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  • Updated 04.30.2024
  • Released 09.17.2001
  • Expires For CME 04.30.2027

Objective tinnitus

Introduction

Overview

The author explains the clinical presentation, pathophysiology, diagnostic workup, and management of objective tinnitus. Objective tinnitus is a perceived sensation of sound that occurs in the absence of external acoustic stimulation, but it can also be heard by the examiner (eg, by placing a stethoscope over the patient's external auditory canal). Objective tinnitus is much less common than subjective tinnitus, but it often has an identifiable cause and may be curable, whereas subjective tinnitus is often idiopathic and is seldom curable.

Key points

• Objective tinnitus is a perceived sensation of sound that occurs without external acoustic stimulation, but it can also be heard by the examiner (eg, by placing a stethoscope over the patient's external auditory canal).

• Objective tinnitus can occur either from the perception of an abnormal somatosound or abnormal perception of a normal somatosound.

• Objective tinnitus is much less common than subjective tinnitus, but it often has an identifiable cause and may be curable, whereas subjective tinnitus is often idiopathic and is seldom curable.

• Tinnitus is frequently associated with depression (in up to half of patients), anxiety, and insomnia.

• Objective tinnitus may be associated with a variety of vascular noises arising from the internal jugular vein or jugular bulb, arteriovenous malformations or fistulas, cavernous hemangiomas, aneurysms, vascular stenoses (particularly of the carotid arteries), vascular tumors, and intracranial hypertension.

• The cervical venous hum is a common but innocuous murmur that can be heard in the anterior neck and sometimes upper chest and is often mistaken for more sinister sounds. A venous hum is caused by turbulence (ie, disruption of the otherwise smooth laminar flow into turbulent eddies) in the internal jugular vein, which causes the vessel walls to vibrate. This is precipitated or accentuated by turning the head away from the auscultated side.

• Objective tinnitus associated with a patulous Eustachian tube is synchronous with nasal breathing (usually more marked in the upright position), gradually disappears with lying down, and often transiently abates with sniffing, snorting, or a Valsalva maneuver.

• Objective tinnitus associated with abnormal clonic muscular contractions of palatal or middle ear muscles may occur as an intermittent series of sharp, regular clicks or with palatal myoclonus as a fairly regular, continuous clicking sound.

Historical note and terminology

Objective tinnitus is a perceived sensation of sound that occurs in the absence of external acoustic stimulation, but it can also be heard by the examiner (eg, by placing a stethoscope over the patient's external auditory canal). Objective tinnitus can occur either from perception of an abnormal somatosound or abnormal perception of a normal somatosound (65). Objective tinnitus is much less common than subjective tinnitus, but it often has an identifiable cause and may be curable, whereas subjective tinnitus is often idiopathic and is seldom curable.

Although pulsatile tinnitus may be objective or subjective, subjective pulsatile tinnitus is not inherently different in terms of likely causes than objective pulsatile tinnitus; therefore, both forms of pulsatile tinnitus are considered in this chapter.

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