Spontaneous temporal encephalocele. Case report

Left Temporal Pole Encephalocele With Independent Hippocampal Seizures: Surgical Strategy and Relevance of Epileptic Biomarkers

SUMMARY

Temporal pole encephalocele (TE) is an increasingly recognized surgically treatable subtype of refractory temporal lobe epilepsy that rarely shows hippocampal involvement. A 27-year-old patient presented with medically intractable epilepsy because of a left temporal pole encephalocele with a normal hippocampus on MRI. Extraoperative electrocorticography showed independent seizure onset with distinct morphology of seizure onset pattern from the temporal pole encephalocele and hippocampus. Additional analysis of ictal and interictal fast ripples revealed different electrophysiological fast ripple profiles in the two seizure onset zones. The patient underwent temporopolar disconnection, eliminating the need for large dural repair and multiple hippocampal transections that helped preserve the intrahippocampal and extrahippocampal memory pathways. Herein, the authors report that independent hippocampal seizures can be observed in patients with temporal pole encephalocele. Features of the ictal and interictal fast ripples can differ depending on the morphology of the seizure onset pattern. The authors suggest that, the interpretation of fast ripples in clinical practice should take seizure onset patterns into consideration.

Temporal encephaloceles and coexisting epileptogenic lesions

OBJECTIVE

This study was performed to identify coexisting structural lesions in patients with epilepsy and known temporal encephaloceles (TEs).

METHODS

Forty-seven structural magnetic resonance imaging (MRI) scans of patients with epilepsy and radiologically diagnosed TEs were retrospectively reviewed visually and using an automated postprocessing software, the Morphometric Analysis Program v2018 (MAP18), to depict additional subtle, potentially epileptogenic lesions in the 3D T1-weighted MRI data. All imaging findings were evaluated in the context of clinical and electroencephalographical findings.

RESULTS

The study population consisted of 47 epilepsy patients (38.3% female, n = 18). The median age at the time of the scan was 40 years (range 12-81 years). Twenty-one out of 47 MRI scans (44.7%) showed coexisting lesions in the initial MRI evaluation; in 38.3% (n = 18) of patients, those lesions were considered probably epileptogenic. After postprocessing, probable epileptogenic lesions were identified in 53.2% (n = 25) of patients. Malformations of cortical development had initially been reported in 17.0% (n = 8) of patients with TEs, which increased to 38.3% (n = 18) after postprocessing. TEs and other epileptogenic lesions were considered equally epileptogenic in 21.3% (n = 10) of the cases in the initial MR reports and 25.5% (n = 12) of the cases after postprocessing.

SIGNIFICANCE

Temporal encephaloceles are a potential cause of MRI-negative temporal lobe epilepsy. According to our data, TEs can occur with other lesions, suggesting that increased awareness is also required in patients with lesional epilepsy. TEs may not always be epileptogenic; hence, their occurrence with other structural pathologies may influence the presurgical evaluation and surgical approach. Finally, TEs can be associated with malformations of cortical development, which may indicate a common developmental etiology of those lesions.

Endonasal endoscopic surgery for temporal lobe epilepsy associated with sphenoidal encephalocele

Background:

Temporal lobe epilepsy (TLE) associated with temporal lobe encephalocele is rare, and the precise epileptogenic mechanisms and surgical strategies for such cases are still unknown. Although the previous studies have reported good seizure outcomes following chronic subdural electrode recording through invasive craniotomy, only few studies have reported successful epilepsy surgery through endoscopic endonasal lesionectomy.

Case Description:

An 18-year-old man developed generalized convulsions at the age of 15 years. Despite treatment with optimal doses of antiepileptic drugs, episodes of speech and reading difficulties were observed 2–3 times per week. Long-term video electroencephalogram (EEG) revealed ictal activities starting from the left anterior temporal region. Magnetic resonance imaging revealed a temporal lobe encephalocele in the left lateral fossa of the sphenoidal sinus (sphenoidal encephalocele). Through the endoscopic endonasal approach, the tip of the encephalocele was exposed. A depth electrode was inserted into the encephalocele, which showed frequent spikes superimposed with high-frequency oscillations (HFOs) suggesting intrinsic epileptogenicity. The encephalocele was resected 8 mm from the tip. Twelve months postoperatively, the patient had no recurrence of seizures on tapering of the medication.

Conclusion:

TLE associated with sphenoidal encephalocele could be controlled with endoscopic endonasal lesionectomy, after confirming the high epileptogenicity with analysis of HFOs of intraoperative EEG recorded using an intralesional depth electrode.

Endoscopic endonasal repair of a temporal lobe meningoencephalocele in the pterygoid fossa: A case report and literature review

Introduction

Meningoceles are defined as herniation of the meninges through a skull base defect. If brain tissue is herniated as well, then it is called meningoencephalocele. The most common locations of meningoceles are the cribriform plate and the lateral recess of the sphenoid sinus, with the most common presentation being CSF leakage. We present a case of temporal lobe meningocele that herniated through a defect in the greater wing of the sphenoid bone to the pterygoid fossa and that was diagnosed incidentally while evaluating the patient for seizures.

Methodology

Case report and literature review.

Conclusion

The endonasal endoscopic approach is a suitable minimally invasive approach for the management of pterygoid fossa lesions, including meningoceles. In this case, the patient had epilepsy with the surgery resulting in the resolution of the seizures.

•

Endonasal approach can be considered as a minimally invasive approach for lesions in the pterygoid fossa.

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Meningocele are to be considered as a possible etiology for pterygoid fossa masses connected with the middle cranial fossa.

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Surgical resection of encephalomeningocele should be considered for the management of intractable seizures.

Temporal encephaloceles in epilepsy patients and asymptomatic cases: Size may indicate epileptogenicity

OBJECTIVE

This study was undertaken to identify temporal encephaloceles (TEs) and examine their characteristics in patients with temporal lobe epilepsy (TLE) and extratemporal lobe epilepsy (ETLE), as well as in asymptomatic cases.

METHODS

Four hundred fifty-eight magnetic resonance imaging scans were examined retrospectively to identify TE in 157 patients with TLE, 150 patients with ETLE, and 151 healthy controls (HCs).

RESULTS

At least one TE was identified in 9.6% of the TLE patients (n = 15, 95% confidence interval [CI] = 5.3%-15.3%), in 3.3% of patients with ETLE (n = 5, 95% CI = 1.1%-7.6%), and in 2.0% of the HCs (n = 3, 95% CI = .4%-5.7%), indicating a significantly higher frequency in patients with TLE compared to ETLE and HC subjects (p = .027, p = .005). Examining the characteristics of TEs in both asymptomatic and epilepsy patients, we found that TEs with a diameter of less than 6.25 mm were more likely to be asymptomatic, with a sensitivity of 91.7% and a specificity of 73.3% (area under the curve = .867, 95% CI = .723-1.00, p = .001).

SIGNIFICANCE

Temporal encephaloceles may occur without presenting any clinical symptoms. Patients with TLE show a higher frequency of TEs compared to the ETLE and HC groups. According to our study, TE size could be used to suggest potential epileptogenicity.

Anatomical Variations, Mimics, and Pitfalls in Imaging of Patients with Epilepsy

Epilepsy is among one of the most common neurologic disorders. The role of magnetic resonance imaging (MRI) in the diagnosis and management of patients with epilepsy is well established, and most patients with epilepsy are likely to undergo at least one or more MRI examinations in the course of their disease. Recent advances in high-field MRI have enabled high resolution in vivo visualization of small and intricate anatomic structures that are of great importance in the assessment of seizure disorders. Familiarity with normal anatomic variations is essential in the accurate diagnosis and image interpretation, as these variations may be mistaken for epileptogenic foci, leading to unnecessary follow-up imaging, or worse, unnecessary treatment. After a brief overview of normal imaging anatomy of the mesial temporal lobe, this article will review a few important common and uncommon anatomic variations, mimics, and pitfalls that may be encountered in the imaging evaluation of patients with epilepsy.

Delayed Cerebrospinal Fluid Rhinorrhea Associated With Ethmoidal Encephalocele After Resection of Remote Meningioma

Diagnosis and treatment of neurosurgical pathology present unique challenges in underserved areas, and many conditions may go undiagnosed, misdiagnosed, or untreated for prolonged periods. The development of an unusual complication, seemingly unrelated to an area of neurosurgical intervention, may be particularly perplexing to non-neurosurgical providers, particularly in areas where neurosurgical procedures have not historically been available. A 44-year-old male presented with a giant meningioma which was successfully resected. A nasal encephalocele was noted preoperatively but was not addressed due to lack of associated symptoms and distance from the tumor. The patient lived on a remote island and was lost to follow-up. He developed delayed cerebral spinal fluid (CSF) rhinorrhea three months after surgery, which was diagnosed and treated by local providers as allergic rhinitis for 11 months until he presented with new-onset seizure. Imaging demonstrated descent of the lateral ventricle into the encephalocele. The encephalocele was amputated and the skull base defect was repaired successfully. The alteration of ventricular anatomy and CSF fluid dynamics following tumor resection appears to have created an environment where a non-traumatic CSF leak could develop where it had previously shown no signs of developing. It may be prudent to treat skull base defects prophylactically to prevent this type of complication, particularly in patients of remote regions where regular follow-up is difficult.

Prevalence of Sigmoid Sinus Dehiscence and Diverticulum among Adults with Skull Base Cephaloceles

BACKGROUND AND PURPOSE

Cephaloceles are relatively rare conditions caused by a congenital and/or acquired skull defect. The incidence of associated venous brain anomalies with regard to cephaloceles remains to be fully elucidated. Accordingly, we sought to assess the prevalence of sigmoid sinus dehiscence and diverticula in patients with spontaneous skull base cephaloceles.

MATERIALS AND METHODS

Our institutional data base was retrospectively queried from 2005 to 2018. Patients in whom spontaneous skull base cephaloceles were identified were ultimately included in the study cohort. These patients subsequently had their sigmoid sinuses re-evaluated with focused attention on the possible presence of dehiscence and/or diverticula.

RESULTS

We identified 56 patients: 12 men and 44 women. After re-evaluation of the sigmoid sinuses, evidence of dehiscence and/or diverticula was noted in 21 patients. The right sigmoid sinus was involved in 11 patients, and the left sigmoid sinus was involved in 7 patients, including 3 cases of diverticulum. In 3 patients, evidence of bilateral sigmoid sinus dehiscence and diverticula was noted. Female sex was associated with sigmoid sinus dehiscence and diverticula by univariate analysis (P = .019). By linear regression, cephalocele volume was negatively associated with sigmoid sinus dehiscence and diverticula (coefficient, -2266, P value < .007, adjusted R ² = 0.1077). By univariate logistic regression using average cephalocele volume as a cutoff, we demonstrate a statistically significant finding of lower volumes being associated with sigmoid sinus dehiscence and diverticula with an odds ratio of 3.58 (P = .05).

CONCLUSIONS

The prevalence of sigmoid sinus dehiscence and diverticula in patients with cephalocele is high. Female sex is associated with sigmoid sinus dehiscence and diverticula. The cephalocele volume appears to be inversely proportional to sigmoid sinus dehiscence and diverticula.

Prevalence of Asymptomatic Middle Cranial Fossa Floor Pits and Encephaloceles on MR Imaging

BACKGROUND AND PURPOSE

Temporal lobe encephaloceles are increasingly identified and treated as epileptogenic foci. However, there is relatively scant research on the prevalence of asymptomatic encephaloceles. This study set out to describe the frequency of incidental temporal lobe encephaloceles and middle cranial fossa pits.

MATERIALS AND METHODS

A retrospective review was completed of high-resolution (≤0.5-mm section thickness) axial T2WI for internal auditory canal protocol imaging. The presence and laterality of middle cranial fossa pits (small bony defects containing CSF) and encephaloceles (brain parenchyma protrusion through osseous defects with or without bony remodeling) were recorded. Electronic medical records of patients with encephaloceles were searched for a history of seizure.

RESULTS

A total of 203 patients were included in the final cohort; 106 (52.2%) women. Forty-five (22.2%) patients had middle cranial fossa pits: 14 (31.1%) unilateral on the right, 17 (37.8%) unilateral on the left, and 14 (31.1%) bilateral. Ten (5.0%) patients had ≥1 encephalocele, none of whom had a documented history of seizure in the electronic medical record. No significant difference was noted in the frequency of pits or encephaloceles based on sex (P = .332 and P = .383, respectively) or age (P = .497 and P = .914, respectively).

CONCLUSIONS

Incidental middle cranial fossa pits are common findings, and their prevalence is not related to age or sex. Temporal lobe encephaloceles, though rarer, also exist occasionally among asymptomatic patients. Such findings have diagnostic implications for encephaloceles identified during imaging work-up for epilepsy.

Epilepsy Surgery for Skull-Base Temporal Lobe Encephaloceles: Should We Spare the Hippocampus from Resection?

The neurosurgical treatment of skull base temporal encephalocele for patients with epilepsy is variable. We describe two adult cases of temporal lobe epilepsy (TLE) with spheno-temporal encephalocele, currently seizure-free for more than two years after anterior temporal lobectomy (ATL) and lesionectomy sparing the hippocampus without long-term intracranial electroencephalogram (EEG) monitoring. Encephaloceles were detected by magnetic resonance imaging (MRI) and confirmed by maxillofacial head computed tomography (CT) scans. Seizures were captured by scalp video-EEG recording. One case underwent intraoperative electrocorticography (ECoG) with pathology demonstrating neuronal heterotopia. We propose that in some patients with skull base temporal encephaloceles, minimal surgical resection of herniated and adjacent temporal cortex (lesionectomy) is sufficient to render seizure freedom. In future cases, where an associated malformation of cortical development is suspected, newer techniques such as minimally invasive EEG monitoring with stereotactic-depth EEG electrodes should be considered to tailor the surrounding margins of the resected epileptogenic zone.

Altered cerebrospinal fluid dynamics in neurofibromatosis type l: severe arachnoid thickening in patients with neurofibromatosis type 1 may cause abnormal CSF dynamic

INTRODUCTION

The object of this study is to understand abnormal dynamic of cerebrospinal fluid (CSF) in patients with neurofibromatosis type 1 (NF1), which may cause temporal lobe herniation and bulging of temporal fossa.

METHODS

Four patients, three females and one male, with NF1 were studied retrospectively. They presented with a similar craniofacial deformity, which consisted of pulsatile exophthalmos, an enlarged bony orbit, dysplasia of the sphenoid wing with the presence of a herniation of the temporal lobe into the orbit, and a bulging temporal fossa.

RESULTS AND DISCUSSION

Surgical exploration demonstrated abnormally thickened arachnoid membrane in one case. Protruding temporal lobe, which was one of the main symptoms in NF1 patients, could be stopped by control of intracranial pressure (ICP) via programmable ventriculoperitoneal shunt (VPS) or extra ventricle drainage implantation. The dense fibrosis of the arachnoid membrane and consequent altered hemispheric CSF dynamics may cause symptoms including pulsatile exophthalmos and consequent worsening of vision, prolapse of the temporal lobe, and enlargement of the temporal fossa. This finding may not present with general features of hydrocephalus, so that delays in diagnosis often result.

CONCLUSION

For the NF1 patients with cranio-orbito-temporal deformities, prior to any surgical reconstruction, control of increased ICP (IICP) should be primarily considered.

Lateral temporal encephaloceles: case-based review

PURPOSE

Lateral temporal encephalocele is an extremely rare clinical condition, with only 18 cases presented in the literature to date. No review articles have examined lateral temporal encephalocele in depth. We therefore reviewed past cases of lateral encephalocele to clarify the clinical characteristics of this extremely rare deformity. We also present a case of lateral encephalocele with arachnoid cyst which has never been reported in past reports.

METHODS

We identified 8 reports describing 18 cases of lateral temporal encephalocele. We therefore reviewed 19 cases of lateral temporal encephalocele, including our own experience, and discussed the clinical characteristics of this pathology.

RESULTS

All the cases with lateral temporal encephalocele were detected at birth except for an occult case. The majority occurred at the pterion, and occurrence at the asterion appears much rarer. Due to the preference for the pterion, the ipsilateral orbital wall was also distorted in some cases. Lateral temporal encephalocele seems to have fewer associated malformations: only 3 cases of lateral temporal encephalocele had associated malformations, including our case which was associated with intracranial arachnoid cyst. The only case of lateral temporal encephalocele to have shown hydrocephalus was our own case. Patients with this deformity have relatively good prognoses: only 3 of the 19 cases showed delayed psychomotor development during follow-up.

CONCLUSIONS

Provision of adequate treatment is likely to achieve a good prognosis in patients with lateral temporal encephalocele, so we should keep in mind this deformity when encountering pediatric patients with mass lesions on the temporal cranium.

Temporal Lobe Parenchyma Herniation into the Transverse Sinus: MRI Findings in a Case

Brain parenchyma herniation into dural venous sinus which is a uncommon entity, can cause dural venous sinus filling and simulate sinus thrombosis and other pathologies. It is isointense to brain parenchyma on all sequences by magnetic resonance imaging, surrounded by a cerebrospinal fluid rim and is seen to be contiguous with brain tissue on images. We report a rare case with spontaneous occult herniation of temporal lobe tissue into the left transverse sinus that may associated with headache.

Meningocele and Meningoencephalocele of the Lateral Wall of Sphenoidal Sinus: The Role of the Endoscopic Endonasal Surgery

BACKGROUND

Meningocele and meningoencephalocele of the lateral wall of the sphenoidal sinus (LWSS) are rare lesions, crossing the borders of multiple disciplines such as ear-nose-throat, maxillofacial, and neurologic surgery. We reviewed our surgical experience to analyze the role of the endoscopic endonasal approach and consider these pathologies from different perspectives.

METHODS

All consecutive cases of meningocele and meningoencephalocele of LWSS operated through an endoscopic endonasal approach from 1998 to 2015 in our institutions were collected. Medical history, focusing on previous episodes of cerebrospinal fluid leak, meningitis or seizures, was considered. The outcome was assessed considering the medical condition and the postoperative neuroimaging.

RESULTS

The series includes 23 patients (7 male, 16 female). Mean age was 52 years (26-73 years). Eleven cases were meningoencephaloceles and 12 meningoceles. A clear cerebrospinal fluid leak occurred on in 19 patients and was associated with meningitis in 3. Two were presenting a history of epilepsy. No complications were observed, but 1 case presented seizures on waking. At follow-up (mean 84 months, 4-167) each patient is in good clinical condition with no further episodes of leaking or seizures.

CONCLUSIONS

Endoscopic endonasal surgery is a safe and effective approach for meningocele and meningoencephalocele of LWSS; it allows resection of herniated tissue and repair of the osteodural defect. The favorable clinical outcome and the possible effectiveness on seizures lead us to support this approach as first minimally invasive treatment also in presence of epilepsy, as a first low risk epilepsy surgical procedure.

Occult temporal lobe encephalocoele into the transverse sinus

In this article we present a case of an incidental encephalocoele protruding through a dural defect into the transverse sinus. Encephalocoeles are usually described as a herniation of the meninges and brain parenchyma through a bony defect of the cranium or base of skull. To our knowledge, there are only a few patients reported in the literature of occult encephalocoeles through dural defects. Our case study highlights that encephalocoele should be a differential diagnosis for a filling defect in this location.

Spontaneous sphenoid wing meningoencephaloceles with lateral sphenoid sinus extension: the endoscopic transpterygoid approach

Spontaneous meningoencephalocele (SME) of the sphenoid wing is a rare cause of cerebrospinal fluid (CSF) leakage. Surgical closure of the fistula is usually required. The approach taken depends on the location of the defect and the extension of the meningoencephalocele. The endoscopic transpterygoid approach may be useful. We prospectively analyzed the three cases of SME of the sphenoid wing with lateral sphenoid sinus extension treated endoscopically at Stanford over the last 3 years with regard to imaging findings, operative technique, and operative morbidity. In our three cases, the extent of pterygopalatine fossa (PPF) exposure undertaken, complete in one and partial in two, depended on the defect site. Follow-up ranged from 17 to 25 months. The fistula was completely closed in all three cases. Extant literature reports a 97% rate of successful closure (N = 65 of 67, with a mean follow-up of 25 months) and no major complications. Endoscopic transpterygoid repair is a useful, safe alternative to traditional approaches for repair of SME of the sphenoid wing. Its feasibility depends on the site of the defect, which can be identified by preoperative imaging. Larger PPF exposure and postoperative lumbar drainage of CSF can be useful and have a low risk of morbidity.

Dural sinus filling defect: intrasigmoid encephalocele

Filling defects of dural venous sinuses are considered to be a challenging problem especially in case of symptomatic patients. Many lesions have to be ruled out such as sinus thrombosis, arachnoid granulations and tumours. Encephalocele into dural sinus is also a rare cause of these filling defects of dural sinuses. Here, we report an extremely rare case with spontaneous occult invagination of temporal brain tissue into the left sigmoid sinus and accompanying cerebellar ectopia.

Spontaneous lateral temporal encephalocele

A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

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.

Transpterygoid Trans-sphenoid Approach to the Lateral Extension of the Sphenoid Sinus to Repair a Spontaneous CSF Leak

OBJECTIVE AND IMPORTANCE

Cerebrospinal fluid (CSF) fistula from the middle cranial fossa into the sphenoid sinus is a rare condition. In the past, the treatment of choice has been closure via a craniotomy. Only few geriatric cases are known, which were successfully operated by endoscopic surgery. We present a further case of nontraumatic CSF fistula originating from the middle cranial fossa. A new endoscopic technique was applied. We discuss treatment options for this rare defect.

CLINICAL PRESENTATION

A 76-year-old patient presented with a 2-year history of rhinorrhea. High levels of beta-trace protein pointed to a diagnosis of CSF fistula. The defect was located at the anterior and inferior aspect of the pterygoid recess of the left sphenoid sinus.

INTERVENTION

The patient was operated using an endoscopic trans-sphenoidal approach. After endoscopic opening of the maxillary and sphenoid sinus, a complete posterior ethmoidectomy was performed. The medial part of the pterygoid process was removed, allowing endoscopic exposure and closure of the defect. At 1-year follow-up, the CSF fistula had not recurred and the patient had no sequel from the surgical procedure.

CONCLUSION

In selected cases, this new endoscopic partial transpterygoid approach to the middle cranial fossa is recommended for surgical repair of CSF fistula involving the lateral extension of the sphenoid sinus. To our knowledge, ours is the oldest patient with this condition successfully operated by endoscopic means at the world's most northern university hospital.

Spontaneous cerebrospinal fluid leaks in congenital and acquired temporal bone defects-a long-term follow-up

Twelve patients presenting with tegmen defects and requiring surgical repair were retrospectively reviewed from 1982 to 1993. One half of the patients presented with a cerebrospinal fluid leak at some time in the course of their illness. Nine cases were considered to be acquired, secondary to previous mastoid surgery or trauma. All 9 had encephalocoeles. Three spontaneous leaks were considered congenital; 2 of these patients had encephalocoeles. This report represents a long-term follow-up of these cases, with an average follow-up of 7,6 years. Computed tomography and magnetic resonance imaging technology, as well as contrast studies, have tremendously aided in diagnosis and planning of surgical repair. Nine repairs were done through a dual transmastoid and middle fossa approach, with the other 3 done via a transmastoid approach only. We favored temporalis muscle flaps and temporalis fascia over synthetic materials for defect repairs. The long-term results and complications are discussed.

Transtemporal management of temporal bone encephaloceles and CSF leaks: review of 56 consecutive patients

CONCLUSIONS

This report details our experience in the management of 56 consecutive patients with mastoid encephaloceles and cerebrospinal fluid (CSF) leaks. The majority were managed through the transmastoid route with temporalis fascia and calvarial bone graft. Among the patients operated on at least 18 months before analysis, there was a median follow-up of 54 months with no intracranial complications. The average body mass index (BMI) of patients with spontaneous CSF leaks was found to be statistically significantly greater than that of patients with CSF leaks with traumatic, infectious or iatrogenic etiologies.

OBJECTIVES

To investigate the long-term follow-up of patients with spontaneous, iatrogenic, and traumatic temporal bone encephaloceles and CSF leaks to determine the effectiveness of the repair, late intracranial complications, and recurrent lesions.

METHODS

This is a retrospective review from a tertiary care center of 56 consecutive patients managed with CSF otorrhea, encephaloceles, and spontaneous pneumocephalus. All patients were repaired through transtemporal, middle cranial fossa or combined approaches for extradural repair and bone grafting.

RESULTS

Of the 56 consecutive cases, 12 had CSF otorrhea alone, 19 had encephaloceles, and 23 had both. Two patients presented with spontaneous pneumocephalus without CSF leak. Thirty-three patients had spontaneous onset of their lesion without any history of temporal bone surgery or trauma. The average BMI of patients with spontaneous CSF leaks was found to be greater than the average BMI of patients with CSF leaks due to traumatic, infectious or iatrogenic causes. This difference was found to be statistically significant. Six of these had either preceding or subsequent contralateral mastoid or anterior fossa (sphenoid, ethmoid) CSF leak. Intracranial pressure was evaluated in these cases and most underwent VP shunting to reduce their intracranial pressure. Sixteen cases followed previous mastoid surgery or chronic ear disease and seven were attributed to previous temporal bone trauma. Lesions were repaired with the transtemporal approach (42), middle fossa (4), and combined (5) approaches. Five cases required petrosectomy and fat obliteration. There was one recurrent CSF leak 4 years after initial repair; the leak was anterior to the previously placed bone graft.

[Atypical etiology of rhinorrhea: spontaneous bilateral temporal encephalocele]

Spontaneous herniation of brain parenchyma through a dural and osseous defect in the temporal bone is a rare entity and a bilateral form is even more infrequent. It usually presents as an intermittent but persistent otorrhea. Manifestation as nose cerebrospinal fluid (CSF) leak is very uncommon. Our objective is presenting this unusual case report of a spontaneous bilateral encephalocele with a bilateral tegmen tympani defect.

Case Report: Anteromedial temporosphenoidal encephalocele with a clinically silent lateral bony defect in the greater wing of the sphenoid

Anteromedial temporosphenoidal encephalocele is the least common type of temporal encephalocele. It commonly presents with spontaneous cerebrospinal fluid rhinorrhea in adults. This article presents the CT cisternography and MRI findings of one such case, which also had an associated clinically silent defect in the greater wing of the sphenoid on the same side.

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.

Acquired encephalocele attributable to tuberculous osteitis: case report

OBJECTIVE

There are many forms of calvarial tuberculosis. In this case report, extensive calvarial tuberculosis caused a large cranial defect and occlusion of the sigmoid sinus in a 10-year-old child. This resulted in a transient increase of the intracranial pressure and formation of an acquired encephalocele.

CLINICAL PRESENTATION

A 10-year-old boy presented with an acquired, infected encephalocele and features of tuberculous mastoiditis. Computed tomographic and magnetic resonance imaging scans demonstrated evidence of left occipital encephalocele with left mastoiditis, extradural granulations, bone destruction, and complete occlusion of the left sigmoid sinus.

INTERVENTION

The encephalocele was surgically excised and combined with left mastoidectomy. Although no mycobacterium had been demonstrated in the excised lesion, the presence of active tuberculous infection in the mastoid led to the conclusion that the bone destruction leading to encephalocele was secondary to the calvarial tuberculosis. The patient received antituberculous treatment with clinical improvement.

CONCLUSION

This is the first report of calvarial tuberculosis causing a cranial defect and venous sinus thrombosis and resulting in an acquired encephalocele. Surgical excision combined with medical treatment was curative.

Transalar Sphenoidal Encephalocele

Classification of cranial encephalocele is based on the anatomic location of the skull defect. Basal sphenoidal encephaloceles are the least common form of encephalocele whose pathogenesis can be congenital, traumatic, tumoral or spontaneous. We present a case of a very rare basal encephalocele protruding through a defect in the greater wing of the sphenoid bone into the pterygoid fossa.

Spontaneous cerebrospinal fluid rhinorrhoea due to temporosphenoidal encephalocele

A 57-year old man was referred to our hospital with spontaneous cerebrospinal fluid (CSF) rhinorrhoea of 6 years duration. He had an episode of meningitis 2 months previously. CT cisternography and cranial MRI revealed a defect in the lateral wall of the sphenoid sinus, with an anteromedial temporosphenoidal encephalocele. Surgery was performed transcranially through a pterional approach. The temporal encephalocele was amputated, the sphenoid sinus obliterated and the dural defect repaired. Lumbar drainage was used for 5 days after surgery. Spontaneous CSF rhinorrhoea is only infrequently due to temporal encephalocele. Anteromedial temporosphenoidal encephaloceles are the least common type of temporal encephalocele, with only 12 reported in the literature.

Spontaneous motor cortex encephalocele presenting with simple partial seizures and progressive hemiparesis

Several cases of congenital or acquired temporal encephaloceles have been reported in the literature as the causative mechanism of simple and/or complex partial seizures. In this report the authors describe a rare case of spontaneous parietal encephalocele presenting with simple partial seizures and progressively increasing contralateral upper-extremity motor deficit. The unusual anatomical location of an encephalocele associated with seizures and the delayed seizure onset represent distinctive characteristics in this case. Preoperative imaging included surface electroencephalography, computerized tomography, and brain magnetic resonance imaging. Frameless neuronavigation and intraoperative cortical mapping were used to aid resection of the encephalocele, and the dural and bone defects were reconstructed. The surgical outcome in this case was excellent, and the patient has remained seizure free. The pertinent literature is reviewed in this report.

Endoscopic endonasal treatment of a spontaneous temporosphenoidal encephalocele with a detachable silicone balloon. Case report

Temporosphenoidal encephaloceles are rare entities that occur when the temporal lobe herniates into the sphenoid sinus through a skull base defect of the temporal bone. Both an iatrogenic and a traumatic pathogenesis have been proposed. The authors describe a spontaneously occurring temporosphenoidal encephalocele in a 63-year-old woman who had a 4-year history of rhinorrhea. Spiral computerized tomography (CT) scanning revealed a bone defect located inside the ophthalmomaxillary triangle. The intrasphenoidal encephalocele had a heterogeneously hypointense signal compared with cerebrospinal fluid (CSF) on T1-weighted magnetic resonance (MR) images and a hyperintense signal compared with CSF on T2-weighted MR images. Two previous endonasal endoscopic procedures, performed by ear, nose, and throat surgeons, had been unsuccessful. The authors performed an endoscopic endonasal right nostril procedure by using 0 degrees and 45 degrees rigid-lens endoscopes that were 4 mm in diameter and 18 cm long. The encephalocele in the sphenoid sinus was partially removed. DuraGen and fat graft were positioned in the bone defect. Two No. 2 French detachable silicone balloons (1.5 cm3 volume) inflated with surgical glue were introduced into the skull defect and into the sphenoid sinus, respectively. The CSF leakage stopped immediately. No nasal packing or postoperative CSF lumbar drainage was necessary. The patient did well. Postoperative CT and MR imaging, obtained at 24 hours and at 3 months, demonstrated that the balloon and the fat graft filled the bone defect and the sphenoid sinus. Eight months postprocedure no CSF leakage was observed. This appears to be the first case reported in the literature of a temporosphenoidal encephalocele successfully treated by an endoscopic endonasal technique involving packing of the defect with inflated detachable balloons.

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.

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.

Absence of the greater sphenoid wing in neurofibromatosis type I: congenital or acquired: case report

unilateral absence of the greater wing of the sphenoid bone is a distinctive but uncommon manifestation of Type I neurofibromatosis, which has until now been regarded as a developmental anomaly of mesodermal origin. A computed tomographic scan was obtained in a 4-week-old infant with an abnormal left eye. The scan demonstrated an intact ipsilateral sphenoid bone, except for minor expansion of the medial end of the left superior orbital fissure. Another computed tomographic scan was obtained 6 years later, when the child had café-au-lait patches, axillary freckling, Lisch nodules, and left phthisis bulbi. This later scan showed typical sphenoid dysplasia. Much of the greater wing was absent, and the anterior temporal pole was displaced anteriorly. In this article, we discuss the implications of this case in terms of the cause of this condition and the diagnosis of Type I neurofibromatosis.

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.