]]> ]]> Material y método. Se disecaron cuatro cabezas de cadáveres adultos, fijadas enformol e inyectadas con siliconas coloreadas y cuatro encefalos de cadáveres adultos, fijados en formol, fueron disecados utilizando microscopio quirúrgico con magnificación 6 a 25 X. Resultados. El sistema coroideo supratentorial está constituido por los plexos coroideos, la tela coroidea superior y la fisura coroidea. Los plexos coroideos se ubican a nivel del techo del tercer ventrículo y en el cuerpo (tapan la tenia coroidea), atrio (tapan la tenia fornicis) y cuerno temporal (tapan la teniajimbriae) del ventrículo lateral. La tela coroidea superior es una prolongación de la piamadre que recubre las estructuras neurales que se ubican en las cisternas ambiens y cuadrigeminal; posee cuatro sectores: a nivel del techo del tercer ventrículo, a nivel del cuerpo del ventrículo lateral, a nivel del atrio del ventrículo lateral y a nivel del cuerno temporal. La fisura coroidea es una grieta natural entre el tálamo (tenia coroidea) y elfornix (teniafornicis /fímbriae) que se extiende desde el agujero de Monro (incluido), pasando por el cuerpo, atrio y cuerno temporal del ventrículo lateral, hasta su terminación a nivel del punto coroideo inferior. A traves de la FC pasan las hojas de la tela coroidea superior (para ingresar a los ventrículos laterales y así poder envolver y _fijar a los plexos coroideos), las arterias coroideas y las venas subependimarias. La físura coroidea posee tres sectores: superior (corporal), posterior (atrial) e inferior (temporal). A nivel del sector corporal, las venas que atraviesan el agujero de Monro/físura coroidea presentan variabilidad anatómica: así, la vena septal anterior y / o la vena tálamoestriada pueden ingresar al velum interpositum atravesando el agujero de Monro o la fisura coroidea; además, cuando la vena tálamocaudada es grande, la vena tálamoestriada es pequeña. Los abordajes a traves de la físura coroidea pueden ser realizados de la siguiente manera: a) agrandando el agujero de Monro hacia atrás, b) por vía subcoroidea (a traves de la tenia coroidea) y c) por vía transcoroidea (a traves de la tenia fornicis /fímbriae).
Conclusión. 1) La físura coroidea posee tres sectores (corporal, atrial y temporal); el primer sector comunica el ventrículo lateral con el tercer ventriculo y los dos sectores restantes comunican el ventrículo lateral con las cisternas peritroncales. 2) La tela coroidea superior es una prolongación de la piamadre y posee dos hojas. Presenta cuatro sectores: uno a nivel del tercer ventrículo (techo) y tres en el ventrículo lateral (cuerpo, atrio y cuerno temporal). 3) La posición de los plexos coroideos en los ventrículos laterales en relación con la fisura coroidea es diferente en cada sector; así, a nivel del cuerpo, para realizar un abordaje subcoroideo es necesario "levantar" el plexo coroideo, sin embargo, a nivel del atrio y cuerno temporal, es necesario "levantar" el plexo coroideo para realizar el abordaje transcoroideo. 4) La disposición anatómica de las venas subependimarias a nivel de la porción corporal de la físura coroidea es determinante en la elección del tipo de abordaje a traves de dicha hendidura. 5) La presentación en 3D (tres dimensiones) del trabajo permite un mejor entendimiento de la anatomía de la físura coroidea y por ende de los diferentes abordajes a traves de la misma.]]> Método. Se consideraron estas variables: presentación clínica, Karnofsky preoperatorio, topografia y multiplicidad lesional, confirmación histopatológica (cirugía versus biopsia) y sobrevida.
Resultados. Cuatro pacientes presentaron un foco neurológico y uno un síndrome depresivo; todos presentaron un Karnofsky > de 70. Las imágenes mostraron cuatro lesiones supratentoriales y una cerebelosa, todas bien delimitadas y captando homogeneamente el contraste: tres se resecaron, dos se biopsiaron estereotácticamente. El tratamiento se realizó con metotrexate aplicando radioterapia conformada en las recaídas. A largo plazo un paciente vive libre de enfermedad, tres con enfermedad y uno falleció al cuarto mes .
Conclusión. Los LPS no presentan características clínicoimagenológicas particulares para diferenciarlos de otros tumores pero su incidencia en aumento y el peor pronóstico asociado a la resección parcial versus biopsia estereotáctica, hace importante considerarlos como diagnóstico diferencial al evaluar pacientes con masa expansiva intracerebral.]]> ]]> Descripción. Paciente de sexo masculino y 65 años de edad que en forma repentina comienza con cefaleas, diplopia y rigidez de nuca. La resonancia magnética mostró una lesión expansiva selar de 30 x 30 mm.
Intervención. Se operó por vía subfrontal, evacuando un hematoma y resecando el tumor. La evolución postoperatoria a los 3 meses mostró ausencia del tumor y desaparición de los síntomas.
Conclusión. La apoplejía pituitaria es poco frecuente. El diagnóstico con resonancia magnetica es sencillo. La cirugía precoz es el tratamiento de elección.]]> Methods: A series of 119 incidental aneurysms in 77 patients were treated by emblization with GDC coils.
Results: One hundred and seven aneurysms were successfully emblized with total or almost total occlus ion rate of 86,8%. Thirteen procedural complications occurred causing definite morbidity in 5 patients and one death. None of the emblized aneurysms bled during the fllow-up.
Conclusion: Embolization of incidental aneurysms is associated to a low morbidity and mortality rates]]> ]]> Methods: Medical records of patients with brain stem cavernous malformations operated during the period 1996-2002 were retrospectively reviewed. Clinical symptoms and signs, bleeding and rebleeding episodes, radiological aspects, and surgical detaills were analized.
Results: Seven patients (mean age: 40,2 years; range: 24-60 years) were operated consecutively. All the patients had experienced at least one bleeding episode and presented different neurological deficits. The mean follow-up period was 27 months (range: 4-73 months). At the last follow-up, the Glasgow Outcome Scale disclosed 3 patients with excellent evolution, 2 patients with good evolution, 2 with severe morbidity and one with poor outcome. Preoperative neurological deficit improved in 5 patients (71,5%), remained stable in one (14,2%), and deteriorated in one (14,2%).
Conclusion: Surgical extirpation is recommendedfor the cavernous malformation of the brain stem which are symptomatic due to haemorrhage.
Key words: cavernous angioma, brain stem.]]> Description. Case 1 (24 years old female) complained of right ciatica and weakness in the last 15 days, with urinary retention. MRI showed a conus medullaris lesion that enhanced with gadolinium. Case 2 (47 years oldfemale) with a previous history ofa high grade B-cell limphoma, complained of astenia, anorexia and radicular pain. Lately she developed neurological deterioration, VII nerve palsy, urinary retention and seizures. A cistemal puncture was positive for neoplastic cells.
Intervention. In case 1 surgery was performed and pathology informed high grade glioma. After 30 days she developed a meningeal syndrome with. bilateral VI and VII cranial nerves pares is and neurological deterioration. Lumbar puncture was positive for neoplastic cells. She died after 15 days. Case 2 received intrathecal chemotherapy. Conclusion: Patients with extraneural malignant tumors and high grade tumors of the nervous system that refer signs and symptoms ofa meningeal dissemination, meningeal carcinomatosis must be suspected.]]> Description. A 46 years old female patient complained of right eye blurred vision and amaurosis since the past 9 months. Examination revealed: right eye 7/ 10 visual acuity and exophthalmos; left eye amaurosis and optic atrophy. CT scan and MRI showed a bilateral intraorbital and intracanal lesions with left intracranial extension.
Intervention. Through a left frontal approach the left intracranial extension was removed and the optic nerve was decompressed. Intraoperative biopsy revealed a linfoproliferative lesion. Surgery ended and definitive pathology was informed as an inflammatory pseudotumor. The patient received corticoids with a good response. Conclusion. The presente of bilateral intraorbital lesions with intracranial extension, should force us too think about ínflammatory pseudotumors]]> Description: A 29 years old woman complained of headache and decreased hearing of the right ear during the iast two years. MRI showed a lesion in the right cerebellopontine angle.
Intervention: The patient was operated through a retrosigmoid approach. During surgery we realized that the lesion was related to the glossopharyngeal nerve. The tumor was totally resected, without postoperative morbidity. The pathologist informed schwannoma.
Conclusion: The possibility of a glossopharyngeal schwannoma with auditive loss is possible.]]> Description: A 26 years old female patient harboring a sacral tumor was treated two years before by surgery with a good clinical outcome.
Intervention: The tumor recurred and it was successfully resected in a second surgery that required fixation by using a modified Galveston technique and bony fusion. Two years later, she suffered a new recurrence without neurological deficit.
Conclusion. In patients harboring sacral neoplasms associated to spinal pelvic instability, tumor resectionfollowed by modified Galveston technique is the best way to achieve stabilization and symptomatic relief]]> Results: 25 aneurysms were microsurgically clipped and one was packed. Global Glasgow Outcome Scale (GOS) was: GOS 5-4: 14/26 patients; GOS 3: 3/26 patients; GOS 1-2: 8/26 patients.
Conclusion: the best treatment for ruptured aneurysms is early surgery. As in many others series we find a relationship between clinical presentation and outcome. ]]> Methods: A questionnaire was designed based on hypothetical case histories. 246 questionnaires were sent between October 2001 and March 2002 by e-mail, post-mail or fax to the ISPN members as well as to the members AANS Pediatric Section e-mail list who wished to enter in the study. 76 responses to the survey (30.8%) were returned. For data analysis, responses were entered in a Microsoft Excel spreadsheet.
Results: Re spondents agreed to not operate asymptomatic Chiari I patients. la asymptomatic patients wíth Chiari 1 and syringomyelia surgical decisions depend on syrinx size. For suboccipital decompression the majority prefers to open the dura and close it with a patch graft. In cases of syrinx progression respondents prefer to shunt it to the subarachnoid space.
Conclusion: There is a consensus on treating conservatively asymptomatic patients with Chiari I malformation. Management is not uniform when there are minimal or doubtful symptoms and for asymptomatic patients with syringomyelia related to the Chiari I. In patients with symptoms due to Chiari I or to syringomyelia, respondents recommend suboccipital decompression as the first tretatment modality. ]]> Informe preliminar
]]> Methods: In a retrospective study we analyzed 360 hídrocephalic patients treated endoscopically in 5 Pediatric Neurosurgical Services in Buenos Aires. 374 procedures were performed: 207 third-ventriculostomies, 70 septal fenestrations, 48 catheter implantations, 26 cyst-ventriculostomies, 11 septostomies, 7 catheter removals, 4 aqueductoplasties and 1 monroplasty.
Results: Third ventriculostomy was the mostfrequent procedure with a very low failure rate (19,8%). The overall complication rate was 4,5%. In pineal tumor related hydrocephalus, a simultaneous biopsy procedure was always successful.
Conclusions: Endoscopic treatment of hydrocephalus must always be considered as an effective method and as the first choice treatment in an important number of patients. Key words: complications, hydrocephalus, neuroendoscopy.]]> Methods: Fourformalin-fixed adults heads were examined using X 6 to X 40 magnification. The vessels were filled with colored silicon.
Results: The dfferent approaches to the basilar bifurcation are: 1) subtemporal approach; 2) transylvian approach; 3) pretemporal approach; 4) transcavernous approach; 5) anterior transpetrosal approach and; 6) trans third ventricle approach. Conclusion: The knowledge of the different approaches to the basilar bifurcation is important in the management of the lesions in this region.]]> Methods: Four formalin-fixed adults heads were examined using X 6 to X 40 magnification. The vessels were filled with colored silicon.
Results: The branches arising from the P1 are: 1) the posterior thalamoperforating arteries; 2) the short and long circumflex branches; 3) the medial posterior choroidal artery; and 4) the meningeal branch of Davidoff and Schechter.
Conclusion: the correct knowledge of the anatomy of the P1 segment of the posterior cerebral artery is very important in the treatment of lesions located in the interpeduncular cistern.
]]> Methods: Angiograms of 106 PCom aneurysms were reviewed.
Results: Fetal Posterior Cerebral Artery was found in 19,8% of the cases; 57,5% of the aneurysms originated in the carotid artery; 78% of the aneurysms were small (less than 10 mm).
Conclusion: Pcom aneurysms most frequently arise from the carotid artery itself. The presence of a fetal posterior cerebral artery is not related to the development of Pcom aneurysms.]]> Description: We present a 67 year old woman with trigeminal neuropathy that arrives to the emergency room with fever, obtundation and meningeal signs. CT scan showed an hypodense les ion with edema.
Intervention: It was evacuated through craniotomy.
Conclusion: We emphasize that magnetic nuclear imaging should be performed for all patients with trigeminal neuropathy.]]> Material and Methods: The use of neuronavigation system was evaluated in 104 consecutive patients operated on during the period September 1999-April 2003 (Range of age: 5 months-75 years), Surgical procedures included the remotion of brain tumor, arteriovenous malformation, cavernous angiomas and epilepsy surgeries. The neuronavigation system is the Elekta Insight TM View Scope R(Elekta Instrument).
Results: The additional time requiredfor preoperative organization of the Neuronavigation system was 30 minutes. There were no differences during the registration process related to the surgical position (prone, supine and park-bench). The reference system registered movements in 5 patients. Neuronavigation system allows preoperative planning of the surgical approach, to guide endoscopical procedures, perform smaller craniotomies, localize deep-seated subcortical lesions, identify the boundaries of lowgrade tumors and evaluate the extent of resection in epilepsy surgeries.
Conclusions: Neuronavigation system improves the surgical approach of intracranial surgeries allowing to short the operating time, define the less invasive trajectory, and identify the margins of low-grade lesions.]]>