_Overview

Many people have experienced tinnitus at some point, often noticing a ringing sound after exposing themselves to a loud noise environment like concerts or clubs, which can trigger tinnitus to appear.  usually goes away in a few hours. However, some people can experience tinnitus due to disease, and it is classified as pulsatile tinnitus (PT) which can either be acute or chronic. 

Introduction

The word tinnitus comes from the Latin word ‘tinnire’, which means ‘to ring’ or. Tinnitus is a sound in one or both ears and usually is described as a ringing, buzzing, whooshing, or clicking sound - there is no external stimulus that creates this sound. Tinnitus is not a disease but rather a symptom of a condition. Non-pulsatile tinnitus occurs independently, with limited treatment options. Pulsatile tinnitus, however, is a symptom of an underlying disease and treating the condition often alleviates the tinnitus.^1,2

Symptoms of pulsatile tinnitus

Pulsatile tinnitus can be classified into two types: pulse synchronous, where the rhythm of the noise is at the same rhythm of the heartbeat, or pulse asynchronous. This is when it gets synchronised which means that the cause of tinnitus must be vascular. The sounds associated with tinnitus include:

• Ringing 
• Whooshing 
• Clicking 
• Whistling³

In pulse synchronous tinnitus, the whooshing sound is due to turbulent blood flow near the cochlea, while the clicking sound results from mechanical issues such as muscle contractions in the middle ear ³

Causes of pulsatile tinnitus

Pulsatile tinnitus is categorised into two groups, vascular and nonvascular causes. When it appears due to vascular causes, that means that there is turbulence in the blood flow. This is created when there is an elevated flow volume of blood or a narrowing of the blood vessel, thus turbulence occurs and creates a noise that travels directly to the ear and results in pulsatile tinnitus. Depending on the origin of the vessel, vascular pulsatile tinnitus can either be venous or arterial.¹

Common causes

• Uncontrolled High Blood Pressure: Elevated blood pressure creates turbulence in arteries, leading to pulsatile tinnitus¹
•  Atherosclerosis Carotid Disease:  A plaque in the major blood vessels that supply blood to the brain (like carotid arteries), narrows the artery so pulsatile tinnitus can be developed.¹
• Rare Conditions: The narrowing can also be developed from fibromuscular dysplasia (a rare blood vessel disorder) or Takayasu disease (which causes inflammation in the arteries) but these are rare conditions.¹
• Arteriovenous Malformations (AVMs) and Intracranial Aneurysms: These conditions can also cause pulsatile tinnitus¹
• Glomus Tumors: Tumours of the middle ear or of the carotid body can also cause pulsatile tinnitus.¹
• Idiopathic Intracranial Hypertension:  Often seen in young, overweight women who can also experience vision problems and headaches.⁴
• Ototoxic Drugs: Certain medications can cause hearing problems, leading to pulsatile tinnitus.⁴
• Hearing Loss and Mental Health Disorders: Conditions like depression and anxiety can worsen pulsatile tinnitus. ²

Diagnosis of pulsatile tinnitus

Medical history 

Recording a detailed medical history is crucial, including previous acoustic injuries, noise exposure, and ototoxic medication use.  Evaluating the tinnitus' pitch, whether it is synchronous or asynchronous, and its impact on daily life helps in diagnosis.  The examiner can also evaluate if the tinnitus is bothersome or not, for example, if the patient is getting distracted by the tinnitus and interferes with their daily routine or not. Additional symptoms like hearing loss, vertigo, headache, sleep, mood and cognitive problems are also assessed.³ The tests that are used to assess the effect of tinnitus are the Tinnitus Handicap Inventory and the Tinnitus Questionnaire. With these tests, it can be determined if there is any connection between tinnitus and hearing loss.²

Physical examination

A thorough physical examination usually checks the head, ears, eyes, neck and neurologic system, and looks at the cranial nerves, cerebellar function and the cardiovascular system. A cardiac examination can assist in the diagnosis of high blood pressure and aortic narrowing. Also, it can show if the tinnitus is synchronous with the heartbeat and thus identify any arterial pathology.²

Audiology

An audiometry test needs to be performed for every patient with tinnitus despite the duration and characteristics of the tinnitus, as it detects the presence, degree and nature of hearing loss.²

Blood test

Tests for a full blood count, vitamin B12 levels and thyroid function need to be checked in case of anaemia or hyperthyroidism as these conditions can increase cardiac output (the amount of blood that gets pumped by the heart) and cerebral blood flow which can result in tinnitus. Paget’s disease, associated with tinnitus, is diagnosed through elevated alkaline phosphatase levels. Lastly, checking cholesterol levels can be helpful to rule out hyperlipidaemia which is a risk factor of atherosclerosis.¹

Imaging test 

CT and MRI scans are essential for identifying vascular causes of pulsatile tinnitus.² MRI and MR angiography (MRA) are used to detect AVMs and fibromuscular dysplasia.¹ MRA is beneficial in imaging arteries whilst CT angiography (CTA)  can capture an image of veins better.⁵ CTA of the neck and head is used to identify narrowing of the blood vessels, idiopathic intracranial hypertension and other causes of pulsatile tinnitus. Ultrasonography can also be used to identify extracranial carotid stenosis but positive findings are usually followed by CTA or MRA.² Atherosclerotic carotid artery disease is also detected with duplex carotid ultrasonography.¹

Treatment of pulsatile tinnitus

Addressing the underlying cause 

Medication 

• Benign Intracranial Hypertension: Treated with medications like acetazolamide and furosemide, along with weight reduction.³
• Mental Health: Melatonin may improve sleep, and antidepressants can be prescribed for pre-existing anxiety and depression, especially tricyclic antidepressants and SSRIs.³
• Paget’s Disease: Treated with bisphosphonates, calcitonin, or a combination of both.³

Surgical management

Surgery is strictly done only when there is an underlying cause of pulsatile tinnitus such as tumours and lesions in the brain.³

• Carotid Endarterectomy: For atherosclerotic carotid artery disease.¹
• Selective Embolization: For AVMs¹
• Gastric Bypass and Lumbo-Peritoneal Shunting: For benign intracranial hypertension¹
• Stapedectomy: For Paget’s disease.¹

Symptom relief measures 

Sound therapy

Ambient sounds through ambient sound generators or hearing aids are used to help correct the hearing loss and help the person with tinnitus to not hear the irritating sounds.¹

Stress management techniques

Cognitive behavioural therapy (CBT) helps individuals cope with tinnitus by providing techniques to distract from the noise.¹ Otolaryngologists recommend people with chronic tinnitus to undergo combination therapy of sound therapy and counselling.²

Summary

Tinnitus can be either acute or chronic, according to the underlying pathophysiology. The most frequent form of tinnitus is non-pulsatile, and it is usually linked to age-related hearing loss (presbycusis). Non-pulsatile tinnitus is hard to treat, unlike the pulsatile tinnitus. Pulsatile tinnitus, being a symptom of an underlying condition, requires identifying vascular or nonvascular causes. If it is a vascular cause then it is categorised into arterial or venous causes. To identify the difference, medical history and physical examination are performed as well as medical imaging tests. Treatment focuses on addressing the underlying cause, possibly through medication or surgery, and symptom relief through sound therapy and stress management. Accurate diagnosis and multidisciplinary treatment can improve the prognosis for those affected by pulsatile tinnitus..⁴