Introduction

Barakat syndrome is a clinically variable (heterogenous) rare genetic condition. It has a wide genotypic and phenotypic variant and is genetically diverse.¹ It causes hypoparathyroidism, sensorineural deafness and renal kidney disease. Hypoparathyroidism is when there are low levels of Ca²⁺ ions in the blood and this leads to muscle pain, seizures and muscle spasms. A key feature of barakat syndrome is hearing loss and kidney failure can range from person to person.²  One of the many forms of treatment for people with deafness in barakat syndrome is the use of cochlear implants and hearing aids. These aid in improving the hearing of a person. 

Hearing loss in Barakat Syndrome

Types of hearing loss associated with Barakat Syndrome 

Sensorineural hearing loss (SNHL)

SNHL occurs when the tiny hairs in the cochlear are damaged and the hair cells are unable to convert the sound waves into neural signals to pass through the auditory nerve to the brain. Some of the symptoms include dizziness, ringing in the ear, muffled hearing and a sudden loss of hearing.³

Conductive hearing loss 

Conductive hearing loss results when there is a problem in delivering sound energy to the cochlea. Common reason for conductive hearing loss is due to a blocked ear canal. Some of the symptoms are draining of the ear, pain in the ear or a stuffy sensation in the ear.⁴

Mixed hearing loss 

A mixed hearing loss is the combination of SNHL and conductive hearing loss. If the loss is mostly conductive, then people may find it hard to hear people talking if there is a lot of background noise or if they speak quietly. If it is more sensorineural they will find it difficult to hear people even when they speak loudly.⁵

Diagnosis of hearing loss 

Audiometric evaluations 

This tests one's ability to hear and it will detect the type of hearing loss one has and can evaluate the severity of the type of hearing loss. Three of the main types of audiometric evaluations are pure-tone testing, bone conduction testing and speech testing. Pure tone testing identifies the quietest volume one can hear at each pitch, bone conduction testing shows if there are issues with the tiny hair cells in the cochlea. In speech testing, one has to listen to and repeat certain words.⁶

Genetic testing 

A gene panel test is done where it checks for many different genes at the same time. Sometimes a genetic test involves looking at a person’s DNA to see if there are any changes related to hearing loss. A person’s DNA sample is often obtained from cheek cells from a person’s mouth using a cheek swab or saliva. The DNA is then tested to find the gene causing hearing loss.⁷

Hearing Aids

Function and purpose 

Hearing aids are not made to make hearing perfect but instead they aim to make the sounds louder and clearer. They help to improve the ability to hear speech and to enjoy doing everyday life things such as watching TV.⁸

Types of hearing aids 

Some of the variety of hearing aids available are:

• Behind the ear hearing aids -  they are attached to a tube to a piece of plastic that sits behind the ear. 
• Receiver in the ear hearing aids - The hearing aid is smaller and is connected by a thin wire to a speaker placed inside the opening of the ear. They are also less visible than the one above. 
• In the ear hearing aids - They sit just outside the opening of the ear and can’t be seen from the behind only on the side. 
• In the canal hearing aids - These ones are a bit smaller than the one above and just fill the opening of the ear. However these are not powerful enough for people with severe hearing loss. 
• Completely in the canal and invisible in the canal hearing aids - They are the smallest types of hearing aids and fit further into the opening of the ear. 
• CROS and BiCROS hearing aids - They are used if one has lost hearing in one ear. It picks up sound and sends it to a hearing aid in the good ear. 
• Body worn hearing aids - They are made up of a small box connected to earphones. The box can be clipped to clothes and put inside a pocket. 

Use of hearing aids in Barakat Syndrome 

Some of the benefits of hearing aids is that it will allow people to communicate with friends and family more easily and it can improve communication in noisy situations. However some of the limitations that come along with them are that sometimes the background noises can be louder than what they actually are. It also may take several months to adjust to the hearing aid in your ear and the new sounds that one can hear may seem uncomfortable or really loud at first.⁹ The most common hearing aid provided by the NHS is the behind ear ones and the earmold sits behind the ear and a small soft tip known as the open ear fitting sits inside the ear. It may take some time to get used to them and the batteries will usually need changing every 1-2 weeks.¹⁰

Cochlear Implants

Function and purpose

Similar to hearing aids, cochlear implants do not fix hearing however help make the sounds more clearer and louder. It is an electronic device that sends sound past the damaged part of the ear straight to the hearing nerve. A cochlear implant uses a sound processor that is fitted behind the ear and it sends sound signals to a receiver that is placed under the skin behind the ear. It takes about 3-6 months for people with cochlear implants to adjust to the implant and to see a difference.¹¹

Components of a cochlear implant 

The implant consists of two parts, an external portion and an internal portion. The external portion contains a speech processor and the headpiece. The speech processor is placed behind the ear and the headpiece is worn on the scalp. The internal portion contains the implant and an electrode array. The headpiece is connected to the implant by magnets on both pieces and the electrode array is surgically placed in the cochlea.¹²

Case Studies and Research

According to the Saudi journal of otorhinolaryngology head and neck surgery, a case study was reported of a 4 year old male, who had a family history of hypoparathyroidism (a type of barakat syndrome). He was fitted with hearing aids from 24 months of age and he wore it for 8 hours a day. However, during his follow up appointments they noticed there was no significant benefit to using the hearing aids. They then later found out that he had congenital malformations of the cochlea and vestibule. Then at the age of 5 he was put on the cochlear implant and after a year of receiving the implant an audiometry test revealed that his hearing improved to the normal to mild hearing range. However the word recognition was at 32%, which was still poor and still had some difficulty in speech. However at the end of the study it determined that the cochlear implantation had a greater effect than a hearing aid. Therefore the hearing aid is more useful in situations where the severity of the hearing loss is low and the cochlear implant is more effective where the hearing is severely poor.¹³

Conclusion

In conclusion, the use of hearing aids and cochlear implants is very important for people with barakat syndrome and the use of each device depends on the severity of the hearing loss. It is very clear that the cochlear implants are more suitable for people with severe hearing loss and over time their ability to hear more clearly does improve.