Apheresis for idiopathic sudden hearing loss: reviewing the evidence

Plasmapheresis has been used for various conditions for a number of years. Recently, its application for idiopathic sudden hearing loss (ISHL) has met with increasing interest. ISHL affects about 10-20 per 100,000 persons per year, impairing not only their hearing but also their ability to interact socially and their quality of life. ISHL is thought to be a sequela of an underlying microvascular disorder caused by a local hyperviscosity syndrome in the cochlear vessels. Plasmapheresis can effectively lower plasma and whole blood viscosity, improve erythrocyte elasticity, and reduce aggregability. Thus, it may be effectively employed in the treatment of ISHL. This article will briefly outline the background against which apheresis procedures are used in the treatment of ISHL and review studies done to date. Furthermore, a broader basis for the use of apheretic applications in the treatment of ISHL will be suggested, correlating age-adjusted ISHL incidence and age-adjusted levels of macromolecular plasma proteins such as fibrinogen. In conclusion, plasmapheresis is a promising new treatment for ISHL but more basic data on ISHL, and on apheresis applications for ISHL, are needed to safely assess treatment outcomes and possible future applications.