Septo-hippocampal networks in chronic epilepsy.

The medial septum inhibits the appearance of interictal spikes and seizures through theta rhythm generation. We have determined that medial septal neurons increase their firing rates during chronic epilepsy and that the GABAergic neurons from both medial and lateral septal regions are highly and selectively vulnerable to the epilepsy process. Since the lateral septal region receives a strong projection from the hippocampus and its neurons are vulnerable to epilepsy, their functional properties are probably altered by this disorder. Using the pilocarpine model of temporal lobe epilepsy we examined the pilocarpine-induced functional alterations of lateral septal neurons and provided additional observations on the pilocarpine-induced functional alterations of medial septal neurons. Simultaneous extracellular recordings of septal neurons and hippocampal field potentials were obtained from chronic epileptic rats under urethane anesthesia. Our results show that: (1) the firing rates of lateral septal neurons were chronically decreased by epilepsy, (2) a subset of lateral septal neurons increased their firing rates before and during hippocampal interictal spikes, (3) the discharges of those lateral septal neurons were well correlated to the hippocampal interictal spikes, (4) in contrast, the discharges of medial septal neurons were not correlated with the hippocampal interictal spikes. We conclude that epilepsy creates dysfunctional and uncoupled septo-hippocampal networks. The elucidation of the roles of altered septo-hippocampal neuronal populations and networks during temporal lobe epilepsy will help design new and effective interventions dedicated to reduce or suppress epileptic activity.

Medial septal beta-amyloid 1-40 injections alter septo-hippocampal anatomy and function.

Degeneration of septal neurons in Alzheimer's disease (AD) results in abnormal information processing at cortical circuits and consequent brain dysfunction. The septum modulates the activity of hippocampal and cortical circuits and is crucial to the initiation and occurrence of oscillatory activities such as the hippocampal theta rhythm. Previous studies suggest that amyloid beta peptide (Abeta) accumulation may trigger degeneration in AD. This study evaluates the effects of single injections of Abeta 1-40 into the medial septum. Immunohistochemistry revealed a decrease in septal cholinergic (57%) and glutamatergic (53%) neurons in Abeta 1-40 treated tissue. Additionally, glutamatergic terminals were significantly less in Abeta treated tissue. In contrast, septal GABAergic neurons were spared. Unitary recordings from septal neurons and hippocampal field potentials revealed an approximately 50% increase in firing rates of slow firing septal neurons during theta rhythm and large irregular amplitude (LIA) hippocampal activities and a significantly reduced hippocampal theta rhythm power (49%) in Abeta 1-40 treated tissue. Abeta also markedly reduced the proportion of slow firing septal neurons correlated to the hippocampal theta rhythm by 96%. These results confirm that Abeta alters the anatomy and physiology of the medial septum contributing to septo-hippocampal dysfunction. The Abeta induced injury of septal cholinergic and glutamatergic networks may contribute to an altered hippocampal theta rhythm which may underlie the memory loss typically observed in AD patients.

[Cemented femoral prosthesis with calcar replacement for intertrochanteric hip fractures in the elderly]. / Endoprótesis femoral cementada con reemplazo de calcar en fracturas intertrocantéricas de cadera en el viejo.

INTRODUCTION: The increase in hip fractures among the elderly and the presence of intercurrent diseases makes it necessary to institute treatments that help patients resume their activities as soon as possible. OBJECTIVE: Analyze the clinical course of patients with a cemented femoral endoprosthesis with calcar replacement and determine the time to resuming walking. MATERIAL AND METHODS: 18 patients were seen from January 2003 to December 2006, all of them with a diagnosis of Tronzo T IV and V intertrochanteric hip fractures, over 70 years of age and treated primarily with a cemented femoral endoprosthesis with calcar replacement. RESULTS: The total number of patients was 18, 14 females (77.77%) and 4 males (22.22%). The fracture types were: Tronzo grade IV in 11 patients and grade V in 7 patients; mean age was 78 years and their functional capacity in the immediate postoperative period was: onset of walking with full weightbearing at 48 hours in 100% of patients. Return to usual activities occurred at 4 weeks in 17 patients (94.44%). CONCLUSIONS: Due to the complexity of these fractures and the patients' bone quality, there are limited chances to treat them with osteosynthesis, as the latter would increase patients' morbidity and mortality. Patients could undergo early rehabilitation.

[Complications on minimal access surgery for total hip arthroplasty]. / Complicaciones en cirugía de mínima invasión en el reemplazo total de cadera.

INTRODUCTION: Recently, the surgical approach for total hip replacement has been refined and has been reduced in size. Controversies exist between advantages and complications it can present. OBJECTIVE: To show the complications of total hip arthroplasty by means of minimal access approach. METHODS: Thirty six patients, 24 women and 12 men (mean age 48 years), grade IV hip arthrosis. Twenty four patients underwent cementless hip arthroplasty and 12 patients hybrid arthroplasty. The preoperative evaluation was done with Harris score. An initial lateral approach of 6 cm (100%) was performed. Complications were grouped on acetabular, femoral and soft tissue complications. RESULTS: Necrosis at the comissure of the wound was seen in 12 patients (33.33%), necrosis at the surface border of the wound in 10 patients (27.77%), mal positioning of the acetabular cup in 3 patients (8.33%), mal positioning of acetabular cup screws in 2 patients (5.55%), eccentric reaming of the acetabulum in one patient (2.77%), and femoral stem malalignment in one patients (2.77%). DISCUSSION: There are many reports on the advantages of minimal invasion total hip replacement but few on complications which include mal positioning of the acetabular cup, eccentric reaming of the acetabulum and femoral stem malalignment. Nevertheless, advantages include a decreased healing time and postoperative recovery with less pain and reduced blood loss. We recommend that this technique should remain in the hands of experienced orthopaedic surgeons.

[Acetabular reconstuction for loosening in uncemented hip revision surgery. A series of 18 cases]. / Reconstrucción acetabular por aflojamiento en cirugía de revisión de cadera no cementada. Una serie de 18 casos.

OBJECTIVE: To describe the clinical and X-ray outcomes of the use of structured bone autograft and uncemented extended-configuration acetabular cup in hip revision surgery. MATERIAL AND METHODS: Eighteen patients, 12 females (66.66%) and 6 males (33.33%), with a diagnosis of uncemented, aseptic acetabular loosening were assessed during the preoperative period, radiologically with the Paprowsky classification and clini cally with the Harris scale. They were considered for revision surgery and exchange of the acetabular component with a structured autograft and an extended-configuration, uncemented acetabular cup. They were reviewed during the period from January 2000 to June 2005. RESULTS: Mean followup was 48 months; according to the Paprowsky scale the acetabular deficiency was: grade I in 11 patients (61.11%), grade II in 5 patients (27.77%), and grade III in 2 patients (11.11%). The following uncemented cups were used: the Healy Flanged in 4 patients (22.22%), and the extended diameter cup in 14 patients (77.77%). The mean time to the assessment of radiological grafting was 14 weeks; the time to assisted weight bearing with a walker was 8 weeks, the time to full weight bearing with a walker was 10 weeks. CONCLUSION: The use of a structured autograft assures the integration and reinforcement of the acetabular bottom with a considerable length of time to healing of 8 to 12 weeks. The use of revision extended-configuration implants and their three-point fixation assures primary and secondary stability and helps the patient resume his activities.

[Treatment of tibial non-union with a large bone defect with half-tubular fibular graft, centromedullary nailing and bone graft]. / Tratamiento de la no unión tibial con gran defecto oseo con peroné en media caña, clavo centromedular e injerto oseo.

INTRODUCTION: Non-union is most frequent in the tibia. It may occur with bone loss and is most often seen in the mid-third, mainly as a result of high-energy trauma. Our purpose is to present a treatment alternative. MATERIAL AND METHODS: Prospective, longitudinal, experimental trial conducted between 1999 and 2004. Five patients classified according to Judet and Paley were included. A half-tubular fibular graft plus an autologous and/or heterologous iliac crest graft were used with a UTN nail for stabilization purposes; mean follow-up was 24 months. RESULTS: All patients were male. High energy trauma was the cause in 100%; 5 were Gustilo III fractures; Paley B1 type was present in 60%; the mean bone defect was 7.8 cm. Grade III Montoya bone healing was observed on average at 13.6 months. There were two complications; one infection that required removal of the synthesis without disrupting the healing, and one re-fracture which was managed at a different service. CONCLUSIONS: An autologous half-tubular fibular graft, plus autologous and/or heterologous graft, stabilized with a UTN nail, restores the loss caused by the bone defect and allows achieving an appropriate bone healing.

[Minimally invasive surgery for total hip arthroplasty. A review of 36 cases]. / Cirugía de mínima invasión en artroplastía total de cadera. Revisi6ón de 36 casos.

INTRODUCTION: A new approach has been developed recently that considerable decreases the size of the skin incision and that has led to controversy around the advantages it offers. OBJECTIVE: To analyze the immediate postoperative course of patients considering the following parameters: operative time, blood loss, postoperative pain. To report the complications that occurred. MATERIAL AND METHODS: Thirty six patients, with a mean age of 48 years, with a diagnosis of grade IV coxarthrosis. Twenty-four patients underwent uncemented total hip arthroplasty, and 12 total hybrid hip arthroplasty. The preoperative Harris clinical assessment was applied and a lateral approach was used in all cases. The initial incision was 6 cm long (100%). RESULTS: The final incision was 6.5 cm in 26 patients (72.22%), 7 cm in 10 patients. Necrosis of wound commissures occurred in 12 patients, superficial necrosis of wound margins in 10 patients; no wound infections were reported. The mean operative time was 65 minutes for uncemented hips and 80 minutes for hybrid hips. Mean intraoperative bleeding was 150 ml. Mean postoperative pain was 3 in the VAS. Complications included performing a neo-acetabulum in one case, and a false passage of the femur component in one case. CONCLUSION: The minimally invasive approach for total hip replacement is indicated for patients with special characteristics. It is less invasive, safe, involves minimal bleeding, shorter operative time, and is reproducible. Moreover, it offers significant benefits during the immediate postoperative period when compared with the standard incision, since it involves ess pain and mobility is resumed sooner.

Septo-hippocampal networks in chronically epileptic rats: potential antiepileptic effects of theta rhythm generation.

A series of experiments was carried out testing the hypothesis that the septal region decreases the hippocampal susceptibility to hyperexcitability states through theta rhythm generation. Medial septal neurons were simultaneously recorded with hippocampal field potentials to investigate the septo-hippocampal function in the pilocarpine model of chronic epilepsy. The theta rhythm from chronically epileptic rats had lower amplitude (20% less) and higher frequency than controls (from 3.38 to 4.25 Hz), suggesting that both generator and pacemaker structures are affected during the epileptic process. At the cellular level, the group of rhythmically bursting firing medial septal neurons, in the epileptic animals, significantly and chronically increased their firing rates in relation to controls (from 13.86 to 29.14 spikes/s). Peristimulus histograms performed around hippocampal sharp waves showed that all high-frequency firing neurons, including rhythmically bursting neurons and most slow firing neurons, decreased firing rates immediately after hippocampal epileptic discharges. Thus inhibitory hippocampo-septal influences prevail during hippocampal epileptic discharges. The occurrence of epileptic discharges was reduced 86-97% of the number observed during spontaneous theta and theta induced by sensory (tail pinch) or chemical stimulation (carbachol), suggesting that the presence of the theta state regardless of how it was produced was responsible for the reduction in epileptic discharge frequency. The understanding of the theta rhythm "anti-epileptic" effect at the cellular and molecular levels may result in novel therapeutic approaches dedicated to protect the brain against abnormal excitability states.

Falsa vía de larga evolución en cirugía protésica de la cadera / Long term femoral dyaphyseal perforation in hip prosthesis

Objetivo. Enfatizar la importancia de la correcta colocación del vástago femoral, debiendo evitar la fractura diafisiaria y la falsa vía femoral, que ocurre del 0 al 4.45 por ciento en diversas series. Material y métodos. Se presentan dos casos en quienes el vástago femoral perforó la cortical posterior en uno y la medial en otro, pudiendo en ambos casos los pacientes caminar. Resultados. Cuando se toma una sola radiografía, la imagen del vástago puede coincidir con la del fémur, dando una falsa apreciación de buena colocación, que a pesar de ser incorrecta, una vez estable, puede ser utilizado eventualmente mediante alguna actitud de compensación de la cadera, según la orientación de la prótesis. Conclusión. Debe aplicarse correctamente tanto la técnica quirúrgica como la radiológica transoperatoria, como siempre se ha establecido con un mínimo de dos proyecciones radiológicas que permitan identificar el error oportunamente. De otra manera podrá estar indicada la cirugía de revisión.

Osteotomía pélvica de Chiari e intertrocantérea en un mismo tiempo quirúrgico, para pacientes con displasia de la cadera / Double pelvis Chiari and intertrochanteric osteotomy in one operating time for patients who has dip dysplasia

Debido a los pobres resultados obtenidos con el reemplazo articular en pacientes jóvenes, especialmente con soporte óseo deficiente tanto en acetábulo como en fémur por displasia, proponemos una solución "Biológica" de centraje y cobertura. Ocho pacientes con artrosis secundaria displasia de la cadera, fueron tratados quirúrgicamente con una osteotomía varizante y derrotadora intertrocantérea y una osteotomía del iliaco tipo Chiari en un mismo tiempo quirúrgico, con edad de 15 a 43 años, y con un seguimiento inicial de 3 a 17 meses. El dolor fue el principal síntoma en todos los pacientes, la indicación de la cirugía se basó en la severidad de la incongruencia articular desde el punto de vista clínico y radiográfico así como el grado de artrosis. El promedio de valoración preoperatoria en la escala de Merle D'Aubigné el dolor estaba en 4 y la movilidad y la marcha en 3.8 y 3.5 respectivamente y con grado de incongruencia III y IV. En la evaluación postoperatoria final, se logró un promedio de 5.7 en dolor y de 4.8 en marcha y movilidad, se corrigió la incongruencia en grado II en promedio y radiográficamente se observó regresión en la artrosis en el 62.5 por ciento de los casos. El ángulo CE de Wiberg fue 8.7º preoperatoriamente y se llevó hasta 24º promedio postoperatorio, el ángulo de Sharp tuvo un valor promedio de 49.1º y se logró corregir hasta 43.1º promedio postoperatorio. Los resultados preliminares de este tipo de cirugía como solución "Biológica" son alentadores sobre todo en los casos de displasia grado II y III. Conclusión. Es un tratamiento quirúrgico adecuado ya que provoca regresión de los cambios degenerativos, al mejorar el rango de movilidad y patrón de marcha

Abordaje lateral directo vs abordaje posterolateral en artroplastía total primaria de la cadera / Lateral versus postero-lateral approach for primary total hip replacement

La elección de la vía de acceso a la articulación de la cadera puede parecer de fácil decisión sin embargo deben considerarse aspectos importantes que nos brindan una mayor exposición, seguridad y éxito en la colocación del implante. El objetivo es determinar los eventos no deseados en la realización de la vía de acceso a la articulación de la cadera y que aumentaron la morbilidad de los pacientes en la artroplastía total de la cadera. Se revisaron 267 pacientes en el periodo de marzo de 1993 a diciembre de 1997 todos con artroplastía total primaria de la cadera, utilizando abordaje lateral directo en 153 de los cuales 25 (9.36 por ciento) cursaron con insuficiencia del glúteo medio. El abordaje posterolateral se hizo en 114 pacientes presentando en su evolución postoperatoria paresia del nervio ciático en 12 (4.49 por ciento). Estos como principales eventos no deseados y secundarios a la realización del abordaje. La elección del abordaje no influyó en los resultados para la colocación del implante ya que los dos tipos dan amplia exposición, las lesiones que se presentaron son dependientes de la habilidad del cirujano por lo que la elección depende de la habilidad quirúrgica del cirujano para el manejo de las estructuras anatómicas que se exponen

Complicaciones transoperatorias en la artroplastía total de la cadera no cementada / Transoperative complications in non-cemented total hip arthroplasty

El objetivo es determinar y analizar las causas de las complicaciones que se presentaron durante la colocación de la artroplastía total de cadera no cementada en el periodo comprendido entre 1987 a 1997. Se seleccionaron todos aquellos que presentaron alguna complicación transoperatoria que en algún momento pusiera en riesgo el éxito de la cirugía, con un total de 93 pacientes y un total de 97 prótesis colocadas (100 por ciento). En 15 casos (15.46 por ciento) hubo mala orientación inexistencia del componente adecuado 8 casos (8.24 por ciento), migración de los tornillos de fijación un caso (1.01 por ciento), luxación transoperatoria por mala orientación de algún componente 18 casos (18.55 por ciento), complicaciones femorales por mala orientación 8 casos (8.24 por ciento), inexistencia del componente adecuado 21 casos(21.64 por ciento), falsa vía 2 casos (2.06 por ciento), fractura lineal femoral 23 casos (23.l71 por ciento). Las complicaciones transoperatorias deben considerarse en la planificación preoperatoria, la experiencia del cirujano y la existencia de implantes con disponibilidad transoperatoria de componentes protésicos con numeración completa

Endoprótesis femoral cementada: procedimiento de elección en las fracturas intertrocantéreas de cadera en el viejo / Cemented femoral endoprosthesis. Election treatment for inter-trochanteric fractures of the hip in the elderly

En los últimos años se ha incrementado el índice de traumatismos y en el paciente viejo con gran frecuencia se afecta la extremidad inferior la cadera. El objetivo principal de este trabajo es brindar y apoyar un tipo de tratamineto que le ofrece al paciente la más pronta reincorporación a sus actividades. Se revisaron 53 pacientes de enero de 1987 a noviembre de 1994, todos con el diagnóstico de fractura intertrocantérea de la cadera, de acuerdo con la clasificación de Tronzo; todos mayores de 60 años y tratados con endoprótesis femoral cementada de primera intención; fueron 53 pacientes cuyo sexo fue en 44 femenino y en nueve masculino. Predominaron las fracturas grado III con 20 casos (37.73 por ciento) y 16 casos (30.18 por ciento) fueron grado II. La edad promedio fue de 78 años; el tiempo quirúrgico promedio fue de 71 minutos, con un sangrado promedio de 255 ml. La capacidad funcional postoperatoria inmediata fue según la escala de Merle D'Aubigné II (20.75 por ciento), IV (32.07 por ciento) y VI (47.16 por ciento). La fecha de inicio de la marcha fue de menos de una semana en 49 pacientes (92.45 por ciento) y más de una semana en cueatro (7.5 por ciento); la reincorporación a sus actividades se logró en el 84.90 por ciento antes de un mes

Fiebre prolongada en el niño / Prolonged fever in the child

Se estudiaron 100 pacientes en el Hospital Pediátrico Docente "William Soler", por fiebre prolongada (de 15 o más días de duración) en el periodo de abril de 1983 a noviembre dew 1987. Las causas infecciosas (40%) fueron las más frecuentes, con predominio de los procesos localizados en el tracto respiratorio alto. En las causas no infecciosas (31%) predominaron las conectivopatías, seguidas por los procesos tumorales. El 29% quedó como causa no precisada, aunque se sospecharon causas infecciosas virales o bacterianas que no pudieron confirmarse. Los datos semiográficos de la fiebre fueron útiles para el diagnóstico de cada paciente, en particular cuando se correlacionaron con otros datos de la anamesis y del examen físico detallado y repetido. El diagnóstico definitivo fue realizado sobre bases clínicas en el 91,5% de los pacientes y en la confirmación de dicho diagnóstico colaboraron la radiografía, ultrasonido, ecocardiografía y la tomografía computarizada, así como la microbiologìa y la anatomìa patológica. Entre los exámenes de laboratorio clìnico, la eritrosedimentaciòn y el preteinograma fueron de la mayor utilidad. El buen estado general del paciente se conservó el 76 % de las veces