Mariano Arrazola

Trochlear nerve palsy after repeated percutaneous balloon compression for recurrent trigeminal neuralgia: case report and pathogenic considerations.

OBJECTIVE AND IMPORTANCERepeated percutaneous balloon compression for the treatment of idiopathic trigeminal neuralgia is infrequent. When a second procedure is performed, the outcome is unknown. A patient developed an isolated trochlear nerve palsy after undergoing percutaneous trigeminal ganglion balloon compression for a second time. The mechanism of diplopia and the complications associated with this technique were studied. CLINICAL PRESENTATIONThe patient was a 67-year-old woman with a history of medically refractory idiopathic trigeminal neuralgia involving all three divisions of the right trigeminal nerve. INTERVENTIONPercutaneous balloon compression was performed. Despite initial total relief from pain without complications, the patient again displayed manifestations of trigeminal neuralgia 3 months after the procedure. The pain disappeared after she underwent a second balloon compression procedure, but she developed an isolated trochlear nerve palsy, which spontaneously resolved in 2 months. CONCLUSIONIsolated trochlear nerve palsy is a rare and reversible complication after percutaneous balloon compression for trigeminal neuralgia. This case illustrates that the mechanism of injury to the fourth nerve is the result of an erroneous technique: excessive penetration of the Fogarty catheter in Meckel’s cave beyond the porus trigemini and compression of the cisternal segment of the trochlear nerve when the inflated balloon is pushed against the tentorium.

Therapeutic strategies targeting glioblastoma stem cells.

Glioblastoma is the most common, aggressive and lethal brain tumor in adults. However, current therapeutic protocols have low success rates and average overall survival is less than 15 months. The resistance to therapy is largely a result of the remarkable cellular and phenotypical heterogeneity that characterizes this type of tumor. The discovery of a subpopulation of cells exhibiting stem cell properties within the tumor bulk has profound implications for therapy as increasing evidence indicates that these cells, glioblastoma stem cells (GSCs), are responsible for the origin, maintenance and recurrence of the glioblastomas. These findings highlight the need to characterize GSCs in order to find novel treatments directly targeted specifically against them. In this review, we summarize the current knowledge regarding this issue, including some recent and relevant patents.

Macroscopic effects of percutaneous trigeminal ganglion compression (Mullan's technique): an anatomic study.

After the use of Mullans technique, macroscopic changes take place on the gasserian ganglion and the surrounding structures. These changes were studied on 20 trigeminal nerves of 10 fresh adult cadavers. Changes took place on the dura as well as in the neural elements. There was compression on the ganglion and on the trigeminal nerve, and there were changes in the position of the trigeminal root, with shortening of its cisternnal segment. When the balloon was inflated to capacity (0.75-1.0 ml), dural stretching in am area of 15×10 mm took place. This stretching of the dura extended from the lateral wall of the cavernous sinus to the level of the porus trigemini. Despite these important mechanical effects, we never found a rupture or tear on the dura or the trigeminal nerve fibers. We discuss the relationship between mechanical effects and clinical results

Macroscopic Effects of Percutaneous Trigeminal Ganglion Compression (Mullan's Technique)

After the use of Mullans technique, macroscopic changes take place on the gasserian ganglion and the surrounding structures. These changes were studied on 20 trigeminal nerves of 10 fresh adult cadavers. Changes took place on the dura as well as in the neural elements. There was compression on the ganglion and on the trigeminal nerve, and there were changes in the position of the trigeminal root, with shortening of its cisternal segment. When the balloon was inflated to capacity (0.75-1.0 ml), dural stretching in an area of 15 x 10 mm took place. This stretching of the dura extended from the lateral wall of the cavernous sinus to the level of the porus trigemini. Despite these important mechanical effects, we never found a rupture or tear on the dura or the trigeminal nerve fibers. We discuss the relationship between mechanical effects and clinical results.

Plasmocitoma de base craneal con inestabilidad cráneo-cervical

Resumen Introduccion La inestabilidad craneo-cervical constituye, en ocasiones, el principal problema neuroquirurgico en la patologia tumoral de la base craneal posterior. Presentamos un caso clinico en el que un plasmocitoma solitario origino inestabilidad craneocervical. Durante la cirugia de estabilizacion, se lesiono la arteria vertebral. Revisamos la anatomia quirurgica desde el punto de vista de la prevencion de las complicaciones vasculares. Caso clinico Mujer de 66 anos diagnosticada de plasmocitoma solitario de base craneal, tratada con radio y quimioterapia con remision completa, que presenta tetraparesia y disfagia. Tras el diagnostico de inestabilidad craneo-cervical, se indica estabilizacion mediante instrumentacion occipito-cervical. Es intervenida bajo traccion craneal con atornillado C1-C2 segun tecnica de Magerl y extension occipital. Durante la cirugia se lesiono la arteria vertebral derecha sin repercusion clinica. Dos anos mas tarde, la paciente es capaz de llevar una vida independiente. Conclusiones La instrumentacion craneo-cervical con tornillos transarticulares C1-C2, como parte del sistema de fijacion C0-C1-C2, parece eficaz para corregir la inestabilidad en lesiones osteoliticas, a expensas de un riesgo considerable de lesion de la arteria vertebral, especialmente en presencia de algunas variaciones anatomicas.

Funciones y organización de un comité de neurooncología en un hospital con servicio de neurocirugía

The Neuro-Oncology Study Group (NOSG) at SENEC has commissioned the elaboration of the present document to the Neuro-Oncology Committee at Donostia University Hospital. It is intended to serve as a NOSG Consensus Guide and a proposed recommendation for the management of this pathological condition at all Spanish Hospitals, both public and private. Neuro-Oncology Committees must be established and active at all centres with a Neurosurgery Service, taking into account the specific diagnostic and therapeutic capacity available. The work presents an example of the constitution, functioning and experience of such a Committee, drawing on 8 years of multidisciplinary work with brain tumour patients.

Referencias anatómicas y límites quirúrgicos en el abordaje suboccipital transmeatal del neurinoma acústico

Resumen Introduccion En la extirpacion completa del neurinoma acustico por via suboccipital retrosigmoidea, es obligada la apertura de la pared posterior del conducto auditivo interno (CAI). Por lo tanto, uno de los pasos clave en el abordaje quirurgico transmeatal es el fresado del CAI. Sin embargo, no existen claras referencias anatomicas intraoperatorias para la identificacion de estructuras tales como los canales semicirculares, el golfo de la vena yugular o las celdas aereas. Las variaciones anatomicas individuales y las producidas por el propio tumor, obligan en cada caso a una correcta planificacion preoperatoria, si queremos evitar complicaciones secundarias a su lesion yatrogena (cofosis, licuorrea, hemorragia y embolismo aereo). Objetivo Se expone la experiencia del primer autor firmante (EU) en el fresado del CAI con especial referencia a la topografia anatomica y limites quirurgicos en el abordaje suboccipital retrosigmoideo a la porcion intracanalicular del neurinoma acustico. Material y metodos Este trabajo esta basado en datos anatomicos obtenidos del fresado de huesos temporales normales extraidos de material autopsico junto a nuestra experiencia sobre 20 pacientes intervenidos de neurinoma acustico siguiendo la tecnica y protocolo de Samii. Resultados No hemos intervenido por esta via ningun tumor puramente intracanalicular. 2 casos han sido de grado II (hasta 20mm de diametro), 12 de grado III y 6 casos de grado IV. En ningun caso se ha llegado a fresar tanto como para visualizar el fondo del CAI, lo que se confirmo con el TAC postoperatorio; a pesar de ello en 17 casos se ha considerado la extirpacion como completa. No ha existido mortalidad y no hemos tenido complicaciones mayores atribuidas al fresado del CAI, como licuorrea o embolismo aereo. No podemos asegurar que la hipoacusia o la cofosis postoperatoria, que han sido la regla excepto en un caso de grado II, haya sido causada por lesion nerviosa, laberintica o isquemica. Conclusiones En nuestro material no ha sido posible la exposicion completa del fondo del CAI por via retrosigmoidea sin lesionar alguna estructura laberintica. Las zonas de mayor riesgo de complicaciones secundarias al fresado son la pared inferior y el fondo del CAL La extension medial de la craniectomia suboccipital facilita al fresado y a la exposicion tumoral intrameatal. No existen referencias intraoperatorias para localizar las estructuras petrosas durante el fresado del CAI excepto la propia experiencia del cirujano.

Spinal cord compression due to a epidural lipoma

INTRODUCTION The spinal extradural space is normally occupied by adipose tissue and a venous plexus, so it should be not surprising that lipomas arise and reach sufficient size to compress symptomatically the spinal cord. Nevertheless, the spinal epidural lipomas are rare and benign tumours may present as a progressive spinal cord compression syndrome. Magnetic resonance imaging is useful in demonstrating the full extent and characteristics of these lesions, the severity of cord compression and the location in the canal. Usually, the lesion is amenable to total surgical extirpation and the functional prognosis is good. Histopathologically the tumour consists of a mature adipose cells matrix intermixed with vascular endothelial channels, that is the reason why it is also named angiolipomas. CASE REPORT A 47 year-old woman complained of dorsal and bilateral submamarian pain lasting two years and progressive loss of sensibility and weakness in her legs. Following magnetic resonance studies a posterior spinal cord compression by an extradural tumour at T3-T7 levels was observed. She was operated on and we found an extradural yellow tumour easily to dissect and it was completely removed. One year later she is asymptomatic. CONCLUSIONS Spinal epidural lipoma is a benign tumour which initially presents itself with local or radicular pain accompanied by progressive spinal cord compression syndrome. The choice treatment is laminectomy and total excision. Probably, this is one of the easiest tumours to remove of the spinal canal and a source of satisfaction because a complete recovery can usually be achieved.

PR-LncRNA signature regulates glioma cell activity through expression of SOX factors

Long non-coding RNAs (LncRNAs) have emerged as a relevant class of genome regulators involved in a broad range of biological processes and with important roles in tumor initiation and malignant progression. We have previously identified a p53-regulated tumor suppressor signature of LncRNAs (PR-LncRNAs) in colorectal cancer. Our aim was to identify the expression and function of this signature in gliomas. We found that the expression of the four PR-LncRNAs tested was high in human low-grade glioma samples and diminished with increasing grade of disease, being the lowest in glioblastoma samples. Functional assays demonstrated that PR-LncRNA silencing increased glioma cell proliferation and oncosphere formation. Mechanistically, we found an inverse correlation between PR-LncRNA expression and SOX1, SOX2 and SOX9 stem cell factors in human glioma biopsies and in glioma cells in vitro. Moreover, knock-down of SOX activity abolished the effect of PR-LncRNA silencing in glioma cell activity. In conclusion, our results demonstrate that the expression and function of PR-LncRNAs are significantly altered in gliomagenesis and that their activity is mediated by SOX factors. These results may provide important insights into the mechanisms responsible for glioblastoma pathogenesis.

[Neuronavigation in the surgery for atlantoaxial instability: «the spinal shift»].

Hemos leído con atención el artículo publicado por Bescós et al en un número anterior de Neurocirugía1. Los autores presentaron una serie casos de pacientes con inestabilidad de las primeras dos vértebras cervicales operados mediante dos técnicas: la instrumentación transarticular de Magerl y la estabilización interarticular de Goel. El mismo grupo, del Hospital Universitario Germans Trias i Pujol de Barcelona, había publicado su experiencia con la primera técnica en 20022. Al igual que los autores, nuestro grupo incorporó la técnica de Goel3 y la neuronavegación para el tratamiento de estos pacientes. De nuestra experiencia, pudimos extraer las siguientes conclusiones que podrían complementar la discusión que tan acertadamente presentan los autores sobre estas técnicas, que en el momento actual siguen en constante evolución. Pedimos disculpas de antemano si incurrimos en repeticiones de conceptos que los citados autores han descrito con mayor eficacia.