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Congenital Hearing Loss PowerPoint Presentation

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Description : Check out this medical presentation on Hearing Disorders, which is titled "Congenital Hearing Loss", to know about congenital hearing loss.

Tags : Hearing Disorders, Congenital Hearing Loss

Published on : Jul 10, 2021 | Views : 1807 | Downloads : 4

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Slide 1-

Congenital Hearing Loss Ashley Starkweather, MD UCLA Head and Neck Surgery
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Etiology Congenital HL 50% Genetic 50% Acquired Childhood Onset HL 50% Genetic 25% Acquired 25% Unknown
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Genetic HL 75% non-syndromal 25% syndromal 75% autosomal recessive (AR) 25% autosomal dominant (AD) 1-2% X-linked Rare mitochondrial
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Autosomal recessive HL Monogenic, 25% risk to offspring if both parents are carriers Severe to profound SNHL, prelingual onset
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Autosomal recessive syndromal HL Usher syndrome Pendred Jervel and Lange Nielsen Goldenhar (Oculoauriculoverterbral spectrum)
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Usher Syndrome Retinitis pimentosa and SNHL Night blindness > field cut > central blindness Most common cause of congenital deafness Dx: electroretinography
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Usher Types Type I (most common): Profound SNHL, no vestibular fxn RP onset in early childhood Atypical myosin (myosin 7A): interferes with mechanoelectrical transduction in labyrinthine hair cells Type II: Congenital sloping SNHL Normal vestibular fxn RP onset in teens
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Usher Types Type III: Progressive SNHL and vestibular dysfunction Vestibulocerebellar ataxia Type IV: Mental retardation and hypotonia
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Usher
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Pendred Syndrome Defect in tyrosine iodination Gene mutation: affects pendrin, molecule involved in chloride-iodine transport Sx: severe to profound SNHL, multinodular goiter in childhood Assoc with Mondini malformation and enlarged vestibular aqueduct Dx: (+) perchlorate test Tx: thyroid hormone to suppress goiter
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Transverse CT scans of the middle ear in a 47-year-old patient with Pendred syndrome. (a) Modiolus is not discernible (short arrow). Vestibular aqueduct (arrowheads) and vestibule (long arrow) are enlarged. (b) Interscalar septum between upper and middle turn of the cochlea is absent (arrow).
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Jervell and Lange Nielsen Congenital profound SNHL Prolonged QT interval with syncope, sudden death Gene mutation: KVKQT1 = abnormal K+ channel Dx: EKG Tx: Beta blockers, hearing aids
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Goldenhar Syndrome First and second arch derivatives, hemifacial CHL and SNHL (mixed) Ocular: epibulbar dermoids, colobomas Auricular: preauricular appendages, pinna abnormalities, EAC atresia, ossicular malformation/absence, abnormal facial nerve, stapedius, semicircular canals and oval window Vertebral: fusion/absence of cervical vertebrae
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Goldenhar Syndrome
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Autosomal Dominant Vertical pattern of inheritance Risk to offspring of 50% if 1 parent affected Variable penetrance and expressivity Often postlingual hearing loss, progressive
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AD Syndromes Waardenburg Treacher Collins Apert Crouzon Stickler Neurofibromatosis Brancio-oto-renal
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Waardenburg Syndrome Abnormal tyrosine metabolism Pigment abnormalities: heterochromic iriditis, white forelock, patchy skin depigmentation Craniofacial abnormalities: dystopia canthorum, synophrys, flat nasal root
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Waardenburg Types Type I: Dystopia canthorum, pigment and craniofacial abnormalities, 20% with SNHL Mutation in PAX3 gene Type II: No dystopia canthorum, 50% with SNHL but not as severe MITF mutation
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Waardenburg Types Type III (most severe): Unilateral ptosis and skeletal abnormalities PAX3 mutation Type IV: Type II plus Hirschsprung’s disease (aganglionic megacolon)
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Treacher Collins (Mandibulofacial dysostosis) Hypoplasia of mandible and facial bones Downsloping palpebral fissures, colobomas Atretic external and middle ear Mixed HL Cleft palate (35%) Gene mutation on chr 5q: TCOF1 codes for a cell transport protein (treacle) Tx: BAHA, bone conduction HA, surgical correction of aural atresia
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Treacher Collins
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Apert Syndrome (Acrocephalosyndactyly) Middle and inner ear affected Stapes fixation (CHL), patent cochlear aqueduct, large subarcuate fossa Hand syndactyly, midface abnormalities, craniofacial dysostosis, trapezoid mouth
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Apert
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Crouzon Syndrome (craniofacial dysostosis) Atresia and stenosis of EAC, CHL, ossicular deformities Cranial synostosis, small maxilla, exophthalmos, parrot nose, short upper lip, mandibular prognathism, hypertelorism Abnormal FGF receptors
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Crouzon
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Stickler Syndrome Progressive Arthro-Ophthalmopathy Progressive SNHL (80%) Marfanoid body habitus Severe myopia, retinal detachment Flat midface Hypermobile joints Pierre Robin sequence: micrognathia, glossoptosis, cleft palate
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Neurofibromatosis NF-1 (Von Recklinghausen Disease) Café au lait spots, neurofibromas, Lisch nodules, 5% risk of unilateral acoustic neuroma NF-1 gene on Chr 17 NF-2 (central neurofibromatosis) Bilateral acoustic neuromas or unilateral with 1st degree relative with NF-2 or multiple central schwannomas NF-2 gene Chr 22q12 (tumor suppressor gene mutation)
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NF-1
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Branchio-oto-renal (Melnick Fraser Syndrome) Renal abnormalities: mild hypoplasia to bilateral aplasia Branchial cleft cyts Preauricular pits EYA1 on Chr 8q13 Hearing loss: Penetrance: 80% Mixed: 50% Conductive: 30% SNHL: 20%
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X-linked Disorders Alport’s syndrome Otopalatal-digital Norrie syndrome
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Alport’s Syndrome X-linked 80%, autosomal dominant 20% Progressive glomerulonephritis and SNHL Abnormal type IV collagen in GBM; gene COL4A5
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Alport’s Syndrome Bilateral degeneration of organ of Corti and stria vascularis Ocular disorders (myopia, cataracts) Dx: UA, BUN, Cr Tx: dialysis, renal transplant
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Otopalatal-digital Ossicular malformation (CHL) Palate defects Digital abnormalities: broad fingers and toes Hypertelorism, short stature, mental retardation
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Otopalatal-digital
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Norrie Syndrome Blindness Progressive mental retardation Hearing loss
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Mitochondrial Disorders Follows maternal line Postlingual HL Associated with systemic metabolic disorders Increased sensitivity to aminoglycoside ototoxicity Ex: MELAS: mitochondrial encephalopath, lactic acidosis, and strokelike syndrome MIDD: maternally inherited diabetes and deafness
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Acquired Congenital HL Prenatal: infections, teratogens Perinatal: NICU admission Postnatal: infections, neoplasms
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Prenatal Infections TORCHS: Toxoplasmosis Rubella CMV HSV encephalitis Syphilis
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Rubella Cataracts, cardiac defects, HL Atrophy of Organ of Corti, thrombosis of stria vascularis, loss of hair cells, endolymphatic hydrops Anemia, metal retardation, LE deformities, microcephaly, thrombocytopenia Dx: culture virus from urine, throat or amniotic fluid; antirubella IgM
Slide 40-

CMV 1-2% of live births Only 10% have HL Hemolytic anemia, microcephaly, mental retardation, HSM, jaundice, cerebral calcifications Dx: serum anti-CMV IgM, intranuclear inclusions “owl eyes” in renal tubular cells on UA
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Syphilis Treponema pallidum crosses placenta Often fatal Hutchinson’s Triad: abnormal central incisors, interstitial keratitis, profound SNHL Dx: VDRL, FTA-ABS, audiogram Tx: long term PCN, ampicillin, tetracycline or erythromycin; steroids for HL
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Prenatal Teratogens EtOH Thalidomide Radiation Aminoglycosides
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Perinatal Causes of HL Hypoxia Kernicterus Persistent fetal circulation
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Postnatal Causes of HL Meningitis (suppurative labryrinthitis) Ossification of labryinth Steroids help prevent HL Most common postnatal cause of HL Viral infection: mumps Ototoxins/Chemotherapy Trauma (acoustic, blunt, penetrating) Perilymph fistula Neoplasm: medulloblastoma, AN, fibrous dysplasia, histiocytosis) Autoimmune (rare in children)
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Inner Ear Dysmorphologies Michel’s aplasia Mondini aplasia Scheibe aplasia Alexander aplasia Bing Siebenmann Enlarged vestibular aqueduct Absence of CN VIII
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Michel’s aplasia AD or thalidomide exposure Complete aplasia of inner ear Anacusis, normal middle and outer ear Dx: CT shows hypoplastic petrous pyramid, absent cochlea and labyrinth
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Mondini Aplasia AD Most common cochlear abnormality Progressive or fluctuating HL  risk of perilymphatic gusher and meningitis from dilated cochlear aqueduct Dx: CT reveals single turned cochlea, no interscalar septum Tx: HA, cochlear implant
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Schiebe Aplasia AR Partial or complete aplasia of pars inferior (cochlea and saccule), normal pars superior (SCC and utricle) Defect of membranous labyrinth only, therefore can not diagnose on CT
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Alexander Aplasia AR Abnormal cochlear duct/ basal turn High frequency SNHL Cannot diagnose on CT
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Enlarged vestibular aqueduct Defined by diameter of duct >2mm at midpoint Progressive cochleovestibular loss No treatment
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Thanks for listening!
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Questions What % of patients with NF-1 have acoustic neuromas? 5% 20% 50% 95%
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What % of patients with NF-2 have acoustic neuromas? 5% 20% 50% 95%
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What is the basic defect that causes Alport syndrome? abnormal renal tubules abnormal collagen IV in glomerulus abnormal collagen I in glomerulus abnormal renal arteries
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What is the primary inheritance pattern for Alport’s syndrome?
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What syndrome does this patient have? Goldenhar Treacher Collins Crouzon Apert
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What inner ear aplasia will not allow for cochlear implants or amplification aids? Mondini aplasia Michel’s aplasia Enlarged vestibular aqueduct Alexander aplasia
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Which inner ear dyplasia is characterized by a lack of septae in the cochlea and only a basal turn? Mondini aplasia Michel’s aplasia Enlarged vestibular aqueduct Alexander aplasia
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What is the inheritance pattern of MIDD and MELAS?
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What abnormality is noted on this temporal bone CT?
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What genetic mutation is responsible for type I and III Waardenburg syndrome? COL2A1 Pendrin PAX3 Chr 22q12
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Thanks for listening!