Sudden sensorineural hearing loss.

Abstract

Hearing is one of our most important senses and its sudden loss can be frightening and frustrating for the patient and his or her physician. Despite multiple reports of sudden SNHL over the years, we still do not have a universally accepted definition. This has led to further confusion in reporting and evaluating the treatment and prognosis of this disease. We generally define any SNHL occurring over 3 days as sudden SNHL. The overall incidence of this disease appears to be low. However, the true incidence may be higher, because those patients who spontaneously recover may never seek medical attention. The etiology is often difficult to identify, leaving a large population of patients labeled as idiopathic SNHL. Before accepting the idiopathic label, the physician must maintain a high level of suspicion to be sure that the SNHL is not a symptom of a larger underlying systemic disorder. Several theories have been proposed to try to explain SNHL. These include the infectious theory, vascular theory, and rupture theory. In addition to these, metabolic imbalances, drug toxicity, and various disease entities may contribute to sudden SNHL. Over the years, many treatment protocols have appeared in the literature, each claiming various rates of success. Unfortunately, they are often based on emotional and empiric considerations, because an exact etiology is unknown. Drugs have been chosen from several categories including the following: vasodilators, diuretics, anticoagulants, plasma expanders, corticosteroids, and contrast material. These medications have been used singly or in combination therapies. One must always be aware of the potential side effects. One factor that appears to be constant in each reported therapy is that those patients who seek medical attention early do better. The type of hearing loss also seems to play a role in the outcome of sudden SNHL; patients with low-frequency hearing losses or upward-sloping audiograms have a better prognosis. The patient must take the first step in seeking medical attention. Once the problem has been recognized, prompt attention by the physician to the medical workup and timely initiation of therapy will offer the patient the best possible chance for recovery. Time is often the greatest factor in the overall recovery, and the physician should reassure the patient that everything is being done to speed this along. However, patience may be the greatest healer of all.