Tegmen attenuation in patients with idiopathic intracranial hypertension is progressive

Objectives: To prove that temporal bone tegmen attenuation in patients with idiopathic intracranial hypertension (IIH) is progressive. Study Design: Retrospective blind study at a tertiary academic medical center. Methods: Enrolled were medical records of patients with IIH that included at least two sequential computed tomography (CT) scans. The vertical distances between the floor of the middle fossa to the superior and lateral semicircular canals (SSC and LSC, respectively), to the scutum and minimal squama thickness were measured. The same measurements were made in scans of control subjects. The impact of demographics and metabolic variables including opening lumbar puncture (LP) pressure were evaluated. Results: Twenty medical records were enrolled. Median age at diagnosis was 21 years; 16 were females. The median body mass index (BMI) was 32 kg/m². Initial LP pressure was 195 mm cerebrospinal fluid (CSF). The median time interval between CT scans was 58 months. A median attenuation of 0.35 mm and 0.25 mm over the right and left LSC and of 0.5 mm and 0.3 mm over the right and left scutum, was found, respectively. The thicknesses of the SSC and squama remained stable. No attenuation was present in controls. The opening pressure on initial LP (median 195 mm CSF), was positively correlated with the degree of tegmen attenuation, but the age at diagnosis and BMI were not. Conclusions: Tegmen attenuation may be progressive in patients with idiopathic increased intracranial pressure and correlated with the opening pressure on LP. Tegmen defects and CSF leak should be looked for in these patients. Level of Evidence: 4 Laryngoscope, 2020.