What causes pulsatile tinnitus

What is Pulsatile Tinnitus?

Tinnitus is the perception of sound when no external sound is present. While most tinnitus is described as a constant ringing, buzzing, or hissing, pulsatile tinnitus is a distinct form characterized by a rhythmic sound that often synchronizes with the individual's heartbeat. This "whooshing," "thumping," or "clicking" sound can be a source of significant distress and anxiety for those experiencing it. Unlike subjective tinnitus, which is only heard by the affected person, pulsatile tinnitus can sometimes be heard by an examiner with a stethoscope placed near the ear (objective tinnitus), although this is less common.

Common Causes of Pulsatile Tinnitus

The underlying cause of pulsatile tinnitus is almost always related to blood flow in the head and neck region. The sound is generated by the turbulence or alteration of blood flow in vessels close to the ear. Here are some of the most frequent culprits:

Vascular Causes:

1. Arteriovenous Malformations (AVMs) and Fistulas: These are abnormal connections between arteries and veins. In the head or neck, such a connection can lead to rapid, turbulent blood flow that creates a pulsatile sound. Arteriovenous fistulas (AVFs) are a common cause, especially dural AVFs which occur in the membranes surrounding the brain.

2. Atherosclerosis: Narrowing or hardening of arteries due to plaque buildup can disrupt smooth blood flow, leading to turbulence. If this occurs in the carotid arteries (in the neck) or the arteries supplying the ear, it can manifest as pulsatile tinnitus.

3. High Blood Pressure (Hypertension): Elevated blood pressure can increase the force and speed of blood flow through the vessels, making normal blood flow sounds more audible and potentially turbulent, especially if there are any underlying vascular abnormalities.

4. Vascular Tumors: Certain tumors, particularly glomus tumors (paragangliomas) that develop in the middle ear or jugular bulb, are highly vascular and can cause pulsatile tinnitus due to their rich blood supply and proximity to the ear.

5. Increased Blood Volume or Flow: Conditions that increase the amount of blood circulating or the speed at which it flows can also contribute. This includes pregnancy (due to increased blood volume), anemia (where the heart pumps faster to compensate for reduced oxygen-carrying capacity), and hyperthyroidism (overactive thyroid gland).

6. Venous Hum: This is a continuous sound caused by blood flow in the jugular vein. It can sometimes become more noticeable and pulsatile, especially when changing head position or if there's increased blood flow.

7. Vasospasm: Spasms in blood vessels can cause temporary disruptions in blood flow.

Non-Vascular Causes:

While less common than vascular causes, some non-vascular conditions can also lead to pulsatile tinnitus:

1. Earwax Impaction: A significant buildup of earwax can sometimes press against the eardrum or create an obstruction that alters the way sounds, including bodily sounds, are perceived.

2. Middle Ear Issues: Conditions affecting the middle ear, such as otosclerosis (abnormal bone growth), fluid in the middle ear (otitis media with effusion), or even spasms of the tiny muscles in the middle ear (stapedius or tensor tympani muscles), can sometimes produce pulsatile sounds.

3. Temporomandibular Joint (TMJ) Disorders: Problems with the jaw joint can sometimes cause sounds that are perceived as pulsatile, although this is often more related to clicking or popping.

4. Eusta­chian Tube Dysfunction: Issues with the tube connecting the middle ear to the back of the throat can sometimes cause unusual sound perceptions.

Diagnosis and When to Seek Medical Advice

Because pulsatile tinnitus can sometimes indicate a serious underlying condition, it's crucial to consult a healthcare professional, particularly an otolaryngologist (ENT specialist) or neurologist. Diagnosis typically involves a thorough medical history, a physical examination (including listening to the neck and ear with a stethoscope), and often imaging studies such as MRI, MRA, CT scans, or Doppler ultrasound to visualize blood vessels and identify any abnormalities. Prompt diagnosis and treatment are essential to manage the condition and address any potential health risks.