**Part 4**

**Tinnitus in the Emergency** 

84 Up to Date on Tinnitus

Zenner, H.P. Zalaman, I.M. Cognitive tinnitus sensitization: Behavioural and

124(4):436–439

neurophysiological aspects of tinnitus centralization. (2004) *Acta Otolaryngol* Vol.

*USA* 

**Evaluation of Tinnitus** 

*2California Academy of Sciences* 

 **in the Emergency Department** 

*1University of Texas Health Science Center at Houston* 

Kerry J. Welsh1, Audrey R. Nath1 and Matthew R. Lewin2

Tinnitus is defined as the perception of abnormal noise by the patient in the absence of an external acoustic source. It may be described as a ringing, whistling, buzzing, roaring, or clicking sound, although any type of sound may be reported. Tinnitus may be unilateral or bilateral, and can be described as occurring within the head or as a distant sound 1. It may occur constantly or intermittently. Tinnitus severity may vary considerably, ranging from a minor annoyance for the patient to distressing enough for certain patients to consider

Tinnitus appears to be a very common symptom, with a reported prevalence ranging from 10 - 25 % 3,4. Of the 35 - 50 million adults with this symptom, approximately 12 million visit a physician; 2 - 3 million of these patients are severely impacted by tinnitus 5. Furthermore, these patients often have numerous associated comorbidities including anxiety, depression, and reduced general health 6-9. Tinnitus occurs more frequently in Caucasians, men, and older age groups 10. Other reported risk factors include exposure to loud noise, hearing loss, smoking, and hypertension 11,12. Tinnitus has also been reported in approximately 36% of children, but often goes undocumented due to the infrequency of their spontaneously

Numerous hypotheses have been developed for the pathophysiology of tinnitus; however, a precise mechanism has not been established 14. Tinnitus may arise from any abnormality of the neural pathway from the cochlear neural axis to the auditory cortex. Proposed etiologies include damage to hair cells with accompanying excess stimulation of auditory nerves, increased activity in the auditory complex, and excessively active auditory nerves 3,15. Multiple mechanisms likely account for tinnitus because of the complexity of the hearing

Several classification types have been used to described tinnitus. One such method classifies tinnitus as objective or subjective. Objective tinnitus indicates that the sound may be heard by the physician by auscultation with a stethoscope over the head and neck adjacent to the patient's ear 3. Subjective tinnitus is considerably more common, and is only perceived by the patient. This chapter will review the differential diagnosis of objective and subjective tinnitus as well as the evaluation and management of these

**1. Introduction** 

suicide 2.

reporting it 13.

patients.

pathways, and thus this symptom is non-specific.
