Hearing loss and tinnitus

Acute hearing loss may be evidence of localized (temporal bone) or systemic disease [1]. Acute tinnitus as an isolated presentation is very rare. However, hearing loss and (non-pulsatile) tinnitus are so closely intertwined that consideration of one merits consideration of the other. In this chapter we will show the intimate relationship between hearing loss, both sensorineural and conductive, with tinnitus. The presentation of hearing loss and tinnitus is a completely subjective experience. There is often no outward, objective manifestation of inner-ear dysfunction other than patients’ reports. For this reason, the acute nature of the start of symptoms is somewhat dependent on patient reporting. This chapter will describe many entities that can lead to hearing loss and/or tinnitus, and we will describe the likelihood of presentation as an acute symptom. Several of these processes are very likely to present immediately with inner-ear symptoms, and others may be less likely to have inner-ear symptoms as the acute presentation; however, they all should remain in the differential diagnosis. Hearing loss and tinnitus: Background Hearing loss (HL) is either unilateral or bilateral. Bilateral HL may be asymmetric [2]. The division of both acute and chronic HL into sensorineural hearing loss (SNHL) and conductive hearing loss (CHL) focuses the search for an etiology. Tinnitus is the perception of auditory sensation, often in the absence of external stimuli [3, 4]. Tinnitus is classified as pulsatile (synchronous with heartbeat) and non-pulsatile (continuous), and further classified as subjective (perceived by the patient only) and objective (perceived by the examiner as well as by the patient) [2]. Tinnitus may be unilateral or bilateral.