Intrasphenoidal encephaloceles?a clinical entity

Abstract

In the current classification basal encephaloceles are grouped together with real transsphenoidal encephaloceles. But those encephaloceles extending only into but not through the sphenoid sinus seem to represent a specific clinical entity and therefore should be regarded as a rare subgroup of sphenoidal encephaloceles. One personal case and six cases from the literature are reviewed, the own case being associated with an empty sella turcica. The initial sign is rhinorrhea, almost invariably. The association with other intracranial anomalies is uncommon. The extradural transsphenoidal or transethmoidal midline approach accompanied by a shunting procedure today is the most suitable method of surgical treatment.

Nontraumatic Skull Base Defects With Spontaneous CSF Rhinorrhea and Arachnoid Herniation: Imaging Findings and Correlation With Endoscopic Sinus Surgery in 27 Patients

“…34,54 On rare occasions, osteodural defects of the lateral sphenoid sinus did not cause herniation of any tissue at all. 46 Sound principles regarding endoscopic surgery of CSF leaks consist of adequate exposure, preparation of the fistula, and adequate grafting.…”

“…In the literature, the entire spectrum of contents of herniation has been described during surgery including meningocele, 14 arachnoid tissue, 4,54 or encephalocele. 34,54 On rare occasions, osteodural defects of the lateral sphenoid sinus did not cause herniation of any tissue at all.…”

Intrasphenoidal Encephalocele Associated with Cerebrospinal Fluid Fistula and Subdural Hematomas: Technical Case Report

“…When none of these causes can be identified, the encephalocele's pathogenesis can be attributed, as in the case we present here, to the existence of a small defect in the bone, probably congenital in nature, located in the middle cranial fossa, through which cerebral tissue may protrude (4,5,17,22). In the available literature, we were able to find descriptions of only 12 cases of this entity (1,6,9,10,16,20,23,25). Rhinorrhea, recurrent meningitis, and headache are mentioned as the complications of encephalocele, but in no case has the association of rhinorrhea with subdural hematoma (SDH) been described.…”

Middle Fossa Approach to a Temporosphenoidal Encephalocele -Technical Note-

“…According to the current classification and depending on the defect location, 7) these developmental anomalies seem to represent a specific clinical entity, so should be differentiated from transethmoidal, sphenoethmoidal, frontosphenoidal, and spheno-orbital encephaloceles. Furthermore, intrasphenoidal encephalocele, in which the herniating brain and meninges are enclosed within the SS, has different morphological and clinical characteristics and thus appropriate surgical treatment compared to true transsphenoidal encephaloceles.…”

“…Modern MR imaging can aid the clinician in discriminating between intrasphenoidal encephalocele and more common causes of isolated SS mass such as polyp, mucocele, fungal ball, and localized sinusitis. 7,8) MR imaging may also provide valuable information about the location of vital structures within the herniated tissue of the basal encephaloceles. 9,10) The goals of surgery for basal encephaloceles include: removal of the herniated sac, preservation of functional neural tissue, closure and reconstruction of the defect with healthy tissue, and restoration of the CSF pathway via shunting.…”