Catatonia and Psychosis Related to Epilepsy: A Case Report.

Although a variety of metabolic, toxic, psychiatric, and neurologic conditions can produce catatonic syndromes, it is less widely recognized that this state may be caused by epilepsy. We present the case of a woman with catatonic behavior, which she could not recall. She also exhibited olfactory, auditory and visual hallucinations. An EEG demonstrated diffuse abnormal electrical activity, mainly on left temporal and frontal areas. Treatment with anticonvulsant drugs yielded excellent response.

Frontal cortex absolute beta power measurement in Panic Disorder with Agoraphobia patients.

UNLABELLED: Panic disorder patients are hypervigilant to danger cues and highly sensitive to unpredictable aversive events, what leads to anticipatory anxiety, that is one key component of the disorder maintenance. Prefrontal cortex seems to be involved in these processes and beta band activity may be related to the involvement of top-down processing, whose function is supposed to be disrupted in pathological anxiety. The objective of this study was to measure frontal absolute beta-power (ABP) with qEEG in panic disorder and agoraphobia (PDA) patients compared to healthy controls. METHODS: qEEG data were acquired while participants (24 PDA patients and 21 controls) watched a computer simulation (CS), consisting of moments classified as "high anxiety" (HAM) and "low anxiety" (LAM). qEEG data were also acquired during two rest conditions, before and after the computer simulation display. The statistical analysis was performed by means of a repeated measure analysis of variance (two-way ANOVA) and ABP was the dependent variable of interest. The main hypothesis was that a higher ABP in PDA patients would be found related to controls. Moreover, in HAM the ABP would be different than in LAM. RESULTS: the main finding was an interaction between the moment and group for the electrodes F7, F8, Fp1 and Fp2. We observed a higher ABP in PDA patients when compared to controls while watching the CS. The higher beta-power in the frontal cortex for the PDA group may reflect a state of high excitability, together with anticipatory anxiety and maintenance of hypervigilant cognitive state. CONCLUSIONS: our results suggest a possible deficiency in top-down processing reflected by a higher ABP in the PDA group while watching the CS and they highlight the recruitment of prefrontal regions during the exposure to anxiogenic stimuli. LIMITATIONS: the small sample, the wide age range of participants and the use of psychotropic medications by most of the PDA patients.

Lower trait frontal theta activity in mindfulness meditators.

Acute and long-term effects of mindfulness meditation on theta-band activity are not clear. The aim of this study was to investigate frontal theta differences between long- and short-term mindfulness practitioners before, during, and after mindfulness meditation. Twenty participants were recruited, of which 10 were experienced Buddhist meditators. Despite an acute increase in the theta activity during meditation in both the groups, the meditators showed lower trait frontal theta activity. Therefore, we suggested that this finding is a neural correlate of the expert practitioners' ability to limit the processing of unnecessary information (e.g., discursive thought) and increase the awareness of the essential content of the present experience. In conclusion, acute changes in the theta band throughout meditation did not appear to be a specific correlate of mindfulness but were rather related to the concentration properties of the meditation. Notwithstanding, lower frontal theta activity appeared to be a trait of mindfulness practices.

Lower trait frontal theta activity in mindfulness meditators / Reduzida atividade teta na região frontal em praticantes de meditação mindfulness

Acute and long-term effects of mindfulness meditation on theta-band activity are not clear. The aim of this study was to investigate frontal theta differences between long- and short-term mindfulness practitioners before, during, and after mindfulness meditation. Twenty participants were recruited, of which 10 were experienced Buddhist meditators. Despite an acute increase in the theta activity during meditation in both the groups, the meditators showed lower trait frontal theta activity. Therefore, we suggested that this finding is a neural correlate of the expert practitioners’ ability to limit the processing of unnecessary information (e.g., discursive thought) and increase the awareness of the essential content of the present experience. In conclusion, acute changes in the theta band throughout meditation did not appear to be a specific correlate of mindfulness but were rather related to the concentration properties of the meditation. Notwithstanding, lower frontal theta activity appeared to be a trait of mindfulness practices.

Os efeitos agudos e de longo prazo da meditação mindfulness sobre a atividade da banda teta não são claros. O objetivo deste estudo foi investigar as diferenças da banda teta na região frontal entre praticantes de mindfulness iniciantes e experientes. Desta forma, vinte participantes foram recrutados (dez meditadores budistas experientes e dez não-meditadores). Apesar do aumento agudo da atividade teta durante a meditação para ambos os grupos, os meditadores apresentaram uma menor potência em ambas as condições. Sugerimos que este achado é um correlato neural da capacidade dos praticantes especialistas em limitar o processamento de informações desnecessárias e aumentar a conscientização sobre o conteúdo essencial da experiência presente. Em conclusão, as alterações agudas na banda teta durante a meditação devem estar relacionadas ao processo de concentração típico de qualquer técnica meditativa. No entanto, a atividade teta reduzida encontrada entre meditadores experientes de mindfulness parece ser uma característica desta prática específica.

Deep brain stimulation: a new treatment in mood and anxiety disorders.

This article considered already existing studies about Deep Brain Stimulation in Mood and Anxiety Disorders. In particular, articles regarding Obsessive-Compulsive Disorder and Major Depression were mostly analyzed, due to the lack of researches about other types of Mood and Anxiety Disorders. We have concentrated on the target areas where Deep Brain Stimulation was most commonly applied, and on the effects this measure had on treatment-refractory patients. The obtained results showed that the stimulation of the: nucleus accumbens, subgenual cingulate cortex and ventral capsule/ventral striatum, has a positive influence on the development of the disorders investigated, sometimes showing the complete remission of the symptoms. Although Deep Brain Stimulation was overall found to be a promising and safe treatment for Mood and Anxiety Disorders, there are not enough studies proving its efficacy in wide samples and in the presence of more complex variables.

Source Imaging of P300 Visual Evoked Potentials and Cognitive Functions in Healthy Subjects.

The P300 event-related potential (EPR) is regarded as a neurophysiological indicator of cognitive processing of a stimulus. However, it is not known whether the P300 is a unitary component recorded on the scalp as a result of the activity of a specific intracerebral structure, or if it represents the sum of underlying components that may reflect the activation of broadly distributed intracerebral structures. The objective of the present experiment was to investigate possible correlations among the source(s) involved in the generation of the P300 and their possible neurocognitive function. The visual-evoked potential (VEP) was elicited by the oddball paradigm and analyzed after employment of sLORETA (standardized low-resolution electromagnetic tomography). The window of the P300 wave encompasses the period during which the response to the target and nontarget condition differs significantly (≈375 ms to ≈465 ms, with a peak at ≈422.5 ms). The results showed sequential and what appeared to be logical activation patterns of specific structures (specific for the processing of the stimulus used here) after presentation of the target stimulus. The peak of the P300 wave represented activation of the parahippocampal gyrus, which is responsible for upgrading memory in response to a target stimulus.

Integrative parietal cortex processes: neurological and psychiatric aspects.

For many decades the parietal cortex (PC) has been considered the key area in tasks which involve the integration of different stimuli. PC is fundamental to determine spatial sense, information navigation and integration, and is involved in several aspects of the complex motor repertoire and in neurological and psychiatric disorders. In this review, we focus on seven different aspects of PC: (i) neuroanatomy of the parietal cortex; (ii) sensory motor integration processes; iii) hand movement control: reaching, grasping, and pointing; (iv) saccadic eye movements; (v) movement observation; (vi) neurological aspects: ataxia, autism and Parkinson's disease; and (vii) psychiatric aspects: schizophrenia, bipolar disorder and depression. Among these, we related the perspectives which involve the functions of the parietal cortex and mirror neurons and that seem to play a fundamental role in action prediction, planning, observation and execution. Furthermore, we focused on the relationship between posterior parietal cortex (PPC) and hand-guided movements. For this review, we conducted an academic paper search which fulfilled the objective of the study. We conclude that the PC has great participation in different motor functions and neurological/psychiatric disorders.

Differences in early and late stages of information processing between slow versus fast participants.

The human brain is a system consisting of various interconnected neural networks, with functional specialization coexisting with functional integration occurring both; temporally and spatially at many levels. The current study ranked and compared fast and slow participants in processing information by assessing latency and amplitude of early and late Event-Related Potential (ERP) components, including P200, N200, Premotor Potential (PMP) and P300. In addition, the Reaction Time (RT) of participants was compared and related to the respective ERP components. For this purpose, twenty right-handed and healthy individuals were subjected to a classical ERP "Oddball" paradigm. Principal Component Analysis (PCA) and Discriminant Function analyses (DFA) used PRE components and the Reaction Time (RT) to classify individuals. Our results indicate that latencies of P200 (O2 electrode), N200 (O2), PMP (C3) and P300 (Pz) components are significantly reduced in the group of fast responding participants. In addition, the P200 amplitude is significantly increased in the group of fast responding participants. Based on these findings, we suggest that the ERP is able to detect even minimal impairments, in the processing of somatosensory information and cognitive and motor stages. Hence, the study of ERP might also be capable of assessing sensorimotor dysfunctions in healthy old-aged people and in neuropsychiatric patients (suffering from dementia, Parkinson's disease, and other neurological disorders).

Changes in the theta band coherence during motor task after hand immobilization.

Many different factors can temporarily or permanently impair movement and impairs cortical organization, e.g. hand immobilization. Such changes have been widely studied using electroencephalography. Within this context, we have investigated the immobilization effects through the theta band coherence analysis, in order to find out whether the immobilization period causes any changes in the inter and intra-hemispheric coherence within the cerebral cortex, as well as to observe whether the theta band provides any information about the neural mechanisms involved during the motor act. We analyzed the cortical changes that occurred after 48 hours of hand immobilization. The theta band coherence was study through electroencephalography in 30 healthy subjects, divided into two groups (control and experimental). Within both groups, the subjects executed a task involving flexion and extension of the index finger, before and after 48 hours. The experimental group, however, was actually submitted to hand immobilization. We were able to observe an increase in the coupling within the experimental group in the frontal, parietal and temporal regions, and a decrease in the motor area. In order to execute manual tasks after some time of movement restriction, greater coherence is present in areas related to attention, movement preparation and sensorimotor integration processes. These results may contribute to a detailed assessment of involved neurophysiological mechanism in motor act execution.

Changes in Cortical Activity During Real and Imagined Movements: an ERP Study.

This study aims to compare the topographic distribution of cortical activation between real and imagined movement through event-related potential (ERP). We are specifically interested in identifying, the topographic distribution of activated areas, the intensity of activated areas, and the temporal occurrence of these activations on preparation and motor response phases. Twelve healthy and right handed subjects were instructed to perform a task under real and imagery conditions. The task was performed simultaneously to electroencephalographic (EEG) recording. When compared the conditions, we found a statistically significant difference in favor of real condition revealed by performing an unpaired t-test with multiple corrections of Bonferroni, demonstrating negative activity on electrode C3 and positive activity on the electrode C4 only in motor response phase. These findings revealed similar functional connections established during real and imagery conditions, suggesting that there are common neural substrate and similar properties of functional integration shared by conditions.

Electroencephalographic findings in panic disorder / Achados eletroencefalográficos no transtorno do pânico

Some studies have reported the importance of electroencephalography (EEG) as a method for investigating abnormal parameters in psychiatric disorders. Different findings in time and frequency domain analysis with regard to central nervous system arousal during acute panic states have already been obtained. This study aimed to systematically review the EEG findings in panic disorder (PD), discuss them having a currently accepted neuroanatomical hypothesis for this pathology as a basis, and identify limitations in the selected studies. Literature search was conducted in the databases PubMed and ISI Web of Knowledge, using the keywords electroencephalography and panic disorder; 16 articles were selected. Despite the inconsistency of EEG findings in PD, the major conclusions about the absolute power of alpha and beta bands point to a decreased alpha power, while beta power tends to increase. Different asymmetry patterns were found between studies. Coherence studies pointed to a lower degree of inter-hemispheric functional connectivity at the frontal region and intra-hemispheric at the bilateral temporal region. Studies on possible related events showed changes in memory processing in PD patients when exposed to aversive stimuli. It was noticed that most findings reflect the current neurobiological hypothesis of PD, where inhibitory deficits of the prefrontal cortex related to the modulation of amygdala activity, and the subsequent activation of subcortical regions, may be responsible to trigger anxiety responses. We approached some important issues that need to be considered in further researches, especially the use of different methods for analyzing EEG signals (AU)

Alguns estudos relataram a importância da eletroencefalografia (EEG) como método de investigação de parâmetros anormais em transtornos psiquiátricos. Achados diferentes na análise do domínio do tempo e da frequência em relação à excitabilidade do sistema nervoso central durante estados agudos de pânico já foram obtidos. O objetivo deste estudo foi revisar sistematicamente os achados de EEG no transtorno do pânico (TP), discuti-los com base em uma hipótese neuroanatômica atualmente aceita para essa patologia e identificar limitações nos estudos selecionados. A pesquisa bibliográfica foi realizada nas bases de dados PubMed e ISI Web of Knowledge, utilizando as palavras-chave eletroencefalografia e transtorno do pânico; 16 artigos foram selecionados. Apesar da inconsistência dos achados de EEG no TP, as principais conclusões sobre a potência absoluta das bandas alfa e beta apontam para uma diminuição da potência em alfa, enquanto em beta a potência tende a aumentar. Diferentes padrões de assimetria foram encontrados entre estudos. Os estudos de coerência apontaram para um menor grau de conectividade funcional inter-hemisférica na região frontal e intra-hemisférica na região temporal bilateral. Estudos de potenciais eventos relacionados demonstraram mudanças no processamento da memória em pacientes com TP quando expostos a estímulos aversivos. Notou-se que a maioria dos resultados reflete a atual hipótese neurobiológica do TP, nos quais déficits inibitórios do córtex pré-frontal em relação à modulação da atividade da amígdala, e a subsequente ativação de regiões subcorticais, podem ser responsáveis por desencadear respostas de ansiedade. Foram abordadas algumas questões importantes que precisam ser consideradas em futuras pesquisas, especialmente o uso de diferentes métodos de análise de sinais de EEG (AU)

Cortical reorganization after hand immobilization: the beta qEEG spectral coherence evidences.

There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes.

Time perception impairs sensory-motor integration in Parkinson's disease.

It is well known that perception and estimation of time are fundamental for the relationship between humans and their environment. However, this temporal information processing is inefficient in patients with Parkinson' disease (PD), resulting in temporal judgment deficits. In general, the pathophysiology of PD has been described as a dysfunction in the basal ganglia, which is a multisensory integration station. Thus, a deficit in the sensorimotor integration process could explain many of the Parkinson symptoms, such as changes in time perception. This physiological distortion may be better understood if we analyze the neurobiological model of interval timing, expressed within the conceptual framework of a traditional information-processing model called "Scalar Expectancy Theory". Therefore, in this review we discuss the pathophysiology and sensorimotor integration process in PD, the theories and neural basic mechanisms involved in temporal processing, and the main clinical findings about the impact of time perception in PD.

The mirror neuron system in post-stroke rehabilitation.

Different treatments for stroke patients have been proposed; among them the mirror therapy and motion imagery lead to functional recovery by providing a cortical reorganization. Up today the basic concepts of the current literature on mirror neurons and the major findings regarding the use of mirror therapy and motor imagery as potential tools to promote reorganization and functional recovery in post-stroke patients. Bibliographic research was conducted based on publications over the past thirteen years written in English in the databases Scielo, Pubmed/MEDLINE, ISI Web of Knowledge. The studies showed how the interaction among vision, proprioception and motor commands promotes the recruitment of mirror neurons, thus providing cortical reorganization and functional recovery of post-stroke patients. We conclude that the experimental advances on Mirror Neurons will bring new rational therapeutic approaches to post-stroke rehabilitation.

Saccadic eye movement applications for psychiatric disorders.

OBJECTIVE: The study presented here analyzed the patterns of relationship between oculomotor performance and psychopathology, focusing on depression, bipolar disorder, schizophrenia, attention-deficit hyperactivity disorder, and anxiety disorder. METHODS: Scientific articles published from 1967 to 2013 in the PubMed/Medline, ISI Web of Knowledge, Cochrane, and SciELO databases were reviewed. RESULTS: Saccadic eye movement appears to be heavily involved in psychiatric diseases covered in this review via a direct mechanism. The changes seen in the execution of eye movement tasks in patients with psychopathologies of various studies confirm that eye movement is associated with the cognitive and motor system. CONCLUSION: Saccadic eye movement changes appear to be heavily involved in the psychiatric disorders covered in this review and may be considered a possible marker of some disorders. The few existing studies that approach the topic demonstrate a need to improve the experimental paradigms, as well as the methods of analysis. Most of them report behavioral variables (latency/reaction time), though electrophysiological measures are absent.

Alpha absolute power measurement in panic disorder with agoraphobia patients.

BACKGROUND: Panic attacks are thought to be a result from a dysfunctional coordination of cortical and brainstem sensory information leading to heightened amygdala activity with subsequent neuroendocrine, autonomic and behavioral activation. Prefrontal areas may be responsible for inhibitory top-down control processes and alpha synchronization seems to reflect this modulation. The objective of this study was to measure frontal absolute alpha-power with qEEG in 24 subjects with panic disorder and agoraphobia (PDA) compared to 21 healthy controls. METHODS: qEEG data were acquired while participants watched a computer simulation, consisting of moments classified as "high anxiety"(HAM) and "low anxiety" (LAM). qEEG data were also acquired during two rest conditions, before and after the computer simulation display. RESULTS: We observed a higher absolute alpha-power in controls when compared to the PDA patients while watching the computer simulation. The main finding was an interaction between the moment and group factors on frontal cortex. Our findings suggest that the decreased alpha-power in the frontal cortex for the PDA group may reflect a state of high excitability. CONCLUSIONS: Our results suggest a possible deficiency in top-down control processes of anxiety reflected by a low absolute alpha-power in the PDA group while watching the computer simulation and they highlight that prefrontal regions and frontal region nearby the temporal area are recruited during the exposure to anxiogenic stimuli.

Lack of systematic topographic difference between attention and reasoning beta correlates.

Based on previous evidence for individual-specific sets of cortical areas active during simple attention tasks, in this work we intended to perform within individual comparisons of task-induced beta oscillations between visual attention and a reasoning task. Since beta induced oscillations are not time-locked to task events and were first observed by Fourier transforms, in order to analyze the cortical topography of attention induced beta activity, we have previously computed corrected-latency averages based on spontaneous peaks of band-pass filtered epochs. We then used Independent Component Analysis (ICA) only to single out the significant portion of averaged data, above noise levels. In the present work ICA served as the main, exhaustive means for decomposing beta activity in both tasks, using 128-channel EEG data from 24 subjects. Given the previous observed similarity between tasks by visual inspection and by simple descriptive statistics, we now intended another approach: to quantify how much each ICA component obtained in one task could be explained by a linear combination of the topographic patterns from the other task in each individual. Our hypothesis was that the major psychological difference between tasks would not be reflected as important topographic differences within individuals. Results confirmed the high topographic similarity between attention and reasoning beta correlates in that few components in each individual were not satisfactorily explained by the complementary task, and if those could be considered "task-specific", their scalp distribution and estimated cortical sources were not common across subjects. These findings, along with those from fMRI studies preserving individual data and conventional neuropsychological and neurosurgical observations, are discussed in support of a new functional localization hypothesis: individuals use largely different sets of cortical association areas to perform a given task, but those individual sets do not change importantly across tasks that differ in major psychological processes.

Electrophysiological correlates of the threshold to detection of passive motion: an investigation in professional volleyball athletes with and without atrophy of the infraspinatus muscle.

The goal of the present study is to compare the electrophysiological correlates of the threshold to detection of passive motion (TTDPM) among three groups: healthy individuals (control group), professional volleyball athletes with atrophy of the infraspinatus muscle on the dominant side, and athletes with no shoulder pathologies. More specifically, the study aims at assessing the effects of infraspinatus muscle atrophy on the cortical representation of the TTDPM. A proprioception testing device (PTD) was used to measure the TTDPM. The device passively moved the shoulder and participants were instructed to respond as soon as movement was detected (TTDPM) by pressing a button switch. Response latency was established as the delay between the stimulus (movement) and the response (button press). Electroencephalographic (EEG) and electromyographic (EMG) activities were recorded simultaneously. An analysis of variance (ANOVA) and subsequent post hoc tests indicated a significant difference in latency between the group of athletes without the atrophy when compared both to the group of athletes with the atrophy and to the control group. Furthermore, distinct patterns of cortical activity were observed in the three experimental groups. The results suggest that systematically trained motor abilities, as well as the atrophy of the infraspinatus muscle, change the cortical representation of the different stages of proprioceptive information processing and, ultimately, the cortical representation of the TTDPM.

Does immobilization of dependent hand promote adaptative changes in cerebral cortex? An analysis through qEEG asymmetry.

This study aimed to elucidate electrophysiological and cortical mechanisms involved when 15 healthy right-handed subjects executed an index finger flexion and extension task before and after hand immobilization, using qEEG beta band (13-30Hz) asymmetry. This beta band is involved in motor activity and sensorial factors. Our hypothesis is that an increase in beta band asymmetry in pre-frontal, motor and parietal areas will occur in post-hand immobilization, because these areas need to reorganize for new planning, preparation and voluntary motor control. We found increase in beta band asymmetry during post-treatment task. We concluded that beta band asymmetry plays an important role in the analysis of cortical changes in several brain areas when associated to motor task. Furthermore, we assume that 48h of hand immobilization change cortical functioning.

Changes in saccadic eye movement (SEM) and quantitative EEG parameter in bipolar patients.

BACKGROUND: There is increasing evidence that neurocognitive dysfunction is associated with the different states in Bipolar Disorder. Gamma coherence is strongly related to cognitive processes and cortico-cortical communication. This paper aims at shedding light on the relationship between cortical gamma coherence within bipolar patients and a control group during a prosaccadic attention task. We hypothesized that gamma coherence oscillations act as a main neural mechanism underlying information processing which changes in bipolar patients. METHOD: Thirty-two (12 healthy controls and 20 bipolar patients) subjects were enrolled in this study. The subjects performed a prosaccadic attention task while their brain activity pattern was recorded using quantitative electroencephalography (20 channels). RESULTS: We observed that the maniac group presented lower saccade latency when compared to depression and control groups. The main finding was a greater gamma coherence for control group in the right hemisphere of both frontal and motor cortices caused by the execution of a prosaccadic attention task. LIMITATIONS: The findings need to be confirmed in larger samples and in bipolar patients before start the pharmacological treatment. CONCLUSIONS: Our findings suggest a disrupted connection of the brain's entire functioning of maniac patients and represent a deregulation in cortical inhibitory mechanism. Thus, our results reinforce our hypothesis that greater gamma coherence in the right and left frontal cortices for the maniac group produces a "noise" during information processing and highlights that gamma coherence might be a biomarker for cognitive dysfunction during the manic state.