[Diagnostic and therapeutic approach to progressive sensorineural hearing loss]

Progressive sensorineural hearing loss (PSNHL) is an important clinical entity that can develop rapidly and evolve to deafness. The causes of PSNHL can be divided into hereditary, developmental, infectious, autoimmune, metabolic, vascular, neoplastic, toxic and degenerative, even if the origin of the hearing impairment often remains unknown and a diagnosis of idiopathic PSNHL is made. In order to establish the etiology of the hypoacusia or to rule out any known etiology of PSNHL and to diagnose an idiopathic form, a detailed family, physiological and medical history has to be obtained, including history of pregnancies. A careful audiological and otoneurological evaluation should also be carried out, followed by laboratory tests. Furthermore, a complete otoneurological evaluation is required, with puretone audiometry, speech audiometry, impedance audiometry and study of the stapedial reflex, brainstem auditory evoked potentials and vestibular examination. Finally, patients with PSNHL must undergo neuroradiological examination (computerized tomography of petrosal bone, cerebral magnetic resonance and inner ear magnetic resonance); ophthalmological, rheumatological and neuropsychiatric (in childhood) advices should be sought, while other advices may be required on the basis of a particular clinical suspicion. When the etiology is established, therapy must be based on specific treatment for the cause of the hearing deficit; for example, hormonal therapy in alterations of thyroid function, antibiotic treatment in bacterial infections, calcium-antagonist and antiaggregant drugs in the vascular forms, corticosteroids or cyclophosphamide or other immunosuppressive drugs in PSNHL associated with systemic autoimmune diseases. In idiopathic hearing loss, treatment must be started in the absence of important contraindications. The therapeutic protocol that we use in such cases is the following: methylprednisolone boluses, 500 mg/day for three consecutive days, and subsequently oral treatment gradually tapering off in association with a cycle of hyperbaric therapy. Patients showing clinical and historical indications are also treated with intravenous glicerolo, calciparina and/or antiaggregant and calcium-antagonist drugs.