Association of Chiari I malformation and cerebellar ectopia with sensorineural hearing loss.

We aimed to examine the prevalence of cerebellar tonsil ectopia and Chiari 1 malformation in sensorineural hearing loss (SHL) that has, to the best of our knowledge, not been studied previously. Magnetic resonance imaging records of 166 subjects with SHL and 50 controls without known otologic disturbances were included in the study. A tonsils descent more than 2 mm was assumed as cerebellar ectopia, and a descent equal to or more than 5 mm was assumed as Chiari 1 malformation. A tonsil descent group was also formed by summation of both groups. Transverse diameters of bilateral intracranial vertebral arteries and transverse sinuses were also measured, and all parameters were analyzed using appropriate statistics. A significant difference of frequencies of Chiari 1, ectopia, and tonsil descent was detected between patients and controls. In comparison of cerebellar ectopia and Chiari 1 groups, SHL did not show any significant difference. The left lateral sinus diameter showed positive correlation with tonsil descent. There was no significant correlation for the diameters of other vessels. A powerful correlation was detected between SHL and age. In addition, right and vertebral artery diameters showed positive correlations with age. Chiari 1 malformation and cerebellar ectopia showed an association with SHL. These patients should also be evaluated for otologic disturbances. Further high-resolution magnetic resonance imaging studies to explain the exact cause of this currently unknown association seems required.