Risk factors in post-dural puncture headache.

INTRODUCTION: Post-dural puncture headache (PDPH) is the most common complication following lumbar puncture. However, its incidence varies according to the series consulted. Different factors associated with its onset have been identified. OBJECTIVES: The purpose of this study is to determine the incidence of PDPH and to identify predisposing factors for its appearance. METHOD: Prospective, descriptive study in 57 patients who underwent lumbar puncture procedures. To this end, variables associated with patient-related risk factors, clinical and procedural factors with the presence of PDPH were analysed. The incidence of PDPH was 38.6% and factors associated with onset included young age and previous history of headache. RESULTS: The incidence of PDPH was higher in women and presented greater intensity in this group, though studies with a larger sample size would need to be conducted. CONCLUSIONS: We must bear in mind the factors associated with the appearance of PDPH, which include: young age, history of headache, and the perception of procedural difficulty, to better inform patients and optimise the techniques used.

Quantitative and qualitative analysis of semantic verbal fluency in patients with temporal lobe epilepsy. / Análisis cuantitativo y cualitativo de la fluidez verbal semántica en pacientes con epilepsia del lóbulo temporal.

INTRODUCTION: Patients with temporal lobe epilepsy (TLE) perform poorly on semantic verbal fluency (SVF) tasks. Completing these tasks successfully involves multiple cognitive processes simultaneously. Therefore, quantitative analysis of SVF (number of correct words in one minute), conducted in most studies, has been found to be insufficient to identify cognitive dysfunction underlying SVF difficulties in TLE. OBJECTIVES: To determine whether a sample of patients with TLE had SVF difficulties compared with a control group (CG), and to identify the cognitive components associated with SVF difficulties using quantitative and qualitative analysis. METHODS: SVF was evaluated in 25 patients with TLE and 24 healthy controls; the semantic verbal fluency test included 5 semantic categories: animals, fruits, occupations, countries, and verbs. All 5 categories were analysed quantitatively (number of correct words per minute and interval of execution: 0-15, 16-30, 31-45, and 46-60seconds); the categories animals and fruits were also analysed qualitatively (clusters, cluster size, switches, perseverations, and intrusions). RESULTS: Patients generated fewer words for all categories and intervals and fewer clusters and switches for animals and fruits than the CG (P<.01). Differences between groups were not significant in terms of cluster size and number of intrusions and perseverations (P>.05). CONCLUSIONS: Our results suggest an association between SVF difficulties in TLE and difficulty activating semantic networks, impaired strategic search, and poor cognitive flexibility. Attention, inhibition, and working memory are preserved in these patients.

PercepFiguras: programa computarizado de estimulación visual para evaluar conductual y electrofisiológicamente la percepción multiestable / PercepFiguras: a computerized visual stimulation program to assess, behaviorally and electrophysiologically, the multistable perception

RESUMEN En la investigación de la percepción visual comúnmente se usan programas computarizados comerciales para la presentación de los estímulos, configurados por lo general para admitir una respuesta por cada estímulo presentado. Sin embargo, el estudio de la percepción multiestable, requiere la presentación de un estímulo que permanece invariable aunque la percepción de éste puede variar en dos o más configuraciones, lo que demanda que el programa admita respuestas para cada cambio en la percepción de un mismo estímulo. Se presenta PercepFiguras desarrollado con lenguaje de programación C++ que es un sistema de estimulación visual que permite al usuario: a) presentar imágenes y recibir una o varias respuestas a cada una, b) sincronizar las respuestas con un sistema de registro electroencefalográfico mediante el envío de pulsos TTL, c) generar un archivo conductual y d) generar un archivo con el total de respuestas y promedios de las latencias a cada tipo de figura. Se realizó un estudio piloto con una tarea de presentación continua de una figura ambigua alternando con dos variantes de menor ambigüedad, se obtuvo mayor frecuencia de cambios perceptuales y menor estabilidad perceptual para la figura ambigua respecto a las de menor ambigüedad, comprobándose la utilidad del programa.

ABSTRACT In the study of visual perception, the use of computerized commercial programs for the presentation of stimuli, usually configured to admit a response for each stimulus presented, is common. However, the study of multistable perception requires the presentation of a stimulus that remains unchanged, although the perception of it can vary in two or more configurations during its observation, which demands that the program admit responses for each change in perception of the same stimulus. PercepFiguras is a system developed with C++ programming language that allows: a) present images and receive multiple responses to the same stimulus, b) synchronize the responses with an electroencephalographic recording system by sending TTL pulses, c) generate a behavioral file, d) generate a file with the total responses and averages of the latencies for each type of figure. In the pilot study with a task of continuous presentation of an ambiguous figure to alternating with two variants of less ambiguity, we observe greater frequency of perceptual and less perceptual stability to the ambiguous figure with respect to the less ambiguous figures, which proves the usefulness of the program.