Sequential Semiology of Seizures and Brain Perfusion Patterns in Patients with Drug-Resistant Focal Epilepsies: A Perspective from Neural Networks.

Ictal semiology and brain single-photon emission computed tomography have been performed in approaching the epileptogenic zone in drug-resistant focal epilepsies. The authors aim to describe the brain structures involved in the ictal and interictal epileptogenic network from sequential semiology and brain perfusion quantitative patterns analysis. A sequential representation of seizures was performed (n = 15). A two-level analysis (individual and global) was carried out for the analysis of brain perfusion quantification and estimating network structures from the perfusion indexes. Most of the subjects started with focal seizures without impaired consciousness, followed by staring, automatisms, language impairments and evolution to a bilateral tonic-clonic seizure (temporal lobe and posterior quadrant epilepsy). Frontal lobe epilepsy seizures continued with upper limb clonus and evolution to bilateral tonic-clonic. The perfusion index of the epileptogenic zone ranged between 0.439-1.362 (mesial and lateral structures), 0.826-1.266 in dorsolateral frontal structures and 0.678-1.507 in the occipital gyrus. The interictal epileptogenic network proposed involved the brainstem and other subcortical structures. For the ictal state, it included the rectus gyrus, putamen and cuneus. The proposed methodology provides information about the brain structures in the neural networks in patients with drug-resistant focal epilepsies.

New Aspects of VEGF, GABA, and Glutamate Signaling in the Neocortex of Human Temporal Lobe Pharmacoresistant Epilepsy Revealed by RT-qPCR Arrays.

In the epilepsy spectrum, temporal lobe epilepsy (TLE) is the most common and devastating focal and symptomatic epilepsy form in adults, where more than 30% of patients develop pharmacoresistance. It is not fully understood how the gene expression contributes to establishing an epileptic phenotype. Cerebrovascular remodeling directed by VEGF (vascular endothelial growth factor) signaling might modulate the synaptic neurotransmission in the epileptic brain. To address this question, the gene expression was profiled in biopsies of the temporal cortex from diagnosed patients with pharmacoresistant TLE that underwent surgical resection to seizure control. One hundred sixty-eight genes related to VEGF signaling and GABA and glutamate neurotransmissions were evaluated. Genes related to downstream signaling -phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinases (MAPK), and Janus-activated kinase/signal transducer and activator of transcription (JAK/STAT) pathways- and neurotransmitters metabolism were evaluated too. Thirty-nine genes were upregulated. The genes encoding for G protein q polypeptide, serine racemase, gephyrin, and glutamate/cystine antiporter system xCT appeared as novel upregulated genes in the pharmacoresistant TLE. ClueGO, a Cytoscape plugin, was used to build a gene network associated using Gene Ontology (GO) terminology. Enrichment analysis by ClueGO retrieves that positive regulation of endothelial cell proliferation, nerve development, and neuronal apoptosis were over-represented categories. In conclusion, VEGF signaling is confirmed as a relevant mediator in the pharmacoresistant TLE. In addition, the enrichment analysis applied to differentially expressed genes suggests new pharmacological targets to be assessed in the treatment of pharmacoresistant TLE. Results make up an approximation to better understand the epileptic brain and complement the available data.

Flanker Task-Elicited Event-Related Potential Sources Reflect Human Recombinant Erythropoietin Differential Effects on Parkinson's Patients.

We used EEG source analysis to identify which cortical areas were involved in the automatic and controlled processes of inhibitory control on a flanker task and compared the potential efficacy of recombinant-human erythropoietin (rHuEPO) on the performance of Parkinson's Disease patients. The samples were 18 medicated PD patients (nine of them received rHuEPO in addition to their usual anti-PD medication through random allocation and the other nine patients were on their regular anti-PD medication only) and 9 age and education-matched healthy controls (HCs) who completed the flanker task with simultaneous EEG recordings. N1 and N2 event-related potential (ERP) components were identified and a low resolution tomography (LORETA) inverse solution was employed to localize the neural generators. Reaction times and errors were increased for the incongruent flankers for PD patients compared to controls. EEG source analysis identified an effect of rHuEPO on the lingual gyri for the early N1 component. N2-related sources in middle cingulate and precuneus were associated with the inhibition of automatic responses evoked by incongruent stimuli differentiated PD and HCs. From our results rHuEPO seems to mediate an effect on N1 sources in lingual gyri but not on behavioural performance. N2-related sources in middle cingulate and precuneus were evoked by incongruent stimuli differentiated PD and HCs.

Autologous bone marrow stem cell neurotransplantation in stroke patients. An open study.

PURPOSE: Bone marrow stem cells (BMSC) were transplanted into the perilesional area in five patients bearing sequels of stroke, to evaluate the safety of the procedure and tolerance to the transplanted cells. METHODS: Cells were obtained from bone marrow samples taken from the same patient and stereotactically implanted into the targets, determined using a combination of images, and trans-operative recording of multiunit activity. The cells were implanted in several points along tracts in the perilesional region. RESULTS: No important adverse events derived from surgery or transplant were observed during the one year follow-up period, or detected using a combination of tests and functional measurements applied pre- and post-surgically. In contrast, some improvements were observed regarding the neurological condition of the patients, but the small number of patients in the study does not allow any conclusive statement. CONCLUSIONS: Our results demonstrate that BMSC can be safely transplanted into the brain of patients, with excellent tolerance and without complications, using the methods described here.

Follow-Up of Peripheral IL-1ß and IL-6 and Relation with Apoptotic Death in Drug-Resistant Temporal Lobe Epilepsy Patients Submitted to Surgery.

Increasing amounts of evidence support the role of inflammation in epilepsy. This study was done to evaluate serum follow-up of IL-1ß and IL-6 levels, as well as their concentration in the neocortex, and the relationship of central inflammation with NF-κB and annexin V in drug-resistant temporal lobe epileptic (DRTLE) patients submitted to surgical treatment. Peripheral and central levels of IL-1ß and IL-6were measured by ELISA in 10 DRTLE patients. The sera from patients were taken before surgery, and 12 and 24 months after surgical treatment. The neocortical expression of NF-κB was evaluated by western blotting and annexin V co-localization with synaptophysin by immunohistochemistry. The neocortical tissues from five patients who died by non-neurological causes were used as control. Decreased serum levels of IL-1 and IL-6 were observed after surgery; at this time, 70% of patients were seizure-free. No values of IL-1 and IL-6 were detected in neocortical control tissue, whereas cytokine levels were evidenced in DRTLE. Increased NF-κB neocortex expression was found and the positive annexin V neurons were more obvious in the DRTLE tissue, correlating with IL-6 levels. The follow-up study confirmed that the inflammatory alterations disappeared one year after surgery, when the majority of patients were seizure-free, and the apoptotic death process correlated with inflammation.

Oxidative Stress in Patients with Drug Resistant Partial Complex Seizure.

Oxidative stress (OS) has been implicated as a pathophysiological mechanism of drug-resistant epilepsy, but little is known about the relationship between OS markers and clinical parameters, such as the number of drugs, age onset of seizure and frequency of seizures per month. The current study’s aim was to evaluate several oxidative stress markers and antioxidants in 18 drug-resistant partial complex seizure (DRPCS) patients compared to a control group (age and sex matched), and the results were related to clinical variables. We examined malondialdehyde (MDA), advanced oxidation protein products (AOPP), advanced glycation end products (AGEs), nitric oxide (NO), uric acid, superoxide dismutase (SOD), glutathione, vitamin C, 4-hydroxy-2-nonenal (4-HNE) and nitrotyrosine (3-NT). All markers except 4-HNE and 3-NT were studied by spectrophotometry. The expressions of 4-HNE and 3-NT were evaluated by Western blot analysis. MDA levels in patients were significantly increased (p ≤ 0.0001) while AOPP levels were similar to the control group. AGEs, NO and uric acid concentrations were significantly decreased (p ≤ 0.004, p ≤ 0.005, p ≤ 0.0001, respectively). Expressions of 3-NT and 4-HNE were increased (p ≤ 0.005) similarly to SOD activity (p = 0.0001), whereas vitamin C was considerably diminished (p = 0.0001). Glutathione levels were similar to the control group. There was a positive correlation between NO and MDA with the number of drugs. The expression of 3-NT was positively related with the frequency of seizures per month. There was a negative relationship between MDA and age at onset of seizures, as well as vitamin C with seizure frequency/month. We detected an imbalance in the redox state in patients with DRCPS, supporting oxidative stress as a relevant mechanism in this pathology. Thus, it is apparent that some oxidant and antioxidant parameters are closely linked with clinical variables.

Consentimiento informado en pacientes con epilepsias intratables / Informed consent in patients with intractable epilepsy

La ética médica aborda, entre otros aspectos, la relación médico-paciente, de la cual se deriva el término consentimiento informado como su máxima expresión. La epilepsia afecta al 1-2 por ciento de la población mundial, y en la búsqueda de soluciones a esta enfermedad los sujetos son involucrados en diferentes tipos de estudios. En el presente trabajo se realiza una breve revisión de algunos aspectos éticos relacionados con la aprobación dada por los pacientes que padecen epilepsia o su representante legal para participar en estudios que presuponen la realización de exámenes diagnósticos y el empleo de formas novedosas de tratamiento, lo que se materializa a través del consentimiento informado. Especialmente, se hace referencia a la participación de los pacientes en ensayos clínicos y el manejo de las pacientes que quedan embarazadas en el transcurso del ensayo clínico, los efectos adversos de la medicación y de la cirugía de epilepsia(AU)

Medical Ethics addresses, among other aspects, the doctor-patient relationship from which the term informed consent is derived as its maximum expression. Epilepsy affects 1-2 percent of the world population, and in the search for solutions to this disease the subjects are involved in different types of studies. In the present paper, a brief review of some ethical aspects related to the approval given by patients suffering from epilepsy or their legal representative to participate in studies that presuppose the performance of diagnostic tests and the use of novel forms of treatment. This is materialized through informed consent. Especially, there is a reference to the participation of patients in clinical trials, and the management of patients who become pregnant during the clinical trial, the adverse effects of medication, and epilepsy surgery(AU)

Inflammatory mediators in epilepsy.

All common contributing factors to epilepsy such as trauma, malignancies and infections are accompanied by different levels of central nervous system inflammation that in turn have been associated with the occurrence of seizure. Emerging data from human brain tissue and experimental models of epilepsy support the proposed involvement of inflammation in epilepsy. Key mediators of this process include, among others: interleukin (IL) -1ß, IL-6, tumor necrosis factor-α, adhesion molecules and component of complement. Recent advances suggest the involvement of specific inflammatory pathways in the pathogenesis of seizures in patients with pharmacoresistant temporal lobe epilepsy, highlighting the potential for new therapeutic strategies. This review provides an overview of the current knowledge on the relationship between inflammatory mediators and epilepsy. We also describe experimental and clinical evidence of inflammation in epilepsy with special emphasis on clinical aspects once the epileptogenic focus has been resected. Further insight into the complex role of inflammation in epileptogenesis may provide new treatment options.