[Computerized atlas for image-guided stereotactic functional neurosurgery]. / Atlas computarizado para la planificación de neurocirugías estereotácticas funcionales guiadas por imágenes.

OBJECTIVE: A computerized version of the Schaltenbrand and Wahren's stereotactic brain atlas for image-guided functional neurosurgery planning has been developed and integrated into our PC-based planning system. METHODS: The SW atlas plates were digitized, contoured and labeled for both hemispheres. The computerized atlas may be interactively registered with patient's data using linear and non-linear transformation. The implemented computational tools and applications are presented. RESULTS: Our computer system permits navigation through original or reconstructed slices, multiple-views synchronization and zoom to improve the localization of the commisures and the surgical targets, likewise the optimum path selection. Atlas position in the target's region can be interactively actualized and lesion's position and volume may be simulated. CONCLUSIONS: Its benefits of this approach include increased accuracy of target definition, decreased the number of electrode tracts and for instance the time of the surgery, and reduced surgical complications.

[Electroencephalogram findings in lesionectomies: preliminary results]. / Hallazgos del electrocorticograma en lesionectomías: resultados preliminares.

INTRODUCTION: Use of the electrocorticogram (EcoG) in planning lesionectomies is a controversial subject at present. MATERIAL AND METHODS: We describe a series of 5 patients with epileptic crises, 3 with arteriovenous malformations in whom the lesion was completely resected, followed by postoperative angiography, and two with gliomas with low grade malignancy in whom iridium 192 was implanted. RESULTS: 1. The most frequent reason for consultation was convulsions. 2. In our series of patients the commonest site was the frontal zone of the right hemisphere. 3. Potentials with epileptiform characteristics were registered at the edges of the lesions and occasionally over the lesion itself. In two cases electro-clinical crises were seen. 4. The lesions were resected from normal tissue independently of the EcoG results. CONCLUSION: Although they are preliminary findings, the results of the study support the usefulness of this technique to guide the surgical procedures used for the treatment of intractable epilepsy.

[Complications of stereotaxic surgery for cerebral tumors. Minimal access neurosurgery]. / Complicaciones de la cirugía estereotáxica de los tumores cerebrales. Neurocirugía de mínimo acceso.

INTRODUCTION: Complications of neurosurgery include the clinical, neurological and neurosurgical aspects. Their prevention and correction depend on satisfactory preoperative assessment and close postoperative follow-up. Although minimum access neurosurgery reduces some problems, the complexity and depth of many cerebral lesions cause problems. Therefore it is important to adhere to the above principles to obtain good results. OBJECTIVES: To determine the clinical complications, their early detection and course to be followed when they occur. PATIENTS AND METHODS: We studied 29 patients with intracranial tumors operated on using stereotaxic surgery during a period of two years. They were evaluated before and after surgery and the complications recorded. RESULTS: We discuss the most significant clinical aspects of peri-operative management. The main complications found were lower respiratory tract infection and hyperglycemia. CONCLUSIONS: These results show the need for suitable management, even in minimum access surgery, in patients with cerebral tumors operated on using stereotaxis and underline the most significant complications.

[Penetrating head injury from harpoon. Case report]. / Trauma craneoencefálico perforante por arpón. Precentación de un caso y revisión de la literatura.

The harpoon presence as aggressor weapon is unusual in the neurosurgical practice. Most cases are associated with diving or sport activities as result of imprudence. A 31 year old patient who sustained a penetrating craniocerebral injury with a fishing harpoon is presented and complementary exams, neurosurgical procedure and postoperative evolution are detailed. We discuss the management of this unusual injury and review the current literature on craniocerebral injuries caused by similar objects.

[Osteochondroma of the atlantooccipital joint. Extreme lateral transcondylar approach. A case description]. / Osteocondroma de la articulación atlantoccipital. Abordaje extremo lateral transcondilar. A propósito de un caso.

INTRODUCTION: We describe a patient diagnosed as suffering from a skull base osteochondroma which affected the atlantooccipital joint and originated in the occipital condyle. It also displayed a growth toward the foramen magnum, which was resected using an extreme lateral transcondylar approach. CASE REPORT: Patient aged 35, with a one year history of vertiginous seizures and unsteady gait, associated with cervical pain that irradiated to the right upper extremity, dysphagia, changes in the tone of the voice and distal numbness of the four extremities. The patient was made to lie in the three quarter prone position and an incision was made in the skin from the C3 spinous apophysis to a point 2 cm below the end of the mastoid process, in relation with the transversal apophysis of C1. The intervention continued with early identification and rotation of the vertebral artery; total resection of the tumour (osteochondroma) with its base in the right occipital condyle and growth toward the foramen magnum, in which the greater resection of the posteromedial third of the condyle is included. CONCLUSIONS: The location of osteochondromas can vary widely, and the condyle is one of the least frequent places inside the occipital bone. The approach employed provides excellent access to the region, in particular to the atlantooccipital joint. The width and angle of exposition are increased as compared with the traditional suboccipital approach, which facilitates the radical resection of the lesion with no neural retraction and without any surgical complications.

[Modes of treatment for arteriovenous malformations of the brain]. / Modalidades de tratamiento de las malformaciones arteriovenosas cerebrales.

INTRODUCTION AND DEVELOPMENT: Over the years new kinds of therapy have been incorporated into the treatment of arteriovenous malformations (AVM). Current treatment of AVM of the brain employs three well established options: radiosurgery, endovascular therapy (embolisation) and microsurgical resection. Radiosurgery is the simplest and least invasive, but 2 3 years are required to achieve total obliteration, and throughout this time there is the risk of bleeding; its use is limited to small AVM. Embolisation today plays a fundamental role more as an adjunct than when it is associated, although the other modes improve their cure interval by 25%. Microsurgery has the advantage of being the only mode of therapy that offers a degree of immediate angiographic obliteration of almost 100% and is still the most widely employed, despite its morbidity rate also being the highest. We establish an AVM management algorithm, in which, according to the size and localisation, we suggest that these therapeutic options should be used alone or in combination. CONCLUSIONS: The management of these lesions requires a combined effort of all the factors that can be of any help in the solution, and these modes are more complementary than competitive in situations in which they are all valid therapeutic options.

[The diagnosis of arteriovenous malformations of the brain]. / Diagnóstico de las malformaciones arteriovenosas cerebrales.

INTRODUCTION: Arteriovenous malformations (AVM) of the brain are, at present, entities that are difficult to diagnose owing to the variations in their clinical presentation and the different localisations in the central nervous system. Their most frequent clinical forms are haemorrhage, which is typically located in the intraparenchymatous region, seizures and, less frequently, vascular headache and progressive neurological deficit. DEVELOPMENT AND CONCLUSIONS: Several imaging studies with different resolutions must be performed for a final and conclusive diagnosis of an AVM, and brain angiography remains the first choice procedure, both in diagnosis and in planning management. The more recent use of functional studies has enabled us to better evaluate the haemodynamic characters of AVM and the repercussion on the surrounding brain tissue. The use of transoperative angiography, as a complement in resective surgery, allows us to determine the level of resection before closing the skull and, thus, to correct technical defects. It therefore diminishes the post operative complications derived from remnants of the lesion.

[Central neurocytoma]. / Neurocitoma central.

INTRODUCTION: A central neurocytoma (CN) is a rare tumor, of neuronal origin, well-differentiated and found intraventricularly. It mainly affects young adults. Firm diagnosis is made on immunohistochemical (IHQ) and ultrastructural studies, since on optic microscopy it is similar in appearance to an oligodendroglioma or to an ependymoma. PATIENTS AND METHODS: We studied 4 cases, three after surgical resection and one on autopsy. The average age was 29, ranging from 3 to 63. Both sexes were equally affected. In all cases IHQ techniques were used (GFAP, neurofilament, synaptophysin and specific neuronal enolase) and they were studied by electron microscopy. RESULTS: IHQ was negative for GFAP and neurofilament, but intensely positive for synaptophysin and specific neuronal enolase. On ultrastructural study there were few neurofilaments, microtubules and dense central granules typical of neural differentiation. CONCLUSIONS: The findings in our cases lead to diagnosis of NC and confirm that this tumor is a distinct clinicopathological entity.

[Sepsis and antibiotic prophylaxis in stereotaxic neurosurgery]. / Sepsis y profilaxis antibiótica en neurocirugía estereotáxica.

INTRODUCTION: Stereotaxic surgery is becoming increasingly important because of the possibility of approaching the deep zones of the brain with less risk. It is in daily use in cerebral tumours and in the functional surgery of Parkinson's disease. The use of antibiotic prophylaxis in neurosurgery is controversial, although in many centres, including ours, all patients receive it. OBJECTIVE: To study the pre-operative clinical characteristics analysing the antibiotic prophylaxis used, septic complications seen and their management. PATIENTS AND METHODS: In this study we included 93 patients with neurosurgical disorders operated on using a stereotaxic approach in the Neurosurgical Department of the Centro Internacional de Restauración Neurologica (Cuba) during 1997 and 1998, in which antibiotic prophylaxis was used and septic patients detected. The variables studied included age, sex, neurological disorders, surgical operations done and the antibiotic used for prophylaxis. We analysed the test of clinical criteria for sepsis in all patients. RESULTS: We found that a greater number of patients operated on had had functional surgery, which showed its importance as an alternative surgical method in Parkinson's disease. There was satisfactory use of antibiotic prophylaxis with a reduction in the rate of nosocomial infection; most infections were seen in the lower respiratory tract. CONCLUSION: These results support the hypothesis of use of antibiotic prophylaxis in stereotaxic surgery to achieve a reduction in intra-hospital infections in surgical patients.

[Presentation of distal saccular aneurysm as a subdural haematoma]. / Aneurisma sacular distal presentándose como hematoma subdural.

INTRODUCTION: Intracranial aneurysms are one of the most frequent vascular diseases. Nevertheless, saccular aneurysms that are not due to an inflammatory aetiology, which are located in the peripheral segment of the posterior circulation, are extremely rare. They are most frequently located in the thickest arterial branches within the region of the anterior brain circulation, as is the case of the complex made up of the anterior cerebral artery posterior communicating artery, middle cerebral artery and posterior communicating artery. No clinical manifestations are produced in many of these aneurysms, and their rupture and the subsequent development of a subarachnoid haemorrhage is the cause of the most intense neurological damage, which on occasions can lead to fatal consequences. CASE REPORT: We report the case of a patient who was a carrier of distal aneurysm, located in the posterior region of the brain circulation, and also the neuroradiological findings, the form of clinical presentation and surgical treatment carried out, which allowed us to identify and close the afferent vessel and the resection of the aneurysmatic sac. CONCLUSION: From the presentation of the symptoms of this patient in the form of a subarachnoid haemorrhage, accompanied by a subdural haematoma, it could be inferred that these clinical and imagenological findings point to the rupture of a distal aneurysm. Application of the stereotactic approach would be one of the first choice treatments for aneurysms in the distal region if we bear in mind the characteristics of the afferent vessel, the size of the neck and the morphology of the sac

[Stereotaxic biopsy and 192Ir implant in intracranial tumors. A review of 7 years of experience]. / Biopsia estereotáxica e implante de Ir-192 en tumores intracraneales. Revisión de 7 años de experiencia.

INTRODUCTION: The combination of stereotaxic techniques, advances in neuroimaging and the creation of continually improving software has permitted stereotaxic biopsy of cerebral lesions at the most varied sites. Improvement in the method of permanent interstitial radiation (brachytherapy) improves the precision with which the radioactive sources may be inserted, releasing a maximum dose of radiation to the tumour with minimum radiation to the surrounding tissue. PATIENTS AND METHODS: We treated 237 patients (aged 1 to 78 years) with intracranial lesions, all included in the protocol of our centre. Stereotaxic systems of Leksell, Riechert-Mundinger, Micromar and Estereoflex were used. The procedure was in three stages: acquisition of the image, surgical planning and surgical operation. The imaging guide was the computerized axial tomography (CAT). RESULTS: Stereotaxic biopsy guided by CAT images was done in 153 patients. These were divided into three groups, taking the biopsy findings as the reference: group A (primary tumors, 128), group B (metastatic tumors, 15) and group C (non-malignant lesions, 10). Ninety six permanent implants of 192Ir were inserted, with a low dose of 4-7 cGy/h and a total dose of 80-120 Gy. CONCLUSIONS: Stereotaxic biopsy is a very effective procedure with a significantly low range of complications. The permanent implant with a low dose rate, well situated and using a source of 192Ir is a safe, simple, effective method for the treatment of primary and recurrent glial tumours, and non-glial tumours which fulfil criteria for this type of brachytherapy.

[Subthalamic nucleus targeting and spatial variability]. / Localización bilateral y simetría del núcleo subtalámico.

AIM: The effectiveness of anatomic localization of the subthalamic nucleus (EAL) was assessed and the mapping method is described here. The symmetry of contralateral nuclei (SCN) was analyzed on 11 parkinsonian patients submitted to bilateral subthalamotomy with ablative lesioning. PATIENTS AND METHODS: To assess EAL the percentage so much of first trajectory (p1) as the total of trajectories (pt) that hit the target and the rest of subthalamic nucleus average distance (d) was calculated. The anatomic localization error (epsilon) is determined as a difference between first trajectory coordinates with those of medial determined nucleus point, through electrophysiological data as to the statistical significance of this error. SCN is analyzed by contrasting equality hypothesis at the nucleus maximum height alongside a trajectory, average electrophysiological position center and spatial distribution of all intranuclear recordings found in each hemisphere in all patients. RESULTS: The pi, pt and d obtained values were 86.36%, 86.13% and 1.41 +/- 1.01 mm respectively. The epsilon value was greater in anteroposterior direction of 1.11 +/- 0.83 mm without statistical significance. The average number of recorded trajectories for the first procedure was 6.45 and 6 for the second. The asymmetry of contralateral nucleus was not significant. CONCLUSIONS: An indirect method with CT brain images and a new electrophysiological mapping method with a multiunitary recording for first and second nucleus is safe enough and it yields a high effectiveness in anatomofunctional nucleus localization. The nucleus of a same patient are symmetrical. There is little space variability among patient non related to the differences in the intercommissural distance.

[Stereotaxic microsurgical resection of intracranial tumors guided by imaging and assisted by computer]. / Resección microquirúrgica estereotáxica de tumores intracraneales guiada por imagen y asistida por computadora.

INTRODUCTION: The microsurgical techniques for resection of intracranial lesions are limited where anatomical references do not exist or cannot be used as guides in the dissection of deeply located lesions or in more superficial eloquent areas. The stereotaxic guide, guided by imaging gives precise volumetric and geometric definition in intracranial lesions. Its application in the resection of intracranial tumors has special characteristics due to their biological condition and varied localization. OBJECTIVES: Spatial orientation during surgery is essential. We show this application of stereotaxic surgery in the Centro Internacional de Restauración Neurológica (CIREN) in La Havana, Cuba, between May 1994 and February 1988, describing 65 microsurgical operations done using stereotaxis in 62 patients with intracranial cerebral tumors. PATIENTS AND METHODS: The procedure was divided into three stages: acquiring an image, computerized axial tomography and surgical planning, with the STASSIS planning system and microsurgical procedures, including systems of stereotaxis: Leksell, Micromar and Estereoflex. RESULTS: Of the total, 27 of these patients had glial tumors, 33 non-glial tumors and only 2 had non-neoplastic lesions of different sites and sizes. A total of 30 resections were done. Surgical morbidity was minimal and there was no surgical mortality. CONCLUSIONS: The main advantages of this method are: exact localization of the site for craniotomy, easy spatial orientation and ease in distinguishing the delimitation between the tumour and the healthy tissue. It has been shown that Estereoflex may be used in cerebral microsurgery.

[Automatic anatomic-physiologic correspondence of deep structures of the central nervous system in stereotaxic functional neurosurgery]. / Automatización de la correlación anatomofisiológica de las estructuras profundas del sistema nervioso central en la neurocirugía funcional estereotáxica.

This work describes in detail the graphic facilities of a neurosurgical deep recording system for the anatomic-physiologic analysis of central nervous system deep structures in stereotaxic function neurosurgery guided by deep semi-microrecordings of the brain, as developed by the International Center of Neurologic Restoration in Cuba. This system for digitization of electrical activity in the brain uses an IBM-compatible 80386/80486 microprocessor in place of analog equipment for the visualization and recording of signals, thereby providing easier manipulation of recorded data and greater flexibility of analysis. The system automatically integrates each pulse recorded and quantifies its average amplitude. For each brain region explored, the behavior of the integrated activity recorded can be displayed on the corresponding sagittal view from the cerebral atlas of Schaltenbrand-Wahren, and then automatically scaled to the anatomic dimensions of each patient. The picture, with its different options, Facilitates analysis of anatomic correspondence of deep electrophysiologic signals so the various structures, nuclei and specific neuronal groups can be precisely located in the patient's brain. To date the system has been used successfully in over 110 neurosurgical procedures ventral intermedios (vim)-thalamotomy, pallidotomy, subthalotomy and neurotransplantation, providing more certain location of lesions or grafting sites for managing symptoms in Parkinson's disease and other movement disorders.

Neurocitoma central / Central neurocitoma

Introducción. El neurocitoma central (NC) es un tumor raro, de origen neuronal, bien diferenciado y de localización intraventricular; afecta preferentemente a adultos jóvenes. El diagnóstico definitivo se establece por el estudio inmunohistoquímico (IHQ) y ultraestructural debido a su semejanza con el oligodendroglioma y el ependimoma al microscopio óptico. Pacientes y métodos. Se procesaron 4 casos, 3 procedentes de resección quirúrgica y 1 de autopsia. La edad media fue de 29 años, con un rango entre 3 y 63 años; ambos sexos se afectaron por igual. A todos los casos se les realizó técnicas de IHQ (GFAP, neurofilamento, sinaptofisina y enolasa neuronal específica) y se estudiaron por microscopía electrónica. Resultados. La IHQ resultó negativa para la GFAP y para el neurofilamento, y fue intensamente positiva para la sinaptofisina y la enolasa neuronal específica. El aspecto ultraestructural evidenció escasos neurofilamentos, microtúbulos y gránulos de centro denso propios de la diferenciación neural. Conclusiones. Los hallazgos encontrados en nuestros casos permitieron realizar el diagnóstico de NC y confirmaron a este tumor como una entidad clinicopatológica distintiva

Automatización de la correlación anatomofisiológica de las estructuras profundas del sistema nervioso central en la neurocirugía funcional estereotóxica / Automatic anatomic-physiologic correspondence of deep structures of the central nervous system in stereotaxic functional neurosurgery

Este trabajo describe en detalle las facilidades gráficas que brinda el sistema de programas NDRS (Neurosurgical Deep Recording System) para el análisis anatomofisiológico de las estructuras profundas del sistema nervioso central en la neurocirugía funcional estereotóxica guiada por semimicrorregistros profundos del cerebro, desarrollado en el Centro Internacional de Restauración Neurológica de Cuba. Este sistema de registro y procesamiento digital de la actividad eléctrica cerebral, además de permitir la sustitución con un microordenador personal 80386/80486 IBM compatible, del equipamiento electrónico de procesamiento analógico, visualización, y grabación de las señales, brinda una mayor facilidad para la manipulación de la información registrada y una mayor flexibilidad para la implementación de diferentes tipos de análisis de las señales. El sistema, como una de sus posibilidades, realiza automáticamente un proceso de integración de cada señal registrada, como cuantificación de su amplitud general. El comportamiento de esta actividad integrada puede ser mostrado a lo largo de cada trayectoria explorada dentro del cerebro, sobre la correspondiente vista sagital del atlas cerebral de Schaltenbrand-Wahren, después de una escala automática del mismo según las dimensiones automáticas de cada paciente. Este gráfico, con sus diferentes opciones, facilita el análisis de la correlaciøn anatómica de los registros electrofisiológicos profundos realizados para localizar la ubicación exacta, dentro del cerebro de cada paciente, de sus diferentes estructuras, núcleos y grupos neuronales específicos. Hasta el presente, este sistema ha sido utilizado con éxito en más de 110 intervenciones neuroquirúrgicas de núcleo ventral intermedio-talamotomías, palidotomías, subtalamotomías y neurotrasplantes, contribuyendo a aumentar la seguridad en la correcta selección de los lugares de lesión o implante para el control de los diferentes síntomas de la enfermedad de Parkinson y otros movimientos anormale