Traumatic atlantoaxial rotatory fixation in an adult patient.

INTRODUCTION: Atlantoaxial rotational fixation (AARF) is a rare entity in adults, with only a few cases reported in the English literature and often associated with a traumatic mechanism. It is an underdiagnosed condition that must be taken into account in the initial assessment of all craniocervical trauma. Both diagnostic and therapeutic delay may be a potential cause of severe neurological damage or even death of the patient. The therapeutic management is controversial given the difficulty of achieving optimum stability and permanent reduction. METHODS AND RESULTS: A 28-year-old woman was involved in a traffic accident a week before coming to the emergency with rotation and irreducible cervical flexion from trauma and severe neck pain. CT and MRI column were performed and showed a cervical spinal AARF with transverse and alar ligaments intact and preserved atlantoaxial distance (Fielding I). The patient was treated by progressive cervical traction with 5 kg and manual reduction was completed in 24 h. Subsequently, an external immobilization was performed by cervical rigid collar for 16 weeks. The clinical course was good, with the patient regaining full mobility with cervical neck pain improvement. CONCLUSIONS: The purpose of this paper is to show a case of a young woman with a posttraumatic AARF successfully treated conservatively. This case delineates the difficulties in diagnosing this pathology, as well as the challenges encountered in its management.

Effectiveness of vagal nerve stimulation in medication-resistant epilepsy. Comparison between patients with and without medication changes.

BACKGROUND: Vagal nerve stimulation (VNS) response is not immediate. A progressive decline in seizure frequency is usually found during a period of 12-18 months after implantation. During this time, the patient's medication is usually modified, which can create doubts about whether their clinical improvement is due to medication changes or to VNS itself. Our goal is to compare two groups of patients treated with VNS, with and without changes in their medication. METHODS: We prospectively analyze 85 patients who were treated with VNS in our hospital between 2005 and 2014. In 43 patients, changes in the antiepileptic drugs (EAD) were not allowed during the postoperative follow-up and they were compared with 42 patients who were left at the option of neurologist make changes in medication. We analyzed the clinical situation at 18 months and compared the two groups. RESULTS: Overall, 54.1% of patients had a reduction in seizures of 50% or higher (responders). In the group with no changes in medication, responders reached 63%, while in the group in which changes in medication were allowed, 45.2% were responders. Between responders and non-responders, there were no statistical differences in type of epilepsy, frequency, previous surgery, or intensity of stimulation. CONCLUSIONS: We did not find a statistical difference in seizure frequency reduction between patients with or without changes in medication during their follow-up, so changes in medication did not improve the outcome. Furthermore, the absence of changes in AED can help to optimize the parameters of the stimulator in order to improve its effectiveness.

Simulation with 3D Neuronavigation for Learning Cortical Bone Trajectory Screw Placement.

BACKGROUND AND OBJECTIVE: Learning a new technique in neurosurgery is a big challenge especially for trainees. In recent years, simulations and simulators got into the focus as a teaching tool. Our objective is to propose a simulator for placement of cortical bone trajectory (CBT) screws to improve results and reduce complications. METHODS: We have created a platform consisting of a sawbone navigated with a 3D fluoroscope to familiarize our trainees and consultants with CBT technique and later implement it in our department. Objective Structured Assessment of Technical Skills (OSATS) and Physician Performance Diagnostic Inventory Scale (PPDI) were obtained before and after the use of the simulator by the five participants in the study. Patients who were operated on after the implementation of the technique were retrospectively reviewed. RESULTS: During the simulation, there were 4 cases of pedicle breach out of 24 screws inserted (16.6%). After having completed simulation, participants demonstrated an improvement in OSATS and PPDI (p = 0.039 and 0.042, respectively). Analyzing the answers to the different items of the tests, participants mainly improved in the knowledge (p = 0.038), the performance (p = 0.041), and understanding of the procedure (p = 0.034). In our retrospective series, eight patients with L4-L5 instability were operated on using CBT, improving their Oswestry Disability Index (ODI) score (preoperative ODI 58.5 [SD 16.7] vs. postoperative ODI 31 [SD 13.4]; p = 0.028). One intraoperative complication due to a dural tear was observed. In the follow-up, we found a case of pseudoarthrosis and a facet joint violation, but no other complications related to misplacement, pedicle fracture, or hardware failure. CONCLUSION: The simulation we have created is useful for the implementation of CBT. In our study, consultants and trainees have valued very positively the learning obtained using the system. Moreover, simulation facilitated the learning of the technique and the understanding of surgical anatomy. We hope that simulation helps reducing complications in the future.

Spontaneous acute hemorrhage within a subependymoma of the lateral ventricle: successful emergent surgical removal through a frontal transcortical approach.

INTRODUCTION. Subependymomas are benign neoplasms intimately related to the ventricular system which only exceptionally associate hemorrhagic events. We present neuroradiological and pathological evidences of intratumoral hemorrhage within a single case of subependymoma operated on at our institution. Additionally we analyze retrospectively the well-defined reports of similar cases published in the scientific literature. CASE REPORT. A 71-year-old man on anticoagulant therapy presented with abrupt and progressive deterioration of his level of consciousness. Emergent computed tomography and magnetic resonance imaging evidenced signs of acute bleeding within a mass located at the frontal horn of the left lateral ventricle, producing obstructive biventricular hydrocephalus. The lesion was immediately and completely removed through a left frontal transcortical approach. Pathological diagnosis was consistent with subependymoma displaying areas of microhemorrhage. After surgery the patient developed global anterograde and retrograde amnesia. CONCLUSIONS. A spontaneous hemorrhagic event within an asymptomatic lateral ventricle subependymoma can result in a surgical emergence as a consequence of sudden obstruction of cerebrospinal fluid pathways. Prompt and radical surgical removal of the mass, which allows a rapid resolution of hydrocephalus and prevents the risk of rebleeding, may constitute the safest management strategy.

[Structure of the arachnoid layer of the human spinal meninges: a barrier that regulates dural sac permeability]. / Morfología de la lámina aracnoidea espinal humana. Barrera que limita la permeabilidad del saco dural.

OBJECTIVES: Drugs injected into the epidural space are known to penetrate the subarachnoid space by simple diffusion through the dural sac. We aimed to study the cellular ultrastructure of the arachnoid membrane and the type of intercellular junctions responsible for creating the barrier that regulates the passage of drugs through the dural sac in humans. MATERIAL AND METHODS: Fourteen tissue samples of arachnoid membrane were taken from 2 patients during procedures that required opening the lumbar dural sac. The samples were treated with glutaraldehyde, osmium tetroxide, ferrocyanide and acetone, and then embedded in resin. Ultrathin sections were stained with lead citrate for examination by transmission electron microscopy. RESULTS: The arachnoid membrane was 35 to 40 microm thick. The outer surface contained neurothelial cells (dural border cells) along the subdural compartment, while the internal portion was made up of a plane 5 to 8 microm thick with 4 to 5 arachnoid cells overlapping to form a barrier layer. The intercellular spaces on this plane were 0.02 to 0.03 microm wide; the arachnoid cells were bridged by specialized junctions (desmosomes and other tight junctions). CONCLUSIONS: Structural features of the arachnoid cells provide a barrier within the human dural sac. They occupy only the internal portion of the arachnoid membrane. Specialized intercellular junctions explain the selective permeability of this membrane.

[Giant cavernous sinus haemangioma. Case report]. / Hemangioma gigante del seno cavernoso. Caso clínico.

INTRODUCTION: Intracranial haemangioma is a benign vascular tumor which seldom affects the cavernous sinus region, being it frequently misdiagnosed as a meningioma. CASE REPORT: A 60-year-old woman presented with a subacute-onset third cranial nerve palsy. A giant extraaxial mass located in the middle cranial fossa which extended into the selar and supraselar areas was diagnosed. It showed homogeneous enhancement after contrast administration. The angiography revealed mild enhancement as well as indirect signs of mass effect, and a tumoral embolization was performed. Surgery and outcome. The tumor was partially removed through a left pterional approach, leaving an intraselar remnant. The patient had an uneventful postoperative course, and did not present new neurological deficits. CONCLUSIONS: The haemangioma must be considered in the differential diagnosis of cavernous sinus tumours. This entity represents a neurosurgical challenge, due to the complexity of this anatomical region and the trend of the tumour to bleed during its dissection.

[Is it possible to extract intracranial pressure information based on the EEG activity?] / Es posible obtener informacion de la presion intracraneal a partir de la actividad electroencefalografica?

INTRODUCTION: The capability of the electroencephalography (EEG) of recording the bioelectrical activity of the brain has made of it a fundamental tool for the evaluation of the patient's neurological condition. In recent years, moreover, it has also begun to be used in obtaining information for other kind of variables, as the ones related with the cerebral hemodynamics. AIM: To study the potential relationship between the EEG activity and the intracranial pressure (ICP) in patients suffering from traumatic brain injury and subarachnoid hemorrhage, during their stay at the intensive care unit. PATIENTS AND METHODS: Twenty-one adult patients (10 women) were included in the present observational prospective cohort study. They suffered from either traumatic brain injury or subarachnoid hemorrhage, requiring continuous EEG and ICP monitoring. In every patient, Granger causality between spectral functions of the EEG and the ICP was evaluated. Temporal windows of 10 minute were used to evaluate whether a causal relationship between those variables exist or not. In all of the cases, several days of continuous recording and assessment were performed. RESULTS: In most patients and during most of the time, Granger causality turns out to be significant in the direction from the EEG to the ICP, meaning that the EEG dynamics actually leads the ICP dynamics. CONCLUSIONS: The present work provides useful information and shed light in discovering a hidden relationship between the ICP and EEG dynamics. The potential use of this relationship could lead to develop a medical device to measure ICP in a non-invasive fashion.

TITLE: Es posible obtener informacion de la presion intracraneal a partir de la actividad electroencefalografica?Introduccion. El electroencefalograma (EEG) permite obtener informacion directa de la actividad bioelectrica del cerebro y es una herramienta fundamental para la evaluacion de la condicion neurologica del paciente. En los ultimos años ha comenzado a emplearse tambien para obtener indirectamente informacion sobre la hemodinamica cerebral y las variables que intervienen en la autorregulacion del flujo sanguineo cerebral. Objetivo. Estudiar la posible relacion entre la actividad electroencefalografica y la presion intracraneal (PIC) en pacientes con traumatismo craneoencefalico y hemorragia subaracnoidea ingresados en cuidados intensivos. Pacientes y metodos. Se incluyo a 21 pacientes (10 mujeres) mayores de 18 años con traumatismo craneoencefalico o hemorragia subaracnoidea que requerian monitorizacion de la PIC y a los que se les registro el EEG de forma continua. Se determino la causalidad de Granger entre la PIC con respecto a las variables espectrales del EEG para ventanas temporales de 10 minutos durante la estancia en cuidados intensivos. Resultados. La causalidad de Granger mostro una alta correlacion entre la PIC con las bandas del EEG. En la mayoria de los pacientes existe una causalidad de Granger significativa en la direccion del EEG hacia la PIC en gran parte del tiempo de monitorizacion, de forma que las variables del EEG precedian a la PIC. Conclusiones. El presente trabajo expone la relacion temporal subyacente entre la dinamica de la PIC y la actividad bioelectrica cerebral registrada mediante EEG en pacientes con traumatismo craneoencefalico y hemorragia subaracnoidea. El potencial uso de esta relacion podria permitir estimar la PIC de manera no invasiva.

Low-frequency bilateral hypothalamic stimulation for treatment of drug-resistant aggressiveness in a young man with mental retardation.

Stereotactic bilateral electrode implantation in the medial portion of the posterior hypothalamus was performed on a 22-year-old male with drug-resistant aggressiveness. To localize the targets during implantation, microrecording was performed, and the clinical and electroencephalographic responses to intraoperative stimulation were monitored. The patient had an improved response to low-frequency stimulation that was sustained 18 months later at a follow-up examination.

[Bilateral two-stage implantation for deep brain stimulation in the treatment of bilateral idiopathic Parkinson's disease: clinical outcomes]. / Implantacion bilateral en dos tiempos para estimulacion cerebral profunda en el tratamiento de la enfermedad de Parkinson idiopatica bilateral: resultados clinicos.

AIMS: Simultaneous bilateral implantation of electrodes in the subthalamic nucleus for idiopathic Parkinson's disease (IPD) is associated with long surgery time, language disorders and post-operative confusion. Moreover, there is evidence of ipsilateral improvement after stimulation of the subthalamic nucleus. In order to optimise perioperative management a prospective study is conducted with deep brain stimulation (DBS) in the subthalamic nucleus in two consecutive unilateral procedures. PATIENTS AND METHODS: We conducted a prospective study of 41 patients with bilateral IPD, with DBS implantation in two unilateral surgical phases. Its clinical outcomes are analysed according to the Unified Parkinson's Disease Rating Scale (UPDRS), the Hoehn and Yahr, and the Schwab and England scales, together with their complications. RESULTS: The mean age was 61 ± 7 years old, 23 males. Five patients (12%) did not undergo surgery of the contralateral subthalamic nucleus due to good control. The mean on the motor UPDRS and the Hoehn and Yahr in preoperative pharmacological off was 44 ± 14 and 3, respectively, and 19 ± 8 and 1.8 at six months' follow-up. The mean improvement on the Schwab and England scale in the pre-operative period and at six months was 39%. Two patients suffered post-operative confusion, and one of them had transient dysarthria. CONCLUSIONS: Bilateral DBS in two unilateral stages was an effective option with few complications in our series of patients with IPD. 10% of the patients did not require contralateral electrodes. It would be necessary to conduct a randomised study in patients who underwent bilateral surgery in one and two stages in order to confirm these results.

TITLE: Implantacion bilateral en dos tiempos para estimulacion cerebral profunda en el tratamiento de la enfermedad de Parkinson idiopatica bilateral: resultados clinicos.Objetivo. La implantacion bilateral simultanea de electrodos en el nucleo subtalamico para la enfermedad de Parkinson idiopatica (EPI) se asocia a una duracion elevada de la intervencion, alteraciones del lenguaje y confusion posquirurgica; ademas, existe evidencia de mejoria ipsilateral tras la estimulacion del nucleo subtalamico. Para optimizar el manejo perioperatorio se realiza un estudio prospectivo con estimulacion cerebral profunda (ECP) en el nucleo subtalamico en dos procedimientos unilaterales consecutivos. Pacientes y metodos. Estudio prospectivo de 41 pacientes con EPI bilateral, con implantacion de ECP en dos fases quirurgicas unilaterales. Se analizan sus resultados clinicos segun las escalas Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn y Yahr, y Schwab y England, asi como sus complicaciones. Resultados. La edad media fue de 61 ± 7 años, 23 hombres. Cinco pacientes (12%) no fueron intervenidos del nucleo subtalamico contralateral por buen control. La media en la UPDRS motora y la Hoehn y Yahr en off farmacologico preoperatorio fue de 44 ± 14 y 3, respectivamente, y de 19 ± 8 y 1,8 a los seis meses de seguimiento. La mejoria media en la escala de Schwab y England en el preoperatorio y a los seis meses fue del 39%. Dos pacientes tuvieron confusion postoperatoria, y uno, disartria transitoria. Conclusiones. La ECP bilateral en dos etapas unilaterales fue una opcion eficaz y con escasas complicaciones en nuestra serie de pacientes con EPI. El 10% de los pacientes no preciso electrodos contralaterales. Seria necesario un estudio aleatorizado en pacientes sometidos a cirugia bilateral en uno y dos tiempos para confirmar estos resultados.

[Treatment of hydrocephalus secondary to intraventricular haemorrhage in preterm infants. A review of the literature]. / Tratamiento de la hidrocefalia secundaria a hemorragia intraventricular en el prematuro. Revisión bibliográfica.

INTRODUCTION: The current incidence of intraventricular haemorrhage in low-weight preterm infants is 20%. The percentage of patients who are going to develop hydrocephalus secondary to this haemorrhage varies greatly. In the last 20 years different medical and surgical treatments have been put forward to prevent both the occurrence of haemorrhage and the development of hydrocephalus. DEVELOPMENT: In this study we review the literature on the different treatments used to control and treat hydrocephalus. From the medical point of view, treatment with pharmacological agents such as azetazolamide or furosemide offers more drawbacks than advantages as far as their capacity to prevent hydrocephalus is concerned. Treatments involving fibrinolytic agents offer a high risk of triggering new haemorrhages but in recent years their use has been taken up again in combination with ventricular drains. As regards surgical treatment of hydrocephalus due to haemorrhage, despite the risk of infection, it is more advisable to use ventricular drains than to introduce subgaleal reservoirs. At the present time, the best definitive treatment for hydrocephalus in preterm infants is still the ventriculoperitoneal shunt. The most suitable time is when the weight of the newborn infant exceeds 1500 g and the cerebrospinal fluid offers a protein count above 200 mg/dL. CONCLUSIONS: The long-term neurological development of these children depends mainly on the severity of the haemorrhage, but poorer prognoses are observed in cases in which complications arise from the control examinations of the valve shunt systems.

[Epidural fat in various diseases: contribution of magnetic resonance imaging and potential implications for neuro axial anesthesia]. / La grasa epidural en diferentes patologías. Aportaciones de la resonancia magnética y posibles implicaciones en la anestesia neuroaxial.

Epidural fat is a reservoir of lipophilic substances that cushions the pulsatile movements of the dural sac, protects nerve structures, and facilitates the movement of the dural sac over the periosteum of the spinal canal during flexion and extension. Excessive epidural fat can compress the underlying structures, however, and affect the placement of catheters and the distribution of injected solutions. This review discusses changes in epidural fat related to various diseases and events: lipomatosis, epidural lymphoma, arachnoid cysts, epidural hematoma, meningiomas, angiolipomas, spondylolysis, scoliosis, spinal stenosis, and liposarcoma. Also discussed are the sequencing and protocols for magnetic resonance imaging that enable epidural fat to be observed and distinguished from neighboring structures. The relevance of epidural fat in spinal surgery is considered. Finally, we discuss the possible anesthetic implications of the abnormal deposition of epidural fat, to explain the unexpected complications that can arise during performance of epidural anesthesia.

[Bromocriptine: could it be the cure for post-surgical akinetic mutism?] / Bromocriptina: podria ser la cura para el mutismo acinetico posquirurgico?

INTRODUCTION: Akinetic mutism is considered as an alteration of the motivational state of the person, which the patient is unable to initiate verbal or motor responses voluntary, even with preserved sensorimotor and surveillance functions. CASE REPORT: A 43 year-old male involved in a cerebellum arteriovenous fistula complicated with hydrocephalus, who responded dramatically to treatment with bromocriptine. CONCLUSION: Typically, akinetic mutism is described as a transient surgeries posterior fossa. However, it can also occur after multiple valvular failure in patients with hydrocephalus.

TITLE: Bromocriptina: podria ser la cura para el mutismo acinetico posquirurgico?Introduccion. El mutismo acinetico se considera una alteracion del estado motivacional de la persona, por el cual el paciente es incapaz de iniciar respuestas verbales o motoras de caracter voluntario, aun teniendo preservadas las funciones sensomotoras y de vigilancia. Caso clinico. Varon de 43 años, intervenido de una fistula arteriovenosa del cerebelo complicada con hidrocefalia, que respondio espectacularmente al tratamiento con bromocriptina. Conclusion. Tipicamente se ha descrito el mutismo acinetico como una complicacion transitoria de las cirugias de la fosa posterior. Sin embargo, tambien puede aparecer tras multiples fallos valvulares en pacientes con hidrocefalia.

[When does post-ictal period start in temporal lobe epilepsy? A quantitative EEG perspective]. / Donde comienza el periodo postictal en la epilepsia del lobulo temporal? Hacia una definicion cuantitativa.

INTRODUCTION: In partial seizures, from a clinical point of view or even from electroencephalography characterization of post-ictal period can be difficult. The spectral and complex network analysis could lead to a more accurate definition of its limits, as well as to a great understanding of the seizures. PATIENTS AND METHODS: Digital EEG recordings from scalp and foramen oval electrodes were used, 32 seizures, from 15 patients with drug-resistant mesial temporal lobe epilepsy (Engel I). We analyzed numerically: the spectral entropy, the different frequency bands and several variables used to characterize the cortical network, density of links, modularity, cluster coefficient and average path length. Variations of for post-ictal versus pre-ictal periods were quantified. RESULTS: The cortical network density of links increased during the post-ictal period of complex seizures matching with an spectral entropy decrease, mainly due to an increase in Delta band activity. This variables reached extreme values around one minute after seizure end, defined by classical electroencephalography. CONCLUSIONS: Our results can be explained by the appearance of an 'ending' mechanism that starts in the ictal period, classically defined, and reach their maximum effect during the post-ictal period. These results could be useful to define the post-ictal period start, as the moment with maximum synchrony, which has a highest density of links and a lowest spectral entropy.

TITLE: Donde comienza el periodo postictal en la epilepsia del lobulo temporal? Hacia una definicion cuantitativa.Introduccion. En las crisis parciales, el periodo postictal presenta grandes dificultades de caracterizacion, tanto desde el punto de vista clinico como en electroencefalografia. Un analisis espectral y de redes complejas permitiria una definicion mas precisa de sus limites y una comprension mas completa de las crisis. Pacientes y metodos. Se analizaron registros digitales de electroencefalografia de electrodos de scalp y foramen oval, 32 crisis, de 15 pacientes con epilepsia farmacorresistente del lobulo temporal (Engel I). Numericamente se estudio la entropia espectral, las distintas bandas de frecuencia y medidas de caracterizacion de la red cortical, la densidad de enlaces, la modularidad, el coeficiente de agrupamiento y la longitud de camino medio, y se cuantifico la variacion del periodo postictal respecto al preictal. Resultados. Durante el periodo postictal de las crisis complejas existe un marcado aumento de la densidad de enlaces en la red cortical coincidente con un descenso en la entropia espectral, principalmente debido al aumento de la actividad en la banda delta. Los valores extremos de estas medidas se alcanzan aproximadamente un minuto despues del fin de las crisis, definidas electroencefalograficamente usando metodos tradicionales. Conclusiones. Nuestros resultados pueden explicarse por la aparicion de un mecanismo de 'finalizacion' de las crisis que comienza dentro del periodo ictal definido clasicamente y que alcanzan su efecto maximo durante el periodo postictal. Estos resultados podrian emplearse para definir el inicio del periodo postictal como aquel donde la sincronizacion es maxima, esto es, donde la densidad de enlaces resulta mayor y la entropia espectral es minima.

[New thalamic potential associated with somatosensory evoked potentials]. / Nuevo potencial talamico asociado con potenciales evocados somatosensoriales.

INTRODUCTION: The response of the thalamus during the study with somatosensory evoked potentials (SSEP) is not sufficiently understood. CASE REPORT: A 17-year-old man undergoing surgery for deep brain stimulation in the centromedian nucleus for drug-resistant epilepsy under complete sedation. During the intervention, the responses to SSEPs of the thalamic nuclei were recorded by means of four microelectrodes. These responses can be decomposed into three types: local field potentials (LFP), low amplitude fast oscillations (LFO), and high amplitude slow oscillations (HSO). LFO are widespread in much of the registered regions. However, HSOs are located at a single point in the registry and are closely associated with LFPs. CONCLUSIONS: Although the presence of LFO has been considered as an indicator of the presence of the sensory thalamus, its wide extension by different thalamic nuclei suggests that it is an unspecific response to SSEPs. However, the restricted spatial location of HSO and their association with LFP suggest that these newly described potentials are the markers for the presence of the sensory thalamus. Their identification may prove very useful in thalamic deep brain stimulation either in awake patients or especially in those requiring sedation.

TITLE: Nuevo potencial talamico asociado con potenciales evocados somatosensoriales.Introduccion. La respuesta del talamo durante el estudio con potenciales evocados somatosensoriales (PESS) no esta suficientemente comprendida. Caso clinico. Varon de 30 años intervenido con sedacion completa mediante estimulacion cerebral profunda en el nucleo centromediano por epilepsia farmacorresistente. Durante la intervencion se registraron las respuestas de los nucleos talamicos mediante cuatro microelectrodos a los PESS. Estas respuestas se pueden descomponer en tres tipos: potenciales de campo local (PCL), oscilaciones rapidas de baja amplitud (ORB) y oscilaciones lentas de gran amplitud (OLG). Las ORB estan muy extendidas por gran parte de las regiones registradas (> 5 mm) y en los cuatro electrodos simultaneamente. Sin embargo, las OLG estan localizadas en un unico punto del registro y estan intimamente asociadas con los PCL. Ademas, el analisis de wavelets muestra un componente espectral y un tiempo de aparicion diferentes. Conclusiones. Aunque se ha considerado la presencia de ORB como indicador de la presencia del talamo sensorial, su amplia extension por diferentes nucleos talamicos sugiere que se trata de una respuesta poco especifica a los PESS. Sin embargo, la localizacion espacial restringida de los OLG y su asociacion con PCL sugiere que estos potenciales de nueva descripcion son los marcadores de la presencia del talamo sensorial. Su identificacion puede resultar muy util en estimulacion cerebral profunda talamica en pacientes despiertos y, especialmente, en los que precisen sedacion.

[Medullar thoracic compression by tophaceous gout: presentation of a case and review of the literature]. / Compresion medular dorsal por tofos gotosos: presentacion de un caso y revision de la bibliografia.

INTRODUCTION: Spine involvement in gout is an extremely uncommon complication. Dorsalgia and quadriplegia are some manifestations that may occur, although these symptoms are seen more frequently in other more prevalent pathologies, such as spinal tumors. CASE REPORT: We present an unusual case of thoracic spinal cord compression at T10-T11 level caused by the extradural deposit of tophaceous material in a 52-year-old woman with uncontrolled chronic tophaceous gout. In addition to intensive medical treatment, the patient required surgery (hemilaminectomy and spinal decompression) and subsequent rehabilitation. Overall and neurological evolution were satisfactory.

TITLE: Compresion medular dorsal por tofos gotosos: presentacion de un caso y revision de la bibliografia.Introduccion. La afectacion de la columna vertebral en la gota es una complicacion extremadamente infrecuente. La dorsalgia y la cuadriplejia son algunas manifestaciones que se pueden presentar, aunque estos sintomas se ven con mas frecuencia en otras patologias mas prevalentes, como los tumores medulares. Caso clinico. Se presenta un caso inusual de compresion medular dorsal en D10-D11 causado por el deposito extradural de material tofaceo en una paciente de 52 años con gota tofacea cronica incontrolada. Ademas de un tratamiento medico intensivo, la paciente requirio cirugia (hemilaminectomia y descompresion medular) y rehabilitacion posterior. La evolucion general y neurologica fue satisfactoria.

Microanatomy of the dysplastic neocortex from epileptic patients.

Focal cortical dysplasia (FCD) is a pathology that is characterized by the abnormal development of the neocortex. Indeed, a wide range of abnormalities in the cortical mantle have been associated with this pathology, including cytoarchitectonic alterations and the presence of dysmorphic neurons, balloon cells and ectopic neurons in the white matter. FCD is commonly associated with epilepsy, and hence we have studied the ultrastructure of cortical tissue resected from three subjects with intractable epilepsy secondary to cortical dysplasia to identify possible alterations in synaptic circuitry, using correlative light and electron microscopic methods. While the balloon cells found in this tissue do not appear to receive synaptic contacts, the ectopic neurons in the white matter were abnormally large and were surrounded by hypertrophic basket formations immunoreactive for the calcium-binding protein parvalbumin. Furthermore, these basket formations formed symmetrical (inhibitory) synapses with both the somata and the proximal portion of the dendrites of these giant ectopic neurons. A quantitative analysis revealed that in the dysplastic tissue, the density of excitatory and inhibitory synapses was different from that of the normal adjacent cortex. Both increases and decreases in synaptic density were observed, as well as changes in the proportion of excitatory and inhibitory synapses. However, we could not establish a common pattern of changes, either in the same patients or between different patients. These results suggest that cortical dysplasia leads to multiple changes in excitatory and inhibitory synaptic circuits. We discuss the possible relationship between these alterations and epilepsy, bearing in mind the possible limitations that preclude the extrapolation of the results to the whole population of epileptic patients with dysplastic neocortex.

[The pathophysiological foundations of temporal-lobe epilepsy: studies in humans and animals]. / Bases fisiopatológicas de la epilepsia del lóbulo temporal: estudios en humanos y animales.

INTRODUCTION: Temporal lobe epilepsy (TLE) is the most frequent form of pharmaco-resistant epilepsy in human. Research using material from TLE patients undergoing surgery and animal models has significantly increased in the last decade. DEVELOPMENT: We review recent findings obtained over the last years from electrophysiological and anatomical studies in human and animal models of TLE. Data suggest a large heterogeneity and inter-individual variability depending on the model and the system under study. However, a common principle that appears to underlie the epileptic condition is the reorganization of excitation and inhibition resulting in hyperexcitability. Recent research combining in vitro electrophysiology together with depth recordings in vivo and new analytical methodologies is also discussed. CONCLUSIONS: A multidisciplinary approach using both human and animal models can help to fill gaps in our knowledge and to provide unique insights into the pathophysiology of TLE.

[Refractory epilepsy as the presenting symptom of a brucellar brain abscess]. / Epilepsia refractaria como presentacioón de absceso cerebral brucelósico.

INTRODUCTION: Brucellosis is a zoonotic disease that is occasionally transmitted to human beings from infected animal reservoirs. It is an important condition in endemic areas. One infrequent complication of systemic brucellosis is the infection of the central or the peripheral nervous systems. CASE REPORT: A 54-year-old male who was being studied prior to surgery for refractory epilepsy, with clinical expression in the form of complex partial seizures. Neuroimaging findings revealed an expansive lesion in the right temporal lobe, which direct serological, histopathological and microbiological evidence showed to be a chronic brucellar abscess. After combined treatment involving complete surgical resection followed by a cycle of standard antimicrobial therapy, the patient was seizure-free at one year of follow-up. CONCLUSIONS: Despite its low frequency, infection by Brucella must be considered in the differential diagnosis of intracranial expansive lesions, as well as in the case of patients whose presenting symptoms are epileptic seizures. To perform the diagnosis it is especially important to be aware of the wide range of clinical and radiological manifestations that can be produced, and which do not always correlate. Identification of risk factors on the patient record is also a crucial step.

[Characteristics and distribution of normal human epidural fat]. / Características y distribución de la grasa epidural humana normal.

Epidural fat provides sufficient cushion for the pulsatile movements of the dural sac, protects nerve structures, facilitates the movement of the dural sac over the periosteum of the spinal column during flexion and extension, and forms a pharmacologic reservoir of lipophilic substances. We review epidural fat and related structures, including their development during the fetal period when the epidural space is filled by undifferentiated loose, areolar mesenchymal tissue that surrounds the dural sac. In the adult, epidural fat has a continuous distribution and follows a certain metameric pattern. It is located mainly on the dorsal side of the epidural space, where it is organized in triangular capsules joined to the midline of the ligamentum flavum by a vascular pedicle. We consider the distribution of epidural fat in the axial and sagittal planes; its presence in the anterior, lateral and posterior epidural space; its presence in the cervical, thoracic and lumbar portions of the spinal column; and its characteristics and variations according to differing body habits and sex. Finally, we speculate on the possible anesthetic implications of epidural fat in terms of the pharmacokinetics of drugs injected into the epidural space and the tasks of locating the epidural space and inserting an epidural catheter during anesthetic procedures.

[Haemorrhagic pineal cysts: two clinical cases successfully treated by means of microsurgery]. / Quistes pineales hemorragicos: dos casos clinicos tratados con exito mediante microcirugia.

INTRODUCTION: Pineal cysts are a relatively frequent incidental finding in imaging tests; yet, pineal apoplexy is considered to be rare and is associated to severe symptoms. CASE REPORTS: We report the cases of a 25-year-old male and a female aged 15 years who visited the emergency department with signs and symptoms of intracranial hypertension. The existence of a pineal haemorrhage was confirmed by imaging tests. They were successfully treated by means of microsurgery. CONCLUSION: In our experience, and backed by the literature, we believe that the best treatment for this infrequent pathology is the microsurgical approach. Nevertheless, we do not rule out the possibility that, sometime in the future, endoscopic techniques may play an important role in the treatment of pineal apoplexy.

TITLE: Quistes pineales hemorragicos: dos casos clinicos tratados con exito mediante microcirugia.Introduccion. Los quistes pineales son un hallazgo incidental relativamente frecuente en las pruebas de imagen; sin embargo, la apoplejia pineal se considera rara y se asocia a sintomas graves. Casos clinicos. Varon de 25 a˜os y mujer de 15 a˜os, que acudieron a urgencias con clinica de hipertension intracraneal; mediante pruebas de imagen se confirmo la existencia de una hemorragia pineal. Se les trato con exito mediante microcirugia. Conclusion. En nuestra experiencia, y avalado por la bibliografia, creemos que el mejor tratamiento de esta infrecuente patologia es el abordaje microquirurgico. Sin embargo, no se excluye la posibilidad de que, en un futuro, las tecnicas endoscopicas puedan tener un lugar importante en el tratamiento de la apoplejia pineal.