Pulsatile tinnitus

What is Pulsatile Tinnitus?

Pulsatile tinnitus is a specific type of tinnitus where a person hears a rhythmic sound, often described as a thumping, whooshing, or pulsing noise. What makes pulsatile tinnitus different from regular tinnitus is that the sound usually syncs with the person’s heartbeat. People may notice it more at night or in quiet settings, and the sound can sometimes be heard in one ear or both. While regular tinnitus is commonly associated with hearing loss or ear conditions, pulsatile tinnitus often signals an issue related to blood flow or vascular structures near the ear.

Unlike regular (non pulsatile) tinnitus, pulsatile tinnitus can often be treated if the cause can be identified.

Types of Pulsatile Tinnitus

Pulsatile tinnitus falls into two main types:

1. "Pulse-Synchronous" Pulsatile Tinnitus: In this type, the pulsing sound matches the heartbeat and is rhythmic with each pulse. It can indicate a vascular (blood flow) issue in the ear, brain or head and neck area where blood vessels are affecting the hearing pathway.
   
   

2. "Non-Pulse Synchronous" Pulsatile Tinnitus: This type does not match your heartbeat and tends to occur at its own rhythm. It’s rarer and is usually related to muscle spasms or other non-vascular causes in or near the ear.

Causes of Pulsatile Tinnitus: A Closer Look

* It is important to understand that 25% of patients with pulsatile tinnitus will not have an identifiable cause despite adequate work-up. The causes of pulsatile tinnitus can be divided based on the type of tinnitus.

Causes of Pulse-Synchronous Pulsatile Tinnitus

• High Blood Pressure: When blood pressure is high, it can create an increased force in the vessels near the ear, making blood flow sounds more noticeable.
  
  
• Atherosclerosis: The buildup of fatty deposits in the blood vessels can narrow arteries, making blood flow turbulent. This turbulence can sometimes be heard as a pulsing sound in the ear.

* For these two reasons above, I highly advise anyone experiencing new pulsatile tinnitus to first consult their family doctor for a general health evaluation.

• Conductive Hearing Loss: This condition blocks or reduces external normal sound transmission, enhancing the perception of internal natural sounds that normally go unnoticed. The most prominent internal sound that will be amplified is of course your blood flow and heartbeat: these noises become more noticeable and lead to pulsatile tinnitus (other sounds include your voice and your breathing). An effective comparison is to plug one ear with your finger and hum; you'll notice the humming is significantly louder in the ear that's blocked. Common causes of conductive hearing loss leading to pulsatile tinnitus include earwax buildup, middle ear infections (otitis media), otosclerosis (abnormal bone growth in the ear), Eustachian tube dysfunction and superior canal dehiscence.
  
  

• Arteriovenous Malformation (AVM): An AVM is an abnormal connection between arteries and veins, which disrupts normal blood flow and creates noise. It can sometimes be detected by imaging studies if suspected. These could be located in the head and neck area, around the ear or sometimes in the brain compartment.
  
  

• Dural Arteriovenous Fistula: This is an abnormal connection between arteries and veins in the dura mater, the outermost layer covering the brain. Normally, blood flows from arteries into smaller vessels and eventually into veins at a slower rate. But in dural fistulas, blood from an artery flows directly into a nearby vein, creating high-pressure, turbulent blood flow. When this occurs near the ear (such as an artery connecting directly to the sigmoid or transverse sinus), the turbulent flow can be heard as a pulsing sound that matches the heartbeat, leading to pulsatile tinnitus. This condition can be treated.
  
  
• Sigmoid Sinus Diverticulum: The sigmoid sinus is a large vein located inside the skull that helps drain blood from the brain back to the heart. It sits in an “S” shape along the side of the brain, and is located close the ear (in fact in runs in the temporal bone, which contains all the ear structures). After the blood flows through the sigmoid sinus, it continues down through the neck in the jugular vein, eventually returning to the heart to get re-oxygenated. A sigmoid sinus diverticulum is an outpouching or bulge that forms in the wall of sigmoid sinus (see image below). This bulge can disrupt normal blood flow, causing it to swirl or become turbulent near the bone structure close to the ear. This turbulence often results in a rhythmic, pulsating sound. Treatment options include observation or surgical repair to restore smooth blood flow.
  
   
  
• Sigmoid Sinus Dehiscence: You now what the sigmoid sinus is. That sinus is normally entirely covered by bone. When part of the bone surrounding the sigmoid sinus becomes thin or even missing, we call that a dehiscence (not a disease but rather an anatomical variant), see image below. This lack of bone makes the blood flow in the vein much easier to hear because there’s little barrier between it and the structures in the ear that pick up sound. As a result, people with sigmoid sinus dehiscence may hear a pulsing sound in their ear that matches their heartbeat. This condition doesn’t usually affect hearing but can be bothersome. It can also be surgically corrected.
  
  
  

• Carotid Artery Stenosis: Narrowing of the carotid artery, a major artery in the neck that supplies blood to the brain, can lead to turbulent blood flow, which may cause pulsatile tinnitus.
  
  

• Carotid Artery Dehiscence: The concept is similar to sigmoid sinus dehiscence, see above. The carotid artery passes in part in through temporal bone of the skull, which contains the ear organs. That section of the carotid is called the "petrous section". When the petrous carotid artery is dehiscent (the bony wall is missing), the pulsations of the carotid, which are arterial and therefore very strong, can be easily heard by the adjacent ear.
  
  

• Glomus Tumors: These are vascular tumors that develop near blood vessels around the ear and can create a pulsing noise as they increase blood flow in their area. These are usually benign but may require treatment if they grow or impact other functions.
  
  

• Idiopathic Intracranial Hypertension (IIH): What is more unique of this condition is that the pulsatile tinnitus would be heard in both ears. This is a condition where there is increased pressure in the fluid surrounding the brain, with no organic cause associated (no tumors for example). This pressure can create pulsatile sounds and often causes other symptoms like headaches, fatigue and more importantly visual changes that may become irreversible if the condition is not addressed in a timely manner. This condition is more common in middle-aged women who are overweight. 
  
  

• Vascular Loops: Vascular loops in the internal auditory canal (IAC) are bends or curves in blood vessels, often the anterior inferior cerebellar artery (AICA), that pass close to or within the auditory canal near nerves responsible for hearing and balance. These vascular loops can, in some cases, press on the auditory nerve, causing a rhythmic pulsing sound that matches the heartbeat, known as pulsatile tinnitus. The mechanism is thought to involve nerve irritation from the vessel’s pulsatile motion, but the link between vascular loops and tinnitus is controversial. Some studies suggest that these loops are often found incidentally (by chance) and may not always cause symptoms, while others propose that only specific configurations of loops cause tinnitus. Because vascular loops are commonly found in asymptomatic individuals, the challenge lies in determining when they are genuinely responsible for tinnitus, making diagnosis and treatment complex. In my practice, I would not recommend any treatment for vascular loops as the data is still lacking.

Causes of Non-Pulse Synchronous Pulsatile Tinnitus

• Middle Ear Myoclonus: Myoclonus means involuntary muscle spasms.  In the middle ear, there are two muscles controlling the eardrum that can spasm: the tensor tympani muscle (more common) and the stapedius muscle. When they spasm, they pull on the eardrum, producing a fluttering or clicking sound. I use the analogy of the eyelid spasms (blepharospasms) with my patients because it is easier to visualize. Unlike pulse-synchronous tinnitus, the sound produced does not match the heartbeat. I often compare the sound heard with myoclonus to the sound of popping Rice Krispies cereal when milk is poured over it. Middle ear myoclonus is hard to diagnose because it's hard to objectify. 
  
  

• Palatal Myoclonus: The muscles of the palate (roof of the mouth) are connected with the Eustachian tube (a tube linking the ear to the back of the nose). When those muscles contract involuntarily (myoclonus), it opens and closes the Eustachian tube, and that sound will transmit to the ear, causing an irregular noise.
  
  

• Eustachian Tube Dysfunction/Patulous Eustachian tube: When the Eustachian tube, which connects the middle ear to the back of the throat, doesn’t open or close properly, it can create a range of sounds  including non-pulsatile and pulsatile noises (hearing one's own breathing or heartbeat, but also sounds of bubbles popping, clicking, etc).

Clinical Evaluation: Steps to Diagnose Pulsatile Tinnitus

Diagnosing pulsatile tinnitus begins with a thorough medical history and physical examination. Your doctor will ask about the nature of the sound, its frequency, and any associated symptoms like hearing loss or dizziness. They may also inquire about your medical history, including any cardiovascular issues or head trauma.

The physical examination will typically involve an inspection of the ears, head, and neck. Your doctor will then auscultate with a stethoscope to listen for pulsations sounds in these areas. Palpation of the neck to reveal pulsating masses will also be done, and manual pressure on the neck will be performed to assess whether the sound changes in intensity or disappears. If the sound disappears when pressing on the neck, it usually means there is a venous cause involved (sigmoid sinus, jugular bulb, etc.). A nasopharyngeal endoscopy (camera down your nose) may be performed to look at palatal myoclonus and the status of the Eustachian tube.

Work Up for Pulsatile Tinnitus

* It is important to understand that 25% of patients with pulsatile tinnitus will not have an identifiable cause despite adequate work-up.

The first step for pulsatile tinnitus should always include a hearing test (audiogram). It is non invasive and inexpensive, and could easily identify common causes of conductive hearing loss such as early otosclerosis, superior canal dehiscence or eustachian tube dysfunction. If positive, it avoids unnecessary imaging.

The imaging selection will then depend on a few factors. 

• If there are cardiac risk factors and vascular risk factors (diabetes, high blood pressure, cholesterol), the first step would be to get a cervical doppler ultrasound. This will evaluate for carotid stenosis or atherosclerosis, which can both cause severe medical issues if not recognized.
  
  
• If the pulsatile tinnitus is bilateral (both ears), and/or if the patient is overweight, an MRI of the brain would be indicated to rule out intracranial hypertension.
  
  
• If there are no obvious risk factors, if the exam reveals an anomaly of the middle ear, or if the hearing test shows conductive hearing loss, a high resolution CT scan of the temporal bones is indicated. This can assess for the vast majority of pulsatile tinnitus disorders (otosclerosis, superior canal dehiscence, sigmoid sinus dehiscence, sigmoid sinus diverticulum, high riding jugular bulb, carotid dehiscence, glomus tumors).
  
  
• If the audiogram is normal and the CT scan of the temporal bones is normal, then an MRI angiography or a CT angiogram may be indicated to look for less common causes such as dural AV fistulas, AVMs or transverse sinus fistulas. If any of those causes are identified, a referral to interventional neuroradiology for potential treatment would be warranted.

In the event intracranial hypertension is diagnosed, a neurology and ophthalmology consultation would be indicated.

Treatment Options for Pulsatile Tinnitus

Unlike regular (non pulsatile) tinnitus, pulsatile tinnitus can often be treated if the cause can be identified.

 

The treatment for pulsatile tinnitus will of course depend on the cause:

• High Blood Pressure and Atherosclerosis: Managing those conditions is usually through lifestyle changes and medications. Sometimes vascular surgery can be recommended if the atherosclerosis plaque is significant.
   
• Glomus Tumors: Surgical removal of the tumor can resolve the tinnitus. This can be done through the ear canal or behind the ear for larger tumors. Some of these tumors can grow to a large size. 
  
  
• Conductive Hearing Loss: Surgical correction of the disorder will lead to improved hearing and usually resolution (or significant improvement) of the pulsatile tinnitus. Examples include surgical repair of the superior canal dehiscence or stapedectomy for otosclerosis.
  
  
• Sigmoid sinus diverticulum or dehiscence: Surgical correction can be performed by an approach called a mastoidectomy. The defect is corrected and the mastoid bone is obliterated with bone paté or abdominal fat. Read more about this surgery here.
  
  
• High Riding Jugular Bulb and Dehiscent Carotid Artery: Usually not amenable to surgical correction. They are hard to reach, and a bleeding in that location with be difficult to control. In my practice, I would also not recommend any treatment for vascular loops as the data is still lacking.
  
  
• Vascular causes (fistulas, malformations, stenosis): Usually corrected by an endovascular approach (through the vessels) by an interventional neuro-radiologist (not by an neuro-otologist like myself).
  
  
• Intracranial Hypertension: Neurology consultation recommended. Treatment is usually by a medication that reduces production of the cerebrospinal fluid (CSF), the fluid that surrounds the brain.
  
  
• Middle Ear Myoclonus: Hard to diagnose because it's hard to objectify. I often try empiric treatment with muscle relaxants first to see whether it provides any relief. If the patient reports improvement, a surgical treatment may be offered which consists of surgical sectioning (cutting) of the tensor tympani muscle. This is done via a short procedure (30 minutes) all done through the ear canal under local anasthesia
  
  
• Eustachian Tube Dysfonction/Patulous Eustachian Tube: Treatments might include decongestants, nasal sprays, or surgical procedures to correct the underlying problem.