Fossa navicularis magna: detección por tomografía computarizada de haz cónico / Fossa navicularis magna: detection by cone-beam computed tomography

Introducción: La identificación, interpretación y manejo de hallazgos incidentales en imagenología dental es imprescindible. Algunos de ellos requieren técnicas de imagen adicionales y remisión a profesionales de experiencia, otros únicamente su descripción. Una de estas variantes anatómicas se halla en el clivus, la fossa navicularis magna, asociada en pocos casos a repercusiones sistémicas. Objetivo: Describir las características de la fossa navicularis magna para su identificación mediante tomografía computarizada de haz cónico. Presentación de los casos: Tres pacientes de sexo femenino, con un rango de edad entre 35-71 años que acuden al Centro Odontológico de la Universidad San Martín de Porres para tratamientos de ortodoncia y rehabilitación oral. En estas áreas, como parte del protocolo se solicita tomografía computarizada de haz cónico por pieza retenida y elaboración de guías quirúrgicas respectivamente. El escaneo permite la identificación de un defecto tipo muesca en el clivus, de límites bien definidos y bordes corticalizados, lo que sugiere fossa navicularis magna. La historia clínica de los pacientes no sugirió implicaciones clínicas. Principales comentarios: Se informa y discute esta variante anatómica cuya presencia no requiere tratamiento y generalmente no tiene repercusiones sistémicas. En contados casos ha estado asociado con cuadros clínicos que amenazan la vida del paciente, precisamente porque puede servir como un trayecto para infecciones intracraneales. De ahí la necesidad de conocer y describir esta variante anatómica(AU)

Introduction: The identification, interpretation and management of incidental findings in dental imaging is essential. Some of them require additional imaging techniques and referral to experienced professionals, others only their description. One of these anatomical variants is found in the clivus, fossa navicularis magna, associated in few cases with systemic repercussions. Objective: Describe the characteristics of fossa navicularismagna for its identification by cone-beam computed tomography. Presentation of cases: Three female patients, with an age range between 35-71 years who come to the Dental Center of San Martín de Porres University for orthodontic treatments and oral rehabilitation. In these areas, as part of the protocol, cone-beam computed tomography per retained piece and development of surgical guides are requested, respectively. The scan allows the identification of a notch-like defect in the clivus, of well-defined boundaries and corticalized edges, suggesting fossa navicularis magna. The patients' medical history did not suggest clinical implications. Main comments: This anatomical variant is reported and discussed and its presence does not require treatment and generally has no systemic repercussions. In rare cases it has been associated with clinical pictures that threaten the patient's life, precisely because it can serve as a path for intracranial infections. Hence the need to know and describe this anatomical variant(AU)

Tortícolis como forma de presentación de quiste de la bolsa de Blake. Diagnóstico ecográfico en atención primaria / Torticolis as a form of presentation of Blake's pouch cyst. Ultrasound diagnosis in primary care

La tortícolis es un signo clínico definido por la inclinación lateral del cuello y rotación de la cabeza, que puede ser fija o flexible y acompañarse o no de dolor cervical. Aparece en trastornos de diferente complejidad. Ante un caso de tortícolis, es preciso realizar una historia clínica cuidadosa y un examen físico completo, y, en caso de ser persistente, solicitar pruebas de imagen.Se hace referencia a una causa de tortícolis no descrita en la literatura. Se trata de una tumoración quística compresiva en la fosa craneal posterior, quiste de la bolsa de Blake, en una lactante pequeña diagnosticada mediante ecografía en la consulta de Pediatría de Atención Primaria. Tras el diagnóstico, se remitió al centro hospitalario de referencia, donde se intervino de urgencia por Neurocirugía Pediátrica, mediante fenestración de la tumoración por ventriculostomía endoscópica y derivación ventrículo-peritoneal. Actualmente, se encuentra asintomática y sin secuelas.

Torticollis is a clinical sign defined by the lateral inclination of the neck and rotation of the head, which can be fixed or flexible and accompanied or not by cervical pain. It appears in disorders of different complexity. In a case of torticollis it is necessary to carry out a careful medical history and a complete physical examination and, if persistent, request imaging tests.Reference is made to a cause of torticollis not described in the literature. This is a compressive cystic tumor in the posterior cranial fossa, Blake's pouch cyst, in a small infant diagnosed by ultrasound in the Primary Care Pediatrics office. After diagnosis, she was referred to the referral hospital, where emergency intervention was performed by pediatric neurosurgery, by fenestration of the tumor by endoscopic ventriculostomy and ventriculo-peritoneal shunt. She is currently asymptomatic and without sequelae.

Dermoid cyst with cerebellar meningoencephalocele at different locations accompanied by posterior fossa abnormalities: case report

ABSTRACT CONTEXT: Dermoid cysts are well-defined cysts containing sebaceous glands and dermal structures. In the literature, dermoid cysts and associated closure defects have been described in the same locations. CASE REPORT: In this case, a dermoid cyst was found at the base of the mouth with a coexisting closure defect in the occipital calvarium. Additional abnormalities were also observed, including posterior myeloschisis, right cerebellar dysgenesis, vermian hypogenesis and posterior fusion of the second and third vertebrae. The finding of a dermoid cyst located at the base of the mouth is discussed here, with additional imaging findings. CONCLUSION: Dermoid cysts in the head and neck region may be accompanied by posterior fossa abnormalities.

Un enfoque clínico e histórico de la Malformación de Chiari Tipo I en adultos / A clinical and historic approach Type I Chiari malformation in adults

RESUMEN Se revisó la literatura existente sobre la Malformación de Chiari Tipo I en el adulto, haciendo énfasis en su diagnóstico imagenológico y tratamiento médico-quirúrgico. La malformación de Chiari es una enfermedad poco frecuente. Representa entre el 1 y el 4 % de todas las patologías neuroquirúrgicas. El diagnóstico se realiza meses y hasta años después de comenzada la sintomatología y se confirma en el 100 % de los casos con resonancia magnética de cráneo. El tratamiento es quirúrgico en los pacientes sintomáticos, siendo controversial en aquellos oligosintomáticos o con diagnóstico casual. La cirugía siempre debe realizarse con el apoyo de monitoreo neurofisiológico, que puede ser determinante en la técnica quirúrgica a emplear. La mortalidad asociada a la cirugía es muy baja, oscilando entre el 0 y 0,5 % según la mayoría de las series. Lo más importante es la selección de los pacientes para el tratamiento quirúrgico. No debe asumirse una actitud expectante en espera de un deterioro neurológico que justifique la cirugía, cuando ésta se hace a tiempo los resultados son mejores y con un mínimo de complicaciones (AU).

ABSTRACT The existent literature on Type I Chiari Malformation in adults was reviewed, making emphasis in its imaging diagnosis and medico-surgical treatment. Chiari malformation is a few frequent disease. It represents between 1 % and 4 % of all the neurosurgery pathologies. The diagnosis is made up months and even years after the beginning of the symptoms and it is confirmed by cranial magnetic resonance in the 100 % of the cases. The treatment is surgical in symptomatic patients, and it is controversial in the oligosymptomatic ones and in those with casual diagnosis. The surgery should be performed with the support of neurophysiological monitoring that might be determinant in the surgical technique to use. The mortality associated to the surgery is low, ranging from 0 and 0.5 % in most of the series. The most important thing is the choice of the patients for the surgical treatment. The neurological deterioration should not be expected to justify the surgery; when the surgery is carried out on time the results are better and with the minimum of complications (AU).

Cavernomas da fossa posterior do crânio: relato de série de seis casos / Posterior fossae cavernomas: study series of six cases

Os cavernomas são lesões classificadas como malformações vasculares, juntamente com malformações arteriovenosas, desenvolvimento venoso anômalo e telangiectasias capilares. Podem ocorrer de forma esporádica ou familiar e acometer qualquer área do sistema nervoso central, sendo a região supratentorial sua localização mais frequente. Neste artigo, é descrita uma série de seis pacientes com cavernoma na fossa posterior. Cinco cavernomas localizavam-se no tronco encefálico e um no cerebelo. A faixa etária dos pacientes variou de 14 a 50 anos. A abordagem cirúrgica diferiu entre os casos. Quatro casos apresentaram piora no pós-operatório imediato, com melhora subsequente. O seguimento dos pacientes variou de quatro meses a sete anos. Não houve óbito na série. Os cavernomas da fossa posterior requerem abordagem individualizada e técnica cirúrgica acurada. Embora possa ocorrer piora momentânea no pós-operatório imediato, a melhora subsequente é a regra, sendo o óbito infrequente.

Cavernomas are lesions classified as vascular malformations, along with arteriovenous malformations, developmental venous anomalies and capillary telangiectasia. They can occur in a sporadic or familial form and can affect any area of the central nervous system, being the region supratentorial the most frequent location. In this article, we describe a series of six cases of posterior fossae cavernoma. Five cavernomas were located in the brainstem and one in cerebellum. The ages ranged from 14 to 50 years old. The surgical approach differed between cases. Four cases worsened in the immediate postoperative period, with subsequent improvement. The follow-up ranged from four months to seven years. There were no deaths. Posterior fossae cavernomas require individualized approach and accurate surgical technique. Although momentary worsening may occur in the immediate postoperative period, the subsequent improvement is the rule, and the death is infrequent.

Endoscopic third ventriculostomy is a safe and effective procedure for the treatment of Blake's pouch cyst / Terceiroventriculostomia endoscopica e um procedimento efetivo e seguro para o tratamento dos cistos da bolsa de Blake

OBJECTIVE: Blake's pouch cyst (BPC) is a midline cystic malformation of the posterior fossa, within Dandy-Walker's complex (DWC), often associated with hydrocephalus. Endoscopic third ventriculostomy (ETV) has been an alternative to conventional methods for BPC treatment. This study aimed at reporting our experience with ETV in a series of patients with BPC. METHODS: Of 33 patients diagnosed with midline posterior fossa cyst, 26 met the protocol criteria for DWC, and eight subjects with BPC were selected (aged one month to two years old). All cases were treated with ETV. RESULTS: Five patients were male; and three were prenatally diagnosed. They had hydrocephalus and motor deficiencies. Motor assessment at a five-year follow-up yielded normal findings. All patients improved, and only one had residual cognitive dysfunction, despite overall neurological improvement. There were no complications. CONCLUSIONS: ETV was a safe and effective procedure, reducing risks and morbidity associated with open surgery and shunt-related problems. .

OBJETIVO: O cisto da bolsa de Blake (CBB) é uma malformação cística mediana da fossa posterior, dentro do complexo de Dandy-Walker (CDW), frequentemente associada à hidrocefalia. A terceiroventriculostomia endoscópica (TVE) tem sido considerada uma alternativa aos métodos convencionais de tratamento do CBB. Este estudo teve como objetivo relatar nossa experiência com TVE em uma série de pacientes com CBB. MÉTODOS: Dos 33 pacientes diagnosticados com cisto mediano da fossa posterior, 26 preencheram os critérios do protocolo para CDW, dos quais oito foram selecionados com CBB (idades variando entre um mês a dois anos). Todos os casos foram tratados com TVE. RESULTADOS: Cinco pacientes eram do sexo masculino, três tiveram diagnóstico no pré-natal; e todos apresentavam hidrocefalia e alterações motoras. A avaliação motora após cinco anos apresentou resultados normais. Todos os pacientes melhoraram, e apenas um apresentou um leve déficit cognitivo, apesar da melhora neurológica geral. Não houve complicações. CONCLUSÕES: A TVE foi um procedimento seguro e eficaz, reduzindo riscos e morbidade associados à cirurgia aberta e a problemas relacionados aos shunts.

Embriopatía por isotretinoína: Un daño evitable / Isotretinoin embryophaty: Report of one case

Retinoic acid is a widely used drug in the treatment of cystic acné. It has teratogenic effects that depend on the gestational period in which it is used. We report a seven months of female whose mother was exposed to retinoic acid in both pregestational and gestational periods. She had a retardation of psychomotor development and a brain MRI showed frontal atrophy and a malformation of the posterior fossa. We discuss the mechanisms ofthe teratogenic effeets of retinoic acid.

[Dandy-walker syndrome]

The Dandy-Walker syndrome represents a cystic malformation of the posterior fossa. It occurs in 1/25000 to 1/35000 pregnancy. Antenatal diagnosis is based on obstetrical sonography. When the cerebellum abnormalities are associated to other visceral malformations, medical abortion can be indicated. We report in this work two cases of Dandy-Walker syndrome diagnosed during pregnancy. The aim of this study is to analyze modalities of diagnosis, obstetric management and outcome of this syndrome

Rhombencephalosynapsis: CT and MRI findings.

An unusual disorder of cerebellar development, rhombencephalosynapsis is a unique entity which presents with cerebellar fusion and absence of cerebellar vermis on imaging studies, often associated with supratentorial findings. No specific clinical syndrome has been described in these patients so far, and most cases are found in infancy and childhood. MRI and its multiplanar capabilities and high spatial and contrast resolution increased its recognition. Two cases are reported, with emphasis on imaging findings.

Clinical presentation and management of unilateral acute and chronic epidural, hematomas of posterior fossa

Posterior Fossa epidural hematomas [PFEDHs] was detect in 14 patients secondary to the head injury in the period from Jan. 1999 to Feb 2001 - the goal of this study was to analyze the differences in preoperative clinical presentation and management between a group of acute [8 patients] and a group of chronic [6 patients] of epidural hematomas of posterior fossa. In this study [chronic epidural hematomas was defined as a delay of more than 72 hours from the accident to surgery]. All patients were admitted to neurosurgery departments of Al Azhar university hospitals. C.T brain scan without contrast and with bone window was used as a tool for diagnosis, followed by surgical evacuation of the hematoma for all patients. The outcome and good recovery was obtained in 13 patients but only one patient died

Experimentally induced Chiari-like malformation with myeloschisis in chick embryos

Though several pathogenetic theories concerning the frequent association of Chiari malformation and hydrocephalus with myeloschisis have been suggested, none of them explains all the aspects of the disorder. To investigate whether myeloschisis is the direct cause of Chiari malformation and hydrocephalus or these conditions are the results of another basic event, we observed the morphological changes of the posterior cranial fossa and its components in the chick embryos with surgically induced myeloschisis. To make myeloschistic lesions, we opened the neural tube for a length of 9-11 somites in Hamburger and Hamilton stage 16-19 chick embryos. They were divided into cervicothoracic (C-T) and lumbosacral(L-S) groups according to the area of incision. The embryos were re-incubated until postoperative day 11. In the control group, embryos were incubated with the eggshell window open as their experimental counterparts. The survival rates of each group were as follows; 11% (9 survivors/85 operated embryos), 8% (7/83), and 17% (10/60) in the C-T, L-S and control groups, respectively. Myeloschisis positive rates were 100% in the operated groups and 0% in the control group. The heads of embryos were sectioned along the sagittal plane to observe the morphological changes in the posterior cranial fossa and its components. Of the survivors, five in the C-T group, two in the L-S group and six in the control group were available for light microscopic inspection. In the majority of embryos with myeloschisis, without difference between the C-T and L-S groups, the fourth ventricles were smaller than those of the control group and the subarachnoid spaces in the posterior cranial fossa were also narrower. In embryos with severe changes, the cerebellum displaced downward comparing with that of the control embryos. No evidence of hydrocephalus was present Though not always typical, morphological changes similar to Chiari malformation were observed in chick embryos with surgically induced myeloschisis. It suggests a strong direct causal relationship between the two conditions and supports the theories of derangements in cerebrospinal fluid dynamics rather than those of primary mesenchymal or neural origin as a pathogenetic mechanism of Chiari malformation.

Experimentally induced Chiari-like malformation with myeloschisis in chick embryos

Though several pathogenetic theories concerning the frequent association of Chiari malformation and hydrocephalus with myeloschisis have been suggested, none of them explains all the aspects of the disorder. To investigate whether myeloschisis is the direct cause of Chiari malformation and hydrocephalus or these conditions are the results of another basic event, we observed the morphological changes of the posterior cranial fossa and its components in the chick embryos with surgically induced myeloschisis. To make myeloschistic lesions, we opened the neural tube for a length of 9-11 somites in Hamburger and Hamilton stage 16-19 chick embryos. They were divided into cervicothoracic (C-T) and lumbosacral(L-S) groups according to the area of incision. The embryos were re-incubated until postoperative day 11. In the control group, embryos were incubated with the eggshell window open as their experimental counterparts. The survival rates of each group were as follows; 11% (9 survivors/85 operated embryos), 8% (7/83), and 17% (10/60) in the C-T, L-S and control groups, respectively. Myeloschisis positive rates were 100% in the operated groups and 0% in the control group. The heads of embryos were sectioned along the sagittal plane to observe the morphological changes in the posterior cranial fossa and its components. Of the survivors, five in the C-T group, two in the L-S group and six in the control group were available for light microscopic inspection. In the majority of embryos with myeloschisis, without difference between the C-T and L-S groups, the fourth ventricles were smaller than those of the control group and the subarachnoid spaces in the posterior cranial fossa were also narrower. In embryos with severe changes, the cerebellum displaced downward comparing with that of the control embryos. No evidence of hydrocephalus was present Though not always typical, morphological changes similar to Chiari malformation were observed in chick embryos with surgically induced myeloschisis. It suggests a strong direct causal relationship between the two conditions and supports the theories of derangements in cerebrospinal fluid dynamics rather than those of primary mesenchymal or neural origin as a pathogenetic mechanism of Chiari malformation.

Tratamiento microquirúrgico de las malformaciones arteriovenosas de la fosa posterior / Microsurgical treatment of posterior fossa arteriovenous malformations

Las malformaciones arteriovenosas(MAV) de la fosa posterior acupan entre el 5 y el 7 por ciento de todas las MAV intracraneales. Se reporta un total de seis pacientes con este diagnóstico, encontrando cinco MAV cerebelosas y una en el tallo cerebral. En cinco casos la manifestación inicial fue la hemorragia parenquimatosa con deterioro de la conciencia. Cinco pacientes fueron intervenidos quirúrgicamente mediante una craniectomía suboccipital, en decúbito ventral. Los resultados postoperatorios fueron satisfactorios. Se recomienda la cirugia principalmente en los casos en que se ha presentado hemorragia. Las técnicas microquirúrgicas permiten obtener los mejores resultados