41. Change in hearing Flashcards
most common causes of hearing loss
ear wax, otitis media and otitis externa.
differentials hearing loss
Conductive hearing loss
(otitis media)
Glue ear
Otosclerosis
Impacted wax
Eustachian tube dysfunction
Sensorineural hearing loss
Presbycusis - Age related
Occupational
(Meniere’s disease)
(labyrinthitis) (Meningitis → labyrinthitis)
Drug toxicity
(Acoustic neuroma)
history taking hearing loss
examination hearing loss
causes conductive hearing loss
(otitis media)
Glue ear
Otosclerosis
Impacted wax
Eustachian tube dysfunction
causes sensorineural hearing loss
Presbycusis - Age related
Occupational
(Meniere’s disease)
(labyrinthitis) (Meningitis → labyrinthitis)
Drug toxicity
(Acoustic neuroma)
what is primary tinnitus
no identifiable cause and often occurs with sensorineural hearing loss
what is secondary tinnitus?
identifiable cause:
Impacted ear wax
Ear infection
Ménière’s disease
Noise exposure
Medications (e.g., loop diuretics, gentamicin and chemotherapy drugs such as cisplatin)
Acoustic neuroma
Multiple sclerosis
Trauma
Depression
what systemic conditions can cause tinnitus
Anaemia
Diabetes
Hypothyroidism or hyperthyroidism
Hyperlipidaemia
red flags tinnitus
Unilateral tinnitus
Pulsatile tinnitus
Hyperacusis (hypersensitivity, pain or distress with environmental sounds)
Associated unilateral hearing loss
Associated sudden onset hearing loss
Associated vertigo or dizziness
Headaches or visual symptoms
Associated neurological symptoms or signs (e.g., facial nerve palsy or signs of stroke)
Suicidal ideation related to the tinnitus
Invetsigation tinnitus
Full blood count (anaemia)
Glucose (diabetes)
TSH (thyroid disorders)
Lipids (hyperlipidaemia)
Audiology can be used to assess the hearing in detail and help establish the underlying cause.
Imaging (e.g., CT or MRI) may be rarely required to investigate for underlying causes such as vascular malformations or acoustic neuromas.
management tinnitus
Tinnitus tends to improve or resolve over time without any interventions.
Underlying causes of tinnitus can be treated, such as impacted ear wax or infection.
Several measures can be used to help improve and manage symptoms:
Hearing aids
Sound therapy (adding background noise to mask the tinnitus)
Cognitive behavioural therapy
newborn hearing test
Otoacoustic emission test
what test is done if otoacoustic emission test is abnormal
Auditory Brainstem Response test
hearing 6-9 months
Distraction test
heairng testing > 3 years
Pure tone audiometry
complications of hearing impairment/unrecognised hearing impairment in children
Poor speech development
Impaired learning
Mental health
Learning difficulties
causes of hearing loss in chidlren
Congenital:
Maternal rubella or cytomegalovirus infection during pregnancy
Genetic deafness can be autosomal recessive or autosomal dominant
Associated syndromes, for example Down’s syndrome
Perinatal:
Prematurity
Hypoxia during or after birth
After birth:
Jaundice
Meningitis and encephalitis
Otitis media or glue ear
Chemotherapy
audiogram interpretation
20dB
anything above the 20dB line is normal
sensioneural = bone and air impaired so both below line
conduction = only air is impaired so air below line and bone above line
what is glue ear
otitis media with effusion. The middle ear becomes full of fluid, causing a loss of hearing in that ear.
ototscopy glue ear
dull tympanic membrane with air bubbles or a visible fluid level, although it can look normal.
investigation glue ear
Referral for audiometry to help establish the diagnosis and extent of hearing loss.
management glue ear
- active observation: the management for a child with a first presentation of otitis media with effusion is active observation for 3 months - no intervention is required
- grommet insertion - to allow air to pass through into the middle ear and hence do the job normally done by the Eustachian tube. The majority stop functioning after about 10 months
- adenoidectomy
Presentation eustachain tube dysfunction
PC: reduced or altered hearing, popping noises/sensations in ear, fullness in ear, pain/discomfort, tinnitus
pathophysiology eustachian tube dysfunction
When the Eustachian tube is not functioning correctly or becomes blocked, the air pressure cannot equalise properly and fluid cannot drain freely from the middle ear. The air pressure between the middle ear and the environment can become unequal. The middle ear can fill with fluid.
invetsigation eustachain tube dysfunction
If typical history and trigger:
clinical diagnosis
If persistent:
Tympanometry, audiometry, nasopharyngoscopy, CT
management eustachian tube dysfunction
Will resolve spontaneously with no treatment
Valsalva manoeuvre (holding the nose and blowing into it to inflate the Eustachian tube)
Decongestant nasal spray
Antihistamine and a steroid nasal spray for allergic rhinitis
Otovent is an over the counter device where the patient blows into a balloon using a single nostril, which can help inflate the Eustachian tube, clear blockages and equalise pressure.
Surgical
Treating any other pathology that might be causing symptoms, for example, adenoidectomy (removal of the adenoids)
Grommets
Balloon dilatation Eustachian tuboplasty
what is otosclerosis
Otosclerosis describes the replacement of normal bone by vascular spongy bone.
It causes a progressive conductive deafness due to fixation of the stapes at the oval window.
inheritance otosclerosis
Otosclerosis is autosomal dominant and typically affects young adults
presentation otosclerosis
Onset is usually at 20-40 years - features include:
conductive deafness
tinnitus
tympanic membrane
the majority of patients will have a normal tympanic membrane
10% of patients may have a ‘flamingo tinge’, caused by hyperaemia
positive family history
management otosclerosis
hearing aid
stapedectomy
management impacted ear wax
olive oil
sodium bicarbonate 5%
almond oil
how may impacted ear wax present
pain
conductive hearing loss
tinnitus
vertigo
sudden onset sensorineural hearing loss plan
urgent referral to ENT.
The majority of SSNHL cases are idiopathic.
High-dose oral corticosteroids are used by ENT for ALL cases of SSNHL.
what type of HL does otosclerosis cause
conductive
what type of HL does presbycusis cause
SN
what type of noise is difficult to hear presbycusis
high-frequency hearing is affected bilaterally, which can lead to conversational difficulties, particularly in noisy environments.
what type of noise is difficult to ehar in otoscleorsis
It tends to affect the hearing of lower-pitched sounds more than higher-pitched sounds. Female speech may be easier to hear than male speech (due to the generally higher pitch). This is the reverse of the pattern seen in presbycusis.
pathophysiology presbycusis
sensory hair cells and neurons in the cochlea atrophy over time
The precise cause is unknown however is likely multifactorial
Arteriosclerosis: May cause diminished perfusion and oxygenation of the cochlea, resulting in damage to inner ear structures
Diabetes: Acceleration of arteriosclerosis
Accumulated exposure to noise
Drug exposure (Salicylates, chemotherapy agents etc.)
Stress
Genetic: Certain individuals may be programmed for the early ageing of the auditory system
presentation presbycusis
chronic, slowly progressing history of:
Speech becoming difficult to understand
Need for increased volume on the television or radio
Difficulty using the telephone
Loss of directionality of sound
Worsening of symptoms in noisy environments
Hyperacusis: Heightened sensitivity to certain frequencies of sound (Less common)
Tinnitus (Uncommon)
investigations presbycusus
Audiometry
what frequencies are particualrly affected occupational hearing loss
3000-6000 Hz
what drugs are ototoxic
aminoglycosides (e.g. Gentamicin), furosemide, aspirin and a number of cytotoxic agents
What is the nerve found within the middle ear?
facial nerve
