By Barry Keate
Barry Keate, has lived with tinnitus over 40 years and has published 170+ research articles on numerous aspects of tinnitus. He is an expert on the condition and a well-known advocate for those with tinnitus.
Pulsatile Tinnitus, a form of ringing in the ears associated with rhythmic heartbeat has a new diagnosis and treatment guideline for physicians. The paper outlines the major categories that cause this debilitating symptom, including specific treatment options that are available. (1)
Pulsatile Tinnitus (PT) is a serious condition affecting millions of Americans and can be a harbinger of hemorrhagic or ischemic stroke. Hemorrhagic stroke involves the bursting of a small blood vessel in the brain causing a buildup of pressure, damaging brain structures. Ischemic stroke is the blockage of a vessel by a clot, cutting off the oxygen supply to the brain. Both are very serious conditions that can lead to debilitation or death.
PT is an abnormal perception of rhythmic sound without an external source, affecting between 3 and 5 million Americans. It can have a negative effect on patients’ psychological and physical health, leading to insomnia, anxiety, depression and poor concentration. Seeking an underlying cause is essential because many of the conditions can lead to the possibility of a significant risk of stroke, blindness or deafness.
An underlying cause of PT can be identified in more than 70% of patients with a thorough evaluation. The authors advocate categorizing the myriad causes of PT into 3 groups: Structural; Metabolic; and Vascular.
Structural causes include malignant or non-malignant abnormal tissue growth (neoplasm) and temporal bone abnormalities. Metabolic causes include ototoxic medications and systemic causes of high cardiac output. Vascular causes include idiopathic (unknown) intracranial hypertension (IIH) and arteriovenous fistula, which is an abnormal connection between an artery and a vein. In this case, blood flows directly from a high-pressure artery to a lower pressure vein without going through the capillaries, causing turbulent blood flow.
We previously published an article on Pulsatile Tinnitus which correctly identified the cause as turbulent blood flow. While several possible causes were discussed, at that time we did not have the depth of understanding this new guideline provides. I have personally heard from several PT sufferers who reported their ENT was either not aware of the condition or didn’t know how to diagnose and treat it. This guideline should provide much needed information for those patients to discuss with their physician.
PT often originates from vascular structures in the head or neck in proximity to the cochlea.
The Different Sounds of Pulsatile Tinnitus
Low-pitch PT (buzzing or humming) is frequently venous, whereas higher-pitch PT (whooshing, hissing or fetal heartbeat) is frequently arterial, and very high-pitch PT (ringing or a continuous high-pitch that takes breaks with each heartbeat) is not likely to be vascular at all. A “drum beat” or “suction cup” sound that is not synchronous with the pulse, is most likely to be related to palatal or middle ear myoclonus, a muscle spasm in the middle ear or palate.
Manual compression of the cervical blood vessels can improve or worsen vascular PT. Specifically, if manual compression of the jugular vein on the same side as PT, or Valsalva maneuver, improves it, a venous cause should be suspected. Valsalva maneuver is the forcible blowing out of air through closed lips and nose, increasing air pressure. However, if neck compression worsens PT, an arterial cause is likely.
Standard audiological testing measures air and bone conduction thresholds. This allows hearing loss to be characterized as conductive, sensorineural or mixed. Almost every cause of conductive hearing loss is thought to cause PT, owing to increased audibility of bone-conducted sounds originating within the body.
Magnetic Resonance Imaging (MRI) is the first-line diagnostic imaging modality for PT evaluation. It has the highest sensitivity for detecting the four most dangerous potential causes of PT, which are: dural Arteriovenous Fistula (dAVF); arterial disease; intracranial hypertension and neoplasm. dAVF is an abnormal connection between an artery and vein in the tough covering over the brain or spinal column. (More on dAVF later in the article.)
Diagnosis of Pulsatile Tinnitus by Category
Structural Causes of Pulsatile Tinnitus
Structural causes of PT are detectable on MRI or CT of the head and neck. They include neoplasms and temporal bone pathologic abnormality. The temporal bone surrounds the cochlea and vestibular system and protects the nerves that control hearing and balance.
The most common neoplasms causing PT are paragangliomas which form on some blood vessels and nerves. Most of these are benign but some can become malignant and grow. Schwannomas are also benign growths on the auditory nerve, also known as acoustic neuroma. These do not spread and are not malignant but do grow and can eventually produce pressure on the brain.
Treatment for neoplasms depends on the stage of progression. They can involve careful monitoring, surgical removal, embolization, which involves blocking a blood vessel feeding the growth, and radiation.
Superior canal dehiscence (pronounced de-HIS-ence) is the thinning or a hole in the temporal bone over the superior vestibular canal responsible for hearing and balance. This results in alterations of the microfluid mechanics of the hearing apparatus, resulting in increased audibility of any internal sound, including brain pulsations. These can be surgically repaired.
Metabolic Causes of Pulsatile Tinnitus
Non-pulsatile tinnitus with pauses can sometimes masquerade as PT. Metabolic causes of tinnitus are many, including hearing loss from exposure to loud sound.
Tinnitus is also often caused by ototoxic medications. See a list of most know ototoxic medications. The most common offenders are antibiotics such as oral aminoglycosides, chemotherapy drugs such as cisplatin, ACE inhibitors for lowering blood pressure, loop diuretics, proton pump inhibitors for gastric reflux, benzodiazepines, and anti-malarial medications such as quinine and chloroquine.
PT can also result from spasm of one or both muscles in the middle ear. This is called Middle Ear Myoclonus and is not synchronous with the heartbeat. It can often be heard by a physician outside the ear and is a form of objective tinnitus.
Systemic conditions like iron anemia or hyperthyroidism can also cause PT that tends to be high-pitched and related to increased cardiac output. These can be diagnosed with blood tests of hemoglobin levels and thyroid function and treated with appropriate medical treatment for these conditions.
Vascular Causes of Pulsatile Tinnitus
Arterial causes of PT include carotid artery narrowing or dissection, which is an abrupt tear along the inside of an artery. Fibromuscular dysplasia refers to the replacement of strong, flexible calls in an artery by softer, stiffer cells. This leads to progressive twisting of the arteries and interferes with blood flow.
Other arterial causes include aneurysm, a bulging or ballooning of the artery, and arteriovenous fistula (AVF), the direct connection discussed previously between an artery and a vein. A murmur typically signifies atherosclerotic disease in the elderly or fibromuscular dysplasia in the young,
Venous causes of PT are suspected when patients have a low-pitched pulse-synchronous sound that improves with jugular vein compression. These can result from turbulent flow in diverticula, small bulges, of the jugular or other abnormalities in the jugular vein.
There are various treatment strategies described that can address these abnormalities, including stenting the vein to prevent rupture. Conservative treatments for abnormal veins include acupuncture and physical therapy directed at improving muscular tension and range of motion.
Idiopathic Intracranial Hypertension (IIH) is commonly associated with bilateral narrowing of vessels that feed the jugular. IIH has an incidence of 20 per 100,000 overweight women of childbearing age, with increasing prevalence owing to the obesity epidemic. Characteristic features include a headache which worsens when bending over, transient or gradual vision loss, and low-pitched, pulse-synchronous PT. For most patients with IIH, first-line treatment consists of weight loss and acetazolamide, which reduces the build-up of fluids in the body.
A dAVF in the covering of the brain or spinal cord carries a high risk of intracranial hemorrhage, with high potential for death or permanent disability if untreated. Therefore, high-risk dAVF is the most dangerous possible underlying cause of PT and cannot be missed during diagnostic evaluation. Endovascular treatment is first-line therapy for AVFs. This treatment utilizes long, thin tubes called catheters, which are inserted through small incisions in the groin or arms and guided to the location of the problem. This surgery is considered an innovative and less invasive procedure than used in the past.
This article contains information about the most common causes of Pulsatile Tinnitus, but not all. People with PT need to consult with their Otolaryngologist (ENT) for treatment and prevention of the most serious possibilities of permanent consequences.
Editor’s Note: The link below in References will take you to the original study, which you can show to practitioners who may not be well-versed in the subject.
1 – Narsinh KH; Hui F; Saloner D. JAMA Otolaryngology Head Neck Surg. Published online February 24, 2022.