1 / 63

Congenital Hearing Loss

Congenital Hearing Loss. Ashley Starkweather, MD UCLA Head and Neck Surgery February 25, 2009. Etiology. Congenital HL 50% Genetic 50% Acquired Childhood Onset HL 50% Genetic 25% Acquired 25% Unknown. Genetic HL. 75% non-syndromal 25% syndromal 75% autosomal recessive (AR)

lirit
Download Presentation

Congenital Hearing Loss

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Congenital Hearing Loss Ashley Starkweather, MD UCLA Head and Neck Surgery February 25, 2009

  2. Etiology • Congenital HL • 50% Genetic • 50% Acquired • Childhood Onset HL • 50% Genetic • 25% Acquired • 25% Unknown

  3. Genetic HL • 75% non-syndromal • 25% syndromal • 75% autosomal recessive (AR) • 25% autosomal dominant (AD) • 1-2% X-linked • Rare mitochondrial

  4. Autosomal recessive HL • Monogenic, 25% risk to offspring if both parents are carriers • Severe to profound SNHL, prelingual onset

  5. Autosomal recessive syndromal HL • Usher syndrome • Pendred • Jervel and Lange Nielsen • Goldenhar (Oculoauriculoverterbral spectrum)

  6. Usher Syndrome • Retinitis pimentosa and SNHL • Night blindness > field cut > central blindness • Most common cause of congenital deafness • Dx: electroretinography

  7. 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

  8. Usher Types • Type III: • Progressive SNHL and vestibular dysfunction • Vestibulocerebellar ataxia • Type IV: • Mental retardation and hypotonia

  9. Usher

  10. 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

  11. 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).

  12. 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

  13. 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

  14. Goldenhar Syndrome

  15. Autosomal Dominant • Vertical pattern of inheritance • Risk to offspring of 50% if 1 parent affected • Variable penetrance and expressivity • Often postlingual hearing loss, progressive

  16. AD Syndromes • Waardenburg • Treacher Collins • Apert • Crouzon • Stickler • Neurofibromatosis • Brancio-oto-renal

  17. Waardenburg Syndrome • Abnormal tyrosine metabolism • Pigment abnormalities: heterochromic iriditis, white forelock, patchy skin depigmentation • Craniofacial abnormalities: dystopia canthorum, synophrys, flat nasal root

  18. 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

  19. Waardenburg Types • Type III (most severe): • Unilateral ptosis and skeletal abnormalities • PAX3 mutation • Type IV: • Type II plus Hirschsprung’s disease (aganglionic megacolon)

  20. 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

  21. Treacher Collins

  22. 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

  23. Apert

  24. 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

  25. Crouzon

  26. 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

  27. 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)

  28. NF-1

  29. 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%

  30. X-linked Disorders • Alport’s syndrome • Otopalatal-digital • Norrie syndrome

  31. Alport’s Syndrome • X-linked 80%, autosomal dominant 20% • Progressive glomerulonephritis and SNHL • Abnormal type IV collagen in GBM; gene COL4A5

  32. Alport’s Syndrome • Bilateral degeneration of organ of Corti and stria vascularis • Ocular disorders (myopia, cataracts) • Dx: UA, BUN, Cr • Tx: dialysis, renal transplant

  33. Otopalatal-digital • Ossicular malformation (CHL) • Palate defects • Digital abnormalities: broad fingers and toes • Hypertelorism, short stature, mental retardation

  34. Otopalatal-digital

  35. Norrie Syndrome • Blindness • Progressive mental retardation • Hearing loss

  36. 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

  37. Acquired Congenital HL • Prenatal: infections, teratogens • Perinatal: NICU admission • Postnatal: infections, neoplasms

  38. Prenatal Infections • TORCHS: • Toxoplasmosis • Rubella • CMV • HSV encephalitis • Syphilis

  39. 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

  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

  41. 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

  42. Prenatal Teratogens • EtOH • Thalidomide • Radiation • Aminoglycosides

  43. Perinatal Causes of HL • Hypoxia • Kernicterus • Persistent fetal circulation

  44. 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)

  45. Inner Ear Dysmorphologies • Michel’s aplasia • Mondini aplasia • Scheibe aplasia • Alexander aplasia • Bing Siebenmann • Enlarged vestibular aqueduct • Absence of CN VIII

  46. 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

  47. 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

  48. 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

  49. Alexander Aplasia • AR • Abnormal cochlear duct/ basal turn • High frequency SNHL • Cannot diagnose on CT

More Related