Investigations into the cause of canal paresis in Menière's disease.

Since the literature has a paucity of documented lesions of the vestibular hair cells and neurons in Menière's disease, the cause of canal paresis remains unexplained. A clinicopathological correlation was sought and demonstrated between ampullary distortion of lateral canal and reduced caloric response. The findings in this investigation make a strong case for ampullary distortion disrupting the tenuous but vital cupulary attachment resulting in canal paresis. This concept is attractive because it explains an important clinical event in Menière's disease on the basis of the only consistent histopathological finding, namely, membrane distension.