Tinnitus: Definition, Classification, Causes and Diagnosis

Tinnitus (ringing in the ears) is a frequent and often debilitating disorder with about 15% of people (who incorporate age from infancy to the elderly) who perceive it continuously and about 3% of the population seriously affects the quality of life. it can affect an individual's entire life, it can prevent intellectual work and compromise the quality of life in general; In some cases, tinnitus can cause suicide. Most of condition of Severe tinnitus is often accompanied by hyperacusis and affective disorders such as phonophobia and depression

The prevalence of tinnitus increases in association with high frequency hearing loss, although the association between the severity of tinnitus and the degree of hearing loss is very weak. Hyperacusis (as opposed to recruitment) is found as an associated symptom in about 40% of patients with tinnitus. Hyperacusis can be defined as an undue sensitivity and anguish for everyday sounds that would not normally disturb a person with "normal hearing"

Definition of Tinnitus

Tinnitus, often described as "ringing in the ears", is a serious problem affecting a significant part of the population today. Depending to our medical knowledge, it is significant to distinguish between people who "experience" tinnitus from those who suffer from it. Tinnitus can be defined as the conscious perception of a sound that is not generated by any source external to the body. In the case that, there are physical sources of sound within the body, by pulsing the blood vessels, tinnitus is called a target because it can be heard by another person with a sensitive microphone and amplifier. In the absence of any source of physical sound, inside or outside the body, tinnitus is called subjective

Pathophysiology

The cause of tinnitus is unknown. When developing an understanding of the mechanisms of tinnitus, two points need to be borne in mind:

• There is a potential generated somewhere in the auditory system
• This signal will undergo extensive auditory processing before it is perceived as tinnitus

Classification of Tinnitus

Tinnitus can be classified into several groups:

• Subjective and Objective
• Pulsatile and Nonpulsatile
• Continuous and Non-Continuous
• Vascular and Non-Vascular
• Aureum and Capitum
• Unilateral and Bilateral
• Mild, Moderate and Severe
• Acute and Chronic
• With Hearing Loss and without Hearing Loss
• Vascular, Myogenic, External ear, Middle ear, Cochlear, Neural and Central
• Central and Peripheral

Types of Tinnitus

Tinnitus has been classified in several ways, such as its alleged generation site and whether it is audible to someone other than the patient (objective tinnitus) or only the patient (subjective tinnitus).
Tinnitus indicates some alteration of the auditory mechanism or its central connections.It is classified as central and peripheral. Peripheral tinnitus can be subjective, which is audible only to the patient or target, which is also audible to others. Peripheral tinnitus can be unilateral or bilateral

Subjective

which can only be heard by the patient. It is not as practical as it seems because objective tinnitus is very rare. Subjective tinnitus can only be perceived by the patient. Someone who does not have tinnitus has no idea how it sounds, how it feels and what it means to have it. This makes it very difficult to communicate what you are experiencing, but the famous people mentioned at the beginning of this chapter have got to do it effectively. Sometimes additional distinctions are made in subjective tinnitus. Transient or reversible tinnitus is often distinguished from chronic tinnitus because it generally does not need treatment and can have a source other than chronic tinnitus

• Subjective
• Otologic

•  Impacted wax
•  Fluid in middle ear
•  Acute otitis media
•  Chronic otitis media
•  Ménière’s disease
•  Presbycusis
•  Noise-induced hearing loss
•  Idiopathic sudden SNHL
•  Acoustic neuroma

• Metabolic

•  Diabetes mellitus
•  Hypothyroidism
•  Hyperthyroidism
•  Obesity
•  Hyperlipidaemia
•  Vitamin deficiency (A, B, B12,zinc )

• Neurologic

•  Head injury (labyrinthine concussion)
•  Temporal bone fractures
•  Whiplash injury
•  Multiple sclerosis
•  Postmeningitic
•  Brain haemorrhage
•  Brain infarct

• Cardiovascular

•  Hypertension
•  Hypotension
•  Anaemia
•  Cardiac arrhythmias
•  Arteriosclerosis

• Pharmacologic

• Certain drugs used by the patient Aminoglycosides,Nonsteroidal anti-inflammatory drugs,Salicylates, Antihypertensives
•  All ototoxic drugs

• Psychogenic

•  Anxiety
•  Depression
•  Stress
•  Heightened emotion

Objective

which can also be felt by the examiner with the use of a stethoscope. it is audible to an observer and has also been called "pseudo-tinnitus", "vibratory" or "extrinsic". Target tinnitus is commonly the result of blood flow becoming audible, e.g. when a vessel presses against the auditory nerve at the site where the nerve enters the brain. It can also be a vessel that pulsates in the middle ear and therefore periodically changes the pressure of the middle ear and produces an audible sound. Pulsating tinnitus is often the result of the sound produced by the turbulent blood flow that is transmitted to the inner ear. Hearing the murmur of the heart itself causes throbbing tinnitus complaints.

• Objective
•  Vascular

•  Hypertension
•  Atherosclerosis
•  Arterial stenosis
•  High jugular bulb
•  Glomus tumours
•  Persistent stapedial artery
•  Benign intracranial hypertension

• Neuromuscular

•  Palatal myoclonus
•  Tensor tympani myoclonus
•  Stapedial myoclonus

• Dental

• Clicking of TM joint

• Other

•  Patulous eustachian tube
•  Audible spontaneous otoacoustic emissions

Causes of Tinnitus

Local Causes

Tinnitus can be a symptom of any abnormal ear condition and can be associated with any form of deafness Some conditions deserve special mention:
• Presbycusis: often causes tinnitus
• Menière's disease: tinnitus tends to worsen with acute attacks
• Noise-induced deafness: tinnitus may worsen immediately after exposure to the noise
• Otosclerosis: Tinnitus can be alleviated with stapedectomy, but it should not be the main one indication for surgery
• Jugular tumor of the gloma: tinnitus is pulsating and can be heard through a stethoscope
• Aneurysm, vascular malformation and some intracranial vascular tumors can also cause tinnitus, which can also be felt by an examiner

General Causes

Tinnitus is often a characteristic of general poor health, as in:
• Fever of any cause
• Cardiovascular diseases: hypertension, atheroma, heart failure
• Blood diseases: anemia, high viscosity
• Neurological diseases: multiple sclerosis, neuropathy
• Drug treatment: aspirin, quinine, ototoxic drugs
• Alcohol abuse

Genetic Risk Factors in Chronic Tinnitus

Tinnitus is a common clinical syndrome. Of those who develop a chronic form of tinnitus, most also experience varying degrees of hearing loss. However, the relationship between the two conditions is complicated by different age-specific prevalence rates and interfering risk factors. For tinnitus, these include male sex, smoking, exposure to workplace noise, lower gains, higher body mass index and reduced overall health, among others

Diagnosis of Tinnitus

The exact diagnosis is also of great importance in clinical trials. Tinnitus is not a single clinical or pathophysiological entity. There are many types of tinnitus that differ in their pathophysiology. An exact diagnosis is required in each patient to provide better tinnitus management. Worsened by ambient sound; in others, the same sound can alleviate their tinnitus. These clinical observations clearly show that tinnitus is not a single entity of the disease, but that there are many different forms of tinnitus that can vary in its pathophysiology and response to therapeutic interventions. This, in turn, implies that an exact differential diagnosis is of the utmost importance in the treatment of tinnitus

History and Physical Examination

History better defines the patient's tinnitus. The patient must describe the nature of the sound. Any changes in tinnitus that occurred during the course of the disease should be noted. 85% of patients with tinnitus have hearing loss. Most patients have a normal neuro-otological examination, with the exception of hearing loss

Otoscopy: in the case of pulsating tinnitus, otoscopy can reveal a mass in the middle ear
Audiogram: may reveal otosclerosis, Meniere's disease or noise-induced hearing loss
Abnormally patented Eustachian tube: in case of abnormal Eustachian tube synchronous tinnitus with breathing can occur

In the future, new methods such as functional neuroimaging may have additional diagnostic value