Ear Flashcards
Describe the structure of the External Auditory Meatus
Sigmoid shaped tube
External 1/3 Cartilage
Internal 2/3 Temporal Bone
Describe the structure of the Tympanic Membrane
Skin on the external surface and mucous membrane on the inside
Connected to surrounding temporal bone by cartilagenous ring
Parts include: Pars Tensa, Pars Flaccida, Anterior and Posterior Malleolar fold
Describe the blood supply to the External Ear
Branches of ECA (Posterior Auricular, Superficial Temporal, Occipital, Maxillary)
Name the four nerves innervating the External Ear
Auriculotemporal
Greater Auricular Nerve
Lesser Occipital
Auricular branch of vagus
How would bites of the external ear be managed?
Wounds left open, irrigated, abx given
Why does a Pinna Haematoma require urgent ENT referral?
Disrupts overlying vessels in the Perichondrium which can lead to avascular necrosis (and cauliflower ear)
How is Tympanic Membrane perforation managed?
Traumatic - Watch and wait for 6 weeks, avoid water, after this if persisting then refer for myringoplasty
Non traumatic (eg post OM) - Antibiotics, water avoidance, and review in 6 months
What is a Haemotympanum?
Blood in the middle ear often associated with Temporal Bone Fracture
Conservatively managed but followed up to check for residual damage
Name the two parts of the middle ear
Tympanic Cavity (containing Malleus, Incus, Stapes)
Epitympanic Recess (superior to Tympanic Cavity near mastoid air cells)
Where does Stapes connect to?
Oval Window of middle ear
What is the purpose of Mastoid Air Cells?
Buffer system of air
Release air if pressure becomes too low
Two muscles are involved in the Acoustic Reflex. What is this and name the muscles involved.
Protective muscles contract in response to loud noises
Tensor Tympani and Stapedius
What is the role of the Eustacian Tube?
Connects middle ear to Nasopharynx, equalising pressure
Otitis Media can be Acute or Chronic. How can Chronic Otitis Media be subclassified?
- Active Mucosal (discharge through perforation)
- Inactive Mucosal (perforation but no discharge)
- Active Squamous (cholesteotoma)
- Inactive Squamous (retraction pocket)
What are the two main roles of the Inner Ear?
Converts mechanical signals into electrical
Maintains balance by detecting position and motion
There are two main components of the Inner Ear. Describe the Bony Labyrinth
Cochlea, Vestibule and three Semicircular Canals
Lined internally with Periosteum and contains Perilymph
There are two main components of the Inner Ear. Describe the Membranous Labyrinth
Lies within the Bony Labyrinth
Contains Endolymph
Cochlear duct, Semicircular Ducts, Utricle, Saccule
Describe the structure of the Vestibule
Central part of the bony labyrinth
Separated from middle ear by oval window
Contains Saccule and Utricle
Describe the structure of the Cochlea
Twists around a central portion of bone called the Midiolus
Spiral lamina bone attaches to cochlear duct
Two perilymph filled chambers (Scala Vestibuli, Scale Tympani)
Describe the structure of the Semicircular Canals
Anterior, Lateral and Posterior
Swelling at one end known as Ampulla
What is the Cochlear Duct?
Sits within the Cochlea and is the organ of hearing
Epithelial cells of hearing - Organ of Corti
What are the Saccule and Utricle?
Two membranous sacs which are organs of balance
Utricle connects to Semicircular Canals and senses position side to side
Saccule recieves cochlear duct and senses upwards and downwards movement
Endolymph drains from here
Describe the distribution of CNVIII
Forms Vestibular Ganglion which splits into superior and inferior parts to supply: Saccule, Utricle, Semicircular Canals
Cochlea portion: Enters at base of Mediolus to supply receptors of Organ of Corti
What is the time frame description for Otitis Externa?
Acute <3 weeks
Chronic >3 months
Describe the protective mechanisms of the External Ear
- Elastic cartilage has protective hairs
- Self cleansing via Epithelial Escalator
- Ear wax
Ear wax is composed of Epithelial Cells, Lysozymes and Oily Secretions. Name four roles
- Cleaning and lubrication
- Protection from bacteria/dust/insects
- Acidic coat inhibits microbial growth
- Hydrophobic coat prevents water reaching canal skin
Name four risk factors for Otitis Externa
Hot and Humid Climates
Swimming
Immunocompromised
Insufficient or Excessive wax
What organisms are implicated in Otitis Externa?
90% Bacterial (S.Aureus, Pseudomonas)
10% Fungal (aspergillous - after prolonged abx)
Herpes Zoster
Name four non infective causes of Otitis Externa
Acne
Eczema
Psoriasis
Ear Plugs (irritants)
Name four symptoms of Otitis Externa
Pain
Itching
Hearing Loss
?Discharge
Name three signs OE of Otitis Externa
Inflamed External Canal
Scaly Skin
Pre-auricular LN
Necrotising Otitis Externa is a subtype of Otitis Externa. Define it
Extension into Mastoid or Temporal Bones (often in immunocompromised, elderly or diabetic)
How does Necrotising Otitis Externa present?
Discharge
Jaw Pain
Headache of great intensity
Facial nerve palsy - if osteomyelitis
How would you investigate Necrotising Otitis Externa?
Bone Scan
CT
How would you manage Necrotising Otitis Externa?
Prolonged Abx
Piperacillin- Tazobactam
Ciprofloxacin if pen allergic
You would only investigate Otitis Externa if it was atypical or non responding. How would you do this?
Ear Swab
Test integrity of membrane - can they taste something put in ear, can they blow out when nose is pinched
How is Otitis Externa managed?
Remove any debris
First line topical Abx (Cipro)+/- Steroids
Severe - Oral Flucloxacillin (if systemically unwell)and Topical Abx
What general advise should you give patients with Otitis Externa?
Use ear plugs when swimming
Keep ears clean and dry
Avoid swimming for 7-10d
What is Recurrent AOM?
> 3 distinct episodes of AOM in the past 6 months
Name the common organisms implicated in AOM
Haemophilus Influenza
Strep Pneumoniae
Rhinovirus
RSV
Name four risk factors for AOM
Smoking
URTI
Eustacian Tube Dysfunction
Craniofacial Abnormalities
Name three presenting features of AOM
Otalgia (tugging at ear)
Fever
Hearing Loss
Give three differentials for AOM
Trigeminal Neuralgia
TMJ dysfunction
GCA
What might you see on Otoscope of AOM
Red/Cloudy TM
Air fluid level
How would you immedately managed AOM?
Simple analgesia
Delayed Abx (5d Amoxicillin - not delayed if systemic sx or at risk)
When would you admit patients with AOM?
Severely systemically unwell
Suspected complications
<3m with temp >38
When would you refer a patient with AOM to ENT?
If recurrent in the present of persistant symptoms/persistent cervical lymphadenopathy/unilateral epistaxis
Name three complications of AOM
Tympanic perforation
Hearing loss
Labyrinthitis
What is Otitis Media with Effusion?
Results from either incomplete resolution of AOM or non infective obstruction of Eustacian Tube
Relative negative pressure in the ear canal drops leading to fluid accumulation
Name four risk factors for Otitis Media with Effusion
Chronic allergy
Sinusitis
Deviated septum
Enlarged tonsils
Name four presenting features of Otitis Media with Effusion
Rarely Otalgia
Fullness
Pressure popping
Poor speech development
What would you see on Otoscopy of Otitis Media with Effusion
Retracted Straw Coloured Tympanic Membrane
Adults with Otitis Media with Effusion should be fully investigated as it is rare. Name two investigations
FNE
Tympanogram
Tympanograms measure compliance of TM by inserting a probe. Describe the three possible results
Type A - Peaks at 0 (normal)
Type B - Flat (Middle ear effusion - eg OME or perforation)
Type C - Tracing peaks at negative pressure (Eustacian Tube Dysfunction)
Name the management options for Otitis Media with Effusion
Valsalva for temporary relief
Grommets
Adenoidectomy
Laser Myringotomy
Normally resolves in 6-12 weeks
Cholesteotomas normally form due to dysfunctional eustacian tube. Describe the formation
Negative pressure pulls Pars Flaccida backwards, allowing epithelial cells to become trapped and proliferate
Osteolytic enzyme release can cause bony destruction
The majority of cases of Cholesteotoma are Primary Acquired. Describe the aetiologies of Congenital and Secondary Acquired.
Congenital - Squamous epithelium becomes trapped in temporal bone during embryogenesis
Secondary - Insult to TM (as a result of trauma, surgery or Otitis Media)
Name four presenting features of Cholesteotoma
Progressive hearing loss
Foul smelling painless otorrhoea
Vertigo
Headache
How is a Cholesteotoma investigated?
Otoscope - pearly white mass behind TM, pus filled canal with granulation tissue
Audiological tests
CT - assesses bone invasion and how successful surgery would be
What are the two surgical options for Cholesteotoma?
Open (Tympanomastoidectomy)
Closed (Tympanoplasty)
What is the difference between Vestibular Neuritis and Labyrinthitis?
Vestibular Neuritis only affect vestibular nerve
Labyrinthitis affects vestibular nerve and labyrinth
Vestibular Neuritis will not alter hearing
What causes Vestibular Neuritis?
Reactivation of latent type 1 HSV in Vestibular Ganglion
Commonly preceded by URTI
What causes Labyrinthitis?
Usually viral in origin
Bacterial is dangerous (passes between anatomical connections)
May be associated with systemic disease
How does Vestibular Neuritis present?
Sudden spontaneous vertigo
Nausea and Vomiting
How does Labyrinthitis present?
Sudden spontaneous vertigo
Nausea and Vomiting
Hearing Loss
Tinnitus
Name three clinical investigations you could do for suspected Labyrinthitis/VN
Head Impulse Test
Nystagmus (consistent and unilateral)
Skew
What is the Head Impulse Test?
Fix patients gaze on your nose then move their head sharply
Patient should maintain gaze, not lag (saccades)
Not +ve in stroke
How is Labyrinthitis investigated?
Culture and sensitivity if middle ear effusions are present
CT - Mastoiditis
How is Labyrinthitis managed?
Sudden unilateral hearing loss - Emergency ENT
Reassurance - lie still in acute attacks and become mobile as soon as possible
Medication - Prochloperazine or Antihistamines
What is Menieres Disease?
Distension of membranous labyrinth due to excess endolymph
Risks - Allergies, Autoimmunity, Genetic succeptibility
Describe the diagnostic criteria for Menieres
2 x 20 minute vertigo
Hearing Loss
Tinnitus and /or aural fullness
Name five investigations for Menieres
Full Neurological exam Pure tone audiometry MRI IAM Video Head Impulse testing ECG
What is an important management step in Menieres?
Inform DVLA
How should acute attacks in Menieres disease be managed?
Prochlorperazine
IM Steroid injection (followed by tapered oral)
Describe the prophylactic management of Menieres
Low salt
Low caffiene
Trial of betahistine or diuretics
Describe the surgical management of Menieres
Endolympatic Sac Decompression
Labyrinthectomy (causes loss of hearing)
What does BPPV stand for?
Benign Paroxysmal Positional Vertigo
Describe the pathophysiology of BPPV
Hairs embedded in Otoliths experience the movement of endolymphs depending on position
If otoliths become detached, there will still be movement - vertigo
Normally idiopathic but can occur after head injury
Name four risk factors for BPPV
Older Age
Women
Menieres (co diagnosis in 30%)
Anxiety Disorders
How does BPPV present?
Vertigo promoted by head movement
Attacks are sudden onset and last 20-30 seconds
Nausea
Symptoms worse in morning
What would you want to examine in BPPV
Cranial Nerve
External Ear
Tympanic Membrane
What is the diagnostic test for BPPV?
Dix Hallpike
Sit patient up so they’re looking at you at a 45 degree angle, then suddenly lower so head is off the bed
Observe for nystagmus
What does the direction of Nystagmus in BPPV indicate about the canals?
Vertical and Rotary - Posterior Canal
Horizontal - Horizontal canal
BPPV is self limiting over a number of weeks but can reoccur. What should you advise the patient?
Notify DVLA
Get out of bed slowly
Epleys Manouvre (Dix Hallpike but wait for Nystagmus to subside then rotate 90 degrees and sit patient up)
Give a differential diagnosis for BPPV
Vestibular Migraine
Name two other causes of hearing loss
Acoustic Neuroma
Otosclerosis
Otosclerosis is caused by the pathological increased bone turnover. Give four risk factors
Genetics (Autosomal Dominant)
Oestrogen
Viral
Lack of fluoride
How does Otosclerosis present?
Progressive hearing loss and tinnitus
Low volume speech
Stapes gradually becomes adhered to oval window
How is Otosclerosis managed?
Bilateral hearing aids
Bisphosphonates or NaF
Stapedectomy or Stapedotomy
What is Tinnitus?
The perception of sound when no external sound is present
Most people hear tinnitus at some pint but it is usually masked by external sounds
There are two types of tinnitus: Pulsatile and Non Pulsatile. What is Pulsatile tinnitus ?
Synchronous with heartbeat due to turbulent flow reaching cochlea
Causes: Carotid Atherosclerosis, AV Malformation, Pagets, Otosclerosis
There are two types of tinnitus: Pulsatile and Non Pulsatile. What is Non Pulsatile tinnitus ?
Buzzing/high pitched/clicking
Causes: Presbyacusis, Menieres, Drugs
Name three drugs associated with Tinnitus
Loop Diuretics
NSAIDs
Salicyclates
How is Tinnitus investigated?
MRI (if unilateral to exclude Acoustic Neuroma)
Pulsatile - CT/MR Angiography
Tinnitus Functional Index
How is Tinnitus managed?
Reassurance
Address underlying cause
Coping mechanisms/Noise generator
Name three causes of Conductive Hearing Loss
Excess earwax
OME
Otosclerosis
Name three causes of Sensorineural Hearing Loss
Presbyacusis
Noise Induced
Acoustic Neuroma
Aside from Webers and Rinnes, Pure Tone Audiometry is used to investigate reduced hearing. What is this?
Evaluates the quietest sound that can be heard in each ear
Must exclude wax/infection beforehand
Describe the difference in audiometry graphs between Presbyacusis and Menieres
Menieres - hearing loss at a lower frequency
Presbyacusis - hearing loss at a higher frequency
Describe four surgical management options for reduced hearing
Bone anchored hearing aid
Cochlea Implant
Stapedectomy and Prosthesis
Tympanoplasty
Give three management options for excess wax
Topical Olive Oil/Sodium Bicarbonate
Microsuction
Syringing
Name three congenital and two acquired causes of childhood deafness
Congenital - Rubella, Ear Atresia, Ossicular Abnormalities
Acquired - Hypoxia, Jaundice, Meningitis, Head Injury
What is Ramsey Hunt Syndrome?
Reactivation of Herpes Zoster in geniculate ganglion
What are the motor branches of the facial nerve?
Within facial canal - Nerve to Stapedius
Prior to Parotid - Posterior Auricular, Nerve to Digastic, Nerve to Omohyoid
Within Parotid - Temporal, Zygomatic, Buccal, Mandibular, Cervical
Name five clinical features of Ramsay Hunt Syndrome
- Vesicular rash on ipsilateral ear/hard palate/ anterior 2/3 of tongue
- Hearing loss
- Ipsilateral facial weakness
- Drooling
- Hyperacusis
How is facial paralysis graded?
House Brackmann (I - IV)
Ramsey Hunt Syndrome is a clinical diagnosis. What features would point towards an alternative?
Systemic Illness
Hearing abnormalities
Forehead sparing
What are the main management points for Ramsey Hunt Syndrome?
Analgesia
Steroids +PPI
Aciclovir
Eye care
What particular things would you want to note in a child with reduced hearing?
Age of first word Milestones Vocab extent Pain/Discharge Imbalance DH
Name three syndromes that include deafness
Waadenberg (+Heterochromia and wide nasal bridge)
Jervell Lange Nielson
CHARGE
What is an electronic hearing aid?
Consists of ear piece, amplifier and microphone
T Setting - allows electromagnetic induction to block background noise
Why do Electronic Hearing Aids work better for conductive hearing loss?
Sensorineural causes recruitment - loud sounds are heard exceptionally loudly
Name three disadvantages to electronic hearing aids
Feedback
Otorrhoea
Dead Battery
Name two environmental aids to help deaf people
Doorbells changed to buzzers/flashing lights
Telephones can be fitted with T Induction
Name three conditions to avoid in someone who has to lip read
Poor background lighting
Beard and Moustache
Covering face with hand
What is a Cochlear Implant?
Processor converts speech into electrical signals, transmitted to electrode in cochlea which then stimulates nerve
Used when abnormal cochlea but normal cochlear nerve
What is a contraindication to Cochlear Implant?
Middle ear infection
Give four otological causes of Otalgia
Otitis Externa
Furunculosis
Otitis Media
Acute Ototic Barotrauma
Name a non otological cause of Otalgia
Referred pain (Tonsillitis, Teeth, TMJ)
Name two causes of watery otorrhoea
Eczema of external ear
CSF
Name two causes of purulent otorrhoea
AOM
Furunculosis
Name two causes of bloody otorrhoea
Trauma
AOM
Name a cause of foul smelling otorrhoea
Cholesteotoma
Define Vertigo
Illusion of rotary movement - worse in the dark
The causes of vertigo can be diagnosed based on time frame. Give two causes of vertigo lasting ‘seconds’
Postural Hypotension
BPPV
The causes of vertigo can be diagnosed based on time frame. Give two causes of vertigo lasting ‘mins to hours’
Menieres
Labyrinthitis
The causes of vertigo can be diagnosed based on time frame. Give two causes of vertigo lasting ‘hours to days’
Ototoxicity
Central vestibular disease
Give three non otological causes of Vertigo
Migraine
TIA
Epilepsy
What are the three commonest causes of episodic vertigo?
BPPV
Menieres
Migraine
What would investigations of Otosclerosis show?
Tympanogram - normal type A
Pure Tone Audiometry - Carhart notch (dip at 2kHz)
Name five things you would want to determine in a Tinnitus History
PHUCD
Pulsation or non Hearing Loss Unilateral of Bilateral Constant or intermittent Dizziness
