Flashcards in Week 208 - Hearing and Balance, ENT Deck (69)
What is hyperthyroidism/thyrotoxicosis?
Thyroid gland produces too much thyroxine (T4) either due to problem at level of the pituitary or thyroid itself.
What is thyroxine (T4)?
A hormone which controls metabolic function throughout the body. If too much is produced everything goes into over-drive; too little everything slows down
What blood tests would you order for a patient with suspected thyroid problems?
TFTs (thyroid function tests) - primary interest in TSH and T4 levels
If TFT results show low levels of TSH and elevated T4 where is the problem coming from?
The thyroid gland - producing too much T4 despite not being provoked by TSH from pituitary
What is the main function of iodine in the body?
Production of thyroxine
List the more common possible symptoms of hyperthyroidism.
restlessness, anxiety, emotional, irritability, poor sleep, tremor, weight loss, palpitations, sweating, intolerance to heat, increased thirst, diarrhoea, SOB, hair thinning, itchiness (pruritis), menstrual changes (light/infrequent), tiredness, muscle weakness, goitre, eye problems (proctosis/exophthalmos, blurred vision, dry eyes, ophthalmoplegia)
What are the main possible complications of hyperthyroidism (especially for women)?
- Increased risk of heart problems (AF, cardiomyopathy, angina, heart failure)
- Increased risk of complications during pregnancy
What is the most common cause of hyperthyroidism?
Graves' disease (women 20-50 / FHx usually)
What occurs in Grave's disease?
It is an autoimmune disorder characterised by antibodies attaching to the thyroid gland and stimulating it to produce/release excessive amounts of thyroxine (trigger not known)
What symptoms are more specific to Grave's than general hyperthyroidism?
- Eye problems - proptosis / exophthalmos, discomfort and watering or dryness, blurred vision
- Pretibial myxoedema (thickening / inflam of skin down shins and on top of feet) - all other symptoms for hyperthyroidism likely / possible too
What are the possible treatments for hyperthyroidism?
Medical - Oral tablets > Carbimazole
Surgical - last resort or if large goitre causing breathing, speech or swallowing difficulties (or aesthetically displeasing)
What is a rare but important side effect of Carbimazole to be aware of?
leukocytopenia / leukopenia (reduced WBC count)
Tell patient to come back if gain a fever, sore throat or mouth ulcers - may be a sign of this
What alternative oral medication is prescribed if Carbimazole is not appropriate for a patient?
Propylthiouracil (given to pregnant or breast-feeding women often)
What is radioiodine therapy?
Px given drink or capsule to radioactive iodine to swallow. Concentrates in the thyroid and the radiation destroys thyroid tissue thus reducing the amount of thyroxine produced
What restrictions are placed on patients treated with radioiodine for the following 2-4 weeks?
Not to have physical contact with others, not to share a bed, not to attend public places such as restaurants/cinemas/pubs/theatres, take time off work if work closely with others (keep arm's length from others) particularly limit contact with children and pregnant women
How long should a woman leave it before attempting to become pregnant after radioiodine Tx and how long should a man leave it before fathering a child?
6 months for a woman
4 months for a man
What additional medication might be introduced in the early stages of treatment for an individual with hyperthyroidism?
Beta-blockers - to help reduce heart rate, tremor, palpitations, sweating, agitation and anxiety
What is the most common cause of deafness?
What is the most common cause of presbycusis?
What sounds are most affected with presbycusis, high or low frequency sounds and what is the consequence of this?
Consonant sounds are less audible so speech loses its intelligibility
Why does increasing your volume to make yourself heard by an elderly person with presbycusis not help them hear you?
It merely increases low frequency sounds (vowels)
What is the most effective treatment for presbycusis?
A high frequency hearing aid
Name three types of drug that cause iatrogenic deafness.
Aminoglycosides (Gentamicin, streptomycin)
Loop diuretics (furosemide)
Why is glue ear common in children under 7 and quite rare in those over 7?
Due to the development of the Eustachian Tube. Before 7 it is more horizontal and narrower. As the child develops its angle increases and it widens improving its draining function of the Middle Ear
What is the pathology behind Glue Ear?
The middle ear becomes fluid filled making it more difficult for the ossicles to vibrate.
Smoke and infection are thought to be two causes though aetiology is essentially unknown
A patient presents with severe otalgia and on inspection with an auriscope the external auditory canal looks inflammed. What is the most likely diagnosis? What is the treatment?
Topical antibiotics (e.g. Dexamethasone and framycin)
If a patient presents with signs of otitis externa and on inspection with an auriscope you notice hair-like structures, what is the likely cause of the otitis externa?
A little boy presents with severe otalgia of his right ear following a cold. On inspection his tympanic membrane looks inflammed and on testing hearing Weber's localises to the right ear, Rinne's is negative on the right. What is the diagnosis and how do you treat?
It is likely otitis media.
Should settle within 72hrs
Advise NSAID treatment to help with pain
Only use systemic ABx if doesn't clear
What is the treatment for otosclerosis?
Hearing aid or Stapedectomy
What occurs in otosclerosis?
Bony deposits grow on the footplate of the stapes between it and the cochlea - hearing loss may be mixed
If a patient presents with sudden sensorineural hearing loss in one ear what should you do and why?
Arrange an MRI to exclude an Acoustic Neuroma (slow growing schwannoma of vestibular nerve)
How do you treat Glue Ear?
Either leave it as the effusion will usually resolve naturally or if persists insert a grommet which will act as a functioning ET and grow out in 6-24 months
What cause tympanic membrane retraction?
Low pressure in the middle ear
Which part of the ear drum is most vulnerable to retraction?
The pars flaccida; the postero-superior part
A hallucination of movement
A disorder of ocular posture characterised by jerky movements
Name the two broad causes of vertigo
What are the main peripheral causes of vertigo?
BPPV (benign paroxysmal positional vertigo)
List 3 causes of central vertigo
Posterior circulation stroke
What is the commonest cause of isolated vertigo?
Benign Paroxysmal Positional Vertigo
What is Benign Paroxysmal Positional Vertigo?
Vertigo which lasts secs to mins
Induced by head movement particularly turning in bed or sitting up
Disease OD otological only
How is BPPV diagnosed?
Using the Dix-Hallpike manoeuvre
How is the Dix-Hallpike manoeuvre performed?
Turn pt head 45 degrees over shoulder of the side testing
Drop them back so head over end of couch and 30 degrees below body
May take a few seconds for the vertigo and nystagmus to begin
How is BPPV managed?
Epley manoeuvre or Brandt-Daroff exercises
How is the Epley manoeuvre performed and how does it treat BPPV?
Begin as with Dix-Hallpike - head 45 degrees over that shoulder for 30-60 secs
Then turn head 90degrees so looking over other shoulder 30-60 secs
Then turn another 45 degrees in same direction, pt looking at floor 30-60 secs then slowly sit up. Encourages otoconia back to ampulla
List the main features of Menieres Disease
Aural pressure, tinnitus, vertigo, hearing loss, nausea, vomiting, sweating (lasts hrs or a day!)
Why are the symptoms so much more complex than with BPPV?
Whole endolymphatic system affected - cochlear Sx as well as vertigo
(one theory is that endolymphatic vol rises, natural drainage to endolymphatic sac hindered, distends and stretches normal neuroepithelia causing malfunction)
How do you diagnose Meniere's Disease?
Typical history and excluding other causes
What is Vestibular Neuritis?
Inflammation that affects the vestibular nerve only, no cochlear symptoms. Causes severe vertigo, nausea and vomiting for a few days followed by gradual resolution and normality within 6wks usually
What is Labyrinthitis?
Behaves like Vestibular Neuritis but additional symptoms as whole labyrinth involved e.g. Permanent changes in hearing with tinnitus
What causes Labyrinthitis?
Usually viral, may be bacterial,occasionally vascular
How do you treat VN and Labyrinthitis?
Both: vestibular sedatives (prochlorperazine)
Labyrinthitis: plus, hearing aid or tactics
What are the Red Flags for acute vertigo?
Signs and symptoms of Cranial nerve disease
Long tract features (weakness or numbness in limbs)
Either of these require urgent MRI head to rule out posterior stroke
List the arteries associated with the vestibule and explain why occlusion is likely to result in deafness.
Basilar artery > anterior inferior cerebellar artery > labyrinthine artery > common cochlear artery > anterior and posterior vestibular arteries
It is an end artery system so no "back up"
From where does the blood supply to the labyrinth come and name 5 branches it gives off?
Basilar artery: anterior inferior cerebellar artery; labyrinthine artery; anterior vestibular artery; posterior labyrinthine artery and common cochlear artery
What two parts of inner ear anatomy make comprise the labyrinth?
Vestibular part (balance) and the cochlear (hearing)
Hearing loss caused by the outer and middle ear is conductive or sensorineural?
Hearing loss caused by the inner ear is conductive or sensorineural?
The chorda tympani comes off which CN?
the facial nerve (responsible for taste sensation to anterior 2/3 of tongue)
What ganglion does the tympanic plexus derive from?
the Geniculate Gangion of the Facial nerve
The weakest part of the tympanic membrane is what part and its locality is described as...?
The pars flaccida / located in the postero-superior quadrant of the tympanic membrane
Which bit of the tympanic membrane is more susceptible to disease such as cholesteatoma / retraction, the pars flaccida or pars tensa?
How does retraction cause hearing loss?
It reduces vibration of the ossicles
How does perforation of the ear drum cause hearing loss?
It reduces vibration surface abd exposes the round window
A child comes in complaining of reduced hearing in his left ear which he says, is not painful but sometimes produces a discharge. His mother tells you the discharge smell foul. o/e you can see a white, cheesy looking patch on the tympanic membrane. What is the likely diagnosis?
What is cholesteatoma?
Keratinising squamous epithelium in the middle ear which is trying to migrate exteriorly but has become trapped due to negative inner ear pressure
List 4 possible complications of cholesteatoma
- Meningitis - Facial nerve paralysis
- Mastoid abscess - Brain abscess
How do you treat cholesteatoma?
Sugically - mastoid surgery to remove sac of squamous debris