Middle fossa approach to a temporosphenoidal encephalocele -technical note-

Repair of lateral temporo-sphenoidal encephalocoele via an endoscopic transorbital approach: ex vivo 3D printed simulation followed by in vivo deployment

BACKGROUND

A temporo-sphenoidal encephalocoele occurs when temporal lobe herniates through a defect in the greater wing of the sphenoid bone into the sphenoid air sinus. The natural history is not well-understood, though presentation in adulthood with CSF rhinorrhoea and/or meningitis is typical. Lateral pneumatisation of the sphenoid sinus and elevated BMI may be contributory.

AIMS

We explored the feasibility of a transorbital approach (TOA) for repair, using a combination of 3D modelling and simulation. We then successfully deployed this technique in vivo.

METHODS

CT imaging for three patients who had previously undergone transcranial repair of lateral temporo-sphenoidal encephalocoele was used to generate data allowing 3D printed models of the skull base to be produced. The transorbital approach was simulated by performing a lateral orbitotomy followed by drilling of the sphenoid wing to expose the antero-basal middle fossa. 3D object scanning was used to create virtual models of the skull base post-surgery, from which surgical access was quantified in two ways: the area (mm2) of the middle fossa exposed by the TOA and the vertical attack angle.

RESULTS

The mean surface area of the cranial access window achieved by simulated TOA was 325mm2. The mean vertical attack angle was 25°. One patient was subsequently treated successfully via TOA with no recurrence of their CSF leak, no orbital morbidity, excellent cosmesis, but resolving V2 numbness (follow-up 7 months).

CONCLUSIONS

We have shown that the transorbital approach provides adequate surgical access. In our single case, surgical repair of a lateral temporo-sphenoidal encephalocoele via TOA was feasible, safe, and effective. This approach may offer some advantages compared with transcranial or endonasal approaches.

Cerebrospinal fluid rhinorrhea with meningoencephalocele related to Sternberg's canal: A report of two cases

Background

Cerebrospinal fluid (CSF) rhinorrhea with meningoencephalocele (MEC) associated with Sternberg's canal is rare. We treated two such cases.

Case Description

A 41-year-old man and a 35-year-old woman presented with CSF rhinorrhea and mild headache worsening with standing posture. Head computed tomography showed a defect close to the foramen rotundum in the lateral wall of the left sphenoid sinus in both cases. Head magnetic resonance (MR) imaging and MR cisternography revealed that brain parenchyma had herniated into the lateral sphenoid sinus through the defect of the middle cranial fossa. The intradural and extradural spaces and bone defect were sealed with fascia and fat through both intradural and extradural approaches. The MEC was cut away to prevent infection. CSF rhinorrhea completely stopped after the surgery.

Conclusion

Our cases were characterized by empty sella, thinning of the dorsum sellae, and large arteriovenous malformations that suggest chronic intracranial hypertension. The possibility of Sternberg's canal in patients with CSF rhinorrhea with chronic intracranial hypertension should be considered. The cranial approach has the advantages of lower infection risk and the ability to close the defect with multilayer plasty under direct vision. The transcranial approach is still safe if performed by a skillful neurosurgeon.

Meningoencephalocele in the Lateral Sphenoid Sinus Showing Malformation of Cortical Development: A Case Report

Meningoencephalocele in the lateral sphenoid sinus (SS) has been determined to be a rare entity often detected by cerebrospinal fluid (CSF) rhinorrhea. To date, the pathology of meningoencephalocele in the lateral SS has remained to be unclear in many cases. In this study, we report on a case of a 72-year-old woman with an arteriovenous malformation who presented with CSF rhinorrhea. Radiologic investigations revealed a left temporal meningoencephalocele in the lateral SS. We removed the meningoencephalocele and performed skull base repair, after which the CSF rhinorrhea resolved. Pathological examination showed congenital cortical abnormalities with dysmorphic neurons in various shapes and acquired chronic tissue alterations including fibrillary gliosis and scattered Rosenthal fibers. These findings may further aid in understanding the etiopathogenesis of meningoencephalocele in the lateral SS.

Spontaneous symptomatic orbital meningoencephalocele in an adult patient. Case report and review of the literature

Symptomatic spontaneous meningoencephalocele (MEC) is a very rare entity in adults and there have been no reported cases of spontaneous MEC through the orbital roof in an adult. We report a 41-year-old woman who presented with a left eyelid swelling for several weeks without any history of trauma. Brain magnetic resonance imaging (MRI) showed a MEC through the orbital roof causing a significant blepharocele in this young patient. Supraorbital craniotomy was performed to repair the bone defect. The symptoms resolved immediately after surgery. Even though blepharocele is a rare manifestation of spontaneous orbital MEC it should be considered in the differential diagnosis for appropriate surgical management.

Delayed presentation of morning glory disc anomaly and transsphenoidal encephalocele: A management dilemma

Background Morning glory disc anomaly (MGDA) is a rare developmental abnormality of the optic disc that is associated with many other neurological and vascular conditions. Most cases are diagnosed in childhood. Case Report We report a 57-year-old woman who presented to the ophthalmology department for assessment of long-standing poor vision in the left eye and exotropia. Examination showed a left MGDA and bitemporal hemianopsia. These findings prompted magnetic resonance imaging, revealing a transsphenoidal basal meningoencephalocele with herniation of the optic chiasm and inferior hypothalamus into the dural sac. Due to the eloquence of the neurovascular structures it contained, a decision was made not to reduce the meningoencephalocele. Instead, a ventriculoperitoneal shunt was placed. The patient's ophthalmologic examination remained stable over the following year. Conclusion While rare, MGDA can be first diagnosed in late adulthood and a thorough evaluation should be completed to assess for midline cranial defects, vascular abnormalities, and other associated abnormalities. Patients presenting late in life with basal encephalocele, herniation of the optic chiasm, and bitemporal hemianopsia present a management dilemma. In this case, a ventriculoperitoneal shunt was placed with the intention of lowering intracranial pressure to prevent further herniation and reduce the risk of cerebrospinal fluid leak.

Endoscopic Endonasal Transpterygoid Approach to Sphenoid Sinus Lateral Recess Defects

Background  Lesions affecting sphenoid sinus lateral recess (SSLR) are difficult to visualize and manipulate through the transnasal routes, especially when the sinus is highly pneumatized. External approaches to this area involve extensive surgery and are associated with significant morbidity. The aims of this study are to present our experience with the endoscopic transpterygoid approach as a method for approaching lesions of the SSLR and to evaluate the outcomes of this procedure. Methods  Clinical charts of patients who had lesions in the SSLR and who were treated at our institution from September 1998 to June 2018 were retrospectively reviewed. All these patients were managed by the endoscopic endonasal transpterygoid approach. Results  Thirty-nine patients were identified. No cerebrospinal fluid leak recurrences were observed during follow-up (range: 1-19.7 years; median: 2.3 years). Hypoesthesia (temporary, 1; persistent, 4) in the region innervated by the maxillary branch of the trigeminal nerve was detected in five (12.8%) patients, while symptoms due to the Vidian nerve damage (dry eye, 3; dry nasal mucosa, 1) were present in four (10%) patients. Conclusions  Although the endoscopic endonasal transpterygoid approach is an excellent corridor for dealing with lesions of the SSLR, limited rate of neurologic and lacrimal complications was observed. Potential morbidity of the intervention should be discussed during preoperative counselling.

Idiopathic intracranial hypertension presenting as bilateral spontaneous lateral intrasphenoidal and transethmoidal meningoceles: a case report and review of the literature

Background

Basal meningoceles are rare herniations of the meninges that tend to present unilaterally with cerebrospinal fluid rhinorrhea. Growing evidence suggests that intracranial hypertension contributes considerably to the formation of spontaneous basal meningoceles.

Case presentation

A 50-year-old man of Middle East ethnicity presented with a 16-week history of cerebrospinal fluid rhinorrhea, short-term memory loss, and slight decline in cognitive function. We present a case of bilateral spontaneous meningoceles with bone defects in the left lateral sphenoid sinus and right anterior cribriform plate, as well as with a remodeled sella. A neuronavigation-assisted expanded endoscopic endonasal surgery was performed to resect the meningoceles. Postoperative imaging demonstrated complete resolution of the bilateral meningoceles.

Conclusions

This case reports the first bilateral basal spontaneous meningoceles in the literature. Furthermore, based on this case’s imaging results and the literature reviewed, elevated intracranial pressure may be a determining factor behind the development of spontaneous meningoceles.

Cerebrospinal fluid rhinorrhea and seizure caused by temporo-sphenoidal encephalocele

This case report describes the symptoms and clinical course of a 35-year-old female patient who was diagnosed with a temporo-sphenoidal encephalocele. It is characterized by herniation of cerebral tissue of the temporal lobe through a defect of the skull base localized in the middle fossa. At the time of first presentation the patient complained about recurrent nasal discharge of clear fluid which had begun some weeks earlier. She also reported that three months earlier she had for the first time suffered from a generalized seizure. In a first therapeutic attempt an endoscopic endonasal approach to the sphenoid sinus was performed. An attempt to randomly seal the suspicious area failed. After frontotemporal craniotomy, it was possible to localize the encephalocele and the underlying bone defect. The herniated brain tissue was resected and the dural defect was closed with fascia of the temporalis muscle. In summary, the combination of recurrent rhinorrhea and a first-time seizure should alert specialists of otolaryngology, neurology and neurosurgery of a temporo-sphenoidal encephalocele as a possible cause. Treatment is likely to require a neurosurgical approach.

Intrasphenoidal encephalocele: an incidental finding in emergency department

Background

Basal encephaloceles are rare clinical entities. Intrasphenoidal encephalocele (ISE) is a rare form of basal encephalocele. The clinical presentation is often subtle and may remain undetected. Only a limited number of cases of ISE have been reported, mostly in middle-aged patients who presented with symptoms. Clinical diagnosis and management remain a challenge. Our case reports ISE as an incidental finding in a very elderly male patient.

Findings

We present a case of ISE discovered as an incidental finding in a 99-year-old male who presented to the emergency department (ED) after a fall from bed. The encephalocele was discovered in the evaluation of the computed tomography (CT) scan of the head.

Conclusion

This is an incidental manifestation of a rare disease. It demonstrates that these encephaloceles may not manifest clinically or symptomatically as other reports have suggested.

Sternberg's canal as a cause of encephalocele within the lateral recess of the sphenoid sinus: A report of two cases

Background:

Intrasphenoidal encephaloceles are extremely rare findings. Sternberg's canal is a lateral craniopharyngeal canal resulting from incomplete fusion of the greater wings of the sphenoid bone with the basisphenoid. It acts as a weak spot of the skull base, which may lead to develop a temporal lobe encephalocele protruding into the lateral recess of the sphenoid sinus (SS).

Case Description:

We present two cases of intrasphenoidal encephalocele due to persistence of the lateral craniopharyngeal canal. The first case presented with cerebrospinal fluid (CSF) rhinorrhea and the second one was referred to the neurosurgical department with CSF rhinorrhea and meningitis. Radiological investigations consisted of computed tomography (CT) scan, CT cisternography and magnetic resonance images in both cases. These imaging studies identified a herniated temporal lobe through a bony defect which communicates the middle cranial fossa with the lateral recess of the SS. Both patients underwent a transcranial repair of the encephalocele because of the previous failure of the endoscopic surgery. There was no complication related to the surgical procedure and no recurrence of CSF leakage occurred 2 and 3 years after surgery, respectively.

Conclusion:

Encephalocele within the lateral recess of the SS is a rare entity which must be suspected in patients who present with spontaneous CSF rhinorrhea. Congenital intrasphenoidal encephaloceles, which are located medial to the foramen rotundum, seem to be due to persistence of the Sternberg's canal. Transcranial approach is a good option when a transnasal approach had failed previously.