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Year : 2012  |  Volume : 60  |  Issue : 6  |  Page : 679--681

Bilateral anteromedial middle cranial fossa defects causing spontaneous cerebrospinal fluid rhinorrhoea

S Rajesh Reddy1, Manas Panigrahi1, DV Narasimha Rao2,  
1 Department of Neurosurgery, Krishna Institute of Medical Sciences, Secunderabad, Andhra Pradesh, India
2 Department of Anaesthesiology, Krishna Institute of Medical Sciences, Secunderabad, Andhra Pradesh, India

Correspondence Address:
Manas Panigrahi
Department of Neurosurgery, Krishna Institute of Medical Sciences, Secunderabad, Andhra Pradesh

How to cite this article:
Reddy S R, Panigrahi M, Narasimha Rao D V. Bilateral anteromedial middle cranial fossa defects causing spontaneous cerebrospinal fluid rhinorrhoea .Neurol India 2012;60:679-681

How to cite this URL:
Reddy S R, Panigrahi M, Narasimha Rao D V. Bilateral anteromedial middle cranial fossa defects causing spontaneous cerebrospinal fluid rhinorrhoea . Neurol India [serial online] 2012 [cited 2020 Mar 30 ];60:679-681
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Full Text


Encephaloceles in middle cranial fossa are rare with anteromedial temporosphenoidal variety being the least common of the five types described under this category. [1] To the best of our knowledge, there has been no documented case of bilateral anteromedial encephaloceles with spontaneous cerebrospinal fluid (CSF) rhinorrhea in the literature till date. We discuss two such cases in whom surgical repair was done in a single stage.

A 45-year-old female presented with watery nasal discharge and associated diffuse, dull aching, continuous headache for 7 days. She had undergone a transnasal surgery elsewhere for the same complaint. Magnetic resonance imaging (MRI) revealed a temporal lobe encephalocele and pneumocephalus [Figure 1]b and e. On computed tomography (CT) scan, Defects were noted on either side in the temporal bone, abutting the sphenoid sinus [Figure 1]a,d,c.

A 10-year-old child Another 10 year old was evaluated for recurrent episodes of CSF rhinorrhea and intermittent watery nasal discharge. CT cisternogram revealed bilateral middle cranial fossa defects with evidence of CSF leak [Figure 2]a and b. MRI brain revealed an encephalocele which was more prominent on the right side [Figure 2]c.{Figure 1}{Figure 2}

Both patients denied history of trauma in the past. Opening CSF pressure was found to be normal in both patients. A single stage repair of the encephaloceles was performed through a bilateral pterional craniotomy, subtemporal, and middle fossa approach. Encephalocele was excised and intradural repair of the defects in sphenoid sinus and middle cranial fossa was performed with fat graft (harvested from abdominal wall) and pedicled temporalis flap. Post-operative recovery was uneventful after a follow up of 8 months in the first patient and 3 months in the second patient.

The embryological basis for congenital anteromedial temporal encephalocele is incomplete development and fusion of the greater wing of the sphenoid with the basisphenoid, leading to the formation of lateral craniopharyngeal (Sternberg) canal. [1] Acquired encephaloceles in this region result from smooth, lobulated bony defects called 'arachnoid pits' which are formed after decades of CSF pulsations on the ectopically located arachnoid villi. Pneumatization of the inferolateral recess of the sphenoid sinus which is present in 23-40% of the population is another factor that favors bony erosion and encephalocele formation. [2] Trauma, infection, tumor, previous surgery, and increased intracranial pressure are also prerequisites for formation of meningo-encephalocele. The ideal operative approach should allow complete exposure of the encephalocele followed by surgical reduction or amputation of the same and meticulous repair of both dural and osseous defects. Middle fossa encephalocele involving lateral extension of the sphenoid sinus requires transcranial approach for direct visualization and repair of the defect, whereas those involving the central portion of the sinus can be obliterated by an endoscopic transnasal route. [2],[3] Open surgical approaches are performed through a fronto-temporal craniotomy with or without zygomatic osteotomy. Once the area of brain herniation is defined extradurally and the encephalocele reduced (preferably) or amputated, dural repair is performed intradurally, extradurally, or by combining both routes. Dural defects can be closed primarily and/or bolstered using free autologous tissue-like fat (as in our case), dural substitutes, or pedicled flaps such as the temporoparietal flap. Hydroxyapatite paste is another useful adjunct with bone grafting to fill small cortical defects. [4] We employed the transcranial route in both our patients because of the location of defect close to the lateral recess of sphenoid sinus.

The recognition and treatment of accompanying intracranial hypertension will benefit the long-term integrity of the surgical repair, prevent the development of new defects, and reduce risks to vision. The risk factors for post-operative recurrence of CSF leaks are spontaneous CSF leaks of idiopathic origin, high-volume leaks, Body Mass Index >30 kg/m 2 , empty sella turcica, and patients with impaired CSF absorption (e.g., meningitis, intracranial hemorrhage, significant closed head injury). Such patients may require an additional CSF diversion procedure.


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