Brenda Giagante

Psychiatric disorders in patients with psychogenic non-epileptic seizures, with and without comorbid epilepsy

PURPOSE The aim of this study is to describe similarities and differences in epidemiological, psychiatric and semiologic variables between patients with psychogenic none epileptic seizures (PNES) and comorbid epilepsy (mixed PNES), and patients with PNES without comorbid epilepsy (pure PNES). RESULTS Forty-three patients with PNES diagnosed by Video-EEG were included. Twenty-four had pure PNES, and ninteen mixed PNES. Female population, age, duration of PNES, psychiatric institutionalization, psychopharmacotherapy, dissociative disorders and posttraumatic stress disorder (PTSD), were significantly higher in the pure PNES patients. Suicide attempts, antiepileptic therapy, conversive, affective and personality disorders were frequent in both groups. In the analysis of seizure semiology, the total lack of responsiveness was significantly higher in the mixed PNES group. CONCLUSIONS Pure PNES patients showed similarities and differences in the psychiatric profile, with a greater prevalence of dissociative disorders and PTSD, factors related to psychiatric severity.

Clinical Features and Prognosis of Nonepileptic Seizures in a Developing Country

Summary:  Purpose: To determine the predictive value of clinical features and medical history in patients with nonepileptic seizures (NESs).

Clinical-electroencephalogram patterns at seizure onset in patients with hippocampal sclerosis.

OBJECTIVE The purpose of this study is to identify specific clinical-electroencephalogram (EEG) patterns at seizure onset in patients with hippocampal sclerosis (HS). METHODS Sixty-six ictal video-EEG recordings corresponding to 26 patients with HS have been reviewed, focusing on the EEG features found during the first 30 ictal s. The EEG activity has been classified into the following groups: (A) according to spatial distribution: type 1: temporal electrodes on one side; type 2: temporal and adjacent frontal electrodes on one side; and type 3: non-lateralizing electrographic activity; and (B) according to morphology; subtype (a): regular 5-9 Hz rhythmic activity (RA); subtype (b): low-voltage rapid activity, followed by a 5-9 Hz RA; and subtype (c): irregular EEG sharp waves. We analyzed the clinical symptoms sequence and established the relationship with the ictal EEG patterns. RESULTS Considering spatial distribution and morphology, the most frequent ictal EEG patterns were type 1 (57%), type 2 (37%), and subtype (a): 62%; subtype (b): 27%; and subtype (c): 11%. The sequence of clinical symptoms observed was: aura-->behavioral arrest-->oro-alimentary automatisms-->unilateral hand automatisms. All seizures with aura and including two or more symptoms of the clinical sequence (65%) were associated with a 1a, 1b, 2a or 2b EEG pattern. CONCLUSIONS The identification of a specific clinical-EEG pattern provides a useful tool for the epileptogenic zone localization in non-invasive pre-surgical assessment of patients with hippocampal sclerosis. SIGNIFICANCE The identification of a specific clinical-EEG pattern associated to neuroimaging findings and neuropsychological testing allows indicating surgery for the treatment of epilepsy in patients with hippocampal sclerosis, without performing any further complementary studies.

Psychotic disorders in Argentine patients with refractory temporal lobe epilepsy: A case–control study

The issue of psychotic disorders in epilepsy has given rise to great controversy among professionals; however, there are not many studies in this area and the physiopathological mechanisms remain unknown. The aim of this study was to describe the spectrum of psychotic disorders in an Argentine population with refractory temporal lobe epilepsy (RTLE) and to determine the risk factors associated with psychotic disorders. Clinical variables of the epileptic syndrome were compared among a selected population with RTLE with and without psychotic disorders (DSM-IV/Ictal Classification of psychoses). Logistic regression was performed. Sixty-three patients with psychotic disorders (Psychotic Group, PG) and 60 controls (Control Group, CG) were included. The most frequent psychotic disorders were brief psychotic episodes (35%) (DSM-IV) and interictal psychosis (50%) (Ictal Classification). Risk factors for psychotic disorders were bilateral hippocampal sclerosis, history of status epilepticus, and duration of epilepsy greater than 20 years.

A comprehensive review of epilepsy in the Arab world.

PURPOSE We conducted a comprehensive review of the epidemiology of epilepsy in the Arab world. METHODS Epidemiological literature about epilepsy from 22 countries of the Arab League was searched in French and English using several keywords (specific and wider) and combinations, individually for each country. The search was conducted on Google first and then on PubMed. The results are presented as counts, proportions, and medians along with 95% confidence intervals (CI). Unpaired t-test with unequal variance and regressions were performed, altogether and individually, for lifetime and active epilepsy prevalence as well as incidence. RESULTS Google provided 21 prevalence, four camp and nine incidence estimates while PubMed provided ten such estimates; none of them was identified by Google. No epidemiological data about epilepsy was found from 10/22 countries. Excluding pediatric studies, 13 prevalence estimates from six countries were identified. Including pediatric studies, 21 estimates from nine countries were found. Median lifetime and active epilepsy prevalence were 7.5/1000 (95% CI 2.6-12.3, range 1.9-12.9) and 4.4/1000 (95% CI 2.1-9.3, range 2.1-9.3), respectively, excluding pediatric studies (1984-2014, N=244081). Median incidence was 56.0/100,000 (n=9, N=122484, 95% CI 13.7-147.9, range 10.4-190). CONCLUSION The fact that no epidemiological data about epilepsy is available in the public domain for almost one half of all Arab countries offers opportunities for future research. This thorough review of existing literature demonstrates a prevalence of epilepsy three times higher than previously reported for this region. The median incidence is similar to other regions of the world, e.g. North America. Google yielded additional valuable sources not indexed in PubMed and provided pertinent references more quickly.

Postoperative neuropsychological outcome in patients with mesial temporal lobe epilepsy in Argentina.

The aim of the present study is to compare pre- and postsurgical neuropsychological outcome in individuals suffering from mesial temporal lobe epilepsy (mTLE), in order to evaluate prognosis. The selected thirty-five patients had medically mTLE and had undergone an anterior temporal lobectomy (ATL). Neuropsychological evaluation was performed in three different stages: before ATL, 6 months after resection, and a year afterwards. Neuropsychological protocol evaluated attention, verbal memory, visual memory, executive function, language, intelligence, and handedness. There was a significant improvement (P = 0.030) in the group with visual memory deficit after surgery, whereas no changes were observed across patients with verbal memory deficit. No changes were observed in language after surgery. Executive function showed significant improvement 6 months after surgery (P = 0.035). Postoperative outcome of cognitive impairments depends on baseline neuropsychological status of the patients with TLE. In our case series, deficits found in patients with mTLE after ATL did not result in a subjective complaint.

Visual defects associated with vigabatrin: a study of epileptic argentine patients.

OBJECTIVE The aim of the present study was to assess visual alterations in a population of Argentine patients treated with the antiepileptic drug vigabatrin. METHODS Twenty patients receiving vigabatrin and 15 patients receiving carbamazepine were examined with automated perimetry using a Humphrey 120-point full screening strategy. In addition, scotopic flash electroretinograms were performed. RESULTS Of 20 patients treated with vigabatrin, two were unable to cooperate with testing. Of the remaining 18 patients, all but two showed at least one non-detected point inside the central 40 degrees of the visual field of each eye. Of the 15 carbamazepine-treated patients, three were unable to perform the study. None of the remaining 12 patients showed visual field defects. Both a- and b-wave amplitudes of the scotopic electroretinogram were significantly reduced in 12 patients receiving vigabatrin. CONCLUSIONS Visual field defects among patients on vigabatrin therapy may occur with a higher frequency than previously recognized. The Humphrey 120-points full field screening test and electroretinography are useful tools to assess the visual dysfunction associated with vigabatrin.

Chapter 67 Wavelet analysis preceding seizures

Publisher Summary Quantification methods and automatic analysis of EEGs offer certain advantages as compared to the more traditional approaches: an objective analysis of the signal, avoiding subjective criteria, the reduction of long-term electroencephalographys (EEGs) to the significant time intervals, during which the epileptic activity is localized, and the detection and classification of epileptic events within these time intervals. Some of the methods are based on the frequency components of the EEG signal. The tools used in these cases have been provided by a specific field within the area of mathematics termed “harmonic analysis.” The foundations are based on Fourier transform. Wavelet transform has allowed achieving major progress in this field. This chapter starts with the history of harmonic analysis as an introduction to the use of wavelets in signal processing and, specifically, in EEG analysis. The chapter addresses a new method based on wavelet transform that leads to a dramatic change in the field of signal analysis, specifically in biomedical signals. Wavelet transforms are based on a basic short oscillating function known as “wavelet.” From this basic wavelet, using translations and dilations, it is possible to build a frame in which the frequential characteristics of the signal and, simultaneously, its localization in time are determined. The EEG signal, the bank of digital filters allows separating epileptiform and back-ground activities. The effective localization of the information in the time-frequency domain and the real-time implementation of the algorithm proposed offer an interesting contribution to the diagnosis of the area epileptogenic.

175. Analysis of ictal and postictal semiology and ictal EEG patterns in patients with Hippocampal Sclerosis Plus

The purpose of the present study was to find a correlation between localized brain rhythmic activity and behavioral states. Using simultaneous video and intracranial as well as scalp EEG recordings in a patient with medial temporal lobe epilepsy, we studied rhythmic activities in 0–100 Hz range in frontal, temporal, and parietal cortex during the patient’s daily activities and in six distinct experimental paradigms. Power spectral density data were analyzed statistically and graphically for each condition across all channels. Unlike the subject’s occipital alpha rhythm which dissipated when he opened his eyes, a task dependent and statistically powerful increase was seen in 10 Hz rhythmic activity in the supramarginal gyrus during resting state, listening to tones with different frequencies and watching or recalling audiovisual images. By contrast, this activity was absent when the subject was engaged in spatial navigation, mimicking others’ actions, or reading words or digits out loud. The activity was also absent during sleep, eavesdropping on others, concentration during visual recall, reaching for objects, and ictal events including staring spells. We conclude that a rhythmic activity can occur in a specific frequency range and brain region during specific behavioral and possibly cognitive contexts. The 10 Hz activity in the right parietal cortex, may in fact be related to these rhythms, and may signal an ongoing conscious or subconscious process that takes place during the default mode of the brain hallmarked by un attained imagery and lack of action or distraction.