Contingent negative variation (CNV) topography, hemispheric asymmetry and time-course were investigated in healthy subjects and non-medicated paranoid schizophrenic patients in two antisaccade paradigms with the short (800-1000 ms) and long (1200-1400 ms) durations of the fixation period. EEG and electrooculogram (EOG) were recorded. Saccade characteristics and mean amplitudes of slow cortical potentials time-locked to peripheral target were analyzed in 23 healthy volunteers and 19 schizophrenic patients. Compared to healthy control subjects, schizophrenic patients had significantly slower antisaccades and committed significantly more erroneous saccades in the both antisaccade tasks. The prolongation of the fixation period resulted in noticeable decrease of error percent in patients group. The analysis of CNV time-course has revealed two distinct stages in both groups. The early CNV stage was represented by a negative wave with the maximal amplitude over midline fronto-central area, and the late stage was characterized by increased CNV amplitude at the midline and left parietal electrode sites. In healthy subjects the simultaneous activation of frontal and parietal areas was observed in the paradigm with the shorter fixation interval; the increase of the fixation period produced consecutive activation of these areas. Schizophrenic patients' CNV amplitude was generally smaller than that of healthy subjects. The most pronounced between-group differences of the negative shift amplitude were revealed at frontal electrode sites during the early CNV stage in both modifications of the antisaccade task. The deficit of frontal activation revealed in patients at the early stage of antisaccade preparatory set in both antisaccadic paradigms may be related to pathogenesis of paranoid schizophrenia.

Nuestro propósito era determinar el efecto del tratamiento de risperidona en monoterapia sobre la discapacidad y sobre la calidad de vida de 318 pacientes esquizofrénicos ambulatorios que habían sido tratados antes con otros neurolépticos. Los pacientes fueron evaluados en la línea de base y a los dos, cuatro y ocho meses utilizando la BPRS, la CGI, la WHO/DDS y la SF-36. Las puntuaciones de la BPRS mostraron una disminución significativa en el segundo mes, tanto en la puntuación total como en cada uno de los tres grupos negativo, positivo y de depresión/ansiedad. Las puntuaciones de la WHO/DDS disminuyeron significativamente tanto en la puntuación global (de 51,8 a 37,4, P < 0,0001) como en las cuatro dimensiones. Las puntuaciones de la escala SF-36 y las medidas de resumen mostraron una mejoría significativa después de ocho meses de tratamiento de risperidona. El tratamiento a largo plazo (ocho meses) de risperidona tiene un efecto positivo sobre la evolución clínica y psicosocial. Las mujeres, los pacientes paranoides y los pacientes sin historia de uso-abuso de sustancias mostraron mejorías mayores en la calidad de vida.