Presentation on theme: "Pediatric Hearing Loss"— Presentation transcript:
1Pediatric Hearing Loss UCLA Head & Neck SurgeryOntario Lau MD
2Epidemiology congenital SNHL 1-3 per 1000 per live births 10x greater for infants with 1 or more risk factor than those with no risk factors, ie 2% to 5%.late-onset and acquired hearing loss in childhood 6x higher than the incidence of hearing loss in the neonatal period1% all children have HL
3EvaluationHistory:intrauterine infections (most commmon prenatal cause)perinatal infection, maternal drug abuse, low Apgar score (most common perinatal causes)Prematurity, NICU stay, bilirubinemia,family history.Meningitis (most commmon postnatal cause)Physical: microscopic exam; auricle, periauricular pits, craniofacial abnormalities,+/- ocular, thyroid, skin, limb exams look for syndromic cause
4EvaluationOAEABRTORCH, meningitis, family hx, craniofacial abnormalities, birth weight <1.5kg, neonatal hyperbilirubinemia, Apgar <4 at 1 minutes, <6 at 5 minutes, prolonged NICU stay or ECMO or mechanical vent, exposure to ototoxic meds.Behavior observation audiometry (birth to 6 mos)Visual Reinforcement Audiometry (6mos-3yrs)Conventional play audiometry (3-6 yrs)Standard Audiometry (6 yrs+)
5Ancillary TestsImaging: CT temporal bone: inner ear disorders, cholesteatoma, & osteodysplasias. CBC, lipid profile, IgM assay for TORCH (Toxoplasmosis, Other[syphilis], Rubella, Cytomegalovirus, Herpes simplex) Connexin-26 test Other tests as indicated by ddx.
7Acquired prenatal hearing loss Congenital Cytomegalovirus most common infectious cause, >4000 annual casesIncidence of infection: 1-2 cases/100 live birth<5% develop multiorgan dx 50% of those develop HL5-15% silently infected infants eventually develop HLOto SSx: B progressive high freq SNHLOther SSx: Cerebral calcification, microcephaly, mental retardation, hepatosplenomegaly, jaundice.
8Acquired prenatal hearing loss Congenital Cytomegalovirus Dx: serum anti-CMV IgM, CMV DNA from body fluid,+ intranuclear inclusions (owl eyes) in renal tubular cells in urinary sediment (1 to 2 weeks of life)Rx: Ganciclovir—little effect for HL since damage happened already in utero
9Acquired prenatal hearing loss Congenital Syphilis Pathophysio: transplacental transmission, 100% inoculation rate40% perinatal deathOto SSx: frequent +Hennebert sign (aka +fistula sign)Early deafness birth to 3 yodelayed 8-20 yo.Other SSx: Hutchinson triad: abnormal central incisors (aka Hutchinson teeth), interstitial keratitis of the eye, bony abnormalitiesDx: RPR,VDRL(sensitive); FTA-ABS(specific)Tx: PCN
10Acquired prenatal hearing loss Congenital Rubella Rare since vaccination (0-3 per year now in USA)Pathophysio: vasculitis resulting in tissue necrosisOto SSx: B often asymmetric severe to profound SNHLOther SSx: growth delay, learning disability, congenital heart disease, and ocular, endocrinologic, and neurologic abnormalities.Dx: urine/throat/amniotic fluid clx, antirubella IgM
11Inner Ear Dysmorphologies Time frame: membranous labyrinth is interrupted during 1st trimester Etiologies: Genetic or teratogenic exposureClassificationsmembranous labyrinth ONLY (seen at autopsy)Osseous & membranous labyrinth ( seen in CT)
12Inner Ear Dysmorphologies Incidence: 20% congenital SNHL will show abnormal inner ear on CT temporal boneBony: Dilated Vestibular aqueduct >cochlea>SCC (as reflected by modern imaging technology)
13Inner Ear Dysmorphologies membranous labyrinth ONLY Complete membranous labyrinthine dysplasia (Siebenmann-Bing)Limited membranous labyrinthine dysplasiaScheibe dysplasia (cochleosaccular dysplasia) MOST common membranous labyrinthine dysplasiaCochlear basal turn dysplasia
14Bing-Siebenmann Extremely rare Associated with Jervell and Lange-Nielsen syndrome and Usher syndrome.
15Scheibe dysplasia cochleosaccular dysplasia Pathophysio: incomplete development of the pars inferiorCochlea dysplasia: severa in the basal turn, lessen toward apex, or severe throughoutSaccule: collapsedOrgan of Corti: partial or completely missingSCCs & utricle: NORMALOtoSSx: SNHLAssociated w/ Usher syndrome & Waardenburg syndrome
16.Cochleosaccular Dysplasia: A Morphometric and Histopathologic Study in a Series of Temporal Bones.Sampaio, Andre; Cureoglu, Sebahattin; Schachern, Patricia; Kusunoki, Takeshi; Paparella, Michael; Oliveira, CarlosOtology & Neurotology. 25(4): , July 2004.FIG. 1. (A) In the apical turn of this right temporal bone from case 10, there is a large cystic area (arrow) in the stria that intersects in its apical portion with a hydropic Reissner's membrane (arrowhead). O, organ of Corti represented by supporting cells; T, deformed tectorial membrane; S, atrophic stria vascularis. (B) There are strial cysts (arrow) in the lower basal turn of this left temporal bone from case 2. (C) In the lower basal turn of this right temporal bone from case 8, there is a strial concretion (short arrow), a collapsed Reissner's membrane (arrowhead), and an amorphous substance (long arrow) within a rolled tectorial membrane.2
17Inner Ear Dysmorphologies osseous & membranous labyrinth Complete labyrinthine aplasia (Michel) 1%Cochlear anomaliesCochlear aplasia 3%cochlear hypoplasia 15%Incomplete partition (Mondini) 55% Common cavity 26%**Jackler RK, Luxford WM, House WF: Congenital malformations of the inner ear: a classification based on embryogenesis, Laryngoscope Suppl 97:2, 1987
18Michel: complete labyrinthine Aplasia Exceedingly rare.Associated w/ anencephaly & thalidomide exposure.Overestimated due to confusion with acquired labyrinthine ossification.
19Mondini: incomplete partition Pathphysio: arrest at 7th week gestation 1.5 turn cochleaOto SSx: normal to profound SNHLOther SSx:20% SCC deformities;dilated cochlear aquaduct: perilymphatic gushers & meningitis
20Mondini: incomplete partition CT/MRI findings:smaller cochlea (5-6mm vs 8-10mm vertical dimension of normal cochlea)absence of a scalar septum
21Common Cavity Pathphysio: arrest at 4th week otocyst stage or later CT/MRI findings:Empty ovoid space (average 7mm vertically, 10mm horizontally)Common cavity cochlear ANTERIOR to the IAC on axial CTOto SSx: variable SNHL, usually poor
22Common CavityImplanting Common Cavity Malformations Using Intraoperative Fluoroscopy.Coelho, Daniel; Waltzman, Susan; Roland, JOtology & Neurotology. 29(7): , October 2008.DOI: /MAO.0b013eFIG. 2 . A transorbital plain x-ray intraoperative view. Note that the array has passed into the IAC. The arrow denotes the junction between the common cavity and the IAC as seen in this orientation. Inset outlines the lumen of the common cavity (cc) and the IAC. Reprinted with permission from Fishman AJ, Roland JT Jr, Alexiades G, Mierzwinski J, Cohen NL. Fluoroscopically assisted cochlear implantation. Otol Neurotol 2003;24:882-6.2
23Inner Ear Dysmorphologies osseous & membranous labyrinth Labyrinthine anomalies Semicircular canal dysplasia Semicircular canal aplasiaAqueductal anomalies Enlargement of the vestibular aqueductEnlargement of the cochlear aqueduct Internal auditory canal anomalies Narrow IAC Wide IAC*Jackler RK, Luxford WM, House WF: Congenital malformations of the inner ear: a classification based on embryogenesis, Laryngoscope Suppl 97:2, 1987
24Semicircular Canal Dysplasia 40% malformed cochlea a/w dysplasia of lateral SCCLateral>>post/superiorPathphysio: arrest at 6th weekCT/MRI findings : short, broad cystic space confluent with the vestibule
25Enlargement of the Vestibular Aqueduct Epid: most common radiographically detectable malformation of the inner earPathphysio: Acquired abnormal communication between the subarachnoid space and the fluid chambers of the inner earOto SSx:born w/ normal or mildly impaired hearing that gradually worsens;hearing variable, 40% profound SNHLCHL possible: AVOID STAPEDECTOMY! (a/w perilymphatic gusher)
26Enlargement of the Vestibular Aqueduct CT/MRI findings :CT: VA> 2mm (normal 0.4-1mm)a/w cochlea or SCC malformationMRI: Dilated endolymphatic sac, sometimes >2cmUsually bilateralRX: CI, avoid endolymphatic surgery/stapedectomy
27Wide Internal Auditory Canal Usually incidental finding in normal hearing subjectsCT/MRI findings : IAC>10mma/w spontaenous CSF otorrhea & gusher during stapes surgery obtain CT for congenital CHL!
28Narrow Internal Auditory Canal Pathphysio : agenesis of CN VIIICT/MRI findings : IAC<3 mm, bony canal only transmits CN VIIRelative contraindication to CI
29GENETIC HL >50% non-syndromic 75% to 80% autosomal recessive 15% to 20% autosomal dominant1% to 2% is X-linked.<<1% mitochondrial inheritance
30Autosomal Recessive Disorders Usher syndrome Most common cause of congenital deafness50% deaf-blind in USAPathophy: unknown, could also be autosomal dominant, X-linkedSSx:Variable SNHL, progressive retinitis pigmentosaDx: Electroretinography
31Usher syndrome subtypes I: profound congenital SNHL, No vestibular response Blind by childhood, most commonII: moderate to severe SNHL, normal vestibular response, blind by early adulthoodIII: progressive SNHL, progressive vestibular dysfunction, varied progression in blindness
32Autosomal Recessive Disorders Pendred syndrome Pathophy: Defect in tyrosine iodination from pendrin (chloride/iodide transporter)OtoSSx: severe to profound SNHL, a/w Mondini deformity, dilated vestibular aqueducts.Other SSx: multinodular goiter in 8-14 yoDx: + perchlorate testRx: Thyroid supplement
33Autosomal Recessive Disorders Jervell and Lange-Nielsen Syndrome Pathophy: mutation in potassium channelOtoSSx: B severe to profound SNHLOther SSx: cardiac abnormalities, recurrent syncope, sudden deathDx: EKG ( prolonged QT, large T-wave)Rx: beta-blocker, HA
35Autosomal Recessive Disorders Goldenhar Syndrome Other SSx:Ocular: epibulbar dermoids, colobomas of upper eyelidsVertebral: fusion or absence of cervical vertebraeFacial asymmetryMild mental retardationDx: PE
37Autosomal Dominant Disorders Waardenberg Syndrome SubtypesI: + telecanthus, % SNHLII: -telecanthus, 57-85% SNHLIII: type 1 + hypoplasia or contracture of the upper limbs. (=Klein-Waardenburg syndrome)IV: WS + Hirschsprung disease (Waardenburg-Shah syndrome) autosomal recessiveDx: clinical H&P, family Hx
38Autosomal Dominant Disorders Stickler Syndrome =Progressive Arthro-OphthalmpathyPathophy: mutation in type II and type XI collagen, variable phenotype; 1:10,000OtoSSx: progressive SNHL, MHL ( from ETD of clefting)Other SSx:myopia, retinal detachmentMarfanoid habitusjoint hypermobilitiesMidline cleftingDx: clinical H&P, family Hx
45Sex-linked Disorders Alport Disease Pathophy: 80% X-linked or autosomal dominant/recessive. Abnormal Type IV collagen formation in glomerular basement renal failureOtoSSx: B degeneration of organ of Corti and stria slowly progressive SNHLOther SSx: hematuria, progressive nephritis, macular/corneal lesionsDx: skin or renal bx w/ electron microscopy, UARx: HD, renal transplant.