Lymphocytes B population profile in a case of multiple sclerosis presenting with sudden sensorineural hearing loss caused by a demyelinating pontine lesion.

Sudden sensorineural hearing loss (SSHL) is a rare manifestation of multiple sclerosis, typically appearing in the early stages of the disease, especially in female subjects. SSHL is produced by the involvement of auditory tract, vestibulocochlear nerve and possibly cochlear structures and rarely due to a single lesion. The authors report the case of a young woman in which the onset of multiple sclerosis presented with SSHL caused by a pontine lesion. Oligoclonal bands in the cerebrospinal fluid (CSF) were absent at the disease onset and appeared during disease progression. Immunophenotyping of cells showed low cellularity of CD19+ cells in the CSF and expression of CD38+ on the majority of CD19+, CD20+ B cells in the peripheral blood, suggesting that many of them were mature B lymphocytes.