Analysis of the Asterion Morphology in Relation to Its Clinical Significance / Análisis de la Morfología del Asterion en Relación con su Importancia Clínica

SUMMARY: The asterion presents a significant anthropological marking and meeting point between three sutures. It is a surface landmark for the transverse-sigmoid venous sinus complex and is also a surgical landmark for access to the posterior cranial fossa, giving it clinical importance. The aim of this research was to analyze the shape of the asterion and to set the measurement methods that will determine distance between the asterion and surrounding features. The study sample, as a part of the Osteological collection of the Department of Anatomy, Faculty of Medicine Novi Sad, consisted of 43 skulls. Morphometric analysis was related to the measurement of the defined parameters and descriptive analysis presented the classification of asterion in relation to the presence of sutural bones, as well as the determination of the position of the asterion according to the transverse-sigmoid venous complex. There was a statistically significant difference between male and female skulls for all the measured parameters. The results show that 34.88 % were type 1 (one or more sutural bones are present) and 65.12 % were type 2 asteria (no sutural bones are present). More frequent occurrence of asteria type 2 was seen on both, male and female skulls. The most frequent position of the asteria on both sides of the skull was in the transverse- sigmoid venous complex (76.92 % on the right side vs. 72.22 % on the left cranial side). Clinical significance of knowing the area of asterion is reflected in order to make the surgical, as well as diagnostic procedures, as successful as possible.

El asterion presenta una importante marca antropológica y punto de encuentro entre tres suturas. Es un punto de referencia de superficie para el complejo del seno venoso sigmoideo transverso y también es un punto de referencia quirúrgico para el acceso a la fosa craneal posterior, lo que le confiere importancia clínica. El objetivo de esta investigación fue analizar la forma del asterión y establecer los métodos de medición que determinarán la distancia entre el asterión y las características circundantes. La muestra del estudio, que forma parte de la colección osteológica del Departamento de Anatomía de la Facultad de Medicina de Novi Sad, estuvo compuesta por 43 cráneos. El análisis morfométrico se relacionó con la medición de los parámetros definidos y el análisis descriptivo presentó la clasificación del asterion en relación a la presencia de huesos suturales, así como la determinación de la posición del asterion según el complejo venoso transverso-sigmoideo. Hubo una diferencia estadísticamente significativa entre los cráneos masculinos y femeninos para todos los parámetros medidos. Los resultados muestran que el 34,88 % eran tipo 1 (hay uno o más huesos suturales presentes) y el 65,12 % eran asteria tipo 2 (no hay huesos suturales presentes). Se observó una aparición más frecuente de asteria tipo 2 en cráneos tanto masculinos como femeninos. La posición más frecuente de la asteria en ambos lados del cráneo fue en el complejo venoso sigmoideo transverso (76,92 % en el lado derecho vs. 72,22 % en el lado craneal izquierdo). La importancia clínica de conocer el área de asterion se refleja en que los procedimientos quirúrgicos y de diagnóstico tengan el mejor resultado posible.

Posterior fossa choroidplexus papilloma in the pediatric population: case series and literature review / Papiloma de plexo coroide na fossa posterior na população pediátrica: série de casos e revisão da literatura

Abstract Choroid plexus papillomas (CPPs) are rare benign neoplasms which are particularly uncommon in the posterior fossa in children. We herein present a case series of five patients treated at a tertiary care hospital. A comprehensive literature review was also carried out. The patients treated at the tertiary care hospital were aged between 4 and 16 years. Gross total resection (GTR) was initially achieved in two patients. All patients showed clinical improvement. Moreover, 27 articles published between 1975 and 2021 were selected for the literature review, totaling 46 patients; with the 5 patients previously described, the total sample was composed of 51 cases, With a mean age was 8.2 years. The lesions were located either in the fourth ventricle (65.3%) or the cerebellopontine angle (34.7%). Hydrocephalus was present preoperatively in 66.7% of the patients, and a permanent shunt was required in 31.6% of the cases. The GTR procedure was feasible in 64.5%, and 93.8% showed clinical improvement. For CPPs, GTR is the gold standard treatment and should be attempted whenever feasible, especially because the role of the adjuvant treatment remains controversial. Neuromonitoring is a valuable tool to achieve maximal safe resection. Hydrocephalus is common and must be recognized and promptly treated. Most patients will need a permanent shunt. Though there is still controversy on its efficacy, endoscopic third ventriculostomy is a safe procedure, and was the authors' first choice to treat hydrocephalus.

Resumo Os papilomas do plexo coroide (PPCs) são neoplasias benignas raras e, na população pediátrica, são particularmente incomuns na fossa posterior. Apresentamos uma série de casos de cinco pacientes atendidos em um hospital terciário. Além disso, foi realizada uma ampla revisão da literatura. Os pacientes atendidos no hospital terciário tinham entre 4 e 16 anos. Ressecção macroscópica total (RMT) foi inicialmente realizada em dois pacientes. Todos os pacientes apresentaram melhora clínica. Além disso, 27 artigos publicados entre 1975 e 2021 foram selecionados para a revisão da literatura, totalizando 46 pacientes. Somados à série de casos atuais, encontramos 51 pacientes, com média de idade de 8,2 anos. As lesões localizavam-se no quarto ventrículo (65,3%) ou no ângulo pontocerebelar (34,7%). Hidrocefalia estava presente no pré-operatório em 66,7% dos pacientes, e derivação ventricular permanente foi necessária em 31,6% dos casos. A RMT foi possível em 64,5%, e 93,8% tiveram melhora clínica. Para os CPPs, a RMT é o tratamento padrão-ouro e deve ser tentado sempre que possível, especialmente porque ainda existem controvérsias quanto ao papel do tratamento adjuvante. A neuromonitorização é uma ferramenta importante para se atingir a máxima ressecção segura. A hidrocefalia é comumente vista nesses pacientes e deve ser identificada e tratada. A maioria dos pacientes irá precisar de uma derivação permanente. Apesar de persistirem controvérsias sobre sua eficácia, a terceiro-ventriculostomia endoscópica foi a primeira escolha para tratar a hidrocefalia na experiência dos autores e é uma opção segura.

A makeshift blue light filter for endoscopic identification of traumatic cerebrospinal fluid leak using fluorescein

Objective@#To describe a makeshift blue light filter for endoscopic visualization of a traumatic cerebrospinal fluid leak repair using intrathecal fluorescein and its application in one patient.@*Methods@# Study Design:Surgical Instrumentation Setting:Tertiary Government Training Hospital Patient:One @*Results@#Intra-operative endoscopic identification of fistulae sites was achieved using intrathecal injection of fluorescein that fluoresced using our makeshift blue light filter in a 43-year-old man who presented with a 3-month history of rhinorrhea due to skull base fractures along with multiple facial and upper extremity fractures he sustained after a fall from a standing height of 6 feet. He underwent transnasal endoscopic repair of cerebrospinal fluid fistulae in the planum sphenoidale, clivus and sellar floor. Post-operatively, there was complete resolution of rhinorrhea with no complications noted. @*Conclusion@#Our makeshift blue light filter made from readily available materials may be useful for endoscopic identification of CSF leaks using fluorescein in a low- to middle-income country setting like ours.

The relationship of the posterior cranial fossa with age and sex / Relación de la fosa craneal posterior con la edad y el sexo

SUMMARY: This paper determined the morphometric measurements of posterior cranial fossa using MRI in Turkish healthy population. Two hundred thirty one (231; 131 females and 100 males) subjects ranging from 20 up to 85 years were included in this study. Measurements of the posterior cranial fossa were taken from subjects having brain MRI in the Radiology Department, Adana, Turkey. Statistical analysis were done by SPSS 21.00 package programme. ANOVA Test and Chi-Square Test were used to determine the relation between measurements and age groups. The p<0.05 value was considered as significant. The overall means and standard deviations of the measurements were: Clivus length,31.10?5.45 mm; McRae line, 32.59?3.89 mm; Supraocciput length,41.99 ? 4.37 mm; Twining line, 79.23?5.53 mm; Posterior cranial fossa height, 66.76?5.06 mm; Cerebellum height, 55.17?5.29 mm; Clival angle, 125.59??6.57?; Cerebellar tentorium angle, 128.30??7.77? mm, Occipital protuberance angle, 93.27??8.02? and hindbrain vertical length, 50.56?3.47 mmin females, respectively, whereas the corresponding values were 32.43?5.99 mm; 32.85?3.77 mm; 42.46?4.68 mm; 80.95?5.94 mm; 69.70?4.67mm; 57.01?3.43 mm; 123.90??7.12? 128.80?8.33?; 95.35?9.19? and 52.71?3.33 mm in males, respectively. Significant difference was found in some parameters such as twining line, posterior cranial fossa height, cerebellum height and hindbrain vertical length between sex (p<0.05). Also, ages were divided into six groups as decades. Significant difference between six decades was also found in parameters including McRae line, twining line, posterior cranial fossa height, cerebellum height, clival angle, cerebellar tentorium angle, occipital tuberance angle and hindbrain vertical length (p<0.05). The posterior cranial fossa dimensions of healthy population provides important and useful knowledge in terms of comparison of abnormalities clinically, and data can be used as an anatomical landmark during surgery involving posterior cranial fossa.

RESUMEN: Se determinaron las medidas morfométricas de la fosa craneal posterior mediante resonancia magnética en una población turca. Se incluyeron doscientos treinta y un (231; 131 mujeres y 100 hombres) sujetos sanos con edades entre los 20 y los 85 años. Por medio de una resonancia magnética cerebral se tomaron medidas de la fosa craneal posterior de sujetos en el Departamento de Radiología de Adana, Turquía. El análisis estadístico se realizó mediante el programa de SPSS 21.00. Se utilizó la prueba ANOVA y la prueba de chi-cuadrado para determinar la relación entre las medidas y los grupos de edad. Se consideró significativo el valor de p <0,05. Las medias generales y las desviaciones estándar de las medidas en las mujeres fueron: longitud del clivus, 31,10 ? 5,45 mm; Línea McRae, 32,59 ? 3,89 mm; Longitud del supraoccipucio, 41,99 ? 4,37 mm; línea de Twining (desde el tubérculo selar hasta la confluencia de los senos), 79,23 ? 5,53 mm; Altura posterior de la fosa craneal, 66,76 ? 5,06 mm; Altura del cerebelo, 55,17 ? 5,29 mm; Ángulo clival, 125,59 ? ? 6,57 ?; Ángulo del tentorio cerebeloso, 128,30 ? ? 7,77 ? mm, Angulo de protuberancia occipital, 93,27 ? ? 8,02 ? y Longitud vertical del rombencéfalo, 50,56 ? 3,47 mm. En los hombres los valores obte- nidos fueron 32,43 ? 5,99 mm; 32,85 ? 3,77 mm; 42,46 ? 4,68 mm; 80,95 ? 5,94 mm; 69,70 ? 4,67 mm; 57,01 ? 3,43 mm; 123,90 ? ? 7,12 ? 128,80 ? 8,33 ?; 95,35 ? 9,19 ? y 52,71 ? 3,33 mm, respectivamente. Se encontraron diferencias significativas entre ambos sexos (p <0,05) en algunos de los parámetros, como la línea de Twining, la altura de la fosa craneal posterior, la altura del cerebelo y la longitud vertical del rombencéfalo. También se encontró una diferencia significativa entre las edades de los individuos (división en seis décadas) en los parámetros que incluyen la línea de McRae, la línea de Twining, la altura de la fosa craneal posterior, la altura del cerebelo, el ángulo de clivación, el ángulo de la tienda del cerebelo, el ángulo de protuberancia occipital y la longitud vertical del rombencéfalo (p <0,05). La población estudiada nos proporciona información importante y útil en términos de comparación clínica de anomalías y los datos pueden eventualmente ser utilizados como un punto de referencia anatómico durante la cirugía que involucra la fosa craneal posterior.

Comparison of Morphometry of Foramen Magnum and Posterior Cranial Fossa in Dry Human Skull

Bougie is an important adjunct in the anaesthesiologist armoury for a difficult airway1. Physical damage to bougie leading to airway trauma is rare but can be catastrophic. We report a case of an anticipated difficult extubation, where the bougie, used to extubate over the tube broke and migrated into the trachea indicating the need of a protocol for routine inspection of bougie which should be strictly adhered to

Morphometric Study of Posterior Cranial Fossa Using Computerized Tomographic (CT) Images

Introduction: The posterior cranial fossa is the largest and the deepest of the three fossae. Contents of posterior cranial fossa include occipital part of cerebral hemispheres, cerebellum, midbrain, pons and medulla oblongata. Variations in the volume of posterior cranial fossa may cause compression of these structures which may lead to various disorders. There is increasing evidence on the diagnostic potential of posterior cranial fossa measurements. The present study on morphometry of posterior cranial fossa based on CT images of patients without any clinical abnormality was undertaken for the first time in south Indian population. Subjects and Methods: To study and compare sex-wise and age-wise differences in the supratentorial and posterior cranial fossa (PF) measurements in the normal CT scan images of 62 males and 38 females who attended the Neurology department of SVIMS belonging to Rayalaseema region was undertaken. The measurements that were recorded are transverse diameter (TD) and anteroposterior diameter (APD) of supratentorial part and also posterior cranial fossa and height and volume of posterior cranial fossa. Results: The mean supratentorial TD and APD were found to be less in male but were not statistically significant sex-wise and age-wise. The mean posterior fossa APD was significant, PF height and volume were highly significantly in males. Discussion: There are no reports on supratentorial parameters in literature for comparing the results of present study. Except for one study on CT on height and volume of posterior cranial fossa there are no other studies for comparing the values of present study. Conclusion: Observations on supratentorial parameters of the present study are the first to be reported in literature.Age-wise and sex-wise observation of parameters of TD and APD of PF are the first to be reported in literature.

Endovascular Treatment Following Gauze Packing for the Control of Massive Bleeding from Traumatic Transverse Sinus Lesion / 대한신경손상학회지

Posterior fossa epidural hematoma (EDH) is uncommon, but the related clinical deterioration can occur suddenly. Accompanying venous sinus injury and lacerations are associated with 40% to 80% mortality. The authors present one clinical case of a patient with posterior fossa EDH from transverse sinus bleeding. A 57-year-old male was injured after falling while working. He was taken to the hospital, where computed tomography scans of his brain revealed a right posterior temporal and cerebellar EDH with a right temporo-occipital fracture. He underwent a right parieto-occipital craniotomy, incorporating the fracture line. Longitudinal laceration of the right transverse sinus extending to the sigmoid sinus with profuse bleeding was identified. Four gauzes were inserted in the epidural space for tamponade of the injured sinus. Conventional angiography and coil embolization for the injured sinus were immediately performed. Subsequently, the patient was transferred to the operating room, wherein staff members removed the gauzes and remnant hematoma. Based on this experience, the authors recommend that for posterior fossa EDH from transverse sinus bleeding, bleeding control should be performed by gauze packing and endovascular treatment.

Congenital Cholesteatoma of Mastoid Temporal Bone and Posterior Cranial Fossa Treated with Transmastoid Marsupialization / 대한이비인후과학회지

A congenital cholesteatoma is a benign mass formed from the keratinizing stratified squamous epithelium. It usually occurs in young children's anterosuperior part of the middle ear. A congenital cholesteatoma which originates from mastoid temporal bone or expands to posterior cranial fossa is rare. Standard treatment of an intracranial cholesteatoma is surgical removal with craniotomy. A 69-year-old woman was diagnosed with a congenital cholesteatoma of mastoid temporal bone that expanded to the posterior cranial fossa, which was successfully treated with transmastoid marsupialization without craniotomy. This is a first documented case of a congenital cholesteatoma of mastoid temporal bone that expanded to posterior cranial fossa, which was successfully treated with transmastoid marsupialization without craniotomy.

The intracranial and posterior cranial fossa volumes and volume fractions in children: a stereological study / Los volúmenes de la fosa craneal intracraneal y posterior y las fracciones de volumen en los niños: un estudio estereológico

SUMMARY: The size of intracranial cavity (IC) and posterior cranial fossa (PCF) plays an important role in the pathophysiology of various disorders. In this study, we aimed at establishing normal volume data of the IC and PCF in Turkish population according to age and sex by using stereological method. This study was carried out retrospectively on 339 individuals (168 females and 171 males) between 0 and 18 years old with no medical or neurological disorders that affected the skeletal morphology of the cranial cavity. Volumetric estimations were determined on computed tomography (CT) images using point-counting approach of stereological methods. Intracranial volume (ICV) and posterior cranial fossa volume (PCFV) were increased with age in both sexes. They reached adult dimensions at 5 years of age during the teenage years. According to sex; the mean ICV and PCFV were 1594.51±245.57cm3 and 244.89±53.86 cm3 in males, 1456.34±241.85 cm3 and 228.24±41.38 cm3 in females, respectively. Generally, significant differences were determined in ICV and PCFV according to sex after they reached maximum growth period. According to age the volume ratios of PCF to IC was ranged from 13.03 to 17.48 in males and 12.06 to 18.54 in females. This study demonstrated that these volume ratios could help the physician for both patient selections for surgery, and for the assessment of any surgical technique used to treatment of PCF malformations. However current study revealed that point counting method can produce accurate volume estimations and is effective in determining volume estimation of IC and PCF.

RESUMEN: El tamaño de la cavidad intracraneal (CI) y la fosa craneal posterior (FCP) desempeñan un papel importante en la fisiopatología de diversos trastornos. En este estudio, se pretende establecer los datos de volumen normal de la CI y FCP en la población turca, de acuerdo a la edad y el sexo, mediante el uso de métodos estereológicos. Este estudio se realizó retrospectivamente en 339 individuos (168 mujeres y 171 hombres) entre 0 y 18 años sin trastornos médicos o neurológicos que afectaron la morfología esquelética de la cavidad craneal. Las estimaciones volumétricas se determinaron en imágenes de tomografía computarizada (TC) utilizando el conteo de puntos de los métodos estereológicos. El volumen intracraneal (VIC) y el volumen posterior de la fosa craneal (VFCP) aumentaron con la edad en ambos sexos. Alcanzaron dimensiones adultas a los 5 años de edad durante la adolescencia. Según el sexo, el promedio de VIC y VFCP fue de 1594,51 ± 245,57 cm3 y de 244,89 ± 53,86 cm3 en los hombres, 1456,34 ± 241,85 cm3 y 228,24 ± 41,38 cm3 en las mujeres, respectivamente. En general, se determinaron diferencias significativas en VIC y VFCP de acuerdo con el sexo después de alcanzar el período de crecimiento máximo. Según la edad, las proporciones de volumen de FCP a CI oscilaban entre 13,03 a 17,48 en los hombres y 12,06 a 18,54 en las mujeres. Este estudio demostró que estas proporciones de volumen podrían ayudar al médico tanto en la selección de pacientes para la cirugía, como para la evaluación de cualquier técnica quirúrgica utilizada en el tratamiento de malformaciones de FCP. Además, el estudio actual reveló que el método de conteo de puntos puede producir estimaciones precisas de volumen siendo eficaz para determinar la estimación de volumen de IC y FCP.

Síndrome de Opalski, una variante del síndrome de Wallenberg: reporte de caso y revisión de la literatura / Opalski Syndrome, a variant of Wallenberg Syndrome: Case report and literature review

RESUMEN Se presenta un caso local de la variante de Opalski, del síndrome medular lateral (síndrome de Wallenberg) y se hace una revisión de la literatura sobre los síntomas de este cuadro clínico, así como las posibles razones que explican esta modificación en la expresión clínica. La variante de Opalski fue descrita en 1948, ochenta y nueve años después de la descripción original del síndrome por Adolf Wallenberg, su principal característica es la presencia de hemiparesia o hemiplejía del cuerpo del mismo lado de la lesión del bulbo raquídeo. La etiología es vascular en la mayoría de casos, por obstrucción de la arteria cerebelosa postero-inferior o de los ostium de vasos penetrantes que se originan en la arteria. No hay estudios que reporten la incidencia exacta de este cuadro clínico a nivel mundial, sin embargo, su presentación no es tan infrecuente. Lo más interesante al analizar cada caso, es que los hallazgos semiológicos son una muestra de la profunda organización del sistema nervioso.

SUMMARY A clinical case of the Opalski variant of the lateral medullary syndrome (Wallenberg's syndrome) is presented and a literature review about the symptoms of this clinical picture is done, as well as the possible reasons explaining this modification in the clinical expression. The Opalski variant was described in 1948, eighty-nine years after the original description of the syndrome by Adolf Wallenberg, its main feature is the presence of hemiparesis or hemiplegia of the ipsilateral side of the injury in the medulla oblongata. In most cases the etiology is vascular when the postero-inferior cerebellar artery is occluded or there is an obstruction of the ostium of penetrating vessels originating in the artery. There are no studies that accurately report the worldwide incidence of this clinical variant, however, its presentation is not uncommon. The most interesting discovery of each case is that semiological findings are a good example of the profound organization of the nervous system.

Surgical treatment of adult Dandy-Walker syndrome / 局解手术学杂志

Objective To discuss the surgical method and efficacy of adult Dandy-Walker syndrome ( DWS) through retrospective anal-ysis and literature review .Methods There were 3 cases of adult DWS in our hospital from August 2010 to August 2011.One case of them was given posterior cranial fossa cyst peritoneal shunt , and the surgery adopted ordinary high voltage shunt .Case 2 was given left side of the lateral ventricle peritoneal shunt , and the surgery adopted ordinary high voltage shunt .Case 3 was given posterior cranial fossa cyst peritoneal shunt combined with left side of the lateral ventricle peritoneal shunt , and the surgery adopted double-end high voltage shunt .The two ends of the shunt were respectively linked with the diverter valve and abdominal cavity drainage tube through T -branch pipe .Results Among the 3 patients, there was 1 case failed to ease the headache symptoms , and it was relieved one month later .The preoperative symptoms of the oth-er 2 cases disappeared immediately after the surgery .During the 4 years of follow-up,preoperative symptoms of the 3 patients disappeared , and there was no positive signs .Conclusion For adult patients with symptomatic DWS ,shunt surgery can eliminate symptoms ,relieve the tension of the posterior fossa cyst ,achieve good curative effect , and there was no surgical complication .

Management of syndromic craniosynostosis using posterior cranial vault distraction osteogenesis: preliminary findings / 中华整形外科杂志

Objective@#To explore the effect of managing syndromic craniosynostosis using posterior vault distraction osteogenesis.@*Methods@#The authors conducted a retrospective cohort study of four children with syndromic craniosynostosis treated between 2015 January to 2016 March using posterior vault distraction osteogenesis. The posterior craniotomy was performed from vertex, biparietally to a point above the occipital protuberance. Two distraction devices were fixed in the parasagittal, collinear position. After a latency of 3 days, the device was activated at 0.5 mm/day. After the distraction, the consolidation period was about 6 months.@*Results@#The average distraction distance was 27.3 mm(range, 25 to 30 mm). Cerebrospinal fluid leak happened in one patient. After taken the 3D CT scan, all of them were undertaken the second operation of removing the distraction devices. All the patients were followed up at a mean of 12.8 months (range, 7 to 20 months).@*Conclusions@#It is effective to enlarge the posterior cranial vault using distraction osteogenesis for the syndromic craniosynostosis.

Utilidad del coeficiente de difusión aparente en resonancia magnética como método auxiliar para la diferenciación entre meduloblastomas y ependimomas de la fosa craneal posterior en niños y adultos tratados en el Hospital Carlos Van Buren de Valparaíso: Una experiencia preliminar / Usefulness of apparent diffusion coefficient in magnetic resonance as an auxiliary method for the differentiation between medulloblastomas and ependymomas of the posterior cranial fossa in children and adults treated at the Carlos Van Buren Hospital in Valparaíso: A preliminary experience

The use of the apparent diffusion coefficient (ADC) in magnetic resonance imaging (MRI) has been shown to be useful in the task of differentiating primary brain tumors. Our objective is to evaluate its use to differentiate between medulloblastomas and ependymomas. We analyzed 37 cases: 21 medulloblastomas (average age 12 years) and 16 ependymomas (average age 5 years) of the posterior fossa treated at the Carlos Van Buren Hospital in Valparaíso between december 2005 and June 2015. There were 15 and 5 males in each group respectively. In addition to age and gender, ADC values of tumors (ADCt) and healthy tissue were collected. The ADCt values for medulloblastoma and ependymoma averaged 0.64 and 0.92 [x10-3 mm²/s] respectively (p< 0.001). The multivariate model included gender and ADCt, with a sensitivity of 0.95 and a specificity of 0.87 to predict medulloblastoma. We can conclude that ADC measurement helps differentiate tumors of different cellularity such as medulloblastoma and ependymoma.

El uso del coeficiente de difusión aparente (ADC) en resonancia magnética (RM) ha demostrado ser útil en la tarea de diferenciar tumores cerebrales primarios. Nuestro objetivo es evaluar su uso para diferenciar entre meduloblastomas y ependimomas. Se analizaron 37 casos: 21 meduloblastomas (edad promedio 12 años) y 16 ependimomas (edad promedio 5 años) de fosa posterior tratados en el hospital Carlos Van Buren de Valparaíso, entre diciembre de 2005 y junio de 2015. Hubo 15 y 5 hombres en cada grupo respectivamente. Además de edad y sexo se recolectaron valores ADC tumorales (ADCt) y de tejido sano. Los valores ADCt para meduloblastoma y ependimoma promediaron 0,64 y 0,92 [x 10-3 mm²/s] respectivamente (p<0,001). El modelo multivariado incluyó sexo y ADCt, con sensibilidad de 0,95 y especificidad 0,87 para predecir meduloblastoma. Podemos concluir que la medición de ADC ayuda a diferenciar tumores de distinta celularidad como el meduloblastoma y el ependimoma.

Considerations in Treating Neonatal and Infantile Patients with a Retrocerebellar Arachnoid Cyst: in the Perspective of Different CSF Dynamics

Arachnoid cysts found under the age of 1 year are more likely to grow in size, relatively short term follow-up is required. Retrocerebellar location predicts a high risk of hydrocephalus, and the time window until irreversible neuronal damage is often narrow if the arachnoid cyst increases in size and becomes symptomatic. However, when and how to treat a neonatal or infantile patient with a retrocerebellar arachnoid cyst is still a controversial subject. We recently experienced 3 differently treated very young pediatric patients with retrocerebellar arachnoid cysts. One patient was treated two weeks after birth by a cystoperitoneal shunt. This patient showed normal development after the surgery. The other patient was treated by a ventriculoperitoneal shunt and subsequent cystoventriculostomy at the age of 4 months because of his mother's refusal on 14th day after birth. This one showed developmental delay despite of decreasing size of ventricles after the surgery. The last patient was treated with microscopic fenestration, which failed in its initial attempt. A revision operation by cyst excision succeeded and had no problem after the surgery. Therefore, we suggest that early surgical intervention for retrocerebellar arachnoid cyst can be considered. Although there are concerns of long term complications related to shunts, a cystoperitoneal shunt would be a feasible treatment if we consider the minor cerebrospinal fluid pathway which is the dominant cerebrospinal fluid dynamic at this age.

Morphometric features of asterion in adult human skulls.

Background: Asterion is the meeting point of temporal, occipital and parietal bones on the posterolateral surface of skull and surgically an important point of reference for approaching the posterior cranial fossa structures. However surgeons have been skeptical about its reliability due to population based differences in its morphology, distance with other external landmarks and also to sigmoid and transverse sinuses. Methods: In this study 50 (27 male & 23 female) adult skulls were investigated to determine the type of asterion, its distance from important bony landmarks and also the nearby venous sinuses were measured. Results: Our study revealed that type II (absence of sutural bones) was commoner than type I (presence of sutural bones) asterion. The asterion was 4.82 ± 0.58 cm from tip of the mastoid process on the right side and 4.70 ± 0.70 cm on the left. It was greater in males than in females, p value being statistically significant (P = 0.00 & P = 0.02 for right & left sides respectively). The distance of asterion from supramastoid crest was 4.22 ± 0.73 cm on the right and 4.23+/-0.58 cm on the left. The distance in males was more than in females. The P value 0.00 was statistically significant on the right side. Regarding the position of the asterion in relation to transverse sinus, it was on the transverse sinus in 62% cases, below it in 32% and above in 6%. Conclusions: The data obtained shows that the asterion is located either at the level or below the level of the transverse sinus in majority of the cases. This information is useful to neurosurgeons to reduce the risk during posterior cranial fossa surgeries. This work will also be useful to anthropologists, forensic science experts for determination of sex of the skull along with other parameters.

The localization of the asterion according to the anatomical landmarks of posterior cranial fossa in newborns: clinical implications / Localización del asterión de acuerdo con los puntos anatómicos de la fosa craneal posterior en recién nacidos: implicaciones clínicas

The purpose of this study was to determine the localization of the asterion according to the anatomical landmarks of posterior cranial fossa and its relation with sinuses for posterolateral surgical approaches in newborns. On 70 head-halves, a needle about 2 mm with diameter was placed on the centre point of asterion (posterolateral fontanel) by inserting into the whole cranial bony tissue by forming an right angle with the bony surface. Various localizations of asterion and its measurements from the internal and external anatomical landmarks were investigated on term neonatal cadavers. The localization of asterion was found as on the sigmoid-transverse sinus junction (STJ) (5., 6., 7., 8. squares) in 40% of cases on right side and in 34%, on left side. Additionally, it was located below the STJ (9., 10., 11., 12. squares) in 60% of cases, on right side and in 63% of cases on left side. We determined that the most frequent localization of asterion as the 11. square both for the right and left sides 12 (34%) cases for the right side and 11 (31,4%) cases for the left side. The asterion was not located on 1., 2., 3., 4., 5. and 12. squares on right side and 1., 3., 4., 8. and 9. squares on left side. It has been found that the region of asterion has an average distance value of 19.9 mm to internal acoustic meatus (MI), 31.7 mm to posterior clinoid process (PC), 34.4 to dorsum sellae (DS), 19.2 mm to jugular foramen (FJ), 23.0 mm to hypoglossal canal (HC), internally. The distance of asterion as 28.8 mm to zygoma root (ZR) and 22.3 mm to Henle's spine (HS) and 15.8 mm to mastoid tip (MT) and 35.9 mm to external occipital protuberance (PE) were observed. By the guide of point asterion on newborns the area of 1cm2 on this point which was placed on superior 4 squares of our scale diagram is suggested as a safe area of placement of first burr hole to avoid from the risk of bleeding of sigmoid and transverse sinuses on craniotomies of posterior fossa.

El propósito de este estudio fue determinar la localización del asterion de acuerdo con los puntos anatómicos de la fosa craneal posterior y su relación con los senos de abordajes quirúrgicos posterolaterales en los recién nacidos. Fueron utilizadas 70 hemicabezas y se colocó una aguja de alrededor de 2 mm de diámetro en el punto central del asterion (fontanela posterolateral) en todo el tejido óseo craneal produciéndose la formación de un ángulo recto con la superficie ósea. La localización del asterion y las mediciones de los puntos de referencia anatómicos internos y externos fueron investigados en cadáveres de neonatos a término. La localización del asterion se encontró en la unión sinusal transverso sigmoide (STJ) (cuadrados 5., 6., 7., 8.) en el 40% de los casos en el lado derecho y en el 34%, en el lado izquierdo. Además, se encontró por debajo del STJ (cuadrados 9., 10., 11., 12.) en un 60% de los casos en el lado derecho y en el 63% de los casos en el lado izquierdo. Se determinó que la localización más frecuente del asterion fue 11., tanto para los lados derecho e izquierdo, 12 casos (34%) para el lado derecho y 11 casos (31,4%) para el lado izquierdo. El asterion no se encuentra en los cuadrados 1., 2., 3., 4., 5. y 12. del lado derecho y 1., 3., 4., 8. y 9. del lado izquierdo. Se determinó que la región del asterion tiene una distancia promedio de 19,9 mm al meato acústico interno, 31,7 mm al proceso clinoides posterior, 34,4 mm al dorso selar, 19,2 mm al foramen yugular y 23,0 mm al canal hipogloso, internamente. La distancia del asterion a la raíz del hueso cigomático fue 28,8 mm y 22,3 mm a la columna vertebral, siendo de 15,8 mm al proceso mastoides y 35,9 mm a la protuberancia occipital externa. En los recién nacidos, se sugiere un área de 1cm2 y se colocan en 4 casillas superiores de nuestro diagrama a escala, como una zona segura para la realización de la primera trepanación para evitar el riesgo de sangrado de los senos sigmoide y transverso en craneotomías de fosa posterior.

Dandy Walker: reporte de un caso / Dandy Walker: case report

Introducción: la malformación de Dandy­Walker es una alteración congénita que compromete el cerebelo y el cuarto ventrículo. Esta condición se caracteriza por agenesia o hipoplasia del vermis cerebeloso, dilatación quística del cuarto ventrículo y alargamiento de la fosa posterior. Aproximadamente el 80% de los pacientes presenta hidrocefalia. La triada característica de la malformación de Dandy-Walker que consiste: agenesia parcial o completa del vermis, dilatación quística del cuarto ventrículo y alargamiento de la fosa posterior. El diagnóstico prenatal es preferible realizarlo luego de las 18 semanas, el postnatal se hace con ultrasonido transfontanelar, resonancia magnética y tomografía axial computarizada. El tratamiento de esta patología está basado en el manejo de la hidrocefalia. 1 Caso: a continuación presentamos un caso clínico de Dandy Walker de la Unidad de Medicina Materno Fetal del Hospital Carlos Andrade Marín de Quito.

Introduction: Dandy-Walker malformation is a rare congenital disease involving the cerebellum and the fourth ventricle. This condition is characterized by agenesia or hypoplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle, and enlargement of the posterior fossa. Approximately 80% of patients have hydrocephalus. Dandy-Walker malformation was described by Dandy and Blackfan in 1914. The characteristic triad of Dandy-Walker malformation is consisting of complete or partial agenesis of the vermis, cystic dilatation of the fourth ventricle and an enlarged posterior fossa. The prenatal diagnosis of Dandy-Walker malformation is better after 18 weeks of gestation. After birth it is best diagnosed with the help of transfontanelar ultrasound, magnetic resonance imaging, and computerized axial tomography. The treatment for this condition is based in the management of hydrocephalus. 1 Case: below is a case report of Dandy Walker at the Maternal Fetal Medical Unit of the Carlos Andrade Marin Hospital in Quito.

Foramen Magnum Meningioma: Some Anatomical and Surgical Remarks through Five Cases

STUDY DESIGN: Foramen magnum meningioma foramen magnum meningioma (FMM) represents 2% all of meningiomas. The clinical symptomatology is usually insidious and consists of headache, neck pain and hypoesthesia in C2 dermatome. Because of their location, the management is challenging. PURPOSE: The purpose of this paper is to present our experience in the surgery of FMM. OVERVIEW OF LITERATURE: Since 1938, numerous series have been published but they are very heterogeneous with high variability of location and surgical approaches. METHODS: During two years, we operated 5 patients with FMM. All the patients had magnetic resonance imaging (MRI) with angio-MRI to study the relationship between tumour and vertebral artery (VA). In all the cases, we used prone position. RESULTS: In one case, considering the tumour localization (posterior and pure intradural) the tumour was removed via a midline suboccipital approach with craniotomy and C1-C2 laminectomy. In all other cases, meningiomas were posterolateral (classification of George) with extradural extension in one case. In all cases, VA was surrounded by tumor. So, we opted for a modified postero-lateral approach with inverted L incision, craniotomy and C1-C2 laminectomy without resect occipital condyle. Epidural part of VA was identified and mobilized laterally. Once VA was identified we opened dura mater and began to remove the tumour. CONCLUSIONS: In this paper, we present five cases of operated FMM, describe our approaches, the reason of each approach and propose some surgical remarks.

Therapeutic effect analysis of small bone flap craniotomy decompression of posterior cranial fossa and duraplasty for 45 patients with Chiari malformation type Ⅰ / 中国医师进修杂志

Objective To evaluate the therapeutic effect of small bone flap craniotomy decompression of posterior cranial fossa and duraplasty in the treatment of Chiari malformation type Ⅰ.Methods The clinical data of 45 Chiari malformation type Ⅰ patients who were treated with small bone flap craniotomy decompression of posterior cranial fossa and duraplasty were retrospectively analyzed,31 cases among them with syringomyelia.Results According to Tator etc.standard,1 month after surgery,the excellent in 30 cases,good in 15 cases.Follow up from 6 months to 6 years,the excellent in 37 cases,good in 8 cases.Among 31 patients with syringomyelia,26 cases were syringomyelia subsided,5 cases were not obvious change.Conclusion The small bone flap craniotomy decompression of posterior cranial fossa and duraplasty can make the craniocervical decompression,and has obvious effect of treating syringomyelia,is safe and effective in treatment of Chiari malformation type Ⅰ.

The Comparative Morphometric Study of the Posterior Cranial Fossa : What Is Effective Approaches to the Treatment of Chiari Malformation Type 1?

OBJECTIVE: The objective of this study was to investigate changes in the posterior cranial fossa in patients with symptomatic Chiari malformation type I (CMI) compared to a control group. METHODS: We retrospectively reviewed clinical and radiological data from 12 symptomatic patients with CMI and 24 healthy control subjects. The structures of the brain and skull base were investigated using magnetic resonance imaging. RESULTS: The length of the clivus had significantly decreased in the CMI group than in the control group (p=0.000). The angle between the clivus and the McRae line (p<0.024), as the angle between the supraocciput and the McRae line (p<0.021), and the angle between the tentorium and a line connecting the internal occipital protuberance to the opisthion (p<0.009) were significantly larger in the CMI group than in the control group. The mean vertical length of the cerebellar hemisphere (p<0.003) and the mean length of the coronal and sagittal superoinferior aspects of the cerebellum (p<0.05) were longer in the CMI group than in the control group, while the mean length of the axial anteroposterior aspect of the cerebellum (p<0.001) was significantly shorter in the CMI group relative to control subjects. CONCLUSION: We elucidate the transformation of the posterior cranial fossa into the narrow funnel shape. The sufficient cephalocaudal extension of the craniectomy of the posterior cranial fossa has more decompression effect than other type extension of the craniectomy in CMI patients.