|Year : 2018 | Volume
| Issue : 2 | Page : 162-164
Anteromedial temporal encephalocele: A rare cause for spontaneous cerebrospinal fluid rhinorrhoea
Saikat Bhattacharjee1, Deepak Chandra Reddy2, Samar Chatterjee3, Bikram Choudhury4
1 Department of Radiology, Military Hospital, Cardiothoracic Centre, Pune, Maharashtra, India
2 Department of Radiology, Military Hospital, Jammu, Jammu and Kashmir, India
3 Department of Radiology, Armed Forces Medical College, Pune, Maharashtra, India
4 Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
|Date of Submission||20-Feb-2018|
|Date of Acceptance||13-Aug-2018|
|Date of Web Publication||10-Jan-2019|
Lt Col Saikat Bhattacharjee
Department of Radiology, Military Hospital, Cardiothoracic Centre, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
Spontaneous cerebrospinal fluid (CSF) rhinorrhea in an adult without prior history of head trauma is a rare occurrence. Neuroimaging is done to ascertain the site of bony defects in the cranium and breach in the continuity of dura to localize the site of CSF leakage. Encephaloceles into the sphenoid sinus occurring through congenital bony defects in the walls of the sinus are an extremely rare cause for CSF rhinorrhea. We present a case of spontaneous, nontraumatic CSF rhinorrhea due to an anteromedial encephalocele where the temporal lobe was seen herniating into the right sphenoid sinus through a congenital bony defect in the wall of the sinus. A review of the present literature is also presented.
Keywords: Anteromedial temporal encephalocele, cerebrospinal fluid rhinorrhoea, magnetic resonance imaging
|How to cite this article:|
Bhattacharjee S, Reddy DC, Chatterjee S, Choudhury B. Anteromedial temporal encephalocele: A rare cause for spontaneous cerebrospinal fluid rhinorrhoea. J Mar Med Soc 2018;20:162-4
| Introduction|| |
Cerebrospinal fluid (CSF) rhinorrhea is a condition in which there is leakage of CSF through the nose because of an abnormal communication between the intracranial subarachnoid space and the nasal cavity. The role of neuroimaging is to localize the site of cranial defects and dural continuity breach to ascertain the site of CSF leakage.
Herniation of the temporal lobe into the sphenoid sinus through congenital bony defects in the walls of the sinus is an extremely rare cause for spontaneous CSF rhinorrhea.
| Case Report|| |
A 50-year-old woman presented to the ENT outpatient department with a history of watery discharge from her right nostril for the past 4 months. The discharge was spontaneous in onset and had no progression in severity. It was in the form of drops of clear watery fluid that came out of her right nostril, more upon bending forward. There was no diurnal variation. There was no associated snoring, sneezing, nasal obstruction, anosmia, parosmia, or cacosmia. There was no history suggestive of nasal allergy or sinonasal polyposis. There was no prior history of trauma to the head. There was no history of fever or headache. There was no other relevant contributory medical history. General and systemic examination of the patient was unremarkable. Following anterior and posterior rhinoscopic examination, the patient underwent a diagnostic nasal endoscopy (DNE) with 0° and 30° Hopkins Rod telescope and a cold light source. DNE revealed a right-sided nasal septal deviation and was otherwise unremarkable. There was no growth in either nasal cavity. There was no turbinate hypertrophy and bilateral middle meati were normal. There was no purulent or mucoid discharge visible in the nose and nasopharynx. No defect was visible during DNE in the cribriform plate region posteriorly and laterally. No active site of watery clear fluid discharge was present; however, right side nasal cavity was seen to be filling up after patients head repositioning by bending her forward.
The otorhinolaryngologist considered this to be a case of CSF rhinorrhoea (right) side nose and asked for investigations. The fluid collected from the right nostril was positive for beta-2-transferrin by immunoelectrophoresis. The blood sugar and glucose levels in the fluid collected from the right nostril were from samples collected simultaneously and measured 80 mg/dL and 44 mg/dL, respectively, which was strongly suggestive of the fluid being CSF.
In view of the above-mentioned findings, the otolaryngologist planned to investigate radiologically for the site of CSF leak in order to plan for further surgical management options available being endonasal, endoscopic repair, or open neurosurgical closure.
A contrast-enhanced computed tomography (CT) paranasal sinuses along with an angiogram for the Circle of Willis was done to delineate the site of CSF rhinorrhea. It revealed a dehiscence of the lateral wall of the right sphenoid sinus [Figure 1]a and [Figure 1]b measuring approximately 10 mm × 20 mm × 15 mm in the anteroposterior, mediolateral, and craniocaudal axes, respectively. The cavernous portion of the right internal carotid artery was located at the superomedial aspect of the herniated brain [Figure 1]c. Bony dehiscence was also seen in the roof of the right sphenoid sinus.
|Figure 1: Contrast-enhanced computed tomography peripheral nervous system reveals dehiscence (white arrows) of the lateral wall of the right sphenoid sinus (a and c). The coronal reformatted angiographic image (c) shows the cavernous portion of the right internal carotid artery located at the superomedial aspect of the herniated brain|
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A magnetic resonance imaging (MRI) was also done for the patient that revealed an anteromedial encephalocele, with the right temporal lobe seen herniating into the right sphenoid sinus through a bony defect in the lateral wall of the sinus [Figure 2]a,[Figure 2]b,[Figure 2]c. The herniated brain in the right sphenoid sinus was surrounded by CSF on all sides [Figure 2]a. There was prominence of the Sylvian fissure on the right. Heavily T2-weighted images obtained using constructive interference in steady state gradient echo sequence through the anterior cranial fossa did not reveal any defects in the cribriform plate. A diagnosis of congenital anteromedial temporal encephalocele was made and the patient underwent neurosurgical repair of the defect through a transnasal, transsphenoidal route. The patient had cessation of CSF rhinorrhea after the surgery and is presently asymptomatic. A follow-up CT scan showed postoperative status with evidence of transnasal transsphenoidal duroplasty [Figure 3]a and [Figure 3]b with aerated sphenoid sinus showing no evidence of cerebral herniation into it [Figure 3]a,[Figure 3]b,[Figure 3]c.
|Figure 2: Coronal T2-weighted imaging (a), axial fluid-attenuated inversion recovery (b) and sagittal T2-weighted imaging (c) Magnetic resonance imaging reveal an anteromedial encephalocele with the right temporal lobe seen herniating into the right sphenoid sinus through a bony defect (white arrows) in the lateral wall of the sinus|
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|Figure 3: Computed tomography peripheral nervous system axial (a), coronal reformatted (b), and sagittal reformatted (c) images reveal postoperative status with evidence of trans-nasal trans-sphenoidal duroplasty (circles in a and b). The right sphenoid sinus (arrows in a, b, and c) is well aerated with no evidence of herniation of brain parenchyma into it|
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| Discussion|| |
The most common cause of CSF rhinorrhoea is trauma, whereas spontaneous nontraumatic CSF rhinorrhoea is much less common and can be caused by various etiologies such as neoplasms, especially skull-base tumors, inflammatory, and granulomatous conditions such as Wegener's granulomatosis, syphilis, and basal encephaloceles.
The cranial encephaloceles have an approximate reported incidence of 1 in 35,000 cases. The commonest site is through the anterior cranial fossa, whereas temporal encephaloceles are the least common. Pathological herniations of the temporal lobe through dural and bony defects are known as temporal encephaloceles and have been classified into five types by Wilkins and Radtke in 1993 based on the site of origin of these lesions. These five types are lateral, anterior, postero-inferior, antero-inferior, and anteromedial. Of these, the anteromedial type is the least common. The congenital nature of these defects has been challenged in literature, supporting the role of acquired arachnoid pits and pneumatization of inferolateral recess of the sphenoid as etiological causes instead. Temporal lobe encephaloceles, based on their site of origin and on the nature of the dural and bony defects, may present in childhood or in adults with clinical presentations varying from an occult CSF rhinorrhea to conditions such as recurrent episodes of meningitis, otitis media, intractable seizures, and conductive hearing loss.
Prompt diagnosis and treatment of CSF leak is of utmost importance to prevent the onset of complications such as bacterial meningitis that has a reported incidence varying from 9% to 50%. To clinically diagnose this condition, the nasal discharge, whenever possible, should be collected in a container and assessed for the presence of beta-2-microglobulin, a polypeptide that is involved in ferrous iron transport and is found exclusively in the CSF, aqueous humor, and perilymph. Therefore, the presence of this beta transferrin in the nasal discharge has a high sensitivity and specificity in the confirmation of CSF rhinorrhea. Besides this test, certain other less sensitive diagnostic modalities involve assessment of glucose and its quantification. In patients with normal blood glucose, presence of >30 mg/dl glucose in the nasal discharge is indicative of a CSF leak. Once the CSF leak is confirmed, the next step is to identify the site of the leak by imaging. CT cisternography and MRI play a vital role in exhibiting the pathology. In CT cisternography, 10 ml of nonionic iodinated contrast is injected through lumbar puncture, the patient is made to lie in a prone position, and sequential coronal or axial sections are obtained. An active leak is readily diagnosed by the presence of contrast in the nasal cavity through the defect, the size and morphology of which can be demonstrated exquisitely by thin section CT through the region, seen in a bone window algorithm. These images give the surgeon a “road map” for preoperative planning of the surgical repair. The principle drawbacks with CT cisternography are its invasive nature and exposure to radiation. Moreover, soft-tissue details such as the temporal lobe encephaloceles may not be well delineated. MRI is being increasingly performed in the present-day scenario in all cases of CSF rhinorrhea. It is a noninvasive procedure with no radiation and excellent soft-tissue contrast, thus overcoming the drawbacks of CT. MR cisternography or flow-sensitive MRI such as constructive interference in steady state gradient echo protocols are performed in such cases and the reported sensitivity to identify a CSF fistula is as high as 100% even if the fistula is inactive.,,
Patients with recurrent or persistent symptoms have to be treated with a definitive surgical repair. The surgical procedure varies depending on the location and size of the osseous defect, presence and the type of CSF leak, and general condition of the patient. An open procedure that included both or either of the intradural and extradural routes was the classic surgical procedure done in the past. The osseous defects are usually repaired using fat, cadaver graft, local muscle, bone chips, or a combination of these materials., With the advent of endoscopic sinus surgeries, managing such cases has become relatively easier with reduced patient discomfort as there is minimal handling of the brain. Endoscopic sinus surgery is the preferred modality of treatment in cases of anteromedial temporal encephalocele, such as our case primarily because of the proximity of these lesions to the easily approachable sinuses. The endoscopic procedures are performed either through the transnasal-transphenoidal or transethmoidal routes, the former approach may at times be unfavorable as it does not always provide complete visualization of the lateral recess of the sphenoid sinus, which is the commonest site of the osseous-dural defect.
To conclude, spontaneous CSF rhinorrhea can occur due to various etiologies such as neoplasm, inflammation, basal encephaloceles, or prior surgery. These cases usually present in adulthood with occult symptoms or rarely with conditions such as recurrent meningitis. Anteromedial temporal lobe encephaloceles are the least common cause of spontaneous CSF rhinorrhea and we report one such case. Diagnosis and prompt surgical repair of an active CSF fistula is very important to avoid complications.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]