Pulsatile tinnitus

Timothy C. Hain, MD. Tinnitus Page Page last modified: October 28, 2009

Structures of the ear. Most tinnitus is due to damage to the cochlea (#9 above)

In pulsatile tinnitus, people hear something resembling their heartbeat in their ear.

• Pulsatile tinnitus is usually due to a small blood vessel that is coupled by fluid to your ear drum. It is usually nothing serious and also untreatable.
• Rarely pulsatile tinnitus can be caused by more serious problems -- aneurysms, increased pressure in the head (hydrocephalus), and hardening of the arteries. A vascular tumor such as a "glomus" may fill the middle ear, or a vein similar to a varicose vein may make enough noise to be heard.
• There are some very large blood vessels -- the carotid artery and the jugular vein -- that are very close to the inner ear (see diagram above). Noise in those blood vessels can be conducted into the inner ear. Accordingly, other possibilities for vascular tinnitus include dehiscence (missing bone) of the jugular bulb -- an area in the skull which contains the jugular vein, and an aberrantly located carotid artery. An enlarged jugular bulb on the involved side is common in persons with venous type pulsatile tinnitus.
• Anything that increases blood flow or turbulence such as hyperthyroidism, low blood viscosity (e.g. anemia), or tortuous blood vessels may cause pulsatile tinnitus.

Tinnitus due to high jugular bulb and related structures

Dural AV fistula of the transverse sinus associated with pulsatile tinnitus. Courtesy of Dr. Dario Yacovino.

This is a venous tinnitus, associated with an unusually located jugular vein. A high-riding jugular bulb is a common vascular anomaly, found in 2.4-7% of temporal bones. One would think that this tinnitus should be present from an early age, as the anatomy does not change over life.

Another variant of the high jugular bulb is a jugular bulb diverticulum - -an outpouching of the jugular bulb - -into the inner or middle ear. Most commonly the outpouching is into the middle ear. This occurs in 6% of the otherwise normal population. When present, this structure can be associated with bleeding during surgery.

The jugular bulb diverticulum is a much rarer anomaly than high riding jugular bulb (Stern and Goldeberg, 1980) . It can be associated with sensorineural hearing loss, tinnitus and vertigo. (Shihada et al, 2008), and may account for some cases of Meniere's disease (Yazawa et al, 1998).

Diagnosis is mainly via MRI/MRA with contrast or similar techniques that show blood flow in relation to the skull. High-resolution CT-angiography is the method of choice, but because it is associated with some radiation, it is generally not the best choice as a screening procedure. On CT, a jugular bulb diverticulum is characterized by continuity with the jugular bulb, smooth edges, and absence of bony destruction. Some have reported that it can be diagnosed by other maneuvers, such as ultrasonography (e.g. Nakagawa et al, 2008).

References:

• Nakagawa et al. a convenient sonographic technique for diagnosis of pulsatile tinnitus induced by a high jugular bulb. J. Ultrasound Med 2008;27:139-140.
• Shihada R and others. Endovascular embolization of a hemorrhagic jugular bulb diverticulum. Int J. Ped Otorhinolaryngology (2008) 72, 1445-1448
• Stern J, Goldenberg M. Jugular bulb diverticula in medial petrous bulb. AJR 134:959-961, 1980
• Yazawa et al, 2009. Surgical observations on the endolymphatic sac in Meniere's disease. Am J. Otol 19:71-75, 1998