Subtorcular occipital encephaloceles. Anatomical considerations relevant to operative management

Anatomical implications of posterior cephaloceles in the dural venous sinuses

OBJECTIVE

To analyze the venous anatomy of the dural sinuses of patients with posterior encephaloceles, in order to formulate anatomical patterns which can ensure safer surgery.

METHODS

This is a retrospective study, analyzing eight patients diagnosed with posterior encephalocele throughout 1 year.

RESULTS

Eight patients with cephaloceles were evaluated in our study from January 2017 to January 2018. The most common alteration was dysgenesis of the straight sinus (n = 7), followed by venous anomalies in the encephalocele and alterations in the SSS (superior sagittal sinus) (n = 4), and the occurrence of a falcine sinus (FC) in 3 patients.

CONCLUSION

Anatomical variations are frequent in patients with cephaloceles. Therefore, an understanding of them is necessary for safe and effective treatment.

Giant Occipital Encephalocele - Challenges in Management

Introduction

Giant occipital encephalocele (GOE) is a term used when the size of the OE is greater than or equal to the size of the head. It has been limited to case reports, with only sporadic exclusive series. This is a series of GOE managed at our center over time with emphasis on practical problems faced in management.

Materials and Methods

This was a retrospective observational study. The patients were evaluated for the age of presentation, sex, and head size. Any associated neural tube defect was also looked for. Imaging was used for associated brain anomalies and to plan the surgical procedure. The requirement of ventriculoperitoneal (VP) shunt was also assessed.

Results

During the study period of 7 years, 11 patients of GOE were admitted. Apart from one, all other patients were <1 year of age. Nine patients underwent surgical intervention, which included excision and repair of swelling with or without VP shunt placement. The content of the sac was only cerebrospinal fluid (CSF) in six patients and CSF and gliotic brain tissue in remaining patients. The attendants of two patients did not give consent for surgery and left against medical advice.

Conclusion

GOE is an uncommon entity with limited information about management. Careful evaluation, proper imaging of patient, and care during intraoperative and postoperative periods with emphasis of factors determining the prognosis may provide satisfactory results.

Giant Occipital Encephalocele in an Infant: A Surgical Challenge

Giant occipital encephalocele is an uncommon condition. The sheer size of the lesion poses a challenge to the surgeon and the anesthetist. Here, we present a 4-month-old girl child presenting with a progressively increasing swelling in the occipital region since birth. The child after evaluation underwent repair of the encephalocele. The purpose of this report was to highlight the difficulties faced during surgery while operating on such a huge occipital encephalocele.

Repair of a large primary subtemporal encephalocele in a 3-year-old child: case report

Primary encephaloceles (PEs) present only rarely in the temporal region; in the rare instance that they project through the floor of the middle fossa they are secondary. In this case report the authors report on the management of a giant PE extending through the floor of the middle fossa.An 8-month-old boy presented to the authors' service with a large PE projecting into his neck through a missing left middle fossa floor; the lesion was causing significant meta-, dys-, and hypoplasia of the structures of the anterolateral neck on that side. Surgical goals for this patient included the following: 1) removal of potentially epileptogenic and dysfunctional tissue; 2) preservation of cranial nerves; 3) prevention of cognitive decline or iatrogenic deficit; 4) prevention of CSF leak; 5) reconstruction of skull base; 6) prevention of airway and swallowing compromise; and 7) cosmesis. After a multidisciplinary evaluation with ENT, plastic surgery, and neurology, an operation was performed using a preauricular infratemporal approach when the patient was 3 years old. Gliotic tissue was resected and amygdala, hippocampus, and middle cerebral artery were preserved.The immediate results of the operation showed good immediate outcome. Seizure freedom and neurodevelopment outcomes remain to be seen at follow-up.

Giant Encephalocoele: A Rare Case Report and Review of Literature

Giant encephalocoeles are rare entities with only one case series and few case reports reported in medical literature. Encephalocoeles, which reach a size larger than the head size, are be called Giant encephalocoeles. We report a case of a 6 month old child who had giant encephalocoele with delayed motor milestones in the form of inability to hold neck. Anesthetic implications include difficulty in securing air way due without undue pressure on the sac. She underwent VP shunt followed by excision of the encephalocele sac. Patient is doing well at 1 year of follow up. Preoperative neurological status and amount of brain tissue herniating into the sac are the most important factors determining the long term prognosis.

Management of median and paramedian craniofacial clefts

BACKGROUND

Median and paramedian craniofacial clefts are associated with hypertelorism, anterior encephalocele, positional abnormalities of the maxilla, and nasal deformity. Cleft lip and palate, eyelid coloboma, and widow's peak are frequently present.

METHODS

The authors collected data from 30 patients (mean age, 5.8 years; range, 4 months to 18 years) operated between 1986 and 2017 with median or paramedian craniofacial clefts of differing degrees of severity. Malformations of the different anatomic units and their surgical treatment were assessed, as well as complication rates.

RESULTS

All patients presented nasal malformations and either telecanthus (n = 16) or hypertelorism (n = 14). Most patients (n = 23) had anterior encephalocele. All patients underwent nasal corrections, and most of them had medial canthopexy (n = 24). Excision of encephalocele was associated with fronto-orbital remodeling. Medialization of the orbits was performed in 11 patients, mainly by box shift (n = 9). Patients from outside Switzerland (n = 23) were operated at an older age than those in the native patient group. Because of staged reconstruction, 13 patients had more than one operation. Surgical complications included three infections and one expander exposition. One patient had bone resorption of a frontal bone flap. Nasal correction needed more than one procedure in 5 patients, and medial canthopexy had to be repeated in 7 patients. Esthetic results were satisfactory, permitting social integration.

CONCLUSION

Median and paramedian craniofacial clefts need adapted and carefully planned corrections respecting the growth of anatomic units. The quality of the medial canthal and nasal reconstruction is to a large extent responsible for the overall result.

Encephalocele development from a congenital meningocele: case report

A fetal MRI study obtained at 21 weeks' gestation revealed a suboccipital meningocele without hydrocephalus. One day after term birth, MRI demonstrated an acquired cerebellar encephalocele, and MRI obtained 5 months later showed progressive enlargement of the encephalocele, still without obvious hydrocephalus. The patient underwent an operation in which an external ventricular drain was placed, the grossly normal cerebellum was reduced into the posterior fossa without resection, and the dural defect was closed. The drain was weaned out over 5 days, and no ventriculoperitoneal shunt was placed. Postoperative MR images revealed normal cerebellum and no hydrocephalus. The patient is developmentally normal. Meningocele and encephalocele are embryologically distinct. An acquired encephalocele could develop from hydrocephalus (which was not present in this case), or secondary to the lower resistance to expansion into the dural defect of the meningocele relative to the resistance to expansion of the fetal skull. The cerebellar tissue was normal in this case, and was thus preserved. The developmental prognosis is excellent. To the authors' knowledge, this is the first reported case of this occurrence. It is important to differentiate between congenital and acquired encephalocele etiologies, because resection of the cerebellar tissue in an acquired encephalocele (as is routinely done in cases of congenital encephalocele) would be expected to result in neurological deficits.

Cefaloceli

I cefaloceli sono difetti congeniti o acquisiti del cranio e della dura attraverso i quail possono erniare diverse strutture intracraniche. Un semplice difetto osseo della teca cranica in sede mediana o paramediana non attraversato da un prolasso delle strutture intracraniche prende il nome di cranio bifido occulto. I cefaloceli congeniti possono essere suddivisi in quattro gruppi a seconda del contenuto del tessuto erniato attraverso il difetto osseo:

– Meningoceli, le strutture erniate consistono in meningi e liquor. – Meningoencefaloceli, oltre a meningi e liquor ernia pure parte dell'encefalo. Se l'encefalo erniato comprende anche parte del sistema ventricolare il cefalocele prende il nome di idroencefalomeningocele. – Glioceli, il tessuto erniato è formato da una raccolta di liquor delimitata da tessuto neurogliale. – Cefaloceli atresici, forme fruste di cefaloceli localizzate in sede parietale o occipitale.

I disrafismi cranici congeniti sono piu rari dei disrafismi spinali: l'incidenza dei cefaloceli varia da 0.3 a 4 per 10.000 nati. La sede più frequente dei cefaloceli è la regione occipitale anche se nelle popolazioni orientali predomina le sede fronto-etmoidale. Vi è una prevalenza femminile per le localizzazioni occipitali e maschile per quelle parietali e sincipitali.

A seconda della loro sede i cefaloceli sono classificati in quattro gruppi: occipitali, della volta cranica, fronto-etmoidali (sincipitali) e del basicranio.

Da un punto di vista diagnostico: l'ecografia è di fondamentale importanza per la diagnosi prenatale delle anomalie più grossolane; lo studio del difetto osseo va condotto sia con i radiogrammi convenzionali che con studi di Tomografia Computerizzata (TC) con successive ricostruzioni tridimensionali; mentre la valutazione della componente erniata parenchimale e vascolare deve essere effettuata mediante la Risonanza Magnetica (RM) e la angiografia RM.

Giant occipital meningohydroencephalocele in an adult: Another historical case in neural tube defects

Meningohydroencephalocele is a herniation of meninges, cerebrospinal fluid, brain parenchyma and a part of the ventricular system through a bony defect in the skull. This bone defect may be congenital, spontaneous or traumatic in origin. The lesions are mostly congenital, discovered generally after birth or in very young infants. We report the first historical case of the entity in this location in a 29-year-old man and discuss the pathogenesis, surgical management and social considerations of this type of neural tube defect in our country.

Parietal and occipital encephalocele in same child: A rarest variety of double encephalocele

An encephalocele is a protrusion of the brain and/or meninges through a defect in the skull. Based on the location of the skull defect they are classified into sincipital, basal, occipital or parietal varieties. Occurrence of more than one Encephalocele in a patient is very rare and very few cases of double encephalocele are reported. We report an interesting case where a parietal and an occipital encephalocele were present together. The patient was a 2 months boy who was brought to us with complaints of two swelling on the scalp since birth. Neuroimaging studies confirmed it to be a case of double encephalocele. The rarity of the findings prompted us to report this case. The presentation and management of the case along with and review of the relevant literature is presented.

Perioperative challenges in patients with giant occipital encephalocele with microcephaly and micrognathia

Meninigo-encepahlocoele (MEC) is a common neurosurgical operation. The size of MEC may vary which has bearing with its management. The association of MEC with micrognathia and microcephaly is rarely reported. The association poses special problem for intubation and maintenance of anaesthesia. Giant MEC may lead to significant CSF loss resulting in hemodynamic alteration. The prior knowledge and care in handling the patient can avoid minor as well as major complications.

Progressive skin necrosis of a huge occipital encephalocele

Objects:

Progressive skin necrosis of giant occipital encephalocoele is an extremely rare complication found in neonates. Infection and ulceration of the necrosed skin may lead to meningitis or sepsis. We present here a neonate with giant occipital encephalocoele showing progressive necrosis during the first day of his life.

Methods:

A newborn baby was found to have a huge mass in the occipital region, which was covered by normal pink-purplish skin. During the last hours of the first day of his life, the sac started becoming ulcerated accompanied with a rapid color change in the skin, gradually turning darker and then black. The neonate was taken up for urgent excision and repair of the encephalocele. Two years after the operation, he appears to be well-developed without any neurological problems.

Conclusion:

Necrosis may have resulted from arterial or venous compromise caused by torsion of the pedicle during delivery or after birth. The high pressure inside the sac associated with the thin skin of the encephalocoele may be another predisposing factor. In view of the risk of ulceration and subsequent infection, urgent surgery of the necrotizing encephalocele is suggested.

Lateral posterior fossa encephalocele with associated migrational disorder of the cerebellum in an infant

Encephaloceles are acquired or congenital defects in which intracranial contents protrude through a defect in the calvaria. The embryogenesis of these lesions is incompletely understood. The vast majority of lesions occur at or near the anatomical midline. The authors present an extremely rare case of a laterally oriented, pathologically proven encephalocele associated with a posterior fossa cyst and cerebellar migrational defect in an infant. The authors review past and current theories of encephalocele formation as it relates to this case.

Tectocerebellar dysraphism with vermian encephalocele

Tectocerebellar dysraphism is a very rare malformation associated with encephalocele and tectal deformity. This article presents tectocerebellar dysraphism with a solely vermian content of encephalocele and tectal beaking defined by magnetic resonance imaging (MRI) in a 5-month-old girl who was successfully treated surgically and demonstrated excellent prognosis at the 4-year follow-up.

Hydrocephalus associated with cystic dilation of the foramina of Magendie and Luschka

Cystic malformations in the posterior cranial fossa result from developmental failure in the paleocerebellum and meninges. The authors present the case of an infant with hydrocephalus associated with cystic dilation of the foramina of Magendie and Luschka. This 7-month-old female infant presented with sudden onset of tonic-clonic seizures. Computed tomography revealed tetraventricular hydrocephalus. Magnetic resonance imaging demonstrated a cyst communicating with the fourth ventricle and projecting to the cisterna magna and the cerebellopontine cisterns through the foramina of Magendie and Luschka. A suboccipital craniotomy was performed for removal of the cyst wall, and the transparent membrane covering the foramen of Magendie was removed under a microscope. After the surgery, the patient's hydrocephalus improved and a phase contrast cine MR imaging study showed evidence of normal CSF flow at the level of the third and fourth ventricles. Three weeks later, however, the hydrocephalus recurred. An endoscopic third ventriculocisternostomy was performed to address the possibility of stagnant CSF flow in the posterior cranial fossa, but the hydrocephalus continued. Finally the patient underwent placement of a ventriculoperitoneal shunt, resulting in improvement of her symptoms and resolution of the hydrocephalus. On the basis of this experience and previously published reports, the authors speculate that the cystic malformation in their patient could be classified in a continuum of persistent Blake pouch cysts. Hydrocephalus was caused by a combination of obstruction of CSF flow at the outlets of the fourth ventricle and disequilibrium between CSF production and absorption capacity.

Large supra- and infra-tentorial occipital encephalocele encompassing posterior sagittal sinus and torcular Herophili

Occipital encephaloceles are the most common type of encephalocele encountered in the Western Hemisphere. The occipital encephalocele is typically classified according to the relationship of the herniated tissue to the torcular. We report the unusual case of a premature infant with a rare, large occipital encephalocele which encompassed the posterior superior sagittal sinus and torcular. We discuss the variable venous anatomy with occipital encephaloceles and review the different options to employ in their surgical repair.

Diagnosis and management of large occipitocervical cephaloceles: a 10-year experience

BACKGROUND/AIMS

Cephaloceles are common malformations of the central nervous system. However, the great majority of clinical experiences in large occipitocervical cephaloceles have not been reported previously. The purpose of this report is to investigate the pathogenetic factors involved in the development of cranial dysraphism and to analyze the clinical and pathological factors that influence the outcome in patients.

METHODS

Three hundred and twenty infants with craniospinal dysraphism and 12 with large occipitocervical cephaloceles were admitted to our institution in a 10-year interval between 1995 and 2005. Infants with cephaloceles, including newborns and 5 within the first year of life, were all operated by two authors in our institution, and they were analyzed retrospectively.

RESULTS

The sex predilection was limited to occipitocervical cephaloceles, where 8 of the 12 cases were females. Hydrocephalus was present in 25% of the patients at the time of diagnosis. Clinical presentation was most often consistent with hydrocephalus, focal neurological findings being a less prominent feature. Associated congenital anomalies were present in 50% of the children. Contemporary neuroimaging techniques including computed tomography and magnetic resonance imaging facilitated the diagnosis. Patients were initially managed by posterior fossa or cervical region exploration, followed by sac excision. Three cases died in the early postoperative period, and the surgical mortality in this series was 25%. They were the ones with the largest encephaloceles and microcephaly. The mean follow-up time was 3.4 years. The overall mortality rate for the whole series was 33.3% (4/12). The size of the cephaloceles and the presence or absence of neural tissue in the sac largely determines the outcome for patients with occipitocervical cephaloceles.

CONCLUSION

Infants with lesions greater than 50 mm in diameter, containing a significant amount of neural tissue, have an extremely poor prognosis, especially if associated with microcephaly.

Surgical closure and reconstruction of a large occipital encephalocele without parenchymal excision

INTRODUCTION

Encephalomeningocele is a herniation of the brain and meninges through a congenital bone defect resulting from the failure of normal midline fusion of the cranial neural tube. Various sites are possible; however, among Caucasians more than 70% of encephaloceles are located on the occipital/posterior part of the cranium. Usually they contain degenerative cerebral cortex, which is often excised during surgical closure of the defect. Techniques to preserve the herniated brain tissue have been described, but they focus on increasing the intracranial cavity by ventriculomegaly and retracting the encephalocele into new intracranial space in a second stage, as a result of hydrocephalic treatment.

TECHNICAL REPORT

The authors report a well-documented newborn with a large encephalocystocele of the left occipital lobe. This encephalocele included the left lateral ventricle and a part of the cerebellum, and was covered with allopathic skin. Initially the cystic portion was removed so that a partial reduction of the encephalocystocele was achieved. Six months later, the surgical closure of the defect was performed, with preservation of the occipital and cerebellar parenchyma, by incising the tentorium and retracting the cortex to the newly created infratentorial space. The bony defect was covered with autologous osseous graft harvested from parietal bone and reconstructed.

OUTCOME

In the long-term follow-up after 13 years, the child has preserved visual function.

Molar tooth sign of the midbrain-hindbrain junction: occurrence in multiple distinct syndromes

The Molar Tooth Sign (MTS) is defined by an abnormally deep interpeduncular fossa; elongated, thick, and mal-oriented superior cerebellar peduncles; and absent or hypoplastic cerebellar vermis that together give the appearance of a "molar tooth" on axial brain MRI through the junction of the midbrain and hindbrain (isthmus region). It was first described in Joubert syndrome (JS) where it is present in the vast majority of patients with this diagnosis. We previously showed that the MTS is a component of several other syndromes, including Dekaban-Arima (DAS), Senior-Löken, and COACH (cerebellar vermis hypoplasia (CVH), oligophrenia, ataxia, coloboma, and hepatic fibrosis). Here we present evidence that the MTS is seen together with polymicrogyria, Váradi-Papp syndrome (Orofaciodigital VI (OFD VI)), and a new syndrome with encephalocele and cortical renal cysts. We also present a new patient with COACH syndrome plus the MTS. We propose that the MTS is found in multiple distinct clinical syndromes that may share common developmental mechanisms. Proper classification of patients with these variants of the MTS will be essential for localization and identification of mutant genes.

Magnetic resonance techniques in the evaluation of the fetal and neonatal brain

Magnetic resonance imaging (MRI) has contributed dramatically to our understanding of the newborn with neurologic problems. Recently developed magnetic resonance techniques, such as fetal MRI and MR spectroscopy, offer additional insight into normal and pathologic processes affecting the fetal and neonatal CNS. This article examines developmental abnormalities as reflected in neuroimaging studies and discusses some of the newer MR modalities and their capabilities.

Infantile hemangioendothelioma of the pericranium presenting as an occipital mass lesion. Case report

The case of a newborn infant with a large midline mass in the occipital region is presented. Skull x-ray films demonstrated multiple radiolucent defects in the occipital bone. A computerized tomography scan revealed an extracranial mass lesion with marked contrast enhancement. A magnetic resonance image demonstrated that the venous drainage of the lesion passed through the occipital bone into the dural venous sinuses. The anatomy of the hindbrain was normal. The neonate was treated by complete surgical removal of the mass. The histopathological diagnosis was infantile hemangioendothelioma, a tumor commonly found in the liver but rarely in this location. The classification, histopathological characteristics, imaging studies, and treatment of this tumor are discussed.

Falcine sinus and occipital encephalocele: a magnetic resonance venography study

OBJECT

Occipital encephaloceles are relatively frequently encountered. Many investigators have addressed the embryogenesis of these formations, but the dural system has never before been studied. In this retrospective analysis the authors sought to gain a better understanding of the origins of these defects.

METHODS

The charts and radiological examinations, especially the magnetic resonance venography studies, were reviewed in seven patients. In six patients the straight sinus was absent. Drainage of the galenic system took place through a sinus within the falx, also known as a falcine sinus. The tentorium was not seen in five patients.

CONCLUSIONS

The combination of an absent straight sinus and dysplastic tentorium is no coincidence: both develop within the same mesenchyme in the mesencephalic flexure. Distortion of the mesenchyme by a neural tube defect, causing an occipital encephalocele, will lead not only to disorders of the tentorium but also of the straight sinus.

Ventricular volume reduction technique--a new surgical concept for the intracranial transposition of encephalocele

The authors propose a new operative technique for the intracranial transposition of an encephalocele by using the associated hydrocephalic state. In the first stage, the intracranial pressure buffering effect of the encephalocele sac is reduced by the closing of the dural defect. The repaired dural defect allows intraventricular pulse pressure to produce ventriculomegaly. In the second stage or in infants with hydrocephalus, the extracranially herniated brain is transposed into the intracranial cavity during ventricular shunting with appropriate drainage of cerebrospinal fluid.

Prenatal ultrasonographic diagnosis of acardiac twin

Acardiac twinning is a rare complication of monozygotic twin gestation occurring in 1/35,000 pregnancies or in 1% of all monozygotic twins. This condition is characterized by partial or complete lack of development of the heart in one of the twins, and requires that the normal twin (pump twin) provides circulation for itself as well as the acardiac sibling (perfused twin) by means of reverse circulation through large artery-to-artery and vein-to-vein anastomoses. The acardiac anomaly is uniformly fatal for the perfused twin, and the perinatal mortality for the normal twin is about 50%, usually as the result of congestive heart failure, polyhydramnios, and preterm delivery. In this report we present two cases of acardiac twin prenatally diagnosed by ultrasound. The principal sonographic features for prenatal diagnosis and the clinical management are briefly discussed.