Dysfunction Of The Ear Flashcards
What is tinnitus?
Perception of abnormal ear or head noises not produced by an external stimulus often described as a ringing of the ears
What are some of the causes of tinnitus?
Noise induced hearing loss Presbycussis Hypertension Atherosclerosis Head injury Cochleae and labyrinthine inflammation or infection
Tinnitus May be due to abnormal firing of auditory receptors, dysfunction of cochleae neurotransmitter function or ionic balance. T/F?
True
What is vertigo?
A disorder of vestibular function in which there is an illusion of movement
Vertigo due to peripheral vestibular disorders tend to be severe but brief. How is central vestibular vertigo described?
Mild and constant, chronic in duration
What is menieres disease?
Auditory disease where there is sudden onset vertigo, low frequenting hearing loss and tinnitus, sensation of fullness in the inner ear
Ménière’s disease is idiopathic. T/F?
True
In Ménière’s disease there is overproduction of endolymph. T/F?
True
How does overproduction of endolymph cause Ménière’s disease symptoms?
The excess fluid provides pressure which causes distension and rupture of Reissners membrane and the release of potassium rich endolymph into the perilmphatic space causes further injury to the sensory and neural elements of the inner ear
What age if patient is most likely to present with Ménière’s disease?
Middle aged
In Ménière’s disease there are several acute attacks.T/F?
True
The Romberg year is often positive in patients with Ménière’s disease. What is this test?
Tests ability to stand with feet together and eyes closed
A positive Fakudq or unterberger test is often found in Ménière’s disease. What is this test?
Patient marches on the sport with eyes closed. They may be unable to stay in one spot and will move to the affected side
Nystagmus May be present in patients with Ménière’s disease. What is this?
Rapid involuntary eye movements
What type of hearing loss typically occurs in Ménière’s disease?
Sensinourinal
What are the differential diagnoses for Ménière’s disease?
Acoustic neuroma Vestibular migraine Vestibular neurons ‘tis Viral labyrinthitis Benign paroxysmal positional vertigo Vertebrobasilar insufficiency
There is a cure for Ménière’s disease. T/F?
False
How is Ménière’s disease treated?
Low salt diet Diuretics Limit caffeine and alcohol consumption Cease smoking Vestibular suppressants Anti emetics Tinnitus maskers Corticosteroids
What are tinnitus maskers?
Devices similar to hearing aids which produce an external sound to distract the patient from the internal tinnitus
What drugs are used as vestibular suppressants and about emetics in the treatment of Ménière’s disease?
Antihistamines
Phenothiazine
Anticholenergics
Benzodiazepine
What is an acoustic neuroma?
Benign rumour which grows from the vestibular component of CNVIII
Pathologically, what type of tumour is an acoustic neuroma?
Shwannoma
Acoustic neuromas can cause life threatening obstructive hydrocephalus. T/F?
True
The amount of hearing loss is related to the size of the acoustic neuroma. T/F?
False
What are the symptoms of an acoustic neuroma?
Unilateral sensinourinal hearing loss Unilateral facial weakness Tinnitus Metallic or reduced taste in affected side Increased or decreased tears on affected side Headache Diplopoda Swallowing difficulties Poor sound localisation
Nystagmus can be present with acoustic neuroma. T/F?
True
What imaging tests are used to diagnose an acoustic neuroma?
Gadolinium enhanced MRI or CT
What are the differential diagnoses of acoustic neuroma?
Meningioma
Epidermoid
Facial nerve schwannoma
Trigeminal schwannoma
How are acoustic neuromas treated?
Radiology and/or surgery
Why can acoustic neuromas cause symptoms related to the facial nerve?
Because as the rumour grows it can impact on the facial nerve which exists in close proximity to CN VIII in the internal acoustic Meatus
Chemotherapy is effective against acoustic neuromas. T/F?
False
Describe he retro sigmoid approach to surgery to treat an acoustic neuroma?
Part of the occipital bone behind the ear is removed to gain access to the tumours. The surgeon must go underneath the sigmoid sinus to reach the internal acoustic meatus. This approach can preserve hearing
What is a facial palsy?
Loss of muscle control on one side of the face which may be temporary or permanent
Facial weakness or paralysis is common following neurosurgery. How long might this persist?
6-12 months
What is otitis media with effusion?
Inflammation of the middle ear with the presence of fluid without signs of acute infection
What are the risk factors for otitis media?
Age between 3 months and 3 years premature birth male native american low socioeconomic status
What upper respiratory tract infections most commonly cause otitis media?
S.pneumonium
H.influenzae
Moraxella catarrhalis
Explain the pathophysiology behind the effusion seen in otitis media
Dysfunction of the Eustachian tube (perhaps caused by upper respiratory tract infection causing swelling of the pharyngeal tonsil around the opening of the Eustachian tube into the nasopharynx), traps the gas volume in the middle ear and some of this is absorbed by surrounding tissue leading to negative pressure in the middle ear. This negative pressure can cause fluid from the surrounding tissue to be sucked into the tympanic cavity resulting in effusion. This fluid can act as a good medium for the growth of bacteria
Otitis media with effusion is often asymptomatic. T/F?
True
What are the signs and symptoms of otitis media with effusion?
Mild, intermittent ear pain Ear fullness Ear popping hearing loss causing lack of attentiveness, behavioural changes and failure to response to conversation ear rubbing excessive irritability sleep disturbances balance problems / unexplained clumsiness delayed speech/language development
Describe the appearance of the tympanic membrane in otitis media?
Discolouration, opacification
decreased or absent motility of the membrane
Most cases of otitis media with effusion resolve spontaneously within what time period?
3 week to 3 month period
What are the medical treatments for otitis media with effusion?
Antibiotics
Corticosteroids
Describe the use of grommets in otitis media with effusion?
May be indicated if effusion is present for more than 4 months
grommet is inserted into the tympanic membrane to relieve the pressure in the middle ear and this essentially takes on the role of the Eustachian tube
Give examples of conditions which can cause conductive hearing loss?
Impacted earwax or foreign body otitis externa trauma otitis media otosclerosis tumours
Give examples of conditions which can cause sensorineural hearing loss?
head injury noise trauma CNS infections presbycussis atherslcerosis sudden deafness ototoxic drugs acoustic neuroma meningioma metastatic tumour menieres disease
Describe the mechanism of conductive hearing loss?
Auditory stimuli are not adequately transmitted through the auditory canal, tympanic membrane, middle ear or ossicle chain to the inner ear
can be temporary or permanent hearing loss
Describe the mechanism of sensorineural hearing loss?
occurs with disorders that affect the inner ear, auditory nerve or auditory pathways in the brain
sound waves are conducted to the inner ear but abnormalities of the cochlear apparatus or auditory nerve decrease or distort the transfer of information to the brain
Describe Rhinne’s hearing test?
512Hz vibrating tuning fork placed on the mastoid process to test bone conduction then placed near to the ear to test air conductance. Normally air conductance should be louder buy bone conductance will be louder in conductive deafness
Describe weber’s hearing test?
Vibrating tuning fork placed at the vertex in the midline between the two ears and the patient is asked whether the sound is perceived equally in both ears. sound is heard louder in the affected ear in conductive deafness and in the unaffected ear in perceptive deafness
Why is it important to identify hearing problems as early as possible?
Hearing problems will impact on a child’s speech and language development, social skills and education
There is newborn screening for hearing. T/F?
True
Most children will have hearing tests when they start school. T/F?
True
The otoacoustic emissions (OAE) test is used as a hearing screening test. What does this involve?
Measures sound waves generated in the cochlea in response to clicks or tone bursts emitted and recorded by a minute microphage place in the external ear canals of the infant
The auditory brain stem evoked responses (ABR) is a test used in hearing screening. What does this involve?
Uses 3 electrodes pasted to the infants scalp to measure the EEG waves generated by clicks
