PROGRESSIVE HEARING LOSS

Fatin Suraya binti Mohd Isa

DEFINITION1. Hearing loss that get worst overtime

(http://www.raisingdeafkids.org/hearingloss/types/progressive)

2. Progressive hearing loss was defined as deterioration in hearing of 10 dB or more at any 1 frequency on behavioral audiometry or ABR threshold (Satoshi Iwasaki, Miwa Yamashita, Makoto Maeda, Kiyoshi Misawa,Hiroyuki Mineta:Audiological Outcome of Infants with Congenital Cytomegalovirus Infection in a Prospective Study. Audiol Neurotol 2007;12:31–36)

3. Progressive hearing loss was defined as sensorineural decrease in hearing equal or more than 10 dB at any 1 frequency or ABR threshold, documented on 2 separated evaluations. (Bopanna et. al : Congenital Cytomegalavirus Infection: Association between virus burden in infancy and hearing loss. The Journal Of Paediatrics 2005)

CAUSES

GENETICSO Connexin 26 The GJB2 gene contains the instructions for a protein called Connexin 26. Its functions is in the inner ear and is involved in the production of junctions that allow the transport of materials between cells. The cochlear is a very complex and specialized part of the body that needs many instructions to guide its development and functioning. These instructions come from genes such as the GJB2, GJB3, and GJB6. any changes in any one of these genes can result in hearing loss (A parents guide genetics & hearing loss)

O TMC1 according to longitudinal study carried out on a dutch family, mutation on TMC1 could lead to progressive hearing loss but intact vestibular function (R. de Heer et. al : Progressive sensorineural hearing loss and normal vestibular function in a Dutch DFNB7/11 family with a novel mutation in TMC1. audiol neurotiol 2011;16:93-105)

Progressive hearing loss in an 8-year-old patient with 2 truncating GJB2 mutations. Hearing loss is shown in the right ear (A) and the left ear (B).

VIRAL INFECTIONO Congenital cytomegelovirus infection common cause of congenital infection and a leading cause of hearing loss in children in the united states . Infection happen during the pregnancy. Statistic :

85% develop normally 10-15 % hearing loss

(bopanna et al. june 2005)

OTOTOXICITYO Chemotheraphy effect - cisplatin effect ongoing studies performed by Children's Hospital and the Dana Farber Cancer Institute in Boston where children with brain cancer were followed for an average of six years after undergoing radiation therapy. The patients received three courses of cisplatin followed by cranial irradiation and shows : 1)One to 18 months after the treatments, 23 percent of the children needed hearing aids.2)In an average of 30 months after receiving treatment, 57 percent required hearing aids and their hearing continues to worsen.

PROGRESSIVE HEARING LOSS DISORDER

O Friedriech’s ataxia -autosomal recessive and dominant traits, causes progressive damage to the nervous system, resulting in symptoms ranging from gait disturbance to speech problems; it can also lead to heart disease and diabetes (http://en.wikipedia.org/wiki/Friedreich%27s_ataxi)

O Alport syndrome -autosomal recessive traits, Alport Syndrome is an inherited disease of the kidney that can also affect the inner ear (cochlea) and eye. It is caused by genetic mutations that affect the type IV collagen family of proteins. Type IV collagen is a major part of important tissue structures called basement membranes that are present in all tissues including the kidney, inner ear, and eye. Generally, Alport Syndrome affects boys more than girls because 80% of the time the disease is passed on by a mutation on the X chromosome (called X-linked Alport Syndrome). Boys only have one X-chromosome whereas girls have two X chromosomes. (http://www.alportsyndrome.org/what-is-alport-syndrome/)

O Usher syndrome type 3 -autosomal recessive traits, Mutations in only one gene, the CLRN1 gene, have been linked to Usher syndrome type III. The CLRN1 gene encodes Clarin-1, a protein that is important for the development and maintenance of the inner ear and retina. (http://cureforsure.org/disease/Usher_syndrome

RISK FACTORSAPPENDIX 2: RISK INDICATORS ASSOCIATED WITH PERMANENT CONGENITAL, DELAYED-ONSET, OR PROGRESSIVE HEARING LOSS IN CHILDHOOD

Risk indicators that are marked with a “§” are of greater concern for delayed-onset hearing loss.O Caregiver concern§ regarding hearing, speech, language, or developmental delay.62O Family history§ of permanent childhood hearing loss.24,140O Neonatal intensive care of more than 5 days or any of the following regardless of length of stay:

ECMO,§ assisted ventilation, exposure to ototoxic medications (gentimycin and tobramycin) or loop diuretics (furosemide/Lasix), and hyperbilirubinemia that requires exchange transfusion.64,131

O In utero infections, such as CMV,§ herpes, rubella, syphilis, and toxoplasmosis.64–67,125,126O Craniofacial anomalies, including those that involve the pinna, ear canal, ear tags, ear pits, and

temporal bone anomalies.24O Physical findings, such as white forelock, that are associated with a syndrome known to include a

sensorineural or permanent conductive hearing loss.24O Syndromes associated with hearing loss or progressive or late-onset hearing loss,§ such as

neurofibromatosis, osteopetrosis, and Usher syndrome131; other frequently identified syndromes include Waardenburg, Alport, Pendred, and Jervell and Lange-Nielson.72

O Neurodegenerative disorders,§ such as Hunter syndrome, or sensory motor neuropathies, such as Friedreich ataxia and Charcot-Marie-Tooth syndrome.131

O Culture-positive postnatal infections associated with sensorineural hearing loss,§ including confirmed bacterial and viral (especially herpes viruses and varicella) meningitis.130,131,141

O Head trauma, especially basal skull/temporal bone fracture§ that requires hospitalization.127–129O Chemotherapy.§

http://pediatrics.aappublications.org/content/120/4/898.full?ijkey=oj9BAleq21OlA&keytype=ref&siteid=aapjournals

SIGN AND SYMPTOMS

O Child’s threshold changes or worsen O They does’nt seems to hear what the

child used to be able to hearO The child speech changes

AUDIOLOGICAL ASSESSMENT

O Recommended pediatric audiologic assessment guidelines for children is from birth to 60 months developmental age (tennesse

department of health : newborn hearing programme. November 2010)

O Infants who are high risk for late onset or progressive hearing loss should receive audiologic evaluations every six months (colorado infant

hearing advisory committee: guidelines for infant hearing screening, audiologic assessment, and early interventio)

O PTA test is carried out, and comparing the threshold with the previous test.

O 0-6 monthsBehavioral observation audiometry

O 6 months-2.5 years oldVisual reinforcement audiometry

O 2.5 years old-6 years oldPlay audiometry

MANAGEMENT

O Hearing AidO Cochlear implant