Cephaloceles

Pediatric Congenital Anterior Skull Base Encephaloceles and Surgical Management: A Comparative Review of 22 Patients Treated With Transnasally, Transcranially, or Combined Approach With a Review of the Literature

BACKGROUND AND OBJECTIVES

Anterior basal encephaloceles are considered a rare entity and are often associated with midline cerebral abnormalities. Those with a large skull base defect and herniation of brain parenchyma in the neonate or young infant present unique challenges for surgical management.

METHODS

We analyzed the neurosurgical administrative and operative databases between 1986 and 2022 to determine clinical presentation, operative approach, and outcome of basal encephaloceles.

RESULTS

Over the 36-year period, 27 pediatric anterior basal encephaloceles were managed, of which 22 had full documentation and images allowing comprehensive review. Mean age at presentation was 5 years (SD 4.94). The majority were transethmoidal encephaloceles (59%), followed by the transsphenoidal-sphenoethmoidal type (32%). Overall, 91% were managed surgically by a transcranial, endoscopic, or combined approach. Four children required subsequent procedures, predominantly for persistent cerebrospinal fluid leak. No significant differences in proportion of patients requiring interval/revision surgery after initial conservative, endoscopic endonasal, or transcranial surgery was identified. Neither age at surgery nor size of the defect on computed tomography scan was associated with the need for revision surgery. Size of cranial defect was significantly smaller in the endoscopic group (P = .01). There was a historic tendency for younger children with larger defects to have a transcranial approach. With the addition of endoscopic skull base expertise, smaller defects in older children were more recently treated endoscopically.

CONCLUSION

Basal encephaloceles are rare and complex lesions and are optimally managed within a skull base multidisciplinary team able to provide multiple approaches. Large skull base defects with brain parenchymal involvement often require a transcranial or combined transcranial-endoscopic approach.

The Need for Emphasis on Intracranial Hypertension Management in Spontaneous Skull Base Meningoencephaloceles

OBJECTIVE

To provide an analysis of patients with spontaneous skull base meningoencephaloceles (MECs) to determine whether definitive surgical treatment requires management of elevated intracranial pressure (ICP).

METHODS

Data of 10 subjects with spontaneous MECs were collected and retrospectively evaluated. Measurement of ICP, prior interventions, treatment with acetazolamide, and characteristics of long-term elevated ICP, among others, were analyzed. Our own indications for cerebrospinal fluid (CSF) diversion and use of postoperative external lumbar drain were analyzed as well.

RESULTS

The sphenoid region was the most common location of MECs. CSF leak was diagnosed in all subjects. The most common graphical signs of elevated ICP were empty sella and arachnoid pits, both of which were present in 90% of cases. Lumbar puncture with opening pressure measurement was performed in 7 patients. Ventriculoperitoneal shunt insertion was indicated in 4 cases before skull base repair and in 2 cases after skull base repair. Two postoperative CSF leaks were managed with external lumbar drain and subsequent shunt installation.

CONCLUSIONS

Spontaneous MECs are often associated with CSF leak. ICP assessment should be a standard of care to ensure successful operative repair of MECs. Insertion of a CSF diversion device must be considered where direct or indirect signs of intracranial hypertension are present.

Unrecognized notochordal lesions as a likely cause of idiopathic clival cerebrospinal fluid leaks

OBJECTIVE

To examine an association between idiopathic transclival cerebrospinal fluid (CSF) leak and notochordal lesions.

METHODS

This study consisted of the illustrations of institutional patients who underwent surgery for transclival CSF leak between January 1, 2009 and April 25, 2020 and comprehensive review of the existing literature conducted on April 25, 2020. The cases were classified based on the presumed etiologies that were originally proposed in the articles ("idiopathic" vs. "secondary"). The baseline characteristics were compared between the groups, and the surgical outcomes were summarized.

RESULTS

In 3 institutional cases, ecchordosis physaliphora (EP) was confirmed at the fistula either pathologically (1) or radiologically (2). Among 42 literature cases, 28 were recognized as idiopathic, while 14 were secondary cases with histologically (n = 12) or radiologically (n = 2) confirmed notochordal lesion at the fistula. Thus, any notochordal lesions were histologically confirmed in 13 among a total of 45 cases (28.9%). Fourteen of the idiopathic cases had undescribed radiographic signs suggestive of small ecchordosis physaliphora at the fistula. Both idiopathic and secondary cases demonstrated resemblance in their ages (mean, 51.4 and 56.6 years; p = 0.102), female predominance (male, 36% vs. 25%; P = 0.521), no association with obesity (7% vs. 18%; P = 0.350) or increased intracranial pressure (7% vs. 6%; P = 1.000). All the fistulas were in the midline or paramidline clivus within several millimeters below the dorsum sellae. All the patients were treated surgically with a multilayer closure, resulting in a success rate of 93% with one surgery.

CONCLUSION

Our analyses suggest the association of transclival CSF leak and notochord lesions. A prospective study is needed for definitive conclusion.

Combined Open Surgical and Endoscopic Approach for Management of a Meningoencephalocele After Iatrogenic Perforation of the Anterior Skull Base in a Young Infant

Traumatic iatrogenic perforation of the anterior skull base is a rare complication following endonasal intubation in preterm infants. Subsequent meningoencephaloceles with concomitant cerebrospinal fluid (CSF) fistulas bear the risk of severe complications, therefore early diagnosis and closure of the skull defect are crucial. However, there is no consensus on the management of such cases of meningoencephaloceles. This case report presents a sophisticated approach of open brain surgery in combination with endonasal endoscopy. A 15-month-old girl presented with a meningoencephalocele and a CSF fistula due to iatrogenic perforation of the left anterior skull base during attempted endonasal intubation after birth. Difficult nasal breathing and an increasing diameter of the skull base defect on imaging controls indicated surgical management. Close multidisciplinary collaboration was essential for diagnosis and decision upon treatment. Open neurosurgical resection and CSF fistula closure combined with endonasal endoscopic removal of the excised meningoencephalocele was performed. Our case report shows that this combined open surgical and endonasal endoscopic approach is a safe procedure in favor of the postoperative outcome and follow-up of the patient.

Transnasal transpterygoid resection of meningoencephalocoele with abolition of seizures

Meningoencephalocoeles are herniations of intracranial contents through skull base defects. Patients may present with a plethora of symptoms ranging from cerebrospinal fluid (CSF) rhinorrhoea to epileptic convulsions, or indeed may be asymptomatic. We present a case of a 24-year-old man suffering from new onset, drug-resistant tonic-clonic seizures. Imaging studies revealed neural tissue and meninges protruding through the pterygoid portion of the sphenoid bone, into the anteromedial aspect of the middle cranial fossa. An image-guided endoscopic transnasal transpterygoid approach was carried out as a joint otolaryngological and neurosurgical procedure, resulting in the patient being seizure-free for over 12 months postoperatively. There is a paucity of literature supporting such an endoscopic approach to treat epilepsy secondary to a meningoencephalocoele. We illustrate that this is a safe and minimally invasive treatment option which ultimately rendered the patient free of all anticonvulsants.

Repair of a Transclival Meningocele Through a Transoral Approach: Case Report and Literature Review

BACKGROUND

Transclival meningoceles and related primary spontaneous cerebrospinal fluid leaks at the clivus are extremely rare lesions, with only a few cases reported in the literature.

CASE DESCRIPTION

An infant presented with nasal airway obstruction and meningitis secondary to cerebrospinal fluid leak from a transclival meningocele. The radiologic investigation and surgical repair of the lesion are reported, along with intraoperative findings. Basic anatomy, embryology, and development of the clivus are reviewed to clarify the relationship of anatomic variants with the formation of transclival meningoceles.

CONCLUSIONS

Transclival meningocele should be considered in patients with spontaneous cerebrospinal fluid rhinorrhea. The existing classification of meningoencephaloceles based on the location of the defect in the cranium should probably be reconsidered, taking into consideration the described entity.

Cerebrospinal fluid rhinorrhea and otorrhea: A multimodality imaging approach

Cerebrospinal fluid (CSF) leaks are extracranial egress of CSF into the adjacent paranasal sinus or tympanomastoid cavity due to an osteodural defect involving skull base. It can be due to a multitude of causes including accidental or iatrogenic trauma, congenital malformations and spontaneous leaks. Accurate localization of the site of the leak, underlying causes and appropriate therapy is necessary to avoid associated complications. In this paper relevant anatomy, clinical diagnosis, imaging modalities and associated findings are discussed along with a brief mention about management.

Intradiploic encephalocele of the primary motor cortex in an adult patient: electrophysiological implications during surgery

Encephaloceles are herniations of brain parenchyma through congenital or acquired osseous-dural defects of the skull base or cranial vault. Different types of symptoms, due to CSF fistulas, meningitis, or seizures, are often associated with this condition. The authors present a rare case of spontaneous right frontal parasagittal encephalocele in a 70-year-old man who was experiencing a spastic progressive paresis of his left lower limb. Results of routine electrophysiological workup (motor evoked potentials, somatosensory evoked potentials, and electroneuromyography), as well as those of MRI of the spinal cord, were normal. A brain MRI study detected a partial herniation of the right precentral gyrus through a meningeal defect into the diploe, embedding corticospinal fibers. The patient underwent navigated craniotomy. Intraoperative neuromonitoring of motor function with transcranial electrical stimulation and direct cortical stimulation indicated the presence of motor cortex inside the encephalocele. Thus, the brain parenchyma was carefully released without resection to preserve motor function and, finally, a cranioplasty was performed. After a few months, the patient demonstrated considerable improvement in his left lower-limb function and, after 1 year, he had fully recovered. Intraoperative electrophysiological monitoring and mapping allowed for the determination of the best surgical strategy for the isolation of the encephalocele and correlated well with preoperative multimodal MRI.

Spontaneous Transethmoidal Meningoceles in Adults: Case Series with Emphasis on Surgical Management

Background. Spontaneous onset transethmoidal meningocele is a rare entity among the adult population. Methods. A retrospective chart review was performed and cases of adults diagnosed with spontaneous transethmoidal meningoceles from November 2000 till February 2014 were reported. Data collected included demographics, clinical presentation, diagnostic modalities, and results. Intraoperative findings, the type of surgical reconstruction performed, and the percentage of recurrence, if present, were also reported. Results. Ten cases of spontaneous transethmoidal meningoceles in adults were diagnosed. Eight were females and two males with a mean age of 47.5 years. All patients presented with CSF leakage with or without meningitis. They underwent a reconstruction of the base of skull defect using the temporalis fascia graft in addition to fibrin glue (Tissucol) and Surgicel (Ethicon). In two cases with a larger defect, a piece of septal bone and turbinate mucosa were applied achieving a watertight seal in all cases. Conclusion. Spontaneous transethmoidal meningocele in adults is a rare condition. It usually presents with clear rhinorrhea with or without meningitis and an endoscopic multilayer reconstruction is advocated for treatment of such conditions.

Malformations of dorsal induction

Dorsal induction includes the formation and closure of neural tube, occurs during 3-5 weeks of gestation. Neurulation occurs in two phases, primary neurulation (formation of the neural plate and subsequently neural tube) and secondary neurulation (formation of distal cord and sacral and coccygeal segments). Failure of dorsal induction leads to anencephaly, exencephaly, cephaloceles, Chiari malformation and spinal dysraphism. In this article we discuss the relevant embryology, etiopathology and detail imaging appearances of these malformations.

Unusual presentations of middle fossa encephaloceles: report of two cases

Basal encephaloceles are rare occurrences with occult and often varied presentations. Frequently, the need for surgical treatment is not clear to the patient or the physician, leading to potentially fatal complications. We report the case of a 44-year-old woman with an 8-year history of nonspecific complaints who presented to us with trigeminal neuralgia. Also, an unsual case is presented of a 60-year-old man with bilateral middle fossa encephaloceles who suffered acutely from widespread pneumocephalus acting as a mess lesion. Both are cases of nontraomatic middle fossa encephaloceles, which are of perficular interest due to the age of the patients, their atypical presentations, and the asseciated complications.

Cerebrospinal fluid leak with recurrent meningitis following tonsillectomy

The authors report an unusual case of bilateral large petrous apex cephaloceles in a 14-year-old boy with a history of recurrent meningitis. Although these lesions are rare and usually asymptomatic, surgical correction is recommended if they are associated with a persistent CSF leak. In this patient, the extensive bilateral cranial defects were not adequately treated by an intracranial approach alone. Repair of a defect in the posterior pharyngeal wall, the site of a prior tonsillectomy, ultimately resulted in repair of the CSF fistula.

SURGICAL MANAGEMENT OF CONGENITAL MEDIAN PERISELLAR TRANSSPHENOIDAL ENCEPHALOCELES WITH AN EXTRACRANIAL APPROACH

OBJECTIVE

Median perisellar congenital transsphenoidal encephalocele (CTE) is a rare entity associated with multiple endocrine, visual, and respiratory deficits. The most likely causative factor for these pathological alterations is distension of neural structures (hypothalamic-pituitary system, optic pathway), resulting in protrusion of the dural sac through a sphenoid bone defect into the pharynx. The continuity with the extracranial space can be associated with an increased risk of tearing of the sac, with consequent cerebrospinal fluid leakage and subsequent increase in the risk of infection. We retrospectively reviewed the surgical treatment of CTE in our hospital using either an extracranial transoral or transnasal approach.

METHODS

We retrospectively reviewed our database. Between July 1994 and June 2005, CTE we identified 6 patients. Five of them were treated by a surgical intervention. The first patient was treated via a transcranial approach but had a relapse of the prolapse 11 years later. The relapse was treated with an extracranial transpalatal approach. Four patients were treated with an extracranial surgical approach: an extracranial transoral approach was performed in 2 cases, and an extracranial transnasal approach was used in the other 2 cases. Surgery was not performed in 1 patient because the parents refused to consent to the procedure.

RESULTS

Preoperative symptoms remained stable or improved in all of the patients after the surgical procedure and worsened in the patient who did not have a surgical intervention. Two patients experienced a palatal dehiscence. No mortality was recorded in this series of patients.

CONCLUSION

The surgical treatment of CTE is indicated to stop the progression or improve symptoms related to this disease entity. If approached correctly, the extracranial approach is a safe procedure with subsequent low morbidity.

Recurrent meningitis and persistence of craniopharyngeal canal: case report

OBJECTS

Craniopharyngeal Canal is a rare malformation of the sphenoid bone described in up to 0.42% of the asymptomatic population. It's been related to the development of the Rathke's pouch during embrionary period although some authors think it's a vestige of a former vascular channel.

METHODS

This report details a case of a four and a half years old child that developed recurrent meningitis associated with this anomaly. Its origin, clinical manifestations and treatment options are discussed.

CONCLUSION

Due to its low incidence and diagnostic difficulties, a high suspicion index is required while studying a case of recurrent meningitis or CSF leakage. Surgical approach is still controversial.

Spontaneous encephaloceles of the temporal lobe

Encephaloceles are pathological herniations of brain parenchyma through congenital or acquired osseus-dural defects of the skull base or cranial vault. Although encephaloceles are known as rare conditions, several surgical reports and clinical series focusing on spontaneous encephaloceles of the temporal lobe may be found in the otological, maxillofacial, radiological, and neurosurgical literature. A variety of symptoms such as occult or symptomatic CSF fistulas, recurrent meningitis, middle ear effusions or infections, conductive hearing loss, and medically intractable epilepsy have been described in patients harboring spontaneous encephaloceles of middle cranial fossa origin. Both open procedures and endoscopic techniques have been advocated for the treatment of such conditions. The authors discuss the pathogenesis, diagnostic assessment, and therapeutic management of spontaneous temporal lobe encephaloceles. Although diagnosis and treatment may differ on a case-by-case basis, review of the available literature suggests that spontaneous encephaloceles of middle cranial fossa origin are a more common pathology than previously believed. In particular, spontaneous cases of posteroinferior encephaloceles involving the tegmen tympani and the middle ear have been very well described in the medical literature.

Endoscopic treatment of traumatic basal encephaloceles: a report of 8 cases

Object

Basal encephaloceles are rare entities that can present as congenital diseases; however, traumatic lesions due to head injuries or iatrogenic causes have been described in the literature. In this study the authors aimed to define placement techniques for free grafts in repairing traumatic basal encephaloceles and to describe the long-term effectiveness of endoscopic treatment.

Methods

Between September 1997 and December 2006, 8 patients with traumatic encephaloceles underwent endoscopic surgery. A free graft following an underlay (2 cribriform plate and 4 ethmoid fovea defects) or obliteration (2 sphenoid defects) procedure was used as the repair material.

Results

All traumatic basal encephaloceles with the associated skull base defects and cerebrospinal fluid (CSF) leakage were successfully treated via the endoscopic approach. There were no major complications or recurrence of meningitis or leakage of CSF encountered after an average follow-up of 77 months.

Conclusions

Long-term follow-up results demonstrated that endoscopic surgery was suitable for the treatment of traumatic basal encephaloceles. The underlay procedure is more appropriate than the overlay procedure in repairing large defects of the anterior skull base. Meticulous manipulations of the endoscope following precise autograft placement are mandatory for the successful repair of traumatic basal encephaloceles.

Difficulties in treatment of CSF leakage associated with a temporal meningocele

Temporal meningocele is a rarely encountered pathology. It is caused by communication between the subarachnoid space of the middle fossa and lateral extension of the sphenoid sinus. Cerebrospinal fluid (CSF) pressures and the hydrostatic pulsatile forces may lead to the development of pitholes on the middle fossa at the sites of arachnoid villi with herniation of dura/arachnoid or brain tissue into the sinus. We describe an adult patient who presented with spontaneous CSF rhinorrhea due to a temporal meningocele. She was first operated on transsphenoidally, but the CSF rhinorrea did not cessate, therefore she was operated transcranially five days after the first operation. There has been no CSF rhinorrhea for three and a half years. Transcranial temporal encephalocele repairment is more effective than transsphenoidal surgery. Recurrent CSF leaks can occur due to both the increased CSF pressure and the insufficient operation technique.

An unusual presentation of an encephalocele to the otolaryngologist

An unusual case of encephalocele causing obstruction of the upper airway in a neonate is described. The patient presented with a large mass in the neck, which extended from the base of the skull to the level of the larynx. Although there was no evidence of a defect of the skull base, subsequent excision and histological examination confirmed an encephalocele.

Surgical treatment of cerebrospinal fluid fistulae involving lateral extension of the sphenoid sinus

OBJECTIVE AND IMPORTANCE

Four cases of spontaneous cerebrospinal fluid rhinorrhea caused by communication between the subarachnoid space of the middle cranial fossa and a lateral extension of the sphenoid sinus are presented. The cause and management of this unique type of cranial base defect are discussed.

CLINICAL PRESENTATION

During the past 10 years, four patients referred to our institution with atraumatic cerebrospinal fluid fistulae were observed to have temporal encephaloceles (encephalomeningoceles) traversing the floor of the middle cranial fossa. Three of the patients had previously undergone unsuccessful transnasal attempts to repair their fistulae by obliteration of the sphenoid sinus. The fourth patient presented before undergoing any treatment. No patient had associated hydrocephalus or tumor. Preoperative computed tomographic cisternograms revealed that all fistulae involved a lateral extension of the sphenoid sinus into the floor of the middle cranial fossa.

INTERVENTION

After definitive localization, each patient was operated on transcranially through an anterior middle cranial fossa approach with extradural and/or intradural exploration. The associated temporal encephalocele was amputated or disconnected, and the dehiscent dura and middle cranial fossa floor defect were oversewn and packed with autogenous tissue, respectively.

CONCLUSION

The surgical treatment of cerebrospinal fluid rhinorrhea secondary to middle fossa encephalocele associated with lateral extension of the sphenoidal sinus differs from the surgical strategy for more medial sphenoidal fistulae. Fistulae involving a lateral extension of the sphenoid sinus require a transcranial approach for direct visualization and obliteration of the defect, whereas fistulae involving the central portion of the sinus may be successfully obliterated transsphenoidally.

Transpalatal approach for the extracranial surgical repair of transsphenoidal cephaloceles in children

The surgical treatment of transsphenoidal cephaloceles in children is controversial. Reduction and repair via a transcranial approach are associated with high postoperative rates of morbidity, mortality, and hypothalamic dysfunction. In this study, four patients, aged 3 to 35 months at surgery, underwent successful transpalatal repair of two encephaloceles and two meningoceles. Two patients presented with nasal obstruction in infancy, one presented with unexplained meningitis, and in one patient the lesion was found incidentally during evaluation for seizures. Two children had median cleft face syndrome, another had an associated Arnold-Chiari type I malformation, and the fourth had no other cranial abnormalities. All patients underwent preoperative evaluation including magnetic resonance (MR) imaging. Auditory, ophthalmological, genetic, endocrinological, or other evaluation was undertaken as indicated. Lesions were approached through the median raphe of the hard and soft palates. All cephaloceles were easily visualized and dissected after division of the nasal palatal mucosa. The dural sac and its contents were reduced by surface coagulation after division and dissection of the overlying mucosa. Once reduced, the bone defect was obliterated in three of four patients. The dura was not opened and anomalous neural elements were not resected. At follow-up evaluation, all patients demonstrated resolution of preoperative symptoms without evidence of infection or lasting morbidity. Follow-up MR imaging showed reduction in all cases. The authors conclude that this transpalatal approach is safe and reliable for the treatment of transsphenoidal cephaloceles in young children.

Congenital encephalocele of the medial skull base

Meningoencephaloceles of the temporal bone are rare. Although most often seen following otologic surgery or trauma, congenital meningoencephaloceles can exist. The clinical presentation, diagnostic evaluation, and surgical management of three patients with congenital meningoencephalocele are presented. Two of the three patients presented to our institution with recurrent episodes of meningitis; one presented with partial complex seizures. Diagnostic evaluation included temporal bone computed tomography with magnetic resonance imaging. In two patients, defects were imaged following high-pressure subarachnoid cisternography with computed tomography. All three patients were found to have congenital defects in the area of Meckel's cave. Early recognition of congenital meningoencephalocele is important to avoid delay of definitive surgical management and neurologic sequelae.

Primary cutaneous meningioma on the scalp: report of two siblings

Primary cutaneous meningioma (PCM) is a rare tumor whose pathogenesis is quite obscure. We reported PCMs occurring on almost the same occipital region of two siblings studied by histology, immunohistochemistry, and electron microscopy. Both lesions were attached to duras, but extracranial. One lesion was histologically diagnosed as meningothelial meningioma; its tumor cells showed electron microscopically interdigitating cytoplasmic processes with junctional complexes. The other was interpreted as fibroblastic meningioma; its tumor cells were arranged linearly in a stepping-stone arrangement and had small dense bodies in the cytoplasm. The tumor cells stained positively with anti-vimentin antibody. Both lesions had adenomatous hyperplasia of the eccrine glands. Although the histologic and electron microscopic features of these two lesions slightly differed from each other, their pathogenesis was essentially considered to be acoelic or rudimentary meningocele.

Repair of temporosphenoidal encephalocele with a vascularized split calvarial cranioplasty: technical case report

A 54-year-old woman was referred for the evaluation and treatment of spontaneous cerebrospinal fluid rhinorrhea. Magnetic resonance imaging revealed a right anteromedial intrasphenoidal encephalocele with cisternography showing the flow of contrast into the sphenoid encephalocele. Transcranial surgical repair was performed. This included the use of a vascularized split-thickness calvarial graft fixated over the cranial base defect with a titanium microplate. The technical details of this repair are discussed. Ten cases of temporosphenoidal encephaloceles have been reported. The literature concerning this rare form of encephalocele is reviewed.

Endoscopic treatment of an oral cephalocele. Case report

This report describes an unusual cephalocele originating in the temporobasal region and protruding through the sphenopetral area into the oral cavity. A rapid and nonaggressive endoscopic procedure was performed. The relationship between this type of cephalocele, spontaneous anteroinferior temporal encephaloceles, and nasopharyngeal brain heterotopia is discussed.

Nasal endotracheal intubation in a premature infant with a nasal encephalocele

After a difficult nasal intubation a premature infant leaked cerebrospinal fluid (CSF) from one nostril. After developing bacterial meningitis, the baby was referred for neurosurgical management of the CSF fistula. Transaxial computed tomograms demonstrated a nasal encephalocele, but coronal scans were needed to show the defect in the cribriform plate.

Imaging the sphenoid bone and basiocciput: pathological considerations

Many diverse pathologic processes can involve the sphenoid bone because of its complex embryologic origin. In addition to primary neoplasia, the central location of the sphenoid predisposes it to involvement by many intracranial and extracranial lesions. The presence of multiple foramina and fissures offer "paths of least resistance" that allow the spread of pathology across the skull base. Sphenoid sinus disease also accounts for a number of pathologic entities occurring in this vicinity. This article reviews the more common lesions affecting the sphenoid bone as well as their CT and MR appearance.

Spontaneous temporal encephalocele. Case report

The authors report a 36-year-old woman with a 23-year history of simple and complex partial seizures who was treated surgically for an anteroinferior temporal encephalocele, with resolution of the seizure disorder. This patient's presentation, findings, and response to treatment are typical of those associated with anteroinferior temporal encephalocele, and different from the clinical patterns of four other types of spontaneous temporal encephalocele.

The foramen ovale. MR and CT correlation

Six patients with lesions involving the foramen ovale are presented and analyzed. Anatomy, pathology and imaging of diseases occurring in the vicinity of the foramen ovale are reviewed. Computerized tomography (CT) and magnetic resonance imaging (MRI) are complimentary in the evaluation of pathology in this region. CT is better able to evaluate bony detail while MR imaging is useful in detailing the anatomical extent and tissue characteristics.

Encephalocoele involving the petrous bone

The rare occurrence of an encephalocoele through a defect in the tegmen of the petrous bone is reported. The case illustrates the association of this abnormality with recurrent meningitis and the importance of imaging in defining the nature and site of the lesion prior to surgery.

Trisomy 18 associated with ectopia cordis and occipital meningocele

A premature infant presented with ectopia cordis, occipital meningocele, and manifestations of trisomy 18; cytogenetic analysis confirmed a 47,XX,+18 chromosome constitution. While most cases of ectopia cordis appear as isolated, sporadic defects, careful evaluation is warranted to detect evidence of an associated chromosome abnormality.