanding of cognitive disturbances in PD, and are reviewed in the current article. Furthermore, insights gained from the use of specific radiotracers in the dopaminergic and cholinergic neurotransmitter systems are discussed, as well as findings from in vivo detection of amyloid-beta. We will also discuss the potential use of a metabolic covariance network as a biomarker in clinical trials for the objective assessment of cognitive dysfunction in PD.