Vestiges of Ossified Spheno-occipital Suture in an Elderly Patient With Down Syndrome and Lateral Skull Base Fracture

Abstract

Background/Aim: Down syndrome (DS) patients often show characteristic changes in the skull, e.g. short cranial base. The synchondroses of the skull base have a significant influence on the shape of the skull. The sphenooccipital synchondrosis (SOS) is the last of the basal synchondroses to ossify. This report is about residual ossification of SOS in an elderly patient with DS. Case Report: The 65-year-old DS patient was polytraumatized by a fall. In the course of treatment, a purulent otitis externa on the right side was diagnosed, which had developed as a result of the fracture of the fossa glenoidalis. Computed tomograms of the skull base showed the fracture of the mandibular condyle, glenoid fossa and vestiges of SOS. Conclusion: The coincidental finding of vestiges of SOS in an elderly patient with DS raises the question of whether cross-sectional skull base images can show differences in the ossification of SOS between DS patients and a normal population.

When does the spheno‐occipital synchondrosis close?

“…Okamoto et al (1996) noted a white line at the site in a 62‐year‐old woman. Similarly, Friedrich et al (2020) reported a pair of radio‐opaque lamellae at the same position in a 65‐year‐old man with Down syndrome. In contrast, Adem et al (1999) noted an incompletely fused spheno‐occipital synchondrosis in a 30‐year‐old man.…”

“…Shirley and Jantz (2011) stated that a fusion scar can persist for decades, but they were referring to a shallow linear groove on the underside of an isolated skull. In terms of how long the fusion line can persist, however, the evidence of Okamoto et al (1996), McKinney (2017) and Friedrich et al (2020) cited earlier indicates that it can remain long after the synchondrosis closes and thus does not indicate recent closure.…”

“…Okamoto et al (1996) noted a white line at the site in a 62-year-old woman. Similarly,Friedrich et al (2020) reported a pair of radioopaque lamellae at the same position in a 65-year-old man with Down syndrome. In contrast,Adem et al (1999) noted an incompletely fused sphenohowever, illustrated a radio-opaque line at the site of the spheno-occipital synchondrosis in a 45-year-old patient and a radiolucency in a 71-year-old; the sexes were not specified.…”