Subclinical Facial Nerve Enlargement in a Case of Chronic Demyelinating Peripheral Neuropathy.

We report an archival temporal bone case from the Otopathology Archives at Johns Hopkins of a man with progressive distal-predominant weakness, sensory loss, areflexia, and bilateral pes cavus, with clinicopathologic features suggestive of a chronic demyelinating peripheral neuropathy. Bilateral temporal bone histopathology demonstrated diffuse enlargement of the facial nerve throughout its intratemporal course, with additional enlargement of the glossopharyngeal and vagus nerves. This case suggests that marked cranial nerve hypertrophy may be clinically unapparent in some hereditary polyneuropathies and supports future correlation of temporal bone pathology with imaging and genotype in confirmed cases.