Long-term surgical results of supplementary motor area epilepsy surgery.

OBJECTIVE Supplementary motor area (SMA) epilepsy is a well-known clinical condition; however, long-term surgical outcome reports are scarce and correspond to small series or isolated case reports. The aim of this study is to present the surgical results of SMA epilepsy patients treated at 2 reference centers in Mexico City. METHODS For this retrospective descriptive study (1999-2014), 52 patients underwent lesionectomy and/or corticectomy of the SMA that was guided by electrocorticography (ECoG). The clinical, neurophysiological, neuroimaging, and pathological findings are described. The Engel scale was used to classify surgical outcome. Descriptive statistics, Student t-test, and Friedman, Kruskal-Wallis, and chi-square tests were used. RESULTS Of these 52 patients, the mean age at epilepsy onset was 26.3 years, and the mean preoperative seizure frequency was 14 seizures per month. Etiologies included low-grade tumors in 28 (53.8%) patients, cortical dysplasia in 17 (32.7%) patients, and cavernomas in 7 (13.5%) patients. At a mean follow-up of 5.7 years (range 1-10 years), 32 patients (61%) were classified as Engel Class I, 16 patients (31%) were classified as Engel Class II, and 4 (8%) patients were classified as Engel Class III. Overall seizure reduction was significant (p = 0.001). The absence of early postsurgical seizures and lesional etiology were associated with the outcome of Engel Class I (p = 0.05). Twenty-six (50%) patients had complications in the immediate postoperative period, all of which resolved completely with no residual neurological deficits. CONCLUSIONS Surgery for SMA epilepsy guided by ECoG using a multidisciplinary and multimodality approach is a safe, feasible procedure that shows good seizure control, moderate morbidity, and no mortality.

Las dos caras del reflejo venoarteriolar: vasoconstricción y vasodilatación cutánea al bajar y subir el brazo / The two faces of veno-arteriolar reflex: cutaneous vasodilatation and vasoconstriction to raise and to lower the arm

Introducción. El reflejo venoarteriolar (RVA) lo provoca un incremento en la presión venosa transmural al colocar una parte del cuerpo en el sentido de la aceleración gravitatoria por debajo del corazón. Objetivo. Evaluar el RVA en sujetos sanos al levantar una parte del cuerpo por encima del corazón. Sujetos y métodos. En 16 sujetos sanos (20-65 años) se estudió el RVA mediante cambios en el flujo sanguíneo de la piel con un fotopletismógrafo digital infrarrojo colocado en el pulpejo en sujetos sanos durante las siguientes condiciones: brazo derecho a la altura del corazón, brazo derecho 40 cm por debajo del corazón y brazo derecho 40 cm por encima del corazón. Las variables medidas fueron: amplitud del flujo sanguíneo de la piel con el brazo a la altura del corazón (amplitud basal), porcentaje de disminución del flujo sanguíneo de la piel con el brazo por debajo del corazón y porcentaje de aumento del flujo sanguíneo de la piel con el brazo por encima del corazón. Resultados. El porcentaje de vasoconstricción con el brazo derecho por debajo del corazón fue del 35%, y el de vasodilatación, del 50%. Conclusiones. La evaluación del RVA con el brazo por debajo del corazón provoca vasoconstricción, y la elevación del brazo produce una importante vasodilatación. La vasoconstricción y la vasodilatación se mantienen mientras la extremidad se mantenga por encima o por debajo del corazón. Éste es un estudio potencialmente muy útil y económico para estudiar la inervación de la microcirculación en diversas neuropatías periféricas de fibras delgadas y mixtas (AU)

Introduction. The veno-arteriolar reflex (VAR) is triggered by an increase in the transmural venous pressure on placing a part of the body in the same direction as the gravitational acceleration below the heart. Aim. To assess the VAR in healthy subjects on raising a part of the body above the level of the heart. Subjects and methods. VAR was studied in 16 healthy subjects (20-65 years old) by means of changes in the blood flow in the skin detected using a digital infrared photoplethysmograph attached to the fingertip under the following conditions: right arm at the height of the heart, right arm below the heart and right arm below the level of the heart. The variables measured were: amplitude of the blood flow in the skin with the arm raised to the height of the heart (baseline amplitude), percentage decrease of the blood flow in the skin with the arm below the heart and percentage increase in blood flow with the arm above the heart. Results. The percentage of vasoconstriction with the right arm below the heart was 35%, and that of vasodilation, 50%. Conclusions. Evaluation of the VAR with the arm below the heart causes vasoconstriction, and elevation of the arm causes an important degree of vasodilation. Vasoconstriction and vasodilation are maintained while the limb is kept above or below the heart. This is an economical and potentially very useful way of studying the innervation of the microcirculation in a number of different peripheral neuropathies of thin and mixed fibres (AU)

Heart Rate and Systolic Blood Pressure Variability in the Time Domain in Patients with Recent and Long-Standing Diabetes Mellitus.

Diabetes Mellitus (DM) affects the cardiovascular response of patients. To study this effect, interbeat intervals (IBI) and beat-to-beat systolic blood pressure (SBP) variability of patients during supine, standing and controlled breathing tests were analyzed in the time domain. Simultaneous noninvasive measurements of IBI and SBP for 30 recently diagnosed and 15 long-standing DM patients were compared with the results for 30 rigorously screened healthy subjects (control). A statistically significant distinction between control and diabetic subjects was provided by the standard deviation and the higher moments of the distributions (skewness, and kurtosis) with respect to the median. To compare IBI and SBP for different populations, we define a parameter, α, that combines the variability of the heart rate and the blood pressure, as the ratio of the radius of the moments for IBI and the same radius for SBP. As diabetes evolves, α decreases, standard deviation of the IBI detrended signal diminishes (heart rate signal becomes more "rigid"), skewness with respect to the median approaches zero (signal fluctuations gain symmetry), and kurtosis increases (fluctuations concentrate around the median). Diabetes produces not only a rigid heart rate, but also increases symmetry and has leptokurtic distributions. SBP time series exhibit the most variable behavior for recently diagnosed DM with platykurtic distributions. Under controlled breathing, SBP has symmetric distributions for DM patients, while control subjects have non-zero skewness. This may be due to a progressive decrease of parasympathetic and sympathetic activity to the heart and blood vessels as diabetes evolves.

Reward and aversion systems of the brain as a functional unit. Basic mechanisms and functions / Sistemas de recompensa y aversión del cerebro como una unidad funcional. Mecanismos básicos y funciones

INTRODUCTION: It is increasingly important to recognize the reward and aversion systems of the brain as a functional unit. A fundamental task of the mammalian brain is to assign an emotional/motivational valence to any stimuli by determining whether they are rewarding and should be approached or are aversive and should be avoided. Internal stimuli are also assigned an emotional/motivational valence in a similar fashion.OBJECTIVE: To understand the basic mechanisms and functions of the reward and aversion system of the brain.METHOD: A bibliographical search was conducted in the Pubmed database using different key words. Documents on relevant aspects of the topic were selected.RESULTS: In the ventral tegmental area, dopaminergic (VTA-DA) neurons play a role in reward-dependent behaviors. It is also known that the inhibition of the VTA-DA neurons by GABAergic neurons contributes to a reward prediction error calculation that promotes behaviors associated with aversion. The ventral dopaminergic mesolimbic system and the nucleus accumbens are activated during reward and inhibited during aversions. The amygdala is activated during aversive behavior.DISCUSSION AND CONCLUSION: The reward/aversion system is highly relevant for survival, which is most likely its primary function. It is involved in important pathologies such as addiction, depression and autonomic and endocrine disturbances. Therefore, its knowledge has become of clinical importance.Although great advances have been made in the knowledge of the basic mechanisms of the reward/aversion system, the detailed circuits within the VTA that mediate reward and aversion and the anatomical substrates are not completely clear.

INTRODUCCIÓN: Es muy importante reconocer el sistema de recompensa y aversión del cerebro como una unidad funcional. Una de las funciones fundamentales del cerebro de los mamíferos es la capacidad para designar un valor emocional/motivacional a cualquier estímulo. Esta capacidad permite identificar un estímulo como gratificante y aproximarnos a él, o reconocerlo como aversivo y evitarlo.OBJETIVO: Comprender los mecanismos fisiológicos del sistema de recompensa-aversión.MÉTODO: Se realizó una búsqueda bibliográfica en la base de datos Pubmed con las diferentes palabras clave. Se seleccionaron los documentos sobre los aspectos relevantes.RESULTADOS: Las neuronas dopaminérgicas del área tegmental ventral (ATV) cumplen un papel importante en los comportamientos dependientes de la recompensa. Asimismo, la inhibición de las neuronas dopaminérgicas ATV por parte de las neuronas GABAérgicas contribuye a predecir la recompensa y promueve comportamientos aversivos. Este sistema se activa durante actividades de recompensa y se inhibe durante la aversión. La amígdala es la principal estructura relacionada con la aversión.DISCUSIÓN Y CONCLUSIÓN: Este sistema se considera de gran importancia para la supervivencia de las especies, la que parece ser su función primordial. Interviene en distintas patologías como adicciones, depresión, trastorno por estrés postraumático, fobias y trastornos endocrinos y autonómicos, por lo que el conocimiento de este sistema es de gran importancia clínica.Aunque se ha avanzado mucho en el estudio y entendimiento de este sistema y de sus circuitos anatómicos ubicados en el ATV mesencefálica y sus conexiones con áreas subcorticales, el conocimiento de este sistema funcional sigue siendo un desafío científico.

[Myasthenia gravis in adults of institutions pertaining to the Mexican public health system: an analysis of hospital discharges during 2010]. / Miastenia gravis (MG) en adultos de instituciones pertenecientes al sistema público sanitario mexicano: un análisis de egresos hospitalarios durante el año 2010.

INTRODUCTION: Epidemiological studies on myasthenia gravis (MG) in Mexico is mainly derived from experiences in referral centers. OBJECTIVE: To describe the epidemiological characteristics of hospital discharges during 2010 with the diagnosis of MG in adults hospitalized in the Mexican public health system. METHODS: We consulted the database of hospital discharges during 2010 of the National Health Information System (Ministry of Health, IMSS, IMSS oportunidades, ISSSTE, PEMEX, and the Ministry of Defense). The MG records were identified by the code G70.0 of the International Classification of Diseases 10th revision. RESULTS: During 2010 there were 5,314,132 hospital discharges (4,254,312 adults). Among them, 587 (0.01%) were adults with MG (median age: 47 years, 60% women). Women with MG were significantly younger than men (median age: 37 vs. 54 years, respectively; p < 0.001). The median hospital stay was six days. The case fatality rate was 3.4%, without gender differences. Age was associated with the probability of death. CONCLUSIONS: We confirmed the bimodal age-gender distribution in MG. The in-hospital case fatality rate in Mexico is consistent with recent reports around the world.

Mortalidad asociada al diagnóstico de síndrome de Guillain-Barré en adultos ingresados en instituciones del sistema sanitario mexicano / Mortality associated with a diagnosis of Guillain-Barré syndrome in adults of Mexican health institutions

Introducción. El síndrome de Guillain-Barré (SGB) es una urgencia neurológica que constituye la principal causa de parálisis flácida en el mundo, y que afecta a todos los grupos etarios. Se desconocen notablemente las características epidemiológicas esenciales del SGB en la mayor parte de los países de América Latina. Objetivo. Determinar la mortalidad asociada con el diagnóstico de SGB en altas hospitalarias efectuadas durante el año 2010 en instituciones de la Secretaría de Salud, México. Pacientes y métodos. Se analizó la base de datos de altas hospitalarias de instituciones que pertenecen a la Secretaría de Salud. Se identificaron los casos de SGB mediante el código G61.0 de la Clasificación Internacional de Enfermedades, 10.ª revisión (CIE-10). Se excluyeron los registros de pacientes menores de 18 años y los casos sin información demográfica completa. Resultados. Durante el año 2010 se registraron 2.634.339 altas de hospitales que pertenecen a la Secretaría de Salud. Se identificó un total de 467 hospitalizaciones por SGB en adultos (mediana de edad: 41 años; 62,1% hombres) de 121 instituciones sanitarias de los 32 estados federados de México. Durante el verano y otoño se registró la mayor frecuencia de hospitalizaciones por SGB. La mediana de la estancia hospitalaria fue de 8 días y la tasa de mortalidad hospitalaria, del 10,5%. La probabilidad de muerte se asoció directamente con la edad, sin una tendencia particular respecto al sexo, hospital de atención o entidad federativa. Conclusiones. En 2010, la mortalidad hospitalaria por SGB en esta parte del sistema sanitario mexicano fue más alta de la que se informa en estudios contemporáneos. Se observó una asociación estacional con la frecuencia de hospitalizaciones por SGB (AU)

Introduction. Guillain-Barré syndrome (GBS) is a neurological emergency representing the main cause of flaccid paralysis around the world, affecting all age groups. Little is known about the essential epidemiology of GBS in most Latin American countries. Aim. To determine the mortality associated with the diagnosis of GBS in hospital discharges during 2010 in hospitals of the Ministry of Health, Mexico. Patients and methods. We analyzed the database of hospital discharges of institutions pertaining to the Ministry of Health. Study cases were identified by the code G61.0 of the International Classification of Diseases, 10th revision (ICD-10). We excluded records of patients younger than 18 years and patients without complete demographic information. Results. During the year 2010 there were 2,634,339 discharges from hospitals of the Ministry of Health. We identified a total of 467 hospitalizations due to GBS in adults (median age: 41 years; 62.1% male) from 121 health institutions of the 32 Republic States. The highest frequency of GBS hospitalizations occurred during summer and fall. The median hospital stay was 8 days. The hospital mortality rate was 10.5%. The probability of death was directly associated with age, without a particular trend regarding gender, hospital care or state. Conclusions. In 2010 GBS hospital mortality in this part of the Mexican health system was higher than that reported in contemporary studies. A seasonal association was observed regarding the frequency of hospitalizations for GBS (AU)

[Mortality associated with a diagnosis of Guillain-Barré syndrome in adults of Mexican health institutions]. / Mortalidad asociada al diagnóstico de síndrome de Guillain-Barré en adultos ingresados en instituciones del sistema sanitario Mexicano.

INTRODUCTION: Guillain-Barré syndrome (GBS) is a neurological emergency representing the main cause of flaccid paralysis around the world, affecting all age groups. Little is known about the essential epidemiology of GBS in most Latin American countries. AIM: To determine the mortality associated with the diagnosis of GBS in hospital discharges during 2010 in hospitals of the Ministry of Health, Mexico. PATIENTS AND METHODS: We analyzed the database of hospital discharges of institutions pertaining to the Ministry of Health. Study cases were identified by the code G61.0 of the International Classification of Diseases, 10th revision (ICD-10). We excluded records of patients younger than 18 years and patients without complete demographic information. RESULTS: During the year 2010 there were 2,634,339 discharges from hospitals of the Ministry of Health. We identified a total of 467 hospitalizations due to GBS in adults (median age: 41 years; 62.1% male) from 121 health institutions of the 32 Republic States. The highest frequency of GBS hospitalizations occurred during summer and fall. The median hospital stay was 8 days. The hospital mortality rate was 10.5%. The probability of death was directly associated with age, without a particular trend regarding gender, hospital care or state. CONCLUSIONS: In 2010 GBS hospital mortality in this part of the Mexican health system was higher than that reported in contemporary studies. A seasonal association was observed regarding the frequency of hospitalizations for GBS.

TITLE: Mortalidad asociada al diagnostico de sindrome de Guillain-Barre en adultos ingresados en instituciones del sistema sanitario mexicano.Introduccion. El sindrome de Guillain-Barre (SGB) es una urgencia neurologica que constituye la principal causa de paralisis flacida en el mundo, y que afecta a todos los grupos etarios. Se desconocen notablemente las caracteristicas epidemiologicas esenciales del SGB en la mayor parte de los paises de America Latina. Objetivo. Determinar la mortalidad asociada con el diagnostico de SGB en altas hospitalarias efectuadas durante el año 2010 en instituciones de la Secretaria de Salud, Mexico. Pacientes y metodos. Se analizo la base de datos de altas hospitalarias de instituciones que pertenecen a la Secretaria de Salud. Se identificaron los casos de SGB mediante el codigo G61.0 de la Clasificacion Internacional de Enfermedades, 10.ª revision (CIE-10). Se excluyeron los registros de pacientes menores de 18 años y los casos sin informacion demografica completa. Resultados. Durante el año 2010 se registraron 2.634.339 altas de hospitales que pertenecen a la Secretaria de Salud. Se identifico un total de 467 hospitalizaciones por SGB en adultos (mediana de edad: 41 años; 62,1% hombres) de 121 instituciones sanitarias de los 32 estados federados de Mexico. Durante el verano y otoño se registro la mayor frecuencia de hospitalizaciones por SGB. La mediana de la estancia hospitalaria fue de 8 dias y la tasa de mortalidad hospitalaria, del 10,5%. La probabilidad de muerte se asocio directamente con la edad, sin una tendencia particular respecto al sexo, hospital de atencion o entidad federativa. Conclusiones. En 2010, la mortalidad hospitalaria por SGB en esta parte del sistema sanitario mexicano fue mas alta de la que se informa en estudios contemporaneos. Se observo una asociacion estacional con la frecuencia de hospitalizaciones por SGB.

Variantes normales o de significado incierto en el electroencefalograma / Electroencephalographic normal variants or with uncertain significance

El electroencefalograma es una herramienta vital en el diagnóstico de afecciones primarias o secundarias del sistema nervioso central, dentro de las cuales la epilepsia es una de las más importantes. En ocasiones, la actividad encefalográfica normal simula actividad epileptiforme. Esta actividad no tiene valor patológico y se considera una variante normal de la actividad cerebral. Hemos dividido las alteraciones en cuatro grupos fundamentales basados en la clasificación propuesta por Blum y Cervone: patrones rítmicos, patrones epileptiformes, ondas lambda y variantes dependientes de la edad. Estos cambios se ven con frecuencia durante la somnolencia o el sueño y durante las maniobras de activación, y son más comunes en los niños y adolescentes. El objetivo de esta revisión es presentar las características más importantes de cada una de estas variantes, con el fin de evitar que sean confundidas con actividad cerebral anormal (AU)

Electroencephalography is an important tool in the diagnosis of primary or secondary disorders of central nervous system, epilepsy is one of the most important. Sometimes normal electroencephalographic activity simulates epileptiform activity. This activity does not have pathological value and is considered a variant of normal brain activity. The main groups based on the classification proposed by Blum and Cervone are: rhythmic patterns; epileptiform patterns; lambda waves, and age dependent changes. These changes are frequently seen during drowsiness, sleep and during activation maneuvers and more common in children and adolescents. The aim of this review is to present the most important characteristics of each of these variants, in order to prevent them being confused with abnormal brain activity (AU)

[A brief history of the baroreceptor reflex: from Claude Bernard to Arthur C. Guyton. Illustrated with some classical experiments]. / Breve historia del reflejo barorreceptor: de Claude Bernard a Arthur C. Guyton. Ilustrada con algunos experimentos clásicos.

The baroreceptor reflex is poorly known by most physicians even though is fundamental in stabilizing the blood pressure on a beat to beat basis and is crucial for survival. Its fascinating history is briefly reviewed in this article. In 1852 Claude Bernard discovered that the sympathetic nerves of the neck innervate the blood vessels of the skin of the rabbit. Edgar Douglas Adrian in 1932 demonstrated that the sympathetic nerves that innervate the blood vessels discharge spontaneously at a rate of 4-6 per second and thus discovered the physiological basis of the vasomotor tone. In the XIX century Ludwig Traube and Karl Constantine Ewald Hering discovered that blood pressure fluctuates synchronously with respiratory movements and Sigmund Mayer observed that there are also slow non respiratory fluctuations of blood pressure. In 1921 Heinrich Ewald Hering found that high pressure baroreceptors are located in the carotid sinuses and demonstrated that the stimulation of the afferent nerve that innervates it induces bradycardia and hypotension. These studies were further advanced by Corneille Heymans who won the Nobel Prize for these studies in 1938. Later Cowley and Guyton produced sino-aortic denervation in dogs and thereby could demonstrate the fundamental importance of the baroreceptor reflex in the stabilization of blood pressure.

Breve historia del reflejo barorreceptor: de Claude Bernard a Arthur C. Guyton. Ilustrada con algunos experimentos clásicos / A brief history of the baroreceptor reflex: From Claude Bernard to Arthur C. Guyton. Illustrated with some classical experiments

El reflejo barorreceptor es poco conocido por la mayoría de los médicos a pesar de que es fundamental en la estabilización de la presión arterial latido a latido y es crucial para la supervivencia. Su fascinante historia es brevemente revisada en este artículo. En 1852 Claude Bernard descubrió que los nervios simpáticos del cuello inervan los vasos sanguíneos de la piel. En 1932 Edgar Douglas Adrian demostró que los nervios simpáticos que inervan los vasos sanguíneos de la piel descargan en forma espontánea a una frecuencia de cuatro a seis por segundo y de esta forma encontró las bases fisiológicas del tono vasomotor. En el siglo XIX Ludwig Traube y Karl Constantine Ewald Hering descubrieron que la presión arterial fluctúa sincrónicamente con la respiración y Sigmund Mayer observó que también existían oscilaciones más lentas no relacionadas con la respiración. En 1921 Heinrich Ewald Hering mostró la existencia de barorreceptores de alta presión en los senos carotideos y probó que la estimulación de los nervios aferentes que inervan estos receptores induce bradicardia e hipotensión. Estos estudios fueron más tarde avanzados por Corneille Heymans quien ganó el premio Nobel por estos estudios en 1938. En la época de los setentas Cowley y Guyton produjeron denervación sino-aórtica en los perros y de esta manera demostraron la importancia fundamental del reflejo barorreceptor en la estabilización de la presión arterial.

The baroreceptor reflex is poorly known by most physicians even though is fundamental in stabilizing the blood pressure on a beat to beat basis and is crucial for survival. Its fascinating history is briefy reviewed in this article. In 1852 Claude Bernard discovered that the sympathetic nerves of the neck innervate the blood vessels of the skin of the rabbit. Edgar Douglas Adrian in 1932 demonstrated that the sympathetic nerves that innervate the blood vessels discharge spontaneously at a rate of 4-6 per second and thus discovered the physiological basis of the vasomotor tone. In the XIX century Ludwig Traube and Karl Constantine Ewald Hering discovered that blood pressure fluctuates synchronously with respiratory movements and Sigmund Mayer observed that there are also slow non respiratory fluctuations of blood pressure. In 1921 Heinrich Ewald Hering found that high pressure baroreceptors are located in the carotid sinuses and demonstrated that the stimulation of the afferent nerve that innervates it induces bradycardia and hypotension. These studies were further advanced by Corneille Heymans who won the Nobel Prize for these studies in 1938. Later Cowley and Guyton produced sino-aortic denervation in dogs and thereby could demonstrate the fundamental importance of the baroreceptor reflex in the stabilization of blood pressure.

Control neural de la circulación periférica y de la presión arterial / Neural control of the peripheral circulation and blood pressure

In the XIX century Claude Bernard discovered the action of the nervous system on the peripheral circulation. In the first half of the XX century Ewald Hering discovered the baro-receptor and the reflex control of the heart rate and blood pressure. Cowley and Guyton demonstrated that sino-aortic denervation induces persistent changes in the blood pressure in the dog. The autonomic nervous system is mainly responsible for the regulation of the circulation and blood pressure in the short term on a beat to beat basis. It controls the vasomotor tone, the heart rate and the cardiac output. With the advent of non invasive methods that measure the blood pressure on a beat to beat basis (Finapres) and with the methods of measurement of the variability of the blood pressure in the frequency domain (spectral analysis) we can currently measure many variables including heart rate, blood pressure, stroke volume, peripheral resistances and the baroreceptor sensitivity and make some inferences about their control mechanisms. These variables can be measured at rest in the supine position, standing up, during rhythmic breathing and during the Valsalva maneuver. In this article we present a review of the neural control of the blood pressure and heart rate.

Cefalea en racimos: [revisión] / Cluster headache: [review]

La cefalea en racimos es un síndrome doloroso primario estereotipado que constituye probablemente la causa de cefalea más severa existente. Se caracteriza por cefalea estrictamente unilateral, de predominio nocturno, con duración de 15 a 180 minutos, acompañada de al menos un fenómeno autonómico ipsilateral. Los síntomas se presentan varias ocasiones al día (en racimos), tienen periodicidad y comportamiento rítmico circadiano. Su incidencia es de 4-15 casos por 100 000, su prevalencia anual es de 53 casos por 100 000, tiene un radio hombre:mujer de 4-9:1 y la edad de inicio más frecuente es de 27 a 31 años. Existe predisposición genética para la enfermedad existiendo un familiar en primera línea en 3,4-12% de los pacientes afectados. En sufisiopatología están involucrados cambios en el sistema trigémino-vascular, el seno cavernoso, el tálamo ventral-posterior, la corteza frontal, el cíngulo, la ínsula, los ganglios basales y la sustancia gris hipotálamica inferior y posterior. Los cambios autonómicos son debidos a activación parasimpática por el nervio facial a través del ganglio pterigopalatino y a deficiencia transitoria del sistema simpático-cervical. Existe modificación en los niveles del péptido relacionado al gen de la calcitonina, péptido intestinal vasoactivo, L-arginina-óxido nítrico, endotelina-1, testosterona, tirotropina, cortisol, hormona del crecimiento, hormona luteinizante, prolactina y melatonina. El tratamiento se divide en: farmacológico agudo que incluye oxígeno, uso de cámara hiperbárica, triptanos -sumatriptán, zolmitriptán, ergotamínicos y lidocaína intranasal; profiláctico transicional y crónico que contiene esteroides, ergotamínicos, verapamilo, metisergide, carbonato de litio, ácido valpróico y melatonina; y tratamiento invasivo consistente en bloqueo, cirugía, entre otros...

Cluster headache is a stereotyped primary pain syndrome that is probably the most severe cause of headache existing. It is characterized by strictly unilateral headache, predominantly nocturnal, lasting from 15 to 180 minutes, accompanied by at least one ipsilateral autonomic phenomena. Symptoms occur several times a day (clusters) having a rhythmic periodicity and a circadian behavior. Its incidence is 4-15 cases per 100 000, the annual prevalence is 53 cases per 100 000, and has a radius male: female 4-9:1. The most common age of onset is 27 to 31 years. There is a genetic predisposition for the disease with the existence of a fi rst line family member in 3,4-12% of affected patients. Pathophysilogically it involves changes in the trigemino-vascular system, the cavernous sinus, the ventralposterior thalamus, frontal cortex, the cingulum, the insula, basal ganglia, the inferior and posterior hypothalamic gray matter. Autonomic changes are due to parasympathetic activation by the facial nerve through the pterygopalatine ganglion and transitory deficiency of the cervical sympathetic system. There is a modification in the levels of gene-relatedpeptide calcitonin, vasoactive intestinal peptide, L-arginine nitric oxide, endothelin-1, testosterone, thyrotropin, cortisol, growth hormone, luteinizing hormone, prolactin and melatonin. The treatment is divided in: acute pharmacology including oxygen, the use of hyperbaric chamber, triptans, sumatriptan, zolmitriptan, ergotamine and intranasal lidocaine, transitional and chronic prophylactic containing steroids, ergotamine, verapamil, metisergide, lithium carbonate, valproic acid and melatonin, and invasive treatment consisting on blockade, surgery, among others...

[Neural control of the peripheral circulation and blood pressure]. / Control neural de la circulación periférica y de la presión arterial.

In the XIX century Claude Bernard discovered the action of the nervous system on the peripheral circulation. In the first half of the XX century Ewald Hering discovered the baro-receptor and the reflex control of the heart rate and blood pressure. Cowley and Guyton demonstrated that sino-aortic denervation induces persistent changes in the blood pressure in the dog. The autonomic nervous system is mainly responsible for the regulation of the circulation and blood pressure in the short term on a beat to beat basis. It controls the vasomotor tone, the heart rate and the cardiac output. With the advent of non invasive methods that measure the blood pressure on a beat to beat basis (Finapres) and with the methods of measurement of the variability of the blood pressure in the frequency domain (spectral analysis) we can currently measure many variables including heart rate, blood pressure, stroke volume, peripheral resistances and the baroreceptor sensitivity and make some inferences about their control mechanisms. These variables can be measured at rest in the supine position, standing up, during rhythmic breathing and during the Valsalva maneuver. In this article we present a review of the neural control of the blood pressure and heart rate.

Respiratory and non respiratory oscillations of the skin blood flow: a window to the function of the sympathetic fibers to the skin blood vessels.

OBJECTIVE OF THE STUDY: The skin blood flow (SBF) has been known to oscillate in frequency and amplitude. The nature and type of these oscillations have remained obscure. We studied the oscillations of the SBF in frequency and amplitude with non invasive techniques during normal breathing at rest and compared it to the oscillations during rhythmic paced breathing at 6 cycles per minute. SUBJECTS AND METHODS: Thirty healthy subjects were studied under normothermic conditions. The following variables were recorded: 1) EKG signal; 2) SBF signal given by an infrared photoplethysmograph; 3) respiratory movements (RM). A correlation of the frequency of the respiration, the SBF and the EKG was made. The variability of the amplitudes of the SBF, RR intervals and pulse intervals was analyzed in the time domain and with spectral analysis using Fourier analysis. RESULTS: We found no clear respiratory modulation of the amplitude of the SBF during natural breathing at rest. With default breathing there was a low frequency oscillations (LF 0.04 to 0.15 Hz) modulation of the amplitude of the SBF that was non respiratory in nature. During rhythmic breathing at 0.1 Hz there was a strong modulation at LF of the SBF with a typical waxing and waning appearance, decreasing in amplitude during the tachycardia period and increasing in amplitude during the bradycardia period. CONCLUSIONS: Under normothermic conditions there is a consistent variability of the frequency and amplitude of the SBF with normal and rhythmic breathing. While breathing at rest the modulation of SBF amplitude was clearly seen at LF and non respiratory related. With rhythmic breathing there is a strong modulation of amplitude and frequency at the respiratory frequency.

Respiratory and non respiratory oscillations of the skin blood flow: a window to the function of the sympathetic fibers to the skin blood vessels

OBJECTIVE OF THE STUDY: The skin blood flow (SBF) has been known to oscillate in frequency and amplitude. The nature and type of these oscillations have remained obscure. We studied the oscillations of the SBF in frequency and amplitude with non invasive techniques during normal breathing at rest and compared it to the oscillations during rhythmic paced breathing at 6 cycles per minute. SUBJECTS AND METHODS: Thirty healthy subjects were studied under normothermic conditions. The following variables were recorded: 1) EKG signal; 2) SBF signal given by an infrared photoplethysmograph; 3) respiratory movements (RM). A correlation of the frequency of the respiration, the SBF and the EKG was made. The variability of the amplitudes of the SBF, RR intervals and pulse intervals was analyzed in the time domain and with spectral analysis using Fourier analysis. RESULTS: We found no clear respiratory modulation of the amplitude of the SBF during natural breathing at rest. With default breathing there was a low frequency oscillations (LF 0.04 to 0.15 Hz) modulation of the amplitude of the SBF that was non respiratory in nature. During rhythmic breathing at 0.1 Hz there was a strong modulation at LF of the SBF with a typical waxing and waning appearance, decreasing in amplitude during the tachycardia period and increasing in amplitude during the bradycardia period. CONCLUSIONS: Under normothermic conditions there is a consistent variability of the frequency and amplitude of the SBF with normal and rhythmic breathing. While breathing at rest the modulation of SBF amplitude was clearly seen at LF and non respiratory related. With rhythmic breathing there is a strong modulation of amplitude and frequency at the respiratory frequency.

A case of tactile agnosia with a lesion restricted to the post-central gyrus.

Tactile agnosia has been described after lesions of the primary sensory cortex but the exact location and extension of those lesions is not clear. We report the clinical features and imaging findings in a patient with an acute ischemic stroke restricted to the primary sensory area (S1). A 73-year-old man had a sudden onset of a left alien hand, without left hemiparesis. Neurological examination showed intact primary sensory functions, but impaired recognition of shape, size (macrogeometrical) and texture (microgeometrical) of objects; damage confined to the post-central gyrus, sparing the posterior parietal cortex was demonstrated on MRI. An embolic occlusion of the anterior parietal artery was suspected as mechanism of stroke. Tactile agnosia with impaired microgeometrical and macrogeometrical features' recognition can result from a single lesion in the primary sensory cortex (S1) in the right parietal hemisphere, sparing other regions of the cerebral cortex which presumably participate in tactile object recognition.

Síndrome de Guillain-Barré: experiencia en un hospital de tercer nivel / Guillain-Barreé syndrome: experience in a third level hospital

Introducción. El síndrome de Guillain-Barré es la causa más común de parálisis generalizada aguda. La enfermedad usualmente es benigna y tiende a autolimitarse, pero en casos severos puede causar la muerte por insuficiencia respiratoria. Objetivo: Describir la experiencia obtenida en un centro de referencia (Instituto Nacional de Ciencias Médicas y de la Nutrición Salvador Zubirán) para pacientes con síndrome de Guillain- Barré (SGB). Material y métodos: Se realizó una análisis retrospectivo de 28 pacientes con el diagnóstico de GB.Resultados: Se analizaron 28 pacientes durante un período de 10 años. La edad promedio del grupo fue 37.6 años + 17.2. 13 pacientes eran del sexo masculino (46 por ciento) y 15 (54 por ciento) eran mujeres. 9 pacientes (32 por ciento) tuvieron una infección de vías respiratorias superiores y 5 (18 por ciento) tuvieron un cuadro de gastroenteritis previo a los síntomas y 14 (50 por ciento) no tuvieron un factor precipitante. El tiempo de evolución tuvo una mediana de 7 días (2-15). 26 pacientes (93 por ciento) tuvieron una presentación clínica típica con una debilidad ascendente de extremidades y 18 (64 por ciento) tuvieron disestesias o parestesias. 18 pacientes (64 por ciento) correspondieron a la variante clínica clásica PDIA (Polirradiculopatía desmielinizante inflamatoria aguda), 5 (18 por ciento) correspondieron a la variante NASMA (Neuropatía axonal sensitivo-motora aguda), 3 (11 por ciento) NAMA (Neuropatía axonal motora aguda), y 2 (7 por ciento) presentaron el síndrome de Fisher-Miller. 24 pacientes (86 por ciento) tuvieron hiperproteinorraquia en el líquido cefalorraquídeo. 15 pacientes (54 por ciento) requirieron ventilación mecánica. 20 pacientes (71 por ciento) tuvieron una recuperación total, 6 (21 por ciento) tuvieron recuperación parcial y 2 (7 por ciento) pacientes no tuvieron ninguna respuesta.Discusión: Aunque la enfermedad tiende a autolimitarse en la mayoría de los casos, los cuadros más severos son frecuentes en las unidades de tercer nivel como se muestra en nuestro estudio donde el 54 por ciento requirieron ventilación mecánica, sin embargo la mayoría de estos casos tuvieron una buena respuesta (71 por ciento).

Síndrome de Klüver-Bucy por radionecrósis bitemporal / Klüver-Bucy syndrom after radiotherapy with bitemporal necrosis

Se presenta el caso de una mujer de 33 años de edad, a quien se diagnosticó un macroadenoma hipofisiario. Después de realizar dos resecciones quirúrgicas del macroadenoma y de observarse recurrencia, se decidió dar radioterapia con un total de 25 sesiones y dosis acumulada de 5,600 cGy. Dos años después la paciente presentó signos y síntomas del síndrome de Klüver-Bucy (SKB) en relación a encefalopatía posradiación. Este síndrome se presenta cuando existe disfunción temporal bilateral y se caracteriza por alteraciones en la conducta sexual y en los hábitos dietéticos, déficit en la memoria, hiperoralidad, apatía y abulia. Existen reportes escasos en la literatura acerca del SKB en relación a trauma, encefalitis y cirugía; la radionecrósis bitemporal como causa del síndrome es rara, por lo que se considera interesante la presentación de este caso, así como una breve revisión con base a los casos reportados.

Hiperventilación central neurogénica en infarto pontino / Central neurogenic hyperventilación associated to a unilateral basal pontine infraction

La hiperventilación central neurogénica en pacientes con preservación del estado de alerta es una entidad rara que sucede como manifestación de lesiones tegmentarias pontinas bilaterales, especialmente neoplasias como linfomas del SNC y gliomas, así como lesiones traumáticas. Los mecanismos fisiopatológicos no se conocen y no existe un tratamiento eficaz para esta entidad. Reportamos un caso de hiperventilación central asociada a un infarto basal pontino unilateral.