[Hospitalization trends of neuropsychiatric disorders in a middle-income country]. / Tendencias en hospitalización de trastornos neuropsiquiátricos en un país de ingresos medios.

BACKGROUND: Neuropsychiatric disorders represent one of the first causes of disability worldwide. Recognizing the main causes for hospitalization may allow the implementation of interventions to prevent hospitalization and promote ambulatory care. OBJECTIVE: To describe the trends of mental disorders requiring hospitalization in a neuropsychiatric referral center of a middle-income country. MATERIAL AND METHODS: Observational, cross-sectional, and analytic study. Information was obtained from dismissal letters and from the Department of Epidemiology database in a 16-year period at a neuropsychiatric referral center. Diagnoses and trends through this period were obtained using Spearman's correlation. RESULTS: Schizophrenia represented most of the cases (19%), followed by bipolar disorder (13%). Psychotic disorders (PD) were found to contribute the most to the length of stay (43.76%), followed by mood disorders (MD) (39.07%). Schizophrenia-related dismissals diminished through the years (r = -751; p = 0.001), whereas depression-related disorders increased (r = 0.857; p < 0.001). CONCLUSIONS: PD are the first cause of neuropsychiatric hospitalization. MD have an increasing frequency of hospitalization. Longer-stay disorders reflect global and economic burden of disease trends. These results might guide interventions that reduce hospital-based models of care, which represent a great burden in low and middle-income countries. Studies aiming to explain the trends reported are needed.

INTRODUCCIÓN: los trastornos neuropsiquiátricos son una de las primeras causas de discapacidad a nivel mundial. Reconocer las principales causas de hospitalización puede permitir implementar intervenciones para evitar la hospitalización y promover un mejor cuidado ambulatorio. OBJETIVO: describir las tendencias en trastornos mentales que requieren hospitalización en un centro de referencia neuropsiquiátrico en un país de ingresos medios. MATERIAL Y MÉTODOS: estudio observacional, transversal y analítico. Se obtuvo información de hojas de egreso y de la base de datos del Departamento de Epidemiología de un centro neuropsiquiátrico en un periodo de 16 años, y las tendencias con el coeficiente de correlación de Spearman. RESULTADOS: la esquizofrenia (ESQ) representó la mayoría de los casos (19%), seguida del trastorno bipolar (13%). Los tranos psicóticos (TP) (43.76%) y los trastornos afectivos (TA) (39.07%) contribuyeron a la mayoría de los días intrahospitalarios. Las hospitalizaciones por ESQ disminuyeron a lo largo de los años (r = −751; p = 0.001) y las relacionadas con depresión aumentaron (r = 0.857; p < 0.001). CONCLUSIONES: los TP son la primera causa de hospitalización neuropsiquiátrica. Los TA tienen una frecuencia de hospitalización ascendente. Los trastornos asociados con una estancia mayor reflejan tendencias globales de carga de enfermedad y económica. Estos resultados pueden guiar intervenciones que reduzcan modelos basados en hospitalización, que representan una carga en países de bajo a medio ingreso. Se requieren estudios que expliquen estas tendencias.

Impact of a Movement Disorders Clinic on the trends of Parkinson's Disease Consultations at a Tertiary Referral Center.

BACKGROUND: Outpatient clinics for movement disorders provide specialized diagnosis and treatment services for the specific needs of this patient population. OBJECTIVE: Describe the impact of implementing a Movement Disorder Clinic on the trends of consultations per year and hospitalizations of subjects with Parkinson's disease at a tertiary referral center. METHODS: A retrospective study was carried out. We collected data from the Clinical File Archive and the Epidemiology Department at the National Institute of Neurology and Neurosurgery in Mexico. Data from January 1, 1999 through December 31, 2015 were included for analysis. RESULTS: The number of total consultations had an increase of 632.1% between 1999 and 2015. Follow-up visits represented up to 95% of the consultations. Peaks found correlated with the inclusion of new specialists in the clinic. Regarding hospitalization, the number of patients discharged with a diagnosis of Parkinson's disease increased from a median of 17 (range 9-35) to 46 patients (range 31-53) per year. CONCLUSIONS: The implementation of a multidisciplinary Movement Disorders Outpatient Clinic in a tertiary referral center had a direct impact on the total number of consultations per year, mainly follow-up visits. The latter may reflect in an improvement in the quality of care.

Historical distribution of central nervous system tumors in the Mexican National Institute of Neurology and Neurosurgery.

OBJECTIVE: To determine the frequency of central nervous system (CNS) tumors in the first fifty years of the National Institute of Neurology and Neurosurgery of Mexico Manuel Velasco Suárez (Instituto Nacional de Neurología y Neurocirugía de México, INNN) from 1965 to 2014. MATERIALS AND METHODS: A total of 16 116 institutional records of CNS tumors were analyzed. The frequency and distribution of CNS tumors were evaluated by tumor type, patient age and patient gender. The annual relationship between CNS tumors and surgical discharges (SD) over the last 20 years was estimated. RESULTS: The frequencies of most CNS tumors were consistent with those found worldwide, and the most common tumors were neuroepithelial tumors (33%), particularly astrocytic tumors (67%); meningeal tumors (26%); and pituitary tumors (20%). The incidence of pituitary tumors in these data was twice as high as that reported in other regions of the world, and the relationship between CNS tumors and SD was consistent over time (0.22-0.39). CONCLUSION: This study summarizes the largest sample of CNS tumor cases analyzed in Mexico and provides an important reference of the frequency of this tumor type in the country. This work will serve as a basis for conducting studies evaluating factors associated with the presence of CNS tumors and for identifying adequate public health interventions.

Historical distribution of central nervous system tumors in the Mexican National Institute of Neurology and Neurosurgery / Distribución histórica de neoplasias del sistema nervioso central en el Instituto Nacional de Neurología y Neurocirugía de México

Abstract Objective: To determine the frequency of central nervous system (CNS) tumors in the first fifty years of the National Institute of Neurology and Neurosurgery of Mexico Manuel Velasco Suárez (Instituto Nacional de Neurología y Neurocirugía de México, INNN) from 1965 to 2014. Materials and methods: A total of 16 116 institutional records of CNS tumors were analyzed. The frequency and distribution of CNS tumors were evaluated by tumor type, patient age and patient gender. The annual relationship between CNS tumors and surgical discharges (SD) over the last 20 years was estimated. Results: The frequencies of most CNS tumors were consistent with those found worldwide, and the most common tumors were neuroepithelial tumors (33%), particularly astrocytic tumors (67%); meningeal tumors (26%); and pituitary tumors (20%). The incidence of pituitary tumors in these data was twice as high as that reported in other regions of the world, and the relationship between CNS tumors and SD was consistent over time (0.22-0.39). Conclusion: This study summarizes the largest sample of CNS tumor cases analyzed in Mexico and provides an important reference of the frequency of this tumor type in the country. This work will serve as a basis for conducting studies evaluating factors associated with the presence of CNS tumors and for identifying adequate public health interventions.

Resumen Objetivo: Determinar la frecuencia de neoplasias del sistema nervioso central (NSNC) en los primeros 50 años del Instituto Nacional de Neurología y Neurocirugía de México (INNN). Material y métodos: Se analizaron 16 116 registros institucionales de las NSNC, atendidas en el INNN de 1965 a 2014; se estimó su frecuencia y distribución por tipo de neoplasia, edad y género, y se determinó la relación anual de NSNC y egresos quirúrgicos (EQ) en un período de 20 años. Resultados: Las frecuencias de la mayoría de NSNC fueron consistentes con las encontradas a nivel mundial. Las más frecuentes fueron las neuroepiteliales (33%), entre las cuales destacaron las astrocíticas (67%); meníngeas (26%), e hipofisiarias (20%). El número de neoplasias hipofisiarias en esta serie fue dos veces mayor al reportado en otras regiones del mundo y la relación NSNC/EQ fue similar a través del tiempo (0.22-0.39). Conclusión: Ésta es la mayor serie de casos de NSNC analizados en México y proporciona un referente importante sobre la frecuencia de este tipo de neoplasias en el país. Este trabajo servirá de base para llevar a cabo estudios de los factores asociados a la presencia de NSNC e identificar intervenciones de salud pública adecuadas.

El trabajo y los Tumores del Sistema Nervioso Central, en población de la ciudad de México / The work and the Central Nervous System tumors in population of Mexico city

El cáncer es un padecimiento que se incrementa en todo el mundo. Existen factores de riesgo bien identificados, no obstante, su aparición es controvertida. Los Tumores del Sistema Nervioso Central (TSNC) son un grupo de neoplasias, no se conoce su causa, algunos autores señalan exposiciones ambientales, causas genéticas y la ocupación; no existen estudios que evalúen el proceso del trabajo en relación a los riesgos y exigencias laborales y la presencia de los TSNC. Se realizó un estudio de casos y controles. Se incluyeron TSNC del Instituto Nacional de Neurología y Neurocirugía de la Ciudad de México. Se obtuvo información de factores de riesgo ambientales, y de riesgos y exigencias laborales. Se calcularon frecuencia simples, razones de momios e intervalos de confianza al 95%, se consideró estadísticamente significativo una p≤0.05, se realizó regresión logística condicional. Se encontró una asociación entre la presencia de los TSNC y las actividades que demandan niveles altos de atención [RM = 4,25; IC 95% (2,44-7,38)] p = 0,001, así como entre el empleo de fertilizantes e insecticidas y el lugar de residencia (p<0,05). Se debe profundizar en el estudio de las exigencias laborales que demandan intensos niveles de atención y concentración y su relación con el estrés y los daños a la salud.

Cancer is increasing worldwide. There are wellestablished risk factors; however, their appearance is controversial. Tumors of the central nervous system (CNST) are a group of neoplasms of unkown cause, and some authors suggest environmental exposures, genetic factors and occupation as possible causal factors, yet, there are no studies evaluating the risks and demands of work and the presence of CNST. A case-control study was performed, using. CNST from the National Institute of Neurology and Neurosurgery of Mexico City. Information on environmental risk factors, and workplace hazards and demands was obtained. Simple frequency, odds ratios and 95% confidence intervals were calculated, with statistical significance set at p ≤ 0.05, using conditional logistic regression. An association between the presence of CNST and activities that require high levels of care was found [OR = 4.25; (95% CI 2.44 to 7.38)] p = 0.001, and between the use of fertilizers and insecticides and place of residence (p <0.05). Further study of the association between those job requirements that require high levels of attention and concentration and both stress and adverse health effects.

[Neurological disease surveillance and mandatory reporting: a trend and outcome of the national neurological institute of health in mexico city from 2005 to 2011]. / Enfermedades neurológicas de vigilancia y notificación obligatoria: tendencia y desenlace en un Instituto Neurológico del Sistema Nacional de Salud de la Ciudad de México, de 2005 a 2011.

INTRODUCTION: There is regulated study and mandatory reporting of epidemiological surveillance of diseases worldwide. However, it is difficult to observe the behavior of conditions especially over time, and especially when it comes to diseases that are addressed by their severity in tertiary care units. OBJECTIVE: Describe and analyze the behavior of the major communicable neurological diseases subject to epidemiological surveillance for a period of seven years in the main National Institution of Health that takes in neurological, neurosurgical and psychiatric disorders in Mexico. The main conditions that are handled and reported were acute inflammatory polyneuropathy (Guillain Barre Syndrome) and viral encephalitis, 19.7 and 18.5%, respectively. The condition showing a tendency to decrease was neurocysticercosis, and conditions most strongly associated with mortality were diseases associated to the human immunodeficiency virus and unspecified viral encephalitis. The conditions were more frequent especially in men in the age group 25 to 44 years old. It is necessary to stress the importance of timely reporting of diseases under epidemiological surveillance in Mexico, since knowledge of the behavior of action allows decisions at all levels of care.

[Coping with medical residency: depression burnout]. / Afrontando la residencia médica: depresión y burnout.

UNLABELLED: Among the most prevalent psychiatric disorders, major depressive disorder is related with high incapacity levels, affecting also physical and mental health, and social, family, and work activities (burnout). OBJECTIVES: This study assessed possible damage and emotional changes in a cohort of recently incoming medical residents to the postgraduate courses of the National Institute of Neurology and Neurosurgery of Mexico City. MATERIALS AND METHODS: We collected information on sociodemographic data, and we applied two instruments: the scale of Maslach Burnout Inventory (MBI-HS) and the Beck Depression Inventory (BDI). Candidates were followed over time, at six and 12 months afterwards. RESULTS: When the authors analyzed depressive symptoms, they found that the percentage of medical residents without depression at baseline was 97.7% and at the second application, this percentage decreased statistically (p = 0.008) and yet there was an increase in mild depressive symptoms (p = 0.017). With respect to MBI-HS, there was high emotional exhaustion with a significant increase at six months after arrival. The psychiatry residents were those more affected. CONCLUSIONS: Exploratory research is needed to be performed among residents to detect depressive symptoms and burnout syndrome, to act in a timely manner and prevent the progression of these diseases.

Epidemiology and trend of neurological diseases associated to HIV/AIDS. Experience of Mexican patients 1995-2009.

OBJECTIVE: The aim of this study was to identify the main neurological conditions associated with HIV/AIDS in Mexican patients treated at the National Institute of Neurology and Neurosurgery (NINN) in Mexico city, the main referral center for patients with disorders of the central and peripheral nervous system. METHODS: An observational, transversal and descriptive analysis was performed. We reviewed the databases from the Department of Epidemiology and the medical records of patients with AIDS seen during the period from January 1st, 1995 to December 31, 2009. RESULTS: 320 patients were detected, the main conditions related to HIV/AIDS were brain toxoplasmosis (42%), cerebral criptoccocosis (28%), tuberculous meningitis (8.7%), linfoma no Hodking (3.75%), acute HIV infection (3.4%) and AIDS dementia complex (3%). No specific trend on morbility and mortality were detected during the period of study. CONCLUSIONS: In Mexico the most common neurological complications of HIV/AIDS are opportunistic infections.

[Overview of hospital mortality at the National Institute of Neurology and Neurosurgery of Mexico City]. / Panorama de la mortalidad hospitalaria en el Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" de la ciudad de México.

BACKGROUND: Knowing the mortality of the population that goes to medical care, allows to the hospitals institutions and the government to make decisions on the services of health and the conditions of attention. Our objective was to describe the frequency and trend of the main causes of neurological hospital mortality for the period 2002-2007 in the National Institute of Neurology andNeurosurgery "Manuel Velasco Suárez". METHODS: The data was obtained from hospital discharge registers and medical records. Rates of hospital mortality and the tendency were calculated during the period of study. RESULTS: The overall mortality rate was 4.9 per each 100 discharges. The leading causes of death were cerebrovascular diseases and brain tumors and there was a tendency for increased mortality in cases associated with human immunodeficiency virus (HIV) for men p = 0.004 and p = 0.05 for women with epilepsy, and with a status of epileptic condition. CONCLUSIONS: The cerebrovascular diseases and brain tumors tend to hold the first places. The mortality for neurological complications resulting from the diseases caused by the HIV is increasing. It is necessary to promote programs to prevent cardiovascular and HIV infection risk factors, to decrease the mortality rates from these diseases.

Creutzfeldt-Jakob disease in Mexico.

Creutzfeldt-Jakob disease (CJD) is classified within the group of transmissible spongiform encephalopathies (TSE). It is a rapidly progressive illness that affects mental functions. The average age of onset is 50 years. Various tests can help orient the clinical diagnosis, but the confirmatory test is still the post mortem analysis. The aim of this study was to describe the epidemiological, clinical and histopathological characteristics of patients diagnosed as suffering from CJD, at the National Institute of Neurology and Neurosurgery of Mexico (NINN). An observational, descriptive and transversal study was conducted. We collected information concerning these cases from the Departments of Epidemiology and Pathology, as well as the clinical charts of the patients with a diagnosis of CJD. Fifteen cases were registered of which three CJD cases were definite, five probable cases were identified, and seven were possible. The average age of the patients was 49 years. Two definite cases were female and one was male. It is important to improve the systems for surveillance of this type of disease and, furthermore, to permit greater accessibility to laboratories where the procedures necessary for supporting diagnosis can be followed.

Magnetic fields and acute leukemia in children with Down syndrome.

BACKGROUND: : We analyzed effects of exposure to magnetic fields on the expression of acute leukemia in children with Down syndrome (who have a 20-fold higher risk of leukemia). METHODS: : We performed a case-control study that included 42 children with both acute leukemia and Down syndrome as cases and 124 healthy children with Down syndrome as controls. We obtained demographic information concerning the children and took spot measurements of magnetic fields at each residence. RESULTS: : The odds ratio for direct measurements of magnetic fields >/=6.00 mG was 3.7 (95% confidence interval = 1.05-13.1). CONCLUSION: : The association between magnetic fields and leukemia in children with Down syndrome suggests the possibility of a causal role for magnetic fields in the etiology of leukemia among a genetically susceptible subgroup of children.

[Hospital mortality at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (1995-2001)]. / Mortalidad hospitalaria en el Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" (1995-2001).

UNLABELLED: To improve health policies directed toward ameliorating quality and also to characterize the profile of patients who attend medical centers, it is necessary to determine causes of mortality in any healthcare organization. OBJECTIVE: To analyze time-trend hospital mortality at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (MVS-NINN) between 1995 and 2001. METHODS: Data were taken from database of morbidity, and mortality of MVS-NINN. All cases were coded by the International Classification of Disease (10th edition). We calculated specific rates of mortality and time-trends during a 7-year-period. RESULTS: When main causes of mortality were included in these analyzes, rates of hospital mortality at MVS-NINN showed a non-significant tendency to decrease during this period. CONCLUSIONS: Decline of mortality time-trend is generally in accordance with increasing life expectancy of Mexican population; this increase is due to progress in medical knowledge and to new technological and therapeutic advances, especially in the third level institutions such as this institute.

Mortalidad hospitalaria en el Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" (1995-2001) / Hospital Mortality at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (1995-2001)

Determinar las causas de muerte en cualquier institución de salud contribuye a la toma de decisiones encaminadas a mejorar los servicios de salud, así como para conocer el perfil de la población que acude a recibir atención médica. Objetivo: analizar la mortalidad hospitalaria y su tendencia durante el periodo de 1995-2001 en el Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" (INNN-MVS). Material y métodos: se utilizó la base de datos con la que cuenta el Departamento de Epidemiología del INNN-MVS, que se encuentra codificada de acuerdo a la Clasificación Internacional de Enfermedades décima versión (CIÉ-10). Se calcularon las diferentes tasas de mortalidad y se determinó su tendencia a través del período de siete años. Resultados: las principales causas de mortalidad durante el periodo de estudio fueron las hemorragias intraencefálicas y las subaracnoideas. En general se encontró una tendencia a la disminución en las principales causas de mortalidad. Conclusiones: la tendencia a la disminución concuerda con el incremento en la esperanza de vida de nuestra población, situación que se ha presentado por el progreso en los conocimientos médicos y a las nuevas técnicas diagnósticas y terapéuticas con las que cuenta una institución de tercer nivel de salud, como lo es el INNN-MVS.

To improve health policies directed toward ameliorating quality and also to characterize the profile of patients who attend medical centers, it is necessary to determine causes of mortality in any healthcare organization. Objective: To analyze time-trend hospital mortality at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (MVS-NINN) between 1995 and 2001. Methods: Data were taken from database of morbidity and mortality of MVS-NINN. All cases were coded by the International Classification of Disease (10th edition). We calculated specific rates of mortality and time-trends during a 7-year-period. Results: When main causes of mortality were included in these analyzes, rates of hospital mortality at MVS-NINN showed a non-significant tendency to decrease during this period. Conclusions: Decline of mortality time-trend is generally in accordance with increasing life expectancy of Mexican population; this increase is due to progress in medical knowledge and to new technological and therapeutic advances, especially in the third level institutions such as this institute.

[Morbility at the Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, 1995-2001]. / Morbilidad en el Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" 1995-2001.

UNLABELLED: Hospital statistics are very important as tools that help to define research objectives and design health programs. OBJECTIVE: To determine the main causes of hospital morbility at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (MVS-NINN) between 1995 and 2001. MATERIAL AND METHODS: Data were taken from the electronic database of morbidity and mortality of MVS-NINN. All outpatient records between 1995 and 2001 were considered. We calculated trends and specific rates of morbidity per 100 discharged patients. RESULTS: The main causes of morbility were brain tumors, schizophrenic illness, neurocysticercosis, and stroke. We found a statistically significant declining time-trend of schizophrenic illness and in non-traumatic brain hemorrhage in males. In the case of females, we observed an increasing time-trend of benign meningeal tumors. The age groups more affected in both genders were those < 51 years of age. CONCLUSIONS: This study is not a population study, but it helps to increase knowledge of the main causes of hospitalization at one of the most important neurologic institutions in the world, which provides care for thinsured population throughout Mexico. These findings facilitate analysis and decision-making to undertake specifications to improve the quality of neurologic medical attention.

Morbilidad en el Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" 1995-2001

La estadística hospitalaria es una herramienta que brinda apoyo a directivos, residentes e investigadores para conocer la demanda de atención médica en cada hospital o Instituto de Salud. Objetivo: identificar las principales causas de morbilidad hospitalaria del Instituto Nacional de Neurología Neurocirugía Manuel Velasco Suárez (INNN-MVS) ocurridas en el período 1995-2001. Material y métodos: análisis retrospectivo de egresos ocurridos de 1995 a 2001 de la base de datos de morbilidad y mortalidad del INNN-MVS; se calcularon tasas específicas de morbilidad por 100 egresos y tendencias. Resultados: las principales causas de morbilidad fueron tumores cerebrales, esquizofrenia, neurocisticercosis y evento vascular cerebral. Se encontró una tendencia hacia la disminución con los años estadísticamente significativa en esquizofrenia y hemorragias intracraneales no traumáticas en el sexo masculino y para el sexo femenino, una tendencia hacia el aumento en tumores benignos de las meninges. Los grupos de edad más atendidos por las principales causas de morbilidad fueron los menores de 51 años. Conclusiones: el presente no es un estudio poblacional, pero permite acercarnos a conocer las principales demandas de atención de uno de los Institutos neurológicos más grandes del mundo, que atiende a población abierta y derechohabiente de todo el país. Esto contribuye a clarificar el panorama para determinar necesidades de atención médica neurológica.

Hospital statistics are very important as tools that help to define research objectives and design health programs. Objective: to determine the main causes of hospital morbility at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (MVS-NINN) between 1995 and 2001. Material and Methods: data were taken from the electronic database of morbidity and mortality of MVS-NINN. All out-patient records between 1995 and 2001 were considered. We calculated trends and specific rates of morbidity per 100 discharged patients. Results: the main causes of morbility were brain tumors, schizophrenic illness, neurocysticercosis, and stroke. We found a statistically significant declining time-trend of schizophrenic illness and in non-traumatic brain hemorrhage in males. In the case of females, we observed an increasing time-trend of benign meningeal tumors. The age groups more affected in both genders were those < 51 years of age. Conclusions: This study is not a population study, but it helps to increase knowledge of the main causes of hospitalization at one of the most important neurologic institutions in the world, which provides care for thinsured population throughout Mexico. These findings facilitate analysis and decision-making to undertake specificactions to improve the quality of neurologic medical attention.

Clinical-histopathologic concordance of tumors of the nervous system at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery in Mexico City.

CONTEXT: When making a diagnosis, the main purpose of clinicians should not be to achieve certainty, but to decrease diagnostic uncertainty in order to make optimal therapeutic decisions. Diagnostic concordance is an essential characteristic if a measurement is to be considered scientific. In the case of tumors of the nervous system (TNS), one of the most accurate diagnostic tests is magnetic resonance imaging. However, histopathologic analyses are essential, because they refine the diagnosis, benefit the patient, and improve our understanding of the disease. By determining the clinical-histopathologic correlation of TNS in one of the main neurologic centers in Mexico, we sought to project reliable morbidity and/or mortality statistics. OBJECTIVE: To assess clinical and histopathologic diagnostic agreement in cases involving TNS admitted to the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery between 1990 and 1999. DESIGN: Cross-sectional diagnostic concordance study, including all clinical hospital records of patients with histopathologically diagnosed TNS, classified according to World Health Organization criteria. RESULTS: Among 2041 TNS cases, the 3 most frequent types were those affecting the neuroepithelial tissue (32.9%), tumors of the sellar region (29.2%), and tumors of the meninges (25.6%). We found that, overall, clinical-histopathologic concordance for these 3 categories was substantial and statistically significant. CONCLUSIONS: Tumors of the nervous system constitute a heterogeneous group of neoplasms. In the present study, clinical diagnoses substantially agreed with pathologic diagnoses. The a priori clinical diagnosis allowed prompt treatment even before diagnostic confirmation by histopathologic analysis, which is the best way to confirm, clarify, and correct a diagnosis.

Evaluación del estado de nutrición de pacientes atendidos en la consulta externa del Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez / Evaluation of nutritional state of out patients in the National Neuroloagical Institute

La nutrición puede influir en el riesgo de una gran variedad de enfermedades e inversamente la enfermedad puede dar como resultado alteraciones nutricionales. La evaluación nutricional, es esencial para identificar aspectos de malnutrición que se manifiesta de manera general como desnutrición u obesidad. El presente trabajo evaluó el estado de nutrición de pacientes que se atienden en la consulta externa del Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez e identificar a los pacientes que son referidos a la consulta de nutrición por presentar alteraciones nutricionales de acuerdo a la opinión del médico tratante. Se estudiaron 100 sujetos con edades >50 años, ambos géneros, que acudían por primera vez a consulta del INNNMVS, durante un año. La información se recolectó mediante una cédula que evaluaba aspectos nutricios, mediciones y cálculo de estimaciones antropométricas, se obtuvieron parámetros bioquímicos y se aplicó una encuesta de dieta habitual. Se encontró que los pacientes que acuden a consulta tienen problemas de malnutrición: desnutrición 3 por ciento, obesidad 38 por ciento y riesgo de desnutrición 42 por ciento, pero pocos son reconocidos por sus médicos. Debido a las implicaciones nutricionales como anorexia, disfagia, dificultad para masticar, pérdida de peso, aumento en el gasto de energía, que pueden presentarse en patologías neurológicas que frecuentemente se atienden en el INNN, es importante que el médico los detecte tempranamente y se canalicen a la consulta de nutrición para ser atendidos y contribuir de esta forma a su recuperación y mejorar su calidad de vida.

El tamaño de muestra: un enfoque práctico en la investigación clínica pediátrica / Sample size: a practical viewpoint in pediatric clinical research

El obejtivo del presente artículo es proporcionar al médico las bases conceptuales y prácticas que le permitan calcular el tamaño de muestra en estudios clínicos. Se presentan las definiciones de los diferentes diseños clínicos, incidencia, prevalencia, error tipo I y II, riesgo relativo y razón de momios. Se desarrolla la respuesta a 4 preguntas: 1) ¿Cuando es necesario calcular un tamaño de muestra?, 2) ¿Qué significa la representatividad de una muestra?. 3) ¿Cuál es el tamaño de muestra mínimo que se necesita para probar una determinada hipótesis?, y 4) ¿Cómo saber si el tamaño de muestra que ya se obtuvo era suficiente para el propósito del estudio? Se presentan también las fórmulas para el cálculo del tamaño de la muestra para los ensayos clínicos aleatorizados, estudios de cohortes, casos y controles y transversales. Finalmente se muestra la utilidad de calcular el poder de la muestra cuando se ha terminado un estudio y no se encontró una asociación estadísticamente significativa