The Lateral Craniopharyngeal Canal (Sternberg’s Canal) in Pediatric and Adult Populations

Introduction: The location of lateral craniopharyngeal canal (LPC) aka Sternberg canal has been a source of controversy in the literature over the years, and there are more studies suggesting that the canal could be a possible source of spontaneous cerebrospinal fluid (CSF) leak in adults. There is controversy regarding the location and even existence of the Sternberg canal. Studies have indicated based on radiographic images of patients with CSF leak that the canal is located lateral to the foramen rotundum1. Others have questioned this suggestion and claimed the canal to be medial to the foramen rotundum. In the original publication by Maximillian Sternberg in 1888, the canal was described to be located at the medial angle of the superior orbital fissure, directly at the base of the outer root of lesser wing of the sphenoid. In addition, he mentioned the canal was constant in the skull of 3 to 4 years old, but only persisted in 4% of adult skulls. The objective of the study is to provide clarification on the existence, prevalence, and surgical anatomy of the lateral craniopharyngeal canal.

Methods: Total 50 contrasted computer tomography (CT) images of 3-year-old patients and 125 adult patients (>18 years), who presented to Albany Medical Center, were studied. The exclusion criteria included were poor quality images (>1.3 mm slices), disorders of anterior skull base including trauma, prior surgery, and congenital brain and skull disease.

Results: A tract was found to be originating at the medial angle of superior orbital fissure below the root of the lesser wing of the sphenoid (Fig. 1). The tract was present in 61.4% of the pediatric group. The tract originates above and slightly medial to the foramen rotundum and it projects posteriomedially and connects with processus vaginalis (Fig. 2). The tract is at the junction of the presphenoid, basisphenoid, and alisphenoid similar to the description by Sternberg. However, this tract is usually obliterated in adult population by the development and pneumatization of the sphenoid sinus (Fig. 3). Only two (1.6%) patients showed a bone defect (Fig. 4) at the same location of the canal with the same trajectory, which is consistent with a remnant of LPC. In the adult population when present, the canal had reduced diameter as compared with the pediatric population (Figs. 1 and 2).

Conclusion: This study showed that LPC, as described by Sternberg, originates medial to the foramen rotundum. The canal projects posteriorly and medially toward the processus vaginalis. LPC is a common occurrence in the 3-year-old age group. Pneumatization and development of the sphenoid bone obliterates the canal in adult population and reduces it to less than 2%.