Sternberg's Canal and Defect: Is the Lateral Craniopharyngeal Canal a Source of Spontaneous Cerebrospinal Fluid Leak? Anatomic and Radiological Analysis in Pediatric and Adult Populations

Abstract

Background: The lateral craniopharyngeal or Sternberg's canal (SC) originates from superior orbital fissure (SOF) and traverses the sphenoid body into the nasopharynx. A remnant of the canal, Sternberg's defect (SD), has been debated as a source of cerebrospinal fluid (CSF) leak. The canal was described in 1888, and there is limited accurate visual illustration in the literature.

Objective: To provide a detailed anatomic and radiological illustration of the canal in pediatric and adult population including the mechanism undermining the incidence of the canal, and the possibility of the canal as a source of CSF leak.

Methods: A total of 195 high-resolution computed tomographies (CT) of patients (50 3-yr-old, 20 5-yr-old, and 125 adults) and 43 dry adult skulls (86 sides) were analyzed for a canal matching the description of the SC.

Results: A SC was identified in 86% of the 3-yr-old and 40% of 5-yr-old patients. The diameter and length were 2.12 mm and 12 mm, respectively. The incidence of the canal decreased with age as sinus pneumatization extended into the sphenoid sinus. Only 0.8% of the adult skull on CT had the canal. The canal was not present on the dry adult skulls examination, but SD was found in 4.65%.

Conclusion: SC exists with high incidence in the pediatric group. Sinus pneumatization obliterates the canal in the adult population, leaving a defect in 4.65% of cases, which given the location and related anatomic structures, is unlikely to be a source of CSF leak.

Keywords: Cerebrospinal fluid leak; Lateral craniopharyngeal canal; Processus vaginalis; Skull; Sternberg's canal; Superior orbital fissure.