Ear, Nose + Throat Flashcards
what is pure tone audiometry / tympanometry / evoked response audiometry?
Pure tone audiometry (PTA)
• Headphones deliver tones at different
frequencies and strengths in a sound-proofed
room.
• Pt. indicates when sound appears and
disappears.
• Mastoid vibrator → bone conduction threshold.
• Threshold at different frequencies are plotted to
give an audiogram.
Tympanometry
• Measures stiffness of ear drum
- Evaluates middle ear function
• Flat tympanogram: mid ear fluid or perforation
• Shifted tympanogram: +/- mid ear pressure
Evoked response audiometry
• Auditory stimulus ¯c measurement of elicited
brain response by surface electrode.
• Used for neonatal screening (if otoacoustic
emission testing negative)
otitis externa
Otitis Externa Presentation • Watery discharge • Itch • Pain and tragal tenderness Causes • Moisture: e.g. swimming • Trauma: e.g. fingernails • Absence of wax • Hearing aid Organisms • Mainly pseudomonas • Staph aureus
steroid +/- abx ear drops
malignant otitis externa
Malignant Otitis Externa • Life-threatening infection which can → skull osteomyelitis • 90% of pts. are diabetic (or other immune compromise) • Presentation § Severe otalgia which is worse @ night § Copious otorrhoea § Granulation tissue in the canal • Rx § Surgical debridement § Systemic Abx
TMJ dysfunction
TMJ Dysfunction Symptoms • Earache (referred pain from auriculotemporal N.) • Facial pain • Joint clicking/popping • Teeth-grinding (bruxism) • Stress (assoc. ¯c depression) Signs • Joint tenderness exacerbated by lateral movements of an open jaw. Investigation • MRI Management • NSAIDs • Stabilising orthodontic occlusal prostheses
acute otitis externa vs acute otitis media
otitis externa - more likely in summer, tragus movement painful, ear canal swollen, eardrum NORMAL, discharge, fever, hearing may be normal
otitis media - more likely winter, tragus not painful, ear canal normal, eardum bulging or perforated, fever, hearing always worse
classify otitis media
Classification
• Acute: acute phase
• Glue ear / OME: effusion after symptom regression
• Chronic: effusion > 3mo if bilat or > 6mo if unilat
• Chronic suppurative OM: Ear discharge ¯c hearing
loss and evidence of central drum perforation
Organisms • Viral • Pneumococcus • Haemophilus • Moraxella
acute otitis media summary
Acute OM Presentation • Usually children post viral URTI • Rapid onset ear pain, tugging @ ear. • Irritability, anorexia, vomiting • Purulent discharge if drum perforates o/e • Bulging, red TM • Fever Rx • Paracetamol: 15mg/kg • Amoxicillin: may use delayed prescription
complications of otitis media
Complications • Intratemporal § OME § Perforation of TM § Mastoiditis § Facial N. palsy • Intracranial § Meningitis / encephalitis § Brain abscess § Sub- / epi-dural abscess • Systemic § Bacteraemia § Septic arthritis § IE
otitis media with effusion
OME Presentation • Inattention at school • Poor speech development • Hearing impairment o/e • Retracted dull TM • Fluid level Ix • Audiometry: flat tympanogram Rx • Usually resolves spontaneously, • Consider grommets if persistent hearing loss § SE: infections and tympanosclerosis
chronic supparative otitis media
Chronic Suppurative OM Presentation • Painless discharge and hearing loss o/e • TM perforation Rx • Aural toilet • Abx / Steroid ear drops Complications • Cholesteatoma
mastoiditis
Mastoiditis • Middle-ear inflam → destruction of mastoid air cells and abscess formation. Presentation • Fever • Mastoid tenderness • Protruding auricle Imaging: CT Rx • IV Abx • Myringotomy ± mastoidectomy
cholesteatoma presentation
Definition • Locally destructive expansion of stratified squamous epithelium within the middle ear. Classification • Congenital • Acquired: 2O to attic perforation in chronic suppurative OM Presentation • Foul smelling white discharge • Headache, pain • CN Involvement § Vertigo § Deafness § Facial paralysis
cholesteatoma o/e treat
o/e • Appears pearly white ¯c surrounding inflammation Complications • Deafness (ossicle destruction) • Meningitis • Cerebral abscess Mx • Surgery
tinnitus causes
Tinnitus • Sensation of sound w/o external sound stimulation Causes • Specific § Meniere’s § Acoustic neuroma § Otosclerosis § Noise-induced § Head injury § Hearing loss: e.g. presbyacusis • General § ↑BP § ↓Hb • Drugs § Aspirin § Aminoglycosides § Loop diuretics § EtOH
hx and exam tinnitus
Hx • Character: constant, pulsatile • Unilateral: acoustic neuroma • FH: otosclerosis • Alleviating/exacerbating factors: worse @ night? • Associations § Vertigo: Meniere’s, acoustic neuroma § Deafness: Meniere’s, acoustic neuroma • Cause: head injury, noise, drugs, FH Examination • Otoscopy • Tuning fork tests • Pulse and BP
inv and manage tinnitus
Ix
• Audiometry and tympanogram
• MRI if unilateral to exclude acoustic neuroma
Mx
• Treat any underlying causes
• Psych support: tinnitus retraining therapy
• Hypnotics @ night may help
vertigo causes
Definition • The illusion of movement Causes Peripheral / Vestibular Central • Meniere’s • Acoustic neuroma • BPV • MS • Labyrinthitis • Vertebrobasilar insufficiency / stroke Head injury • Inner ear syphilis Drugs (central/ototoxic) • Gentamicin • Loop diuretics • Metronidazole • Co-trimoxazol
hx, exam, tests vertigo
Hx • Is it true vertigo or just light-headedness? § Which way are things moving? • Timespan • Assoc. symptoms: n/v, hearing loss, tinnitus, nystagmus Examination and Tests • Hearing • Cranial nerves • Cerebellum and gait • Romberg’s +ve = vestibular or proprioception • Hallpike manouvre • Audiometry, calorimetry, LP, MRI
meniere’s presentation
Ménière’s Disease Pathology • Dilatation of endolymph spaces of membranous labyrinth (endolymphatic oedema) Presentation • Attacks occur in clusters and last up to 12h. • Progressive SNHL • Vertigo and n/v • Tinnitus • Aural fullnes
meniere’s inv and manage
Ix • Audiometry shows low-freq SNHL which fluctuates Rx • Medical § Vertigo: cyclizine, betahistine • Surgical § Gentamicin instillation via grommets § Saccus decompression
vestibular neuronitis
Vestibular Neuronitis / Viral Labyrinthitis Presentation • Follows febrile illness (e.g. URTI) • Sudden vomiting • Severe vertigo exacerbated by head movement Rx • Cyclizine • Improvement in days
BPPV presentation
Pathology • Displacement of otoliths in semicircular canals • Common after head injury. Presentation • Sudden rotational vertigo for <30s - Provoked by head turning • Nystagmu
BPPV inv and treat and causes
Causes • Idiopathic • Head injury • Otosclerosis • Post-viral Dx • Hallpike manoeuvre → upbeat-torsional nystagmus Rx • Self-limiting • Epley manoeuvre • Betahistine: histamine analogue
categorise conductive causes of adult hearing loss
Conductive • Impaired conduction anywhere between auricle and round window. External canal obstruction • Wax • Pus • Foreign body TM perforation • Trauma • Infection Ossicle defects • Otosclerosis • Infection • Trauma
categorise sensineural causes of adult hearing loss
Sensorineural • Defects of cochlea, cohlear N. or brain. Drugs • Aminoglycosides • Vancomycin Post-infective • Meningitis • Measles • Mumps • Herpes Misc. • Meniere’s • Trauma • MS • CPA lesion (e.g. acoustic neuroma) • ↓B12
acoustic neuroma present
Acoustic Neuroma / Vestibular Schwannoma
Pathology
• Benign, slow-growing tumour of superior vestibular N.
• Acts as SOL → Cerebellopontine angle syndrome
§ 80% of CPA tumours
• Assoc. ¯c NF2
Presentation
• Slow onset, unilat SNHL, tinnitus ± vertigo
• Headache (↑ICP)
• CN palsies: 5,7 and 8
• Cerebellar signs
acoustic neuroma inv and manage
Ix • MRI of cerebellopontine angle § MRI all pts. ¯c unilateral tinnitus / deafness • PTA Differential • Meningioma • Cerebellar astrocytoma • Mets Rx • Gamma knife (RadioT) • Surgery (risk of hearing loss)
otosclerosis summary
Otosclerosis
• AD condition characterised by fixation of stapes at the
oval window.
• F>M=2:1
Presentation
• Begins in early adult life
• Bilateral conductive deafness + tinnitus
• HL improved in noisy places: Willis’ paracousis
• Worsened by pregnancy/ menstruation/ menopause
Ix
• PTA shows dip (Caharts notch) @ 2kHz
Rx
• Hearing aid or stapes impla
