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1.
Nat Commun ; 13(1): 3736, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768419

RESUMO

The thalamus is much more than a simple sensory relay. High-order thalamic nuclei, such as the mediodorsal thalamus, exert a profound influence over animal cognition. However, given the difficulty of directly recording from the thalamus in humans, next-to-nothing is known about thalamic and thalamocortical contributions to human cognition. To address this, we analysed simultaneously-recorded thalamic iEEG and whole-head MEG in six patients (plus MEG recordings from twelve healthy controls) as they completed a visual detection task. We observed that the phase of both ongoing mediodorsal thalamic and prefrontal low-frequency activity was predictive of perceptual performance. Critically however, mediodorsal thalamic activity mediated prefrontal contributions to perceptual performance. These results suggest that it is thalamocortical interactions, rather than cortical activity alone, that is predictive of upcoming perceptual performance and, more generally, highlights the importance of accounting for the thalamus when theorising about cortical contributions to human cognition.


Assuntos
Córtex Pré-Frontal , Tálamo , Animais , Humanos , Vias Neurais , Núcleos Talâmicos , Percepção Visual
2.
Front Cell Neurosci ; 16: 838432, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35480959

RESUMO

The neural extracellular matrix (ECM) composition shapes the neuronal microenvironment and undergoes substantial changes upon development and aging, but also due to cerebral pathologies. In search for potential biomarkers, cerebrospinal fluid (CSF) and serum concentrations of brain ECM molecules have been determined recently to assess ECM changes during neurological conditions including Alzheimer's disease or vascular dementia. Here, we measured the levels of two signature proteoglycans of brain ECM, neurocan and brevican, in the CSF and serum of 96 neurological patients currently understudied regarding ECM alterations: 16 cases with amyotrophic lateral sclerosis (ALS), 26 epilepsy cases, 23 cerebral small vessel disease (CSVD) patients and 31 controls. Analysis of total brevican and neurocan was performed via sandwich Enzyme-linked immunosorbent assays (ELISAs). Major brevican and neurocan cleavage products were measured in the CSF using semiquantitative immunoblotting. Total brevican and neurocan concentrations in serum and CSF did not differ between groups. The 60 kDa brevican fragment resulting from cleavage by the protease ADAMTS-4 was also found unchanged among groups. The presumably intracellularly generated 150 kDa C-terminal neurocan fragment, however, was significantly increased in ALS as compared to all other groups. This group also shows the highest correlation between cleaved and total neurocan in the CSF. Brevican and neurocan levels strongly correlated with each other across all groups, arguing for a joint but yet unknown transport mechanism from the brain parenchyma into CSF. Conclusively our findings suggest an ALS-specific pattern of brain ECM remodeling and may thus contribute to new diagnostic approaches for this disorder.

3.
Neurol Res Pract ; 3(1): 63, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34865660

RESUMO

BACKGROUND: With the increased efficacy of stroke treatments, diagnosis and specific treatment needs of patients with post-stroke seizures (PSS) and post-stroke epilepsy have become increasingly important. PSS can complicate the diagnosis of a stroke and the treatment of stroke patients, and can worsen post-stroke morbidity. This narrative review considers current treatment guidelines, the specifics of antiseizure treatment in stroke patients as well as the state-of-the-art in clinical and imaging research of post-stroke epilepsy. Treatment of PSS needs to consider indications for antiseizure medication treatment as well as individual clinical and social factors. Furthermore, potential interactions between stroke and antiseizure treatments must be carefully considered. The relationship between acute recanalizing stroke therapy (intravenous thrombolysis and mechanical thrombectomy) and the emergence of PSS is currently the subject of an intensive discussion. In the subacute and chronic post-stroke phases, important specific interactions between necessary antiseizure and stroke treatments (anticoagulation, cardiac medication) need to be considered. Among all forms of prevention, primary prevention is currently the most intensively researched. This includes specifically the repurposing of drugs that were not originally developed for antiseizure properties, such as statins. PSS are presently the subject of extensive basic clinical research. Of specific interest are the role of post-stroke excitotoxicity and blood-brain barrier disruption for the emergence of PSS in the acute symptomatic as well as late (> 1 week after the stroke) periods. Current magnetic resonance imaging research focussing on glutamate excitotoxicity as well as diffusion-based estimation of blood-brain barrier integrity aim to elucidate the pathophysiology of seizures after stroke and the principles of epileptogenesis in structural epilepsy in general. These approaches may also reveal new imaging-based biomarkers for prediction of PSS and post-stroke epilepsy. CONCLUSION: PSS require the performance of individual risk assessments, accounting for the potential effectiveness and side effects of antiseizure therapy. The use of intravenous thrombolysis and mechanical thrombectomy is not associated with an increased risk of PSS. Advances in stroke imaging may reveal biomarkers for PSS.

4.
Seizure ; 91: 228-232, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34233237

RESUMO

BACKGROUND: This observational study was done to develop a score based on clinical predictors that enables a guided decision for the necessity of cerebrospinal fluid (CSF) analysis after first unprovoked epileptic seizures and to validate this score in a retrospective patient cohort. METHODS: Clinical predictors were identified by two panels of epilepsy experts and selected according to content validity ratios. Based on these predictors a score was created and applied to a cohort of patients with first epileptic seizures. RESULTS: The "IDEAL score" consists of 9 items (fever, prolonged disturbance of consciousness, headache, imaging results, cognitive dysfunction, status epilepticus, malignancy, autoimmune encephalitis symptoms) that are collected at two different time points (< 3 h [A-score]; > 3 h [B-score] after hospital admittance). A CSF analysis is recommended, if at least one clinical finding is present, either one of the items evaluated during the acute phase (A-score) or later in the diagnostic process (B-score). In 41 patients (13%) CSF analysis provided essential clues to the cause of the seizure. The combined IDEAL score reached a sensitivity of 98%, a specificity of 53%, a positive predictive value of 24% and a negative predictive value of 99% in this patient cohort. CONCLUSIONS: A CSF analysis after first epileptic seizures provided decisive etiological findings in only 13% of all investigated patients. The IDEAL score offers clinicians a simple and easy-to-implement algorithm to assess the necessity of a CSF analysis, and to prevent unnecessary diagnostic procedures.


Assuntos
Encefalite , Epilepsia , Estado Epiléptico , Epilepsia/diagnóstico , Humanos , Estudos Retrospectivos , Convulsões/diagnóstico
5.
Neurosci Biobehav Rev ; 126: 146-158, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33737103

RESUMO

Extensive neuroanatomical connectivity between the anterior thalamic nuclei (ATN) and hippocampus and neocortex renders them well-placed for a role in memory processing, and animal, lesion, and neuroimaging studies support such a notion. The deep location and small size of the ATN have precluded their real-time electrophysiological investigation during human memory processing. However, ATN electrophysiological recordings from patients receiving electrodes implanted for deep brain stimulation for pharmacoresistant focal epilepsy have enabled high temporal resolution study of ATN activity. Theta frequency synchronization of ATN and neocortical oscillations during successful memory encoding, enhanced phase alignment, and coupling between ATN local gamma frequency activity and frontal neocortical and ATN theta oscillations provide evidence of an active role for the ATN in memory encoding, potentially integrating information from widespread neocortical sources. Greater coupling of a broader gamma frequency range with theta oscillations at rest than during memory encoding provides additional support for the hypothesis that the ATN play a role in selecting local, task-relevant high frequency activity associated with particular features of a memory trace.


Assuntos
Núcleos Anteriores do Tálamo , Neocórtex , Animais , Eletroencefalografia , Hipocampo , Humanos , Memória
6.
Neuromodulation ; 24(2): 373-379, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33577139

RESUMO

INTRODUCTION: Following electrode implantation, a subgroup of patients treated with deep brain stimulation (DBS) for focal epilepsy exhibits a reduction of seizure frequency before stimulation is initiated. Microlesioning of the target structure has been postulated to be the cause of this "insertional" effect (IE). We examined the occurrence and duration of this IE in a group of patients with focal epilepsy following electrode implantation in the anterior nuclei of the thalamus (ANT) and/or nucleus accumbens (NAC) for DBS treatment. MATERIALS AND METHODS: Changes in monthly seizure frequency compared to preoperative baseline were assessed one month (14 patients) and five months (four patients) after electrode implantation. A group analysis between patients with implantation of bilateral ANT-electrodes (four patients), NAC-electrodes (one patient) as well as ANT and NAC-electrodes (nine patients) was performed. RESULTS: In this cohort, seizure frequency decreased one month after electrode implantation by 57.1 ± 30.1%, p ≤ 0.001 (compared to baseline). No significant difference within stimulation target subcohorts was found (p > 0.05). Out of the four patients without stimulation for five months following electrode insertion, three patients showed seizure frequency reduction lasting two to three months, while blinded to their stimulation status. CONCLUSION: An IE might explain seizure frequency reduction in our cohort. This effect seems to be independent of the number of implanted electrodes and of the target itself. The time course of the blinded subgroup of epilepsy patients suggests a peak of the lesional effect at two to three months after electrode insertion.


Assuntos
Núcleos Anteriores do Tálamo , Estimulação Encefálica Profunda , Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Epilepsia Resistente a Medicamentos/terapia , Eletrodos Implantados , Epilepsias Parciais/terapia , Humanos
7.
BMJ Neurol Open ; 2(2): e000077, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33681800

RESUMO

OBJECTIVES: The vestibulo-medial temporal lobe (MTL) axis model proposes that the vestibular system and the MTL are tightly linked both structurally and functionally so that alterations of one structure should entail disturbances in the other. Accordingly, patients with temporal lobe epilepsy (TLE) with their functional and possible structural temporal lobe pathology should show deficits in vestibular-related behaviour. This study aimed at assessing behavioural deficits related to a suspected disturbance of the vestibulo-MTL axis in patients with TLE. METHODS: Twenty patients with TLE (46.7±15.1 years, seven females) and their age-matched and gender-matched controls (46.7±15.1, seven females) underwent three test batteries that challenged vestibular and MTL functions: balancing, path integration (triangle completion test) and rotational memory. In addition, participants underwent a structural MRI for grey matter analysis using voxel-based morphometry. RESULTS: Compared with controls, patients with TLE showed significantly inferior performance in all three behavioural tests, with large effect sizes. There were no significant grey matter differences between the two groups. CONCLUSION: These results indicate a potential disturbance in the vestibulo-MTL axis in TLE; these are to be verified by future large-scale studies. In the current study, these behavioural deficits emerged without evidence of any brain volume differences between the patients and their controls as depicted by high-resolution MRI. This speaks for a dissociation between functional and structural alterations in TLE.

8.
Brain ; 142(10): 3059-3071, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31373622

RESUMO

The aim of epilepsy surgery in patients with focal, pharmacoresistant epilepsies is to remove the complete epileptogenic zone to achieve long-term seizure freedom. In addition to a spectrum of diagnostic methods, magnetoencephalography focus localization is used for planning of epilepsy surgery. We present results from a retrospective observational cohort study of 1000 patients, evaluated using magnetoencephalography at the University Hospital Erlangen over the time span of 28 years. One thousand consecutive cases were included in the study, evaluated at the University Hospital Erlangen between 1990 and 2018. All patients underwent magnetoencephalography as part of clinical workup for epilepsy surgery. Of these, 405 underwent epilepsy surgery after magnetoencephalography, with postsurgical follow-ups of up to 20 years. Sensitivity for interictal epileptic activity was evaluated, in addition to concordance of localization with the consensus of presurgical workup on a lobar level. We evaluate magnetoencephalography characteristics of patients who underwent epilepsy surgery versus patients who did not proceed to surgery. In operated patients, resection of magnetoencephalography localizations were related to postsurgical seizure outcomes, including long-term results after several years. In comparison, association of lesionectomy with seizure outcomes was analysed. Measures of diagnostic accuracy were calculated for magnetoencephalography resection and lesionectomy. Sensitivity for interictal epileptic activity was 72% with significant differences between temporal and extra-temporal lobe epilepsy. Magnetoencephalography was concordant with the presurgical consensus in 51% and showed additional or more focal involvement in an additional 32%. Patients who proceeded to surgery showed a significantly higher percentage of monofocal magnetoencephalography results. Complete magnetoencephalography resection was associated with significantly higher chances to achieve seizure freedom in the short and long-term. Diagnostic accuracy was significant in temporal and extra-temporal lobe cases, but was significantly higher in extra-temporal lobe epilepsy (diagnostic odds ratios of 4.4 and 41.6). Odds ratios were also higher in non-lesional versus lesional cases (42.0 versus 6.2). The results show that magnetoencephalography provides non-redundant information, which significantly contributes to patient selection, focus localization and ultimately long-term seizure freedom after epilepsy surgery. Specifically in extra-temporal lobe epilepsy and non-lesional cases, magnetoencephalography provides excellent accuracy.


Assuntos
Epilepsia/cirurgia , Magnetoencefalografia/métodos , Adolescente , Adulto , Estudos de Coortes , Eletroencefalografia/métodos , Epilepsias Parciais/diagnóstico , Epilepsias Parciais/cirurgia , Epilepsia/diagnóstico , Epilepsia do Lobo Temporal/cirurgia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/cirurgia , Resultado do Tratamento
9.
Sleep ; 42(3)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30476248

RESUMO

STUDY OBJECTIVES: Complex sexual behavior during sleep (CSBS) is a well described clinical entity in nonrapid eye movement (NREM) sleep parasomnias (i.e. sexsomnia). We report a retrospective case series of CSBS as clinical manifestation of epileptic seizures and compare them with the semiology of sexsomnia. METHODS: Video-electroencephalopraphy (EEG)-monitoring data of patients with epileptic and nonepileptic paroxysmal events from one tertiary epilepsy center between 2013 and 2016 were retrospectively reviewed. Clinical features and presurgical, electroclinical, and follow-up data are presented and then discussed in the context of other published cases. RESULTS: From 4,629 patients, 6 patients had CSBS. EEG, single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), and histopathology confirmed an epileptic origin in four female patients, with temporal or frontal seizures. Two male patients had sexsomnia. None of the epilepsy patients had parasomnias. Clinical criteria to differentiate epileptic from parasomnic CSBS were: events also occurred out of wakefulness; current presence of additional nonsexual manifestations of epilepsy; sexual behavior only as part of a broad spectrum of emotional and motor automatisms; stereotyped behavior pattern without modulability by bystanders; unarousability during the event; no completion of sexual intercourse. The accuracy of the clinical diagnosis was improved by the development of an algorithm comparing patients' fulfillment of the criteria of epilepsy versus parasomnia. CONCLUSIONS: In our cohort, CSBS was a rare ictal phenomenon in temporal or frontal seizures. Symptomatological similiarities with sexsomnia might be explained by the same phylogenetically primitive "central pattern generator" manifesting in ictal CSBS by activation and in sexsomnia by disinhibition. Ictal CSBS should be considered in the differential diagnosis of sexsomnia.


Assuntos
Epilepsia/fisiopatologia , Parassonias/fisiopatologia , Comportamento Sexual/fisiologia , Sono/fisiologia , Adulto , Diagnóstico Diferencial , Eletroencefalografia/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Projetos de Pesquisa , Estudos Retrospectivos , Convulsões/fisiopatologia
10.
Neurobiol Learn Mem ; 155: 104-112, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29981424

RESUMO

Previous imaging studies independently highlighted the role of the anterior thalamus (ANT) and nucleus accumbens (NAcc) in successful memory retrieval. While these findings accord with theoretical models, the precise temporal, oscillatory and network dynamics as well as the interplay between the NAcc and ANT in successfully retrieving information from long-term memory are largely unknown. We addressed this issue by recording intracranial electroencephalography in human epilepsy patients from the NAcc (n = 5) and ANT (n = 4) during an old/new recognition test. Our findings demonstrate that differences in event-related potentials between correctly classified old (i.e., studied) and new (i.e., unstudied) images emerged in the NAcc and ANT already between 200 and 600 ms after stimulus onset. Moreover, time-frequency analyses revealed theta (4-8 Hz) power decreases for old compared to new items in the NAcc and the opposite effect in the ANT. Importantly, Granger causality analyses revealed a directional communication from ANT to NAcc suggesting that entrainment from ANT drives successful memory retrieval. Together, our findings show evidence for the notion that the NAcc and ANT receive memory signals, and that theta oscillations may serve as a mechanism to bind these distributed neural assemblies.


Assuntos
Núcleos Anteriores do Tálamo/fisiologia , Eletrocorticografia/métodos , Potenciais Evocados/fisiologia , Rememoração Mental/fisiologia , Núcleo Accumbens/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Ritmo Teta/fisiologia , Adulto , Epilepsia/fisiopatologia , Humanos , Processamento de Sinais Assistido por Computador
11.
Brain Sci ; 8(7)2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29941788

RESUMO

BACKGROUND: In advanced Parkinson’s disease, the pedunculopontine nucleus region is thought to be abnormally inhibited by gamma-aminobutyric acid (GABA) ergic inputs from the over-active globus pallidus internus. Recent attempts to boost pedunculopontine nucleus function through deep brain stimulation are promising, but suffer from the incomplete understanding of the physiology of the pedunculopontine nucleus region. METHODS: Local field potentials of the pedunculopontine nucleus region and the globus pallidus internus were recorded and quantitatively analyzed in a patient with Parkinson’s disease. In particular, we compared the local field potentials from the pedunculopontine nucleus region at rest and during deep brain stimulation of the globus pallidus internus. RESULTS: At rest, the spectrum of local field potentials in the globus pallidus internus was mainly characterized by delta-theta and beta frequency activity whereas the spectrum of the pedunculopontine nucleus region was dominated by activity only in the delta and theta band. High-frequency deep brain stimulation of the globus pallidus internus led to increased theta activity in the pedunculopontine nucleus region and enabled information exchange between the left and right pedunculopontine nuclei. Therefore, Conclusions: When applying deep brain stimulation in the globus pallidus internus, its modulatory effect on pedunculopontine nucleus physiology should be taken into account.

12.
Epilepsy Res ; 142: 176-178, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29526516

RESUMO

New treatment approaches in epilepsy - such as novel antiepileptic drugs and neurostimulation - generally at first are assessed in animal models in regard to feasibility, efficacy and safety. The aim of this review was to elucidate and summarize the available literature on in vivo experimental studies on radiofrequency thermoablation and laser interstitial thermal therapy. We have found two in vivo studies on radiofrequency ablation of an acute seizure focus, one assessed the conventional transcranial and the other one a transvenous approach. All other studies focused on technical issues of functional ablation of brain structures assessing parameters such as maximal temperature and duration of thermal ablation as well as electrode devices. As the concept of functional ablation is evident - destruction of the epileptogenic focus as performed in "open" resective surgery - general "proof of concept" experiments do not seem to be necessary.


Assuntos
Modelos Animais de Doenças , Epilepsia/cirurgia , Terapia a Laser/métodos , Pesquisa Translacional Biomédica , Animais , Humanos
13.
Front Hum Neurosci ; 11: 358, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28775684

RESUMO

Cross-frequency coupling (CFC) between slow and fast brain rhythms, in the form of phase-amplitude coupling (PAC), is proposed to enable the coordination of neural oscillatory activity required for cognitive processing. PAC has been identified in the neocortex and mesial temporal regions, varying according to the cognitive task being performed and also at rest. PAC has also been observed in the anterior thalamic nucleus (ATN) during memory processing. The thalamus is active during the resting state and has been proposed to be involved in switching between task-free cognitive states such as rest, in which attention is internally-focused, and externally-focused cognitive states, in which an individual engages with environmental stimuli. It is unknown whether PAC is an ongoing phenomenon during the resting state in the ATN, which is modulated during different cognitive states, or whether it only arises during the performance of specific tasks. We analyzed electrophysiological recordings of ATN activity during rest from seven patients who received thalamic electrodes implanted for treatment of pharmacoresistant focal epilepsy. PAC was identified between theta (4-6 Hz) phase and high frequency band (80-150 Hz) amplitude during rest in all seven patients, which diminished during engagement in tasks involving an external focus of attention. The findings are consistent with the proposal that theta-gamma coupling in the ATN is an ongoing phenomenon, which is modulated by task performance.

14.
Clin Neurophysiol ; 128(11): 2334-2346, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28838815

RESUMO

Standardized terminology for computer-based assessment and reporting of EEG has been previously developed in Europe. The International Federation of Clinical Neurophysiology established a taskforce in 2013 to develop this further, and to reach international consensus. This work resulted in the second, revised version of SCORE (Standardized Computer-based Organized Reporting of EEG), which is presented in this paper. The revised terminology was implemented in a software package (SCORE EEG), which was tested in clinical practice on 12,160 EEG recordings. Standardized terms implemented in SCORE are used to report the features of clinical relevance, extracted while assessing the EEGs. Selection of the terms is context sensitive: initial choices determine the subsequently presented sets of additional choices. This process automatically generates a report and feeds these features into a database. In the end, the diagnostic significance is scored, using a standardized list of terms. SCORE has specific modules for scoring seizures (including seizure semiology and ictal EEG patterns), neonatal recordings (including features specific for this age group), and for Critical Care EEG Terminology. SCORE is a useful clinical tool, with potential impact on clinical care, quality assurance, data-sharing, research and education.


Assuntos
Encéfalo/fisiologia , Eletroencefalografia/métodos , Eletroencefalografia/normas , Humanos , Software
16.
Data Brief ; 8: 557-61, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27508216

RESUMO

The data presented here comprise clinical, neuropsychological, and intrathalamic electrophysiological data from 7 patients with pharmacoresistant focal epilepsy and are related to the article "Pre-stimulus thalamic theta power predicts human memory formation" C.M. Sweeney-Reed, T. Zaehle, J. Voges, F.C. Schmitt, L. Buentjen, K. Kopitzki, et al. (2016) [1]. The patients participated in a memory paradigm after receiving electrodes implanted in the DMTN due to the surgical approach taken in electrode insertion for deep brain stimulation of the anterior thalamic nucleus. Epilepsy duration and pre-operative neuropsychological tests provide an indication of the profile of patients receiving intrathalamic electrode implantation and the memory capabilities in such a patient group. The electrophysiological data were recorded from the right DMTN preceding stimulus presentation during intentional memory encoding. The patients viewed a series of photographic scenes, which they judged as indoors or outdoors. The 900 ms epochs prior to stimulus presentation were labeled as preceding successful or unsuccessful subsequent memory formation according to a subsequent memory test for the items. The difference between theta power preceding successful versus unsuccessful subsequent memory formation is shown against time for each patient individually.

17.
J Neurol ; 263(10): 2120-6, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27485172

RESUMO

The relationships between interictal epileptiform discharges (IEDs) in the anterior (ANT) and dorsomedial nuclei (DMNT) of the thalamus and electro-clinical parameters in pharmacoresistant focal epilepsy patients receiving intrathalamic electrodes for deep brain stimulation (DBS) were investigated. Thalamus-localized IEDs (LIEDs) and surface EEG (sEEG)-IEDs were evaluated in eight patients who underwent ANT-DBS. Occurrence and frequency of ANT- and DMNT-LIEDs and pre-operative sEEG-IEDs were examined with respect to seizure onset location and seizure outcome following ANT-DBS. LIEDs were identified in all eight patients, in the ANT, DMNT, or both. ANT-LIEDs were observed in all patients with an unequivocal temporal seizure onset zone. The ANT-LIED frequency correlated with pre-surgical sEEG-IED frequency (ρ = 0.76, p = 0.033) and predicted ANT-DBS responsiveness (T = -2.6; p = 0.0428). Of the five patients with bilateral sEEG-IEDs, all had ANT-LIEDs, but only one patient had DMNT-LIEDs. All patients with no or unilateral sEEG-IEDs had DMNT-LIEDs. Observation of LIEDS in the ANT and DMNT supports the hypothesis that these nuclei are involved in propagation of focal epileptic activity. Their correspondence with differing electro-clinical features suggests that these nuclei are functionally distinguishable nodes within the epileptic networks of individual patients.


Assuntos
Estimulação Encefálica Profunda/métodos , Epilepsia Resistente a Medicamentos/terapia , Tálamo/fisiologia , Idoso , Mapeamento Encefálico , Ondas Encefálicas , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Eletrodos , Eletroencefalografia , Feminino , Lateralidade Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Sistemas On-Line , Tomografia Computadorizada por Raios X
18.
J Neurophysiol ; 116(4): 1663-1672, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27486103

RESUMO

The human nucleus accumbens is thought to play an important role in guiding future action selection via an evaluation of current action outcomes. Here we provide electrophysiological evidence for a more direct, i.e., online, role during action preparation. We recorded local field potentials from the nucleus accumbens in patients with epilepsy undergoing surgery for deep brain stimulation. We found a consistent decrease in the power of alpha/beta oscillations (10-30 Hz) before and around the time of movements. This perimovement alpha/beta desynchronization was observed in seven of eight patients and was present both before instructed movements in a serial reaction time task as well as before self-paced, deliberate choices in a decision making task. A similar beta decrease over sensorimotor cortex and in the subthalamic nucleus has been directly related to movement preparation and execution. Our results support the idea of a direct role of the human nucleus accumbens in action preparation and execution.


Assuntos
Ritmo alfa/fisiologia , Ritmo beta/fisiologia , Atividade Motora/fisiologia , Núcleo Accumbens/fisiologia , Adulto , Comportamento de Escolha/fisiologia , Sincronização Cortical/fisiologia , Estimulação Encefálica Profunda , Epilepsia/diagnóstico por imagem , Epilepsia/fisiopatologia , Epilepsia/cirurgia , Epilepsia/terapia , Feminino , Dedos/fisiologia , Dedos/fisiopatologia , Lateralidade Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Testes Neuropsicológicos , Núcleo Accumbens/diagnóstico por imagem , Núcleo Accumbens/fisiopatologia , Núcleo Accumbens/cirurgia
19.
Neuroimage ; 138: 100-108, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27208861

RESUMO

Pre-stimulus theta (4-8Hz) power in the hippocampus and neocortex predicts whether a memory for a subsequent event will be formed. Anatomical studies reveal thalamus-hippocampal connectivity, and lesion, neuroimaging, and electrophysiological studies show that memory processing involves the dorsomedial (DMTN) and anterior thalamic nuclei (ATN). The small size and deep location of these nuclei have limited real-time study of their activity, however, and it is unknown whether pre-stimulus theta power predictive of successful memory formation is also found in these subcortical structures. We recorded human electrophysiological data from the DMTN and ATN of 7 patients receiving deep brain stimulation for refractory epilepsy. We found that greater pre-stimulus theta power in the right DMTN was associated with successful memory encoding, predicting both behavioral outcome and post-stimulus correlates of successful memory formation. In particular, significant correlations were observed between right DMTN theta power and both frontal theta and right ATN gamma (32-50Hz) phase alignment, and frontal-ATN theta-gamma cross-frequency coupling. We draw the following primary conclusions. Our results provide direct electrophysiological evidence in humans of a role for the DMTN as well as the ATN in memory formation. Furthermore, prediction of subsequent memory performance by pre-stimulus thalamic oscillations provides evidence that post-stimulus differences in thalamic activity that index successful and unsuccessful encoding reflect brain processes specifically underpinning memory formation. Finally, the findings broaden the understanding of brain states that facilitate memory encoding to include subcortical as well as cortical structures.


Assuntos
Núcleos Anteriores do Tálamo/fisiologia , Mapeamento Encefálico/métodos , Formação de Conceito/fisiologia , Estimulação Encefálica Profunda/métodos , Núcleo Mediodorsal do Tálamo/fisiologia , Memória/fisiologia , Rede Nervosa/fisiologia , Adulto , Feminino , Humanos , Masculino , Prognóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Seizure ; 39: 5-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27161669

RESUMO

PURPOSE: This non-interventional study was conducted to evaluate the efficacy and tolerability of intravenous lacosamide (LCM-iv) under routine conditions in daily clinical practice as a prospective registry. METHODS: Patients with any type of seizure or epilepsy syndrome were recruited in 16 neurological and neuropediatric centers in Germany if the treating physician decided to administer LCM-iv for any reason. Observation time per patient was 10 days with daily documentation of LCM-iv administration, type and frequency of seizures, currently used drugs and doses, and adverse events. Treatment efficacy, tolerability, and handling of LCM-iv were assessed using a five-step scale. RESULTS: In 119 patients treating physicians classified epilepsies as focal in 66.1% and generalized in 17.4% (16.5% unclassifiable). Most common etiologies of seizures were tumors (36.1%) and cerebrovascular diseases (21.8%). Reasons for LCM-iv treatment included preparation for surgery (25.2%), convulsive (24.4%) and non-convulsive (18.5%) status epilepticus (SE), series of seizures (16.0%), gastrointestinal causes (5.9%), and acute seizures (4.2%). The median dose of LCM-iv was 300mg per day. In 45 of 64 patients (70.3%) with SE or series of seizures, epileptic activity ceased during observation time. Five patients showed abnormalities in ECG prior to the infusion and one patient afterwards, but during infusion no abnormalities were reported. Treating physicians rated efficacy and tolerability as very good or good in 77.6% and 93.1% of patients, respectively. CONCLUSIONS: This large and independent multicenter registry on the use of LCM-iv in clinical practice demonstrates that LCM-iv is well-tolerated and highly efficacious when given in emergency situations, including patients experiencing SE. It is advisable to perform an electrocardiogram prior to LCM-iv administration.


Assuntos
Acetamidas/farmacologia , Anticonvulsivantes/farmacologia , Epilepsia/tratamento farmacológico , Avaliação de Resultados em Cuidados de Saúde , Sistema de Registros , Acetamidas/administração & dosagem , Acetamidas/efeitos adversos , Administração Intravenosa , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/efeitos adversos , Criança , Pré-Escolar , Feminino , Alemanha , Humanos , Lactente , Lacosamida , Masculino , Pessoa de Meia-Idade , Convulsões/tratamento farmacológico , Estado Epiléptico/tratamento farmacológico , Adulto Jovem
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