Biomedical subjects

Silvia Kochen

Publications and source records attributed to Silvia Kochen.

6 recordsLinked to original sources

PubMed2006

Prevalence and clinical features of epilepsy in Argentina. A community-based study.

OBJECTIVE: To ascertain the prevalence of epilepsy in Junín, a town of 70,000-80,000 inhabitants from the Province of Buenos Aires, Argentina. BACKGROUND: Some South American communities have reported extremely high prevalences of epilepsy. We investigated whether Junín would also have a high prevalence. DESIGN/METHODS: Systematic sampling was used to select 5,839 households (sampling fraction = 25%). Participating households amounted to 5,648 (97%), with 17,049 persons. A two-phase case-finding strategy was used. Phase 1 was the screening of the 17,049 persons, which was performed by trained but medically unsophisticated interviewers. Phase 2 was the neurological evaluation of the 250 persons who were screened positive for epilepsy. Diagnoses were based on defined diagnostic criteria. RESULTS: As of January 1, 1991 (prevalence day), 106 persons had epilepsy, including 64 (60%) with active epilepsy. Among these, 9 (14%) were epilepsy cases newly diagnosed by survey neurologists, and 50 (78%) were on antiepileptic treatment at the time of the survey. Regarding the same 64 persons, seizures were generalized in 37 (58%) and partial in 24 (38%). Lifetime prevalence of epilepsy was 6.2/1,000 (6.3/1,000, age adjusted to the world standard population). Total point prevalence for active epilepsy was 3.8/1,000 (4.0 for females and 3.5 for males). In addition, prevalence peaked at the ages of 40-59 for females and 0-4 for males. CONCLUSIONS: This is one of the first community-based studies of epilepsy in Argentina, and the prevalence results provide new epidemiological data contributing to our understanding of the different prevalence rates found in Latin America.

Adolescent↗

PubMed2006

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.

Adult↗

PubMed2005

Automatic detection of interictal spikes using data mining models.

A prospective candidate for epilepsy surgery is studied both the ictal and interictal spikes (IS) to determine the localization of the epileptogenic zone. In this work, data mining (DM) classification techniques were utilized to build an automatic detection model. The selected DM algorithms are: Decision Trees (J 4.8), and Statistical Bayesian Classifier (naïve model). The main objective was the detection of IS, isolating them from the EEG's base activity. On the other hand, DM has an attractive advantage in such applications, in that the recognition of epileptic discharges does not need a clear definition of spike morphology. Furthermore, previously 'unseen' patterns could be recognized by the DM with proper 'training'. The results obtained showed that the efficacy of the selected DM algorithms is comparable to the current visual analysis used by the experts. Moreover, DM is faster than the time required for the visual analysis of the EEG. So this tool can assist the experts by facilitating the analysis of a patient's information, and reducing the time and effort required in the process.

Action Potentials↗

PubMed2005

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.

Adult↗

PubMed2003

Magnetic resonance imaging identifies cytoarchitectonic subtypes of the normal human cerebral cortex.

BACKGROUND: Magnetic Resonance Imaging (MRI) allows a detailed "in vivo" macroscopic study of the human brain; previously, it has been demonstrated that Fluid Attenuated Inversion Recovery (FLAIR) sequence shows higher signal intensity of cortices belonging to limbic structures. PURPOSE: To measure and compare signal intensities (SI) of cytoarchitectonically different cortical regions. METHODS: In 22 adult subjects, without psychiatric or neurological diseases, FLAIR sequence was performed in coronal slices, perpendicular to the main hippocampal axis. Signal intensity was measured, with a region-of-interest (ROI) function, in 12 different cortical regions. We compared these values and grouped the cortices into five groups: (1) limbic cortices, (2) paralimbic agranular cortices, (3) paralimbic granular cortices, (4) parietal-type neopallium, (5) frontal-type neopallium. A t-test for comparison of paired samples was performed, considering p</=0.05 as statistically significant. RESULTS: We found statistically significant differences amongst the different groups, with the exception of groups 1 and 2, which did not show differences between them. No statistically significant differences were found among cortices belonging to the same group. CONCLUSION: Structural characteristics of the cerebral cortex cause changes in its signal intensity. Magnetic resonance imaging (FLAIR sequence) allows discrimination of different cytoarchitectonic areas of the human cerebral cortex.

Adult↗

PubMed2003

Mesial temporal lobe epilepsy and hippocampal sclerosis: cognitive function assessment in Hispanic patients.

PURPOSE: The goal of this study was to assess the cognitive function status in patients with mesial temporal lobe epilepsy and hippocampal sclerosis (TLE+HS) to determine their cognitive function profile and to correlate material-specific memory deficits with HS laterality diagnosed by MRI. METHODS: Seventy-one patients were assessed with a neuropsychological protocol that includes IQ, attention, handedness, verbal memory, visual memory, language, and the executive function. chi(2) and correlation tests were used. RESULTS: Memory impairment was found in 46 patients (66%): patients without any memory deficit (n=25), patients with verbal memory deficit (n=21), patients with visual memory deficit (n=17), patients with deficit for both types of memory (n=8). Correlation between MRI lesion and memory was 66%. Language was impaired in 33 patients (46%). Eighteen patients (25%) had a deficit of the executive function. CONCLUSIONS: Patients with TLE+HS presented with a deficit in material-specific episodic memory correlating in large proportion with HS lateralization. We also found language and executive function impairments.

Adult↗