The Nucleus Hybrid L24 Cochlear Implant System for sensorineural

hearing loss

Presentation By :Indu Nath. SM Pharm part IIPharmacy Practice

Contents

Introduction Physiology of hearing Hearing loss

Sensorineural hearing loss

The Nucleus Hybrid L24

Cochlear Implant System

Advantage

Limitation Conclusion References

Introduction

The ear is the organ of hearing and balancing.

It is supplied by the 8th cranial nerve, i.e. the cochlear part of the vestibulocochlear nerve which is stimulated by vibrations caused by the sound waves.

The ear has three divisions, namely external ear, middle ear and inner ear.

Physiology of hearing

Hearing loss

Hearing loss ,hearing impairment, or deafness, is a partial or total inability to hear.10 % of adults has some hearing loss and one third of individuals over the age of 65 have a hearing loss of sufficient magnitude and require hearing aid.

Results from disorder of the auricle, external auditory canal, middle ear, inner ear, or central auditory pathway.

Lesions in the auricle, external auditory canal, or middle ear cause conductive hearing losses.

Lesions in the inner ear or eighth nerve cause sensorineural hearing losses.

Types of hearing loss

Hearing loss

Conductive

Sensorineural Mixed

Hearing impairments are categorized by their type, severity, ad the onset of age.

Conductive hearing loss: a conductive hearing impairment occurs when the sound is not reaching the inner ear and the cochlea.

External ear canal malformation, dysfunction of the ear drum or malfunction of the bones of the middle ear.

Other reasons include trauma and infections. Mixed hearing loss: conductive and sensorineural

hearing loss in combination is termed mixed hearing loss.

Otosclerosis involving the ossicles and cochlea, head trauma, chronic otitis media, middle ear tumors and inner ear malformations.

Sensorineural hearing loss

Sensorineural hearing loss is the most common form of

hearing loss and occurs when there is a lesion in the inner ear or eighth cranial nerve

(vestibulocochlear nerve) .

It may be caused by aging, heredity, exposure to loud noise, ototoxic drugs, viral infections and certain other

illnesses .

Sensorineural hearing loss can be mild, moderate, or severe,

including total deafness.

Sensorineural hearing loss can be treated with hearing aids

and also with cochlear implants.

Sensorineural hearing loss

• Epidemiology:

Gender: Males affected by hearing loss at an age earlier age than females Age : Older people are affected. Onset of age is over 40 years

• Causes : Presbycusis (related to aging) Noise induced hearing loss Cranial nerve 8 diseaseo Meniere's diseaseo Acoustic neuroma Viral Micro vascular diseaseo Diabetes mellituso Hyperlipidemia

Ototoxic medications Endocrine disease

o Hypothyroidism Autoimmune hearing loss Congenital deafness Traumao Temporal bone fracture involving  Cochlea or vestibule• Signs and symptoms: Tinnitus Pain with loud noise exposure Impaired word understanding Loud patient's voice Hearing difficult in noisy environments

• Management: Formal audiology testing Acute hearing loss

o High dose steroidso Carbogen Inhalation (5% CO2 and

95% Oxygen) Chronic hearing loss o Cochlear implants

The Nucleus Hybrid L24 Cochlear Implant System

The U.S. Food and Drug Administration approved the first implantable device for people 18 and older with

severe or profound Sensorineural hearing loss of

high-frequency sounds in both ears.

The Nucleus Hybrid L24 Cochlear Implant System may help those with this specific kind of hearing loss who do

not benefit from conventional hearing aids.

The hybrid system is mainly used for candidates who have good low-frequency hearing but very poor high-frequency

hearing.

The hybrid works on the concept of combining

electrical stimulation for high frequency sound with

acoustic hearing for low frequency information in the

same ear.

Components of a cochlear implant

The basic part of this includes:

External part• Micro phone and sound processor• Transmitter

Internal part• A receiver and stimulator• Array of electrodes.

The Nucleus Hybrid L24 Cochlear Implant System combines the functions of a cochlear implant and a hearing aid.

This electronic device consists of an external microphone and sound processor that picks up sounds from the environment and converts them into digital code.

The sound processor transmits the digitally coded sound via the coil to the implant just under the skin.

The implant converts the digitally coded sound to electrical signals and sends them along the electrode array, which is positioned in the cochlea.

The implants electrodes stimulate the cochlea’s hearing nerve fibers, which relay the sound signals to the brain to produce hearing sensations.

Advantages

Helps those with Sensorineural hearing loss who do not benefit from conventional hearing aids.

No loss of residual natural hearing

Reduce the risk of infection and complications while improving the

patients ability to hear.

Preserve low frequency hearing

Minimal invasive surgery.

Limitations

Rapid fluctuations in sounds are not well

transmitted by cochlear implant.

Surgical issues like tinnitus, vertigo.

Medical costs , device, processor

and accessories are expensive.

conclusion Sensorineural hearing loss is the most common

form of hearing loss and occurs when there is a lesion in the inner ear or eighth cranial nerve (vestibulocochlear nerve) .

The Nucleus Hybrid L24 Cochlear Implant System is the first approved device by the FDA for Sensorineural hearing loss.

The hybrid L24 implant provides a better treatment option for suitable candidates with high frequency hearing loss.

References

E. Murugasu. Recent advances in the treatment of sensorineural deafness. Ann Acad Med Singapore 2005;34:313-21.

Harrison’s Principle of Internal Medicine, Vol 1 by Longo, Fauci Kasper, Hasper, Jamesoli Page No: 179-183 ,18 th edition.

www.fda.gov www.medscape.com  www.nlm.nih.gov/medlineplus/ency/article/003291.html emedicine.medscape.com/article/856116-overview

– All data were collected from various sources.. only for educational purpose.