A perilymphatic fistula (PLF) is an abnormal connection between the inner ear and the middle ear. It often results from trauma. It presents with hearing symptoms (hearing loss, hyperacusis, tinnitus) and disequilibrium. Symptoms are often worsened by pressure changes (e.g., sneezing, coughing) or by exposure to a burst of loud sound. The most confident way to diagnosis PLF is at surgery, during which the surgeon visualizes fluid emerging from the fistula into the middle ear. Other diagnostic methods for PLF have not been as successful. Treatment is surgery by an otolaryngologist. Surgery is not always successful, and even when surgery is initially successful, PLF can recur.