A simulated environment for early development stages of reinforcement learning algorithms for closed-loop deep brain stimulation.

In recent years, closed-loop adaptive deep brain stimulation (aDBS) for Parkinson's disease (PD) has gained focus in the research community, due to promising proof-of-concept studies showing its suitability for improving DBS therapy and ameliorating related side effects.The main challenges faced in the aDBS control problem is the presence of non-stationary/non-linear dynamics and the heterogeneity of PD's phenotype, making the exploration of data-driven dynamics-aware control algorithms a promising research direction. However, due to the severe safety constraints related to working with patients, aDBS is a sensitive research field that requires surrogate development platforms with growing complexity, as novel control algorithms are validated.With our current contribution, we propose the characterization and categorization of non-stationary dynamics found in the aDBS problem. We show how knowledge about these dynamics can be embedded in a surrogate simulation environment, which has been designed to support early development stages of aDBS control strategies, specifically those based on reinforcement learning (RL) algorithms. Finally, we present a comparison of representative RL methods designed to cope with the type of non-stationary dynamics found in aDBS.To allow reproducibility and encourage adoption of our approach, the source code of the developed methods and simulation environment are made available online.

[The relationship between placental lesions and early hemorrhagic-ischemic cerebral injury in very low birth weight infants]. / Asociación entre lesiones placentarias y lesiones isquémico hemorrágicas cerebrales precoces detectadas por ecografía en prematuros menores de 1500 gramos y 32 semanas.

INTRODUCTION: The histopathological features of the placenta are central for screening a lot of pregnancy related disorders associated to hemorrhagic-ischemic cerebral injury in preterm infants that can jeopardize his long term neurodevelopment. The objective of this study was to examine the relationship between placental lesions and early hemorrhagic-ischemic cerebral injury in very low birth weight infants (VLBW). METHODS: This is a case-control study of VLBW born at Sardá Maternity Hospital, Buenos Aires, between 2006 and 2012. Inclusion criteria's were gestational age ≥ 24 and ≤ 32 weeks and birth weight between 500 g and 1500 g, Exclusion criteria's were multiple pregnancy, congenital anomalies, intrauterine infections and mortality before 24 hours of life. RESULTS: 198 VLBW were included, 49 cases and 149 controls. There was no significant difference in the incidence of histopathological lesions between the groups, although inflammatory placental lesions predominated in cases (67,3%) compared with controls (48%, p= 0.018). Intraventricular hemorrhage was the most common injury. On bivariate analysis inflammation was the only placenta lesion associated with early hemorrhagic-ischemic cerebral injury (OR 7.0, 95% CI 1.54 - 31.71) whereas the risk of severe hemorrhagic-ischemic cerebral injury was twofold greater in the presence of inflammation (p= 0.20). After adjusting for perinatal variables, placental lesions were not independently associated with increased risk of hemorrhagic-ischemic cerebral injury. There was a trend towards lesser risk of hemorrhagic-ischemic cerebral injury with increasing gestational age. CONCLUSION: Placental injuries were not independently associated with hemorrhagic-ischemic cerebral injury within 72 hours of life, although inflammation showed a clear predominance un cases.

Introducción: El examen histopatológico de la placenta es trascendente para evidenciar desordenes relacionados con el embarazo que se asocian a lesiones isquémico hemorrágicas cerebrales (LIHC) en recién nacidos prematuros (RNPT). Objetivo: Estudiar la asociación entre lesiones placentarias y LIHC precoces detectadas con ecografía en RNPT ≤ 1500 g y 32 semanas. Material y Métodos: diseño caso ­ control. Criterios de inclusión: RNPT ≥ 24 y ≤ 32 semanas, ≥ 500 y ≤ 1500 g, nacidos en la Maternidad Sardá entre años 2006 y 2012. Criterios de exclusión: RNPT gemelares, con malformaciones o infecciones intrauterinas específicas y los fallecidos antes de las 24 horas de vida. Resultados: fueron incluidos 198 RNPT, 49 con LIHC (casos) y 149 sin LIHC (controles). No se encontraron diferencias en las lesiones histopatológicas placentarias entre los dos grupos, aunque se apreció una clara tendencia de lesiones inflamatorias en los casos (67.3%) en comparación con los controles (48 %, p = 0.018). La ruptura prematura de las membranas (p = 0.027) y la corioamnionitis clínica fueron más frecuentes en los casos. Complicaciones fuertemente asociadas a prematurez fueron estadísticamente más evidentes entre los casos. La hemorragia intraventricular fue la lesión cerebral más hallada. El 50% de los casos persistieron con LIHC a las 36-40 semanas, mientras que a mayor edad gestacional el riesgo de LIHC fue menor . Conclusiones: las lesiones histopatológicas placentarias no estuvieron asociadas independientemente a mayor riesgo de LIHC, aunque se observó un predominio de lesiones inflamatorias en los casos.

Mortalidad neonatal: análisis causa raíz: estudio prospectivo de los factores vinculados a la muerte de recién nacidos internados en maternidades seleccionadas del sector público de la República Argentina / Neonatal mortality: root cause analysis: prospective study of factors related to the death of newborns admitted to selected maternity of the public sector of Argentina

Objetivo: identificar y caracterizar a los RN que fallecen en 5 principales maternidades públicas y explorar factores relacionados a las muertes reducibles a través del análisis de Causa Raíz (ACR). Métodos: Estudio prospectivo multicéntrico, descriptivo y observacional. Estrategia cuantitativa de corte transversal y cualitativa tipo ACR. Resultados: durante 10 meses se produjeron 238 muertes neonatales sobre 22.324 nacimientos más 651 RN derivados (TM global 10,35‰). La media de PN de los fallecidos fue 1838 ± 999 g y la mediana 1635 g (1000-2650) y la de edad gestacional 32 ± 5 sem. La edad materna fue de 25 ± 7años y sólo el 20% no tuvo ningún control en su embarazo. Las principales causas de internación fueron dificultad respiratoria (42%), malformaciones (39%), infecciones y asfixia perinatal. El 65% presentó alguna complicación en la evolución. La principal causa de muerte fueron las malformaciones congénitas (38%) seguida por la infección intrahospitalaria (27%). Con respecto al ACR la dimensión institucional (coordinación de la atención, experiencia, capacitación, infección hospitalaria) estuvo vinculada a 48% de las muertes mientras que la dimensión RRHH fue la más frecuentemente reconocida como deficitaria y relacionada con el evento muerte (57%). El 56,7% de las muertes fueron clasificadas como potencialmente reducibles, oscilando entre 35,5% y 76,2% según los centros. Conclusiones: La mayor parte de las muertes neonatales analizadas parecen reducibles. Dentro de las medidas preventivas necesarias a nivel de los sistemas y procesos, resulta fundamental establecer estrategias de capacitación y fortalecimiento del recurso humano que asiste a esta población vulnerable.

Asociación entre lesiones placentarias y lesiones isquémico hemorrágicas cerebrales precoces detectadas por ecografía en prematuros menores de 1500 gramos y 32 semanas / [The relationship between placental lesions and early hemorrhagic-ischemic cerebral injury in very low birth weight infants].

INTRODUCTION: The histopathological features of the placenta are central for screening a lot of pregnancy related disorders associated to hemorrhagic-ischemic cerebral injury in preterm infants that can jeopardize his long term neurodevelopment. The objective of this study was to examine the relationship between placental lesions and early hemorrhagic-ischemic cerebral injury in very low birth weight infants (VLBW). METHODS: This is a case-control study of VLBW born at Sardá Maternity Hospital, Buenos Aires, between 2006 and 2012. Inclusion criteria’s were gestational age ÔëÑ 24 and Ôëñ 32 weeks and birth weight between 500 g and 1500 g, Exclusion criteria’s were multiple pregnancy, congenital anomalies, intrauterine infections and mortality before 24 hours of life. RESULTS: 198 VLBW were included, 49 cases and 149 controls. There was no significant difference in the incidence of histopathological lesions between the groups, although inflammatory placental lesions predominated in cases (67,3

) compared with controls (48

, p= 0.018). Intraventricular hemorrhage was the most common injury. On bivariate analysis inflammation was the only placenta lesion associated with early hemorrhagic-ischemic cerebral injury (OR 7.0, 95

CI 1.54 - 31.71) whereas the risk of severe hemorrhagic-ischemic cerebral injury was twofold greater in the presence of inflammation (p= 0.20). After adjusting for perinatal variables, placental lesions were not independently associated with increased risk of hemorrhagic-ischemic cerebral injury. There was a trend towards lesser risk of hemorrhagic-ischemic cerebral injury with increasing gestational age. CONCLUSION: Placental injuries were not independently associated with hemorrhagic-ischemic cerebral injury within 72 hours of life, although inflammation showed a clear predominance un cases.