What Is Tinnitus?
Tinnitus is the perception of sound, such as ringing, buzzing, clicking or the sound of running water, in the absence of a corresponding external acoustic source. It is one of the most common yet disproportionately underestimated symptoms encountered in otology.
It is estimated to affect up to 15% of the general population on a persistent basis, with a significant impact on sleep quality, concentration, psychological well-being and overall quality of life.
Its causes are complex and multifactorial. Tinnitus may result from exposure to loud noise, ototoxic medication, Ménière’s disease, sudden sensorineural hearing loss, vascular disorders, metabolic conditions or neurological disease.
In many cases, it coexists with some degree of sensorineural hearing loss, although hearing loss is not always present. Chronic tinnitus, particularly when it affects sleep or professional life, may carry a considerable psychological burden and contribute to anxiety and depression.
Characteristics and Causes
Tinnitus of vascular or metabolic origin, meaning tinnitus associated with cochlear ischaemia or hypoxia, is the form for which improving oxygenation of the inner ear has the strongest therapeutic rationale.
In these cases, the sound perceived by the patient is not random. It reflects disorganised neural activity originating from cochlear cells under metabolic stress.
Unlike other forms of tinnitus caused by central neurological reorganisation, which are generally more difficult to treat, vascular tinnitus originates peripherally within the cochlea, precisely where improved oxygenation may have a direct therapeutic effect.
Establishing this differential diagnosis is essential for identifying patients who are most likely to benefit from treatment.
Clinical Studies on the Use of Hyperbaric Oxygen Therapy
Clinical studies evaluating the use of hyperbaric oxygen therapy in patients with tinnitus of vascular or metabolic origin have reported reductions in tinnitus severity, as measured using standardised assessment scales, together with improvements in perceived discomfort and sleep quality.
The most favourable outcomes have been observed in patients with a subacute onset and in those whose tinnitus accompanies sudden sensorineural hearing loss or another ischaemic otological condition.
The proposed mechanism of action centres on restoring the metabolic function of the cochlear cells responsible for generating abnormal neural activity. When these cells receive adequate oxygenation, the pathological “noise” they produce may diminish or resolve.
The Role of Hyperbaric Oxygen Therapy
In tinnitus, hyperbaric oxygen therapy may be used as an adjunctive option for specific groups of patients, primarily those with a vascular or metabolic cause, a subacute onset or tinnitus associated with another ischaemic otological condition. It is not a universal treatment for every form of tinnitus.
Each session increases oxygen delivery to the cochlea through the dissolution of oxygen in the endolymph, improving the metabolic function of affected hair cells and reducing the frequency and intensity of the abnormal neural activity perceived as tinnitus.
Its anti-inflammatory effects may also reduce inflammation within cochlear tissue when this contributes to the condition.
A typical treatment course consists of 10 to 20 sessions, under specialist otological supervision, with progress assessed using standardised tinnitus rating scales.