Otology

Description

Specials (ENT) Flashcards on Otology, created by Liam Musselbrook on 04/12/2016.
Liam Musselbrook
Flashcards by Liam Musselbrook, updated more than 1 year ago
Liam Musselbrook
Created by Liam Musselbrook almost 8 years ago
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Resource summary

Question Answer
What is the difference between subjective and objective tinnitus? Subjective: perception of sound in the absence of an acoustic stimulus, only heard by patient Objective: noise generated by structures near the ear, can sometimes be heard by examiner, uncommon
What are the causes of subjective tinnitus? Disrupted auditory pathway -> abnormal neuronal activity in the auditory cortex Aucoustic trauma, Presbycusis Ototoxic drugs Meniere's disease Infections and CNS lesions Sometimes causes of conductive hearing loss
What are the causes of objective tinnitus? Turbulent flow of blood through Vascular middle ear tumour Dural arteriovenous malformations Muscle spasms/myoclonus of palatal or middle ear muscles
Otitis media with effusion (OME/'glue ear'): what is it? Sterile collection of fluid in middle ear Results in conductive hearing loss and flat tympanogram May follow an URTI and resolve spontaneously in a few weeks Most common in children
Treatment of OME Re-evaluate child at 3 months If glue still present grommets are inserted Grommets last on average 9 months Adenoidectomy reduces risk, not usually performed at 1st grommet insertion
Acute Suppurative Otitis Media Bacterial infection of middle ear Pus formation Painful outward bulging of eardrum Rutures and pus drains out of ear, eardrum heals within 4-5 days
Treatment of Acute Suppurative Otitis Media 1st line: Co-amoxiclav Myringotomy is required if failure to resolve or if facial nerve palsy/other neuro-otological complications develop
What is a cholesteatoma? Pouch formed in tympanic membrane filled with keratinising squamous epithelium. Gets infected with anaerobic bacteria and produce enzymes which can erode through local structures
Clinical features of cholesteatoma Main features = foul smelling discharge and hearing loss Other features are determined by local invasion: - vertigo - facial nerve palsy - cerebellopontine angle syndrome
What can a cholesteatoma erode through and what are the results from this? Ossicles - conductive deafness Lateral semicircular canal - vertigo Facial nerve - facial palsy Cochlea - sensorineural deafness Tegmen - intracranial abscess or sepsis Sigmoid sinus - thrombosis
What is tympanosclerosis? Calcification of collagenous scar tissue on tympanic membrane
What is otosclerosis? Familial condition Spongy bone formation around the oval window - as it grows it fuses with the stapes -> conductive deafness Treat by replacing stapes with prosthesis or hearing aid
Management of Chronic Suppurative Otitis Media Confined to middle ear - myringoplasty Involvement of mastoid - cortical mastoidectomy + myringoplasty
Pinna anatomy
Noise-induced hearing loss Temporary threshold shift - cochlear fatigue, reversible hearing loss within 2hrs of exposure Further exposure -> permanent shift Usually notch at 4Khz, 6Khz
What is obscure auditory dysfunction? Difficulty in understanding speech in the presence of noise, with clinically normal hearing thresholds and the absence of any obvious cause
How can Menieres disease present? Triad of: 1)Fluctuating and progressive sensorineural hearing loss 2) Tinnitus (louder in affected ear) 3) Recurrent vertigo (15mins-24hrs) Horizontal nystagmus, N+V
Management of Meniere's disease Inv: Pure tone audiometry + MRI Acute phase: Bucastem and rest Prophylaxis: Salt restriction and bendroflumethiazide Surgery: chemical neurectomy, vestibular nerve section, labyrinthectomy
Presbyacusis Sensorineural, progressive, high frequency hearing loss due to ageing Wear and tear on outer hair cells Usually bilateral and symmetrical Removes consonants from heard speech -> non-intelligible
What is an acoustic neuroma and how can it initially present? Vestibular schwannoma Benign NF2 is a risk factor Unexplained unilateral hearing loss and tinnitus, and vestibular (disequilibrium) symptoms
Management of acoustic neuroma Early as possible referral and treatment Inv: Pure tone audiometry and MRI/CT T: Gamma knife radiosurgery
What are the 3 types of otitis externa? Diffuse Furuncle Malignant
Features suggestive of severe inflammation in otitis externa - Red, oedematous ear canal which is narrowed and obscured by debris - Conductive hearing loss - Discharge - Regional lymphadenopathy - Cellulitis spreading beyond the ear fever
Diffuse Otitis Externa Generalized inflammation of ear canal Symptoms: pruritis, otalgia, swelling, otorrhoea, deafness (occlusion) Generalized (eczema, psoriasis) or localized (trauma)
Infective causes of Otitis Externa Bacterial: Pseudomonas (secondary colonisation), Staph aureus Fungal: Candida, Aspergillus Viral: Herpes zoster
Management of mild otitis externa (mild cases = mild discomfort and/or pruritus; no deafness or discharge) Topical acetic acid 2% spray
Management of more severe otitis externa 7 days of a topical antibiotic with or without a topical steroid
Furuncle Infection of hair follicle of the outer 1/3 of the the EAM Usually Staph. Red swelling from one aspect of the outer wall
Malignant Otitis Externa Aggressive Pseudomonas aeruginosa More common in diabetics or immunocompromised Spreads to the bone ->osteitis -> pain and VII, IX, X and XI cranial nerve palsies High dose IV antibiotics
Chondrodermatitis Nodularis Helicis (CNH) Painful, inflamed nodule of the ear, involving the cartilage and skin of the pinna Usually apex of helix
Management of CNH Biopsy to exclude carcinoma Conservative - reduce pressure on lesion Topical nitroglycerin and steroids, Cryotherapy Surgery
What is Ramsey-Hunt syndrome? Condition where reactivation of pre-existing Varicella Zoster virus occurs in the geniculate ganglion
How can Ramsey-Hunt syndrome present? Auricular pain is often the first feature Facial nerve palsy Vesicular rash around the ear Other features include vertigo and tinnitus
Management of Ramsey-Hunt syndrome? Oral aciclovir and corticosteroids
Above what value on an audiogram is considered 'normal'? 20dB
Cause of referred otalgia Due to one of five neural pathways (cranial nerve V, cranial nerve VII, cranial nerve IX, cranial nerve X, and via the second and third spinal segments, C2 and C3).
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