Computed Tomography of the Anterior Skull Base in Kallmann Syndrome Reveals Specific Ethmoid Bone Abnormalities Associated With Olfactory Bulb Defects

Context: Kallmann syndrome (KS) is characterized by congenital hypogonadotropic hypogonadism (CHH) and an impaired sense of smell related to defective development of the olfactory system. Objective: The aim of the study was to use high-resolution computed tomography (CT) to detect specific abnormalities in the ethmoid bone region surrounding the olfactory bulbs in patients with KS. Patients: Thirty-seven KS patients were compared to normosmic CHH (nCHH) patients (n = 15) and controls (n = 30) of similar age. Design and Methods: We conducted a prospective study in a single referral center. Subjects underwent CT in bone windows with axial, coronal, and sagittal reconstructions centered on the olfactory fossa (OF) and cribriform plate (CP). We characterized the OF structure by measuring OF height, width, and surface area and a series of angles. The CP foramina were counted bilaterally. Olfactory bulb magnetic resonance imaging, performed in parallel, was compared with CT findings. Results: OF height, width, ...