The ear consists of three anatomical regions:
- The outer ear: is made up of the pinna and external auditory canal (EAC). The EAC is closed by the tympanic membrane which separates it from the middle ear. The role of the outer ear is to capture and concentrate sound waves, acting as an amplifier.
- The middle ear: this is formed from the middle ear cavity and the chain of three ossicles which transmit and amplify sound vibrations to the inner ear.
- The inner ear: this contains 2 neurosensory organs:
- The cochlea, which is the hearing organ, contains ciliated sensory cells (hair cells) or mechanoreceptors which capture the sound vibrations transmitted through the middle ear and convert the mechanical message into an electrical one, which is carried to the brain along the auditory nerve.
- The vestibule, the balance organ, which is responsible for detecting accelerations of the head, which are also transduced by ciliated sensory cells (hair cells) or mechanoreceptors. The vestibular apparatus is made up of a set of specialist sensory sensors to detect movement or position of the head in space. It therefore helps to continuously inform the brain about the position of the body and the head in space.
The inner ear can be affected by a variety of diseases of different origin, which are generally poorly understood. Different factors are responsible for causing damage to the inner ear which then results in impaired hearing and/or balance function, depending on whether they are located in the cochlea and/or vestibular apparatus
Various possible causes responsible for these damages can be distinguished:
- Vascular: hypertension or a localized stroke,
- Trauma: head trauma, acoustic trauma, nose blowing, barotrauma from diving,
- Drug-induced: antibiotics such as aminoglycosides or macrolides, salicylates, quinine, diuretics and platinum salts used in chemotherapy are “ototoxic” substances and generally cause irreversible damage,
- Infectious: bacterial infection of the outer and middle ear or some viral infections of the inner ear,
- Aging: pathophysiological deterioration of the inner ear tissues as a result of age can cause presbycusis (reduced hearing) and presbyvertigo (global reduced vestibular responsiveness causing loss of balance) in the elderly.
There are three main symptoms due to inner ear damages :
They are associated with sensory neural disability, which greatly reduces daily function and quality of life for many patients.
On the treatment side, currently available therapies offers no cure. The palliative treatments used are mostly non-specific for particular injuries or impairments, thus many patients experience lack of efficacy, constituting a large unmet medical needs.
Increased life expectancy, sound pollution, polymedication and the chronic nature of serious diseases such as cancers are liable to increase the prevalence of inner ear disorders and their related neurosensory disabilities. We are committed to finding innovative and targeted solutions for all patients suffering daily from the consequences of inner ear diseases.