[Auditory-evoked brainstem response in a schwannoma of the VIIIth cranial nerve: an anatomophysiological and functional correlation. Our experience]. / Respuesta evocada auditiva de tronco en el schwannoma del VIII par: correlación anatomofisiológica y funcional. Nuestra experiencia.

INTRODUCTION: Schwannomas are tumors charasteristically originated from the nerve sheath. They expande eccentrically from the nerve promoting a disturbance in the neural function either due to vascular compresion or to the effect of the tumor itself on the nerve, disturbance that can be evidenced with the Auditory-evoked Brainstem Response (ABR), fact that constituted the base for their diagnosis in the past. The new radiological techniques developed over the last decades have made possible an earlier diagnosis, and therefore changed their prognosis in terms of nerve function. Diagnosis is more certain today with these techniques so it could seem that ABR may not have any longer a role in the management of this condition. OBJECTIVE: To describe the most frequent ABR patterns in those patients suffering from acoustic schwannoma related to the size of the tumour and the remanent audition thresholds, and to determine the value of this test in our practice. MATERIAL AND METHODS: We describe the ABR features found in our series of 72 patients. Whose diagnosis was done between 1997 and 2003 in relation to the size of the tumour and the residual auditory function. RESULTS AND CONCLUSIONS: ABR has a good sensibility for detection of acoustic schwannoma. This sensibility decreases in small-sized tumours, specially in intracanalicular ones. ABR patterns do not relate to the size of the tumour but they do to the auditory function. The authors defend ABR to be a very valuable test due to the information and accesibility they provide.

Respuesta evocada auditiva de tronco en el schwannoma del VIII par: correlación anatomofisiológica y funcional. Nuestra experiencia / Auditory-evoked brainstem response in a schwannoma of the VIIIth cranial nerve: an anatomophysiological and functional correlation. Our experience

Introducción: Los schwannomas son tumores que se originan a partir de las células de schwann de la vaina neural. Se extienden excéntricamente desde el nervio y producen un trastorno de la función neural, tanto por compresión vascular como por la propia acción del tumor sobre el nervio, que puede ser demostrado mediante pruebas de Potenciales Evocados Auditivos de Troncoencéfalo (PEATC), hecho que fue antaño la base para su diagnóstico. Las nuevas técnicas radiológicas desarrolladas en las últimas décadas han posibilitado un diagnóstico más precoz y, por tanto, un cambio en su pronóstico en términos de función. Hoy día, con estas técnicas, el diagnóstico es más certero y podría parecer que los PEATC ya no tienen papel alguno en el manejo de esta entidad. Objetivo: Determinar los patrones de registro de PEATC más frecuentes en pacientes afectos de schwannoma del VIII par en relación al tamaño del tumor y de la audición residual y hallar el valor que dicha prueba tiene en nuestro medio hoy día en el manejo de esta entidad. Material y métodos: Describimos los hallazgos más frecuentes en el registro de PEATC de nuestra serie de 72 pacientes afectos de schwannoma del VIII par craneal, cuyo diagnóstico fue realizado entre 1997 y 2003, en relación con el tamaño tumoral y la función auditiva residual. Resultados y conclusiones: Los PEATC tienen una alta sensibilidad para la detección del schwannoma del VIII par. Esta sensibilidad disminuye sustancialmente en tumores de pequeño tamaño, especialmente los intracanaliculares. Los patrones del registro no guardan relación con el tamaño tumoral pero sí con la función auditiva del paciente. Los autores creemos que es una prueba que todavía hoy tiene un gran valor por la información que proporciona así como por su accesibilidad

Introduction: Schwannomas are tumors charasteristically originated from the nerve sheath. They expande eccentrically from the nerve promoting a disturbance in the neural function either due to vascular compresion or to the effect of the tumor itself on the nerve, disturbance that can be evidenced with the Auditory-evoked Brainstem Response (ABR), fact that constituted the base for their diagnosis in the past. The new radiological techniques developed over the last decades have made possible an earlier diagnosis, and therefore changed their prognosis in terms of nerve function. Diagnosis is more certain today with these techniques so it could seem that ABR may not have any longer a role in the management of this condition. Objective: To describe the most frequent ABR patterns in those patients suffering from acoustic schwannoma related to the size of the tumour and the remanent audition thresholds, and to determine the value of this test in our practice. Material and methods: We describe the ABR features found in our series of 72 patients. Whose diagnosis was done between 1997 and 2003 in relation to the size of the tumour and the residual auditory function. Results and conclusions: ABR has a good sensibility for detection of acoustic schwannoma. This sensibility decreases in smallsized tumours, specially in intracanalicular ones. ABR patterns do not relate to the size of the tumour but they do to the auditory function. The authors defend ABR to be a very valuable test due to the information and accesibility they provide

[Mnemonic performance in patients following surgery to treat an aneurysm affecting the anterior circulation of the brain]. / Rendimientos mnésicos en pacientes intervenidos de un aneurisma de la circulación cerebral anterior.

INTRODUCTION: Patients submitted to surgery to treat a brain aneurysm, who have suffered a subarachnoid haemorrhage, sometimes present cognitive disorders that can affect their social, familial, academic or occupational relationships. Memory disorders are frequent, although other cognitive functions may also be affected. AIMS: The purpose of this research work was to study performance in logical verbal memory and visual-constructional memory in subjects following a surgical intervention (at least a year ago) to treat an aneurysm in the territory of the anterior circulation of the brain. We also wanted to analyse whether the location of the aneurysm in the brain had any effect on memory performance. PATIENTS AND METHODS: We examined a sample of 24 adult subjects of both sexes, with no previous history of cognitive or psychiatric disorders, who had undergone surgical treatment of brain aneurysms in the middle cerebral, anterior communicating and posterior communicating arteries. Neuropsychological tests were performed to assess the general cognitive status, as well as logical verbal and visual-constructional memory. RESULTS: 79% of the patients present a general cognitive status within the range of what could be considered to be normal. In logical verbal memory, 92% present performances within the limits of the expected range of values and 83% did the same in visual-constructional memory. Depending on the location of the aneurysm, significant differences were only found in the delayed evocation of logical verbal material. CONCLUSIONS: A year after the intervention, most of the patients present a pattern of normality in the general cognitive status, and in logical verbal and visual-constructional memory. Yet, in spite of the good neurological resolution, alterations to memory are still to be found, although less frequently. The anatomical location of the aneurysm in the brain affects performance in tasks involving delayed logical verbal memory.

Rendimientos mnésicos en pacientes intervenidos de un aneurisma de la circulación cerebral anterior / Mnemonic performance in patients following surgery to treat an aneurysm affecting the anterior circulation of the brain

Introducción. Los sujetos intervenidos de aneurisma cerebral, que han sufrido una hemorragia subaracnoidea, presentan en ocasiones trastornos cognitivos que pueden alterar sus relaciones sociales, familiares, académicas o laborales. Las alteraciones en la memoria son frecuentes, aunque también pueden afectarse otras funciones cognitivas. Objetivos. Estudiar los rendimientos en memoria verbal lógica y memoria visuoconstructiva en sujetos que se han intervenido (al menos hace un año) de aneurisma en el territorio de la circulación cerebral anterior. Analizar también si estos rendimientos en memoria varían en función de la localización cerebral del aneurisma. Pacientes y métodos. 24 sujetos adultos de risma. Doentes e métodos. 24 indivíduos adultos de ambos os sexos, sem antecedentes de perturbação cognitiva nem psiquiátrica prévia, submetidos a intervenção sobre aneurisma cerebral em: cerebral média, comunicante anterior e comunicante posterior. Efectuam-se testes neuropsicológicos para avaliar a situação cognitiva geral, memória verbal lógica e visuoconstrutiva. Resultados. 79 por ciento dos doentes apresentam uma situação cognitiva geral dentro do intervalo de normalidade. Na memória verbal lógica, 92 por ciento apresentam rendimentos dentro do esperado e 83 por ciento na memória visuoconstrutiva. Em função da localização do aneurisma, apenas existem diferenças significativas na evocação atrasada de um material verbal lógico. Conclusões. Um ano após a intervenção, a maioria dos doentes apresenta um padrão de normalidade na situação cognitiva geral, memoria verbal lógica e visuoconstrutiva; contudo, apesar da boa resolução neurológica, podemos encontrar alterações na memória, embora com menor frequência. A localização anatómica cerebral do aneurisma influi sobre os rendimentos em tarefas da memória verbal lógica atrasada (AU)

Introduction. Patients submitted to surgery to treat a brain aneurysm, who have suffered a subarachnoid haemorrhage, sometimes present cognitive disorders that can affect their social, familial, academic or occupational relationships. Memory disorders are frequent, although other cognitive functions may also be affected. Aims. The purpose of this research work was to study performance in logical verbal memory and visual-constructional memory in subjects following a surgical intervention (at least a year ago) to treat an aneurysm in the territory of the anterior circulation of the brain. We also wanted to analyse whether the location of the aneurysm in the brain had any effect on memory performance. Patients and methods. We examined a sample of 24 adult subjects of both sexes, with no previous history of cognitive or psychiatric disorders, who had undergone surgical treatment of brain aneurysms in the middle cerebral, anterior communicating and posterior communicating arteries. Neuropsychological tests were performed to assess the general cognitive status, as well as logical verbal and visual-constructional memory. Results. 79% of the patients present a general cognitive status within the range of what could be considered to be normal. In logical verbal memory, 92% present performances within the limits of the expected range of values and 83% did the same in visual-constructional memory. Depending on the location of the aneurysm, significant differences were only found in the delayed evocation of logical verbal material. Conclusions. A year after the intervention, most of the patients present a pattern of normality in the general cognitive status, and in logical verbal and visual-constructional memory. Yet, in spite of the good neurological resolution, alterations to memory are still to be found, although less frequently. The anatomical location of the aneurysm in the brain affects performance in tasks involving delayed logical verbal memory (AU)

[Mnemonic performance in mild traumatic brain injury]. / Rendimientos mnésicos en el traumatismo craneoencefálico leve.

INTRODUCTION: Over the past few years there has been a lot of discussion over whether the mnemonic disorders that can appear after a mild traumatic brain injury (TBI) present as transitory deficits or can remain as permanent sequelae. AIMS: To study whether there are mnemonic disorders in mild TBI or not, and to examine their evolution over the first year. PATIENTS AND METHODS: 60 adult subjects of both sexes with mild TBI, all of whom satisfied the criteria of the Mild Traumatic Brain Injury Interdisciplinary Special Interest Group of the American Congress of Rehabilitation Medicine, were studied at four different moments of their evolution (during the first seven days, at one month, at six months and at one year after the traumatism). The sample was completed with 60 normal adult subjects who shared similar demographic characteristics. MATERIAL: clinical scales for measuring TBI, cognitive screening tests and neuropsychological mnemonic tests that measure verbal learning, immediate and delayed logical verbal memory, visuospatial and visuo constructive memory. STATISTICAL ANALYSIS: data were analysed using ANOVA of repeated measures and a posteriori testing using Scheffe F test. CONCLUSIONS: Memory was affected in these patients for at least the first week after the traumatic injury took place. At one month, immediate and delayed logical verbal memory and visuo constructive memory showed cognitive performances that were similar to the control group. Learning and the verbal auditory capacity to retain a list of words were still altered one year after the traumatic injury occurred.

[High jugular bulb and its relationship with acoustic neurinoma surgery]. / Golfo yugular prominente y su repercusión en la cirugía de los neurinomas del acústico.

The jugular bulb is formed by the junction of the sigmoid sinus, inferior petrous sinus and the jugular vein. It is housed in the jugular fossa of the petrous pyramid. Variations in its size, location and relationship to the internal acoustic canal (IAC) have been reported. When the jugular bulb is located medial and less than 2 mm from the posterior wall of the internal acoustic canal, it is named as high jugular bulb. If the surgeon is not aware of this variation, damage to this structure can result in profuse haemorrhage and air embolism. This anatomical change also makes difficult the access to the intracanalicular portion of acoustic neurinomas when these tumours are excised by a retrosigmoid approach. We present the case of a patient with an acoustic schwannoma in whom a preoperative axial cranial CT revealed a high jugular bulb. To control this venous structure, we opened the IAC in a longitudinal manner achieving a total excision of the lesion preserving the function of the facial nerve. We conclude that preoperative radiological investigations in acoustic schwannomas surgery should include cranial MR and TC, to rule out the presence of a high jugular bulb. Cranial axial CT including bony windows and slices of 1.5 mm thick, should be carried out to exclude a high jugular bulb.

Rendimientos mnésicos en el traumatismo craneoencefálico leve / Mnemonic performance in mild traumatic brain injury

Introducción. En los últimos años se ha cuestionado mucho si las alteraciones mnésicas que pueden aparecer tras un traumatismo craneoencefálico (TCE) leve se presentan como déficit transitorios o pueden mantenerse como secuelas permanentes. Objetivo. Estudiar la existencia o no de alteraciones mnésicas en TCE leve y su evolución a lo largo del primer año. Pacientes y métodos. 60 sujetos adultos de ambos sexos con TCE leve estudiados en cuatro momentos evolutivos -durante los primeros siete días, al mes, a los seis meses y al año del traumatismo-, que cumplían los criterios de Mild Traumatic Brain Injury Interdisciplinary Special Interest Group of the American Congress of Rehabilitation Medicine, y 60 sujetos adultos normales con características demográficas similares. Material: escalas clínicas para medir la gravedad del TCE, tests de rastreo cognitivos y pruebas neuropsicológicas mnésicas que miden aprendizaje verbal, memoria verbal lógica inmediata y demorada, memoria visuoespacial y visuoconstructiva. Análisis estadísticos: ANOVA de medidas repetidas y pruebas a posteriori Scheffe F-test. Conclusiones. La memoria se afecta en estos pacientes al menos durante la primera semana después del traumatismo. La memoria verbal lógica inmediata y demorada y la memoria visuoconstructiva muestran al mes rendimientos cognitivos similares al grupo control. El aprendizaje y capacidad de retención auditiva verbal de una lista de palabras continúan alterados al año del traumatismo (AU)

Golfo yugular prominente y su repercusión en la cirugía de los neurinomas del acústico / High jugular bulb and its relationship with acoustic neurinoma surgery

El golfo de la yugular es una estructura venosa que se encuentra en la fosa yugular de la pirámide petrosa y que está formada por la confluencia de los senos sigmoideo, petroso inferior y de la vena yugular. Se han descrito variaciones en su tamaño, localización y relación con respecto al conducto auditivo interno (CAI). Cuando esta estructura venosa es medial y dista menos de 2 mm de la pared posterior del CAI, se le denomina golfo yugular alto o prominente. Esta variante anatómica representa una importante dificultad para el acceso quirúrgico a la porción intracanalicular de los neurinomas del acústico cuando son abordados por vía retrosigmoidea. Asimismo, si el cirujano no es consciente de esta anomalía, puede tener graves repercusiones quirúrgicas como hemorragia profusa o embolismo aéreo. Presentamos el caso de un paciente con un schwannoma del acústico en el que se diagnosticó un golfo yugular prominente mediante estudios preoperatorios de TC. Para controlar esta estructura venosa, se realizó una apertura longitudinal del CAI, llevándose a cabo una exéresis total del tumor y respetándose la función del nervio facial. Concluimos que los estudios radiológicos preoperatorios de la cirugía de los schwannomas del acústico deben incluir RM y TC craneal siendo necesarias, en esta última, ventanas óseas con cortes finos de 1.5 mm para poder identificar una posible presencia de un golfo yugular prominente (AU)