Importancia del estigma en epilepsia / Importance of Stigma in Epilepsy

Resumen El estigma es un fenómeno caracterizado por una respuesta negativa hacia una persona poseedora de un atributo diferente dentro del grupo social en el que se desarrolla. Se han descrito dos tipos de estigma: el percibido (sentido o interiorizado) y el promovido (social o promulgado). Dentro de las enfermedades con más carga asociada a estigma se encuentra la epilepsia, una de las enfermedades neurológicas más prevalentes a nivel mundial y de curso crónico. En los últimos años, se ha mostrado mayor interés en el estudio de este fenómeno, ya que afecta de manera directa la calidad de vida de las personas con epilepsia, influyendo en su desarrollo personal, escolar, laboral y pronóstico.

Abstract Stigma is a phenomenon characterized by a negative response to a person possessing a different attribute within the social group it develops. Two types of stigmas have been described: perceived (felt) and promoted (enacted). Among the diseases with the greatest burden associated with stigma is epilepsy, one of the most prevalent neurological diseases worldwide and with a chronic course. In recent years, greater interest has been shown in the study of this phenomenon since it directly affects the quality of life of people with epilepsy, influencing their personal, academic and work development and prognosis.

Olfactory function in patients with temporal lobe epilepsy; correlation of functional magnetic resonance imaging for olfaction with the laterality of the epileptic focus.

The olfactory function shares the same cerebral structures as those involved in the origin and propagation of focal temporal lobe seizures. Likewise, functional magnetic resonance imaging (fMRI) allows the study of olfactory function. This suggests that by quantitatively studying the olfactory function with an olfactory paradigm through fMRI it is possible to identify the functional alteration produced by the epileptic focus. The objective of the present study was to assess the olfactory function in the side of the epileptic focus in patients with mesial temporal lobe epilepsy, using fMRI for smell, and propose a non-invasive diagnostic method for patients candidates to mesial temporal lobe epilepsy surgery. METHODS: Patients (n = 18) with clinical diagnosis of mesial temporal lobe epilepsy, refractory to pharmacological treatment: 7 patients (38.9%) with non-invasive studies consistent enough to submit them to anterior temporal lobectomy, and 11 (61.1%) patients where focal onset seizures were identified by stereoelectroencephalography (SEEG) on the left temporal lobe in 5 (27.8%) and in both temporal lobes in 2 (11.1%). Patients were evaluated using EEG, MRI, neuropsychological data, and fMRI with olfactory paradigm. Results of the fMRI were compared with the laterality of the epileptic focus determined by intracranial electroencephalogram recordings through stereotactically placed electrodes, and with post-surgical outcome at one year of follow-up. RESULTS: fMRI showed a lower olfactory activation in 81.8% concordant with unilateral onset seizures. There were significant differences of olfactory fMRI activation between epileptic and non-epileptic foci. CONCLUSION: Functional magnetic resonance imaging with an olfactory paradigm may be a non-invasive diagnostic tool to determine the laterality of seizure onset in the mesial temporal lobe.

Centromedian Nucleus and Epilepsy.

SUMMARY: Centromedian thalamic nucleus is an intralaminar nucleus with vast connectivity to cerebral cortex and basal ganglia. It receives afferents from the brain stem through the central tegmental tract and is part of the diffuse thalamic projection system. Because the reticulothalamic system has been related to initiation and propagation of epileptic activity (centroencephalic theory of epilepsy), deep brain stimulation has been proposed to interfere with seizure genesis or propagation. Centromedian thalamic nucleus is a large nucleus laying nearby the anatomical references for stereotaxis and therefore a convenient surgical target to approach. Electrodes are implanted in the anterior ventral lateral part of the nucleus (parvocellular area), guided by intraoperative recruiting responses elicited by unilateral 6 to 8 Hz electrical stimulation delivered through the deep brain stimulation electrode. Therapeutic stimulation is delivered with the following parameters: 60 Hz, 450 µs, 3.0 V. Seizure control runs between 69% and 83% in different reports, decreasing mainly generalized seizures from the start, with significant improvement in neuropsychological performance. Significant decrease in seizure occurs from hours to days after the onset of deep brain stimulation. Some reports refer that seizure improvement may occur by the simple insertion of the deep brain stimulation electrodes, and therefore, it was used to treat refractory epileptic status.

Radiofrequency ablation of the centromedian thalamic nucleus in the treatment of drug-resistant epilepsy.

OBJECTIVE: To determine the usefulness and efficacy of radiofrequency ablations (RFA) of the Centromedian thalamic nucleus (CMN) to control primarily generalized or multifocal seizures in refractory epilepsy. METHODS: Six patients with clinical diagnosis of multifocal or primarily generalized drug-resistant epilepsy were included. Bilateral RFA of the CMN was performed through a monopolar 1.8 mm. tip electrode with a temperature of 80 °C during 90 seconds. Patients were followed in every 3 months visit for 20 to 36 months and kept a monthly seizure count calendar. We also compared maximal paroxysmal electroencephalogram (EEG) activity and neuropsychological evaluation pre and 6 months postoperatively. RESULTS: A significant reduction in the number of generalized seizures was observed in all subjects in the range of 79-98%, starting the first post-operative month. Although focal aware seizures remained unchanged throughout follow-up, there was an important reduction on paroxysmal activity between the pre and postoperative EEG. No major changes on cognitive status were detected. There was post-operative dysphagia and odynophagia lasting one week and there was no mortality in this group of patients. CONCLUSION: Preliminary results of CMN RFA suggest safety and a trend toward reduction of some seizure types, it may reduce the seizure frequency like other palliative procedures since the first post-operative month, but a larger, controlled study would be needed to establish the value of this therapy.