Sphenoid sinus expansion: a radiographic sign of intracranial hypotension and the sunken eyes, sagging brain syndrome (an American Ophthalmological Society thesis).

PURPOSE To test the hypothesis that in patient with sunken eyes, sagging brain syndrome, bone remodeling is not limited to the orbits. Volumetric analysis of the sphenoid sinus is performed in this study. METHODS In this university-based retrospective case-control study, the dimensions of the sphenoid sinus were measured in four patients (2 males, 2 females; mean age 26.3 years, range 16-38 years) out of five individuals identified with sunken eyes, sagging brain syndrome. Three measurements were taken: the distance between the orbital apices, the posterior extension of the sphenoid sinus posterior to the orbital apices, and the maximal horizontal width. The mean of each was determined and compared to that of the control group (5 males, 5 females; mean age 35.6 years, range 23-45 years). RESULTS Posterior extension and width of the sphenoid sinus were markedly larger in the enophthalmic patients than in the control group: posterior extension (26.3 ± 4.1 mm vs 13.4 ± 6.3 mm, P=.0015, Student's t test), width (39.2 ± 8.7 mm vs 25.1 ± 6.9 mm, P=.0035, Student's t test). Mean distance between the orbital apices was slightly greater (36.3 ± 1.7 mm vs 34.1 ± 2.1 mm, P=.047, Student's t test). CONCLUSIONS Skull remodeling occurring in association with intracranial hypotension after ventriculoperitoneal shunting is not limited to the orbits. In this study we have demonstrated expansion of the sphenoid sinus. This finding adds to our knowledge and understanding of the scope of the sunken eyes, sagging brain syndrome and elucidates a clinically useful radiographic sign.