docTopics - Meningitis Research Foundation
download 
Report Transcription
Topics - Meningitis Research Foundation
Hearing Loss and Meningitis Gerard O´Donoghue Professor of Otology and Neurotlogy, Queen’s Medical Centre, Nottingham Co-Director, National Biomedical Research Unit in Hearing,NIHR Meningitis Research Foundation, London, November 2009 Topics Historical Perspective The temporal bone – meningitis ‘highways’ Labyrinthitis ossificans Hearing Loss - characterisitics Cochlear Implants Herman Knapp 1871 Inflammatory infections of inner ear 3 autopsy studies – meningitis Purulence in labyrinth Herman Knapp 1871 Loss of sensory neuroepithelium Knapp 1873 Meningitis Deafness: Prevalence Experimental Meningitis & Labyrinthitis Honda 1927 Routes of infection Time course Inner ear immune response Lebel et al 1988 Dexamethasone therapy for bacterial meningitis Two double-blind, placebo controlled trials Topics Historical Perspective The temporal bone – meningitis ‘highways’ Labyrinthits ossificans Hearing Loss - characterisitics Cochlear Implants The Temporal Bone Dural coverings temporal bone Anatomical ‘Highways’: Meninges Inner ear Cochlear Aqueduct HF Schuknecht & AJ Gulya (1986) Anatomical ‘Highways’: Meninges Inner ear Rosenthal’s Canal HF Schuknecht & AJ Gulya (1986) Anatomical ‘Super - Highways’: Meninges Inner ear Malformation Topics Historical Perspective The temporal bone – meningitis ‘highways’ Labyrinthitis ossificans Hearing Loss - characterisitics Cochlear Implants Labyrnthitis ossificans - CT Normal CT Cochlea Ossified cochlea Labyrnthitis ossificans - MRI Normal Ossified Topics Historical Perspective The temporal bone – meningitis ‘highways’ Labyrinthitis ossificans Hearing Loss - characterisitics Cochlear Implants Characteristics Hearing loss Conductive Sensorineural Conductive Sensorineural Characteristics Hearing loss Occurs early (Kaplan et al 1984, Vienny 1984) Incidence 10% ; [Severe profound 5%] Baraff et al 1993 May be transient, unilateral Dexamethasone reduces risk hearing loss Lebel 1988 Ossification – onset variable Hearing loss predisposes (rr 5.0) Parner et al 2007 Topics Historical Perspective The temporal bone – meningitis ‘highways’ Labyrinthits ossificans Hearing Loss - characterisitics Cochlear Implants Cochlear Implants – ‘by pass’ Cochlear Implants – ‘by pass’ Cochlear Implants Beth: post meningitis : 18 mo. Cochlear Implants Beth: Post Implant - Age 16y Cochlear Implantation and Meningitis Severe to profound deafness Risk of ossification - early referral Capitalises on established language Partially restores hearing Other disablities affect prognosis Post-implantation meningitis:vaccination NICE 2009 : bilateral implantation routine Thank you