Summary:Purpose: Determination of epilepsy etiology in population-based studies is difficult because of the high cost of diagnostic tests. However, cost-effectiveness may be proven if preventive public-health strategies can be established from the test results. We report an epilepsy population-based study using clinical and laboratory techniques.Methods: A medical team administered an epilepsy survey to 88% of the residents by census in the rural county of Salamá, Honduras. Ninety of 100 participants identified with active epilepsy underwent a neurologic examination, videoelectroencephalography (video-EEG), brain computed tomography (CT) scan, and serum enzyme-linked immunoelectrotransfer blot (EITB) for cysticercosis. Final diagnoses were based on the International League Against Epilepsy classifications for seizures and epilepsy syndromes. Combined epidemiologic, clinical, video-EEG, neuroimaging, and serum EITB assays were used for the diagnosis of epilepsy etiologies.Results: Among 6,473 residents surveyed, 151 persons with epilepsy (prevalence rate, 23.3/1,000) were identified, 100 of whom had active epilepsy (15.4/1,000) on the prevalence day. Incidence was determined to be 92.7/100,000. Partial seizures with or without secondary generalization were common (92.2%). Symptomatic epilepsy (62%) was primarily due to neurocysticercosis (37%), perinatal brain damage (8%), post-traumatic (3%), and poststroke (2%). Eight percent were idiopathic, and 30% were cryptogenic (unknown cause).Conclusions: Symptomatic epilepsies primarily explained the high prevalence and incidence of epilepsy in Salamá. Integration of video-EEG and brain CT scan with clinical-epidemiologic evaluation was critical for determination of epilepsy etiology. Establishment of specific programs for continuation of epidemiologic surveillance, education, intervention, and long-term follow-up will benefit the Salamá region. Key Words: Honduras-Epilepsy-Epidemiology-Etiology-IncidencePrevalence-Neurocysticercosis.Epilepsy is a worldwide health problem (1-3). Recent analyses concluded that Latin America, especially Central America, has high epilepsy prevalence rates that appear to be secondary to a high frequency of symptomatic "preventable" epilepsies (4,5). Comparison data are not always available because few worldwide epidemiologic studies used standardized case-ascertainment criteria (1,3,(6)(7)(8). Primarily because of the high costs and/or multiple logistic factors, the vast majority of previous epidemiologic studies were two-phased and did not use neuroimaging or electroencephalography (EEG) to determine the etiology and syndromic classification of the epilepsies (9).The International League Against Epilepsy (ILAE) has published standardized diagnostic criteria for epileptic seizures and syndromes (10,11) and recently proposed the use of a five-axes approach to include ictal phenomena, seizure type, syndrome, etiology, and impairment (12). The cost-effectiveness of obtaining complete seizureevaluation information will be demonstrated by esta...

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Categorising psychotic states associated with epilepsy according to their temporal relationship with seizures is clinically and prognostically useful because it provides important information regarding disease treatment and progression. The treatment of peri-ictal or acute mental disorders is based on epileptic seizure control, while the treatment of interictal or chronic disorders has more in common with managing disorders which are purely psychiatric in origin. In addition to improving the patient's quality of life and reducing disability, achieving strict control over seizures may also prevent the development of interictal psychosis. For this reason, we believe that establishing a treatment protocol for such cases is necessary.

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Formation of the dynamic population gratings in optical fibers with randomly oriented rare-earth ions is analyzed with a special interest to the grating component for readout with the orthogonal light polarization. It is shown that as compared with a simple model case of the collinearly oriented dipole-like centers their random orientation leads to approximately 2-times growth of the effective saturation power P sat when it is estimated from the incident power dependence of the fiber absorption or from that of the fluorescence intensity. An optimal incident power, for which the maximum of the dynamic population grating amplitude for collinear light polarization is observed, also follows this change in P sat , while formation of the grating for orthogonal polarization needs essentially higher light power. The reduced anisotropy of the active centers, which is in charge of the experimentally observed weakening of the polarization hole burning (PHB) and of the fluorescence polarization, compensates in some way the effect of random ion orientation. The ratio between the maximum conventional (i.e. for the interacting waves collinear polarizations) two-wave mixing (TWM) amplitude and the initial not saturable fiber optical density proves to be, however, nearly the same as in the model case of collinearly oriented dipoles. The ratio between the PHB effect and the amplitude of the anisotropic grating, which is responsible for TWM of the orthogonally polarized waves, is also not influenced significantly by the reduced anisotropy of ions.