Ear Pathologies Included in Lectures Flashcards
Basal cell carcinomas
Most common skin cancer - 80%
Rare metastasises but local tissue destroyed
Risk: sunlight, lighter pigmentation skin, family he
Presentation: firm nodule - dark brown/black but pearly white around periphery
Diagnosis: biopsy
Treatment: Surgery, topical chemotherapy
Squamous cell carcinomas
20% skin cancers Able to metastasise Sun exposure Presentation: Appearance of ulcer, reddish skin plaque that continues to grow Immune surpressed patients greater risk Diagnosis: biopsy Treatment: excision
Otitis Externa
1% UK pop every year
Slightly more common in women
Types:
Localised - “Furuncle”
Diffuse further split into acute and chronic
Furuncle
Outer third ear canal hair follicles
Furuncle = infection of hair root follicle by Staph. aureus or other back./fungi
Damage to hair root follicle allows invading organism in = swollen nodule that’s tender pink/reddish
Feverish, feelings of fatigue
May develop into boil that obstructs EAM
To resolve needs to drain - usually will do this on its own but a warm moist compress nay help. Careful hygiene procedures.
Deep lesions surgical intervention may be necessary.
Diffuse Otitis Externa
Widespread inflammation of whole ear canal
= Acute if less than 3 weeks
= Chronic if more than 3 months
Itchy. Scaly skin. Painful. Discharge.
Possibly engaged lymph nodes in neck
HL is swelling
Causes: TRAUMATIC BACTERIAL FUNGAL CHRONIC DERMATOLOGICAL DISEASE - exczema, psoriasis COMPROMISED IMMUNE SYSTEM
Otomycosis
Inflection caused by Aspergillus Niger/ Canida Albicans
= OTITIS EXTERNA CAUSED BY FUNGI
Hot climates/swimmers
9% all otitis externa conditions
Severe discomfort and inflammation. Ob white filament ours hyphae accompanied with presence of fungal spores.
Excessive /impacted wax
Blocked HL
Itchy
No sebaceous/ceruminous glands in the deeper art of the canal so wax there manually assisted
Perforations
TM tends to heal itself
Healed area a lot thinner as fibrous layer missing - may therefore look as it perf still present even when healed over
Healed perforations may lead to the development of cholesteoma when the refraction pocket is deep and is situated in the posterior superior quadrant
Symptoms - whistling when sneezing/blowing nose, HL, Ear infections, Ongoing discharge, tinnitus
Ossicular disconitnuity
Max loss 60dB with TM intact
Most common disconnection after temporal bone trauma is joint between incus and stapes
Second most common malleus and incus
Fracture of arch of stapes can also happen
Otosclerosis
Abnormal growth of bone
Commonly affects oval window of middle ear
Leads to fixation of footplate affecting normal piston action of stapes
Spreads to cochlea HL becomes SN
Generic component
Acute Otitis Media
Where there is an infection in the middle ear
More prevalent in children
Arises from preceding viral infection or upper respiratory tract
Secretions lead to occlusion of eustacian tube - target for bacterial growth e.g. By Peumonococcus/ Haemophilius influenza
Infection spreads up eustacian tube and invades middle ear cavity and infects the mucosal lining.
Causes suppuration and the resulting pus fills the middle ear and pushes the tympanic membrane OUTWARDS which leads to pain.
If infection unchecked - TM will rupture
Chronic supparative otitis media
When infection continues for more than 3 months
Perf present and continuous drainage from the ear
Can lead to long term damage to the structures of the middle ear
Mastoiditis if the infection gets into the porous mastoid bone
Necrosis of middle ear structures - ossicles discontinuity
SNHL
Symptoms - recurrent discharge, persistent deep ear pain/headache. HL, balance problems, temperature and facial weakness - indicators of intracranial complications
Cholesteotoma considered if condition continues
Cholesteatoma
Retraction pocket forms on the tympanic membrane
Primary type where the pars Flaccida portion of the TM is deeply retracted into the epitympanum portion of the middle ear.
Can develop in the posterior portion of the TM as well
Mastoiditis
Mastoid bone becomes infected due to spread of infection
Has many air gaps - if gets infected difficult to get rid as not possible to get antibiotics to site therefore surgery necessary
Pt may need reconstructive surgery of TM and ossicles following this
Labyrinthitis
Membranous labyrinth becomes infected
Damage to vestibular and hearing organs
Adults 30-60 yrs - no set pattern of problems but does tend to give balance and HL to various degrees
Mostly compensated by the brain within 3-8 weeks
Ménière’s disease
0.2% pop
No did between sexes
Onset 40yrs
Often starts unilateral but after about 30yrs half of cases become bilateral
Symptoms : Episodic rotational vertigo, HL, Tinnitus, sensation of fullness in the affected ear
Onset: feeling of pressure, fluctuation in hearing, attach = severe vertigo casing nausea and vomiting.
Attack lasts 2-4 hours
Following which partial recovery of hearing
Presbycusis
Age related hearing loss
High freqs first, bilateral
Causes: General degeneration of cell structures throughout the auditory system due to age
Speed of degeneration genetic and environmental factors
ME - stiffening of TM and ossicles
IE - loss of hair cells, loss of metabolic function, restriction of blood supply, thickening and stiffening of basilar membrane. Atrophy and loss of nerve cells in auditory nerve
Sensory prebyacusis
Outer hair cell degeneration at the basal end
Inner hair cell degeneration at the basal end
Over 50yrs loss of OHCs more severe
Evidence of stereocilia derangement and alterations
Slowly progressive
Neural Presbycausis
Greater loss of neurones than sensory cells
Strial presbycusis
Stria vescularis atrophies due to age
Normally regulates metabolic function of the cochlea to maintain endocochlear potential
Result in flat SNHL but with good speech discrimination when speech is audible
Cochlear conductive presbycusis
Unfavourable alteration of basilar membrane micromechanics which affects propagation of the travelling wave.
Effects greatest where basilar membrane narrowest (base) therefore affects higher frequencies
Noise induced hearing loss
Too much sound energy transmitted to the inner ear.
Stereocilia get damaged and cannot transmit signal to nerves
Extreme = TM rupture
ALWAYS SENSORY NEURAL, most severe at 4KHz
Temporary threshold shift - drop of 40dB following exposure, several hours hearing recover as damage to hair cells repaired
Permanent threshold shift - multiple episodes hearing does not recover - damage accumulates
Aminoglycosides e.g. Gentamycin
Cochlea rich blood supply.
Affects hair cell membrane - permanent damage starting in high frequencies
Antineoplastic drugs
(Chemotherapy)
Site of action outer hair cells of cochlea
High freq HL starting 4000-8000KHz - can be accompanied with tinnitus
Asprin
Metabolic changes in cochlea
Tinnitus first sign, lead to HL
Quinine
Anti-malarial
Tinnitus and HL
Acoustic neuroma
Tumour of Schwann cells that cover the vestibular nerve
Benign but can press on the brainstem if large
Grows either in internal auditory meatus or the cerebellopontine angle
Affect function of auditory nerve and the facial nerve and restrict blood supply to the cochlea
6% all intercranial tumours
Symptoms: Asymmetrical SNHL/unilateral tinnitus. Vertigo may be present. Facial nerve may become involved with large tumours - tingling sensation, twitching, numbness
Tinnitus
Perception of sound in the absence of external sounds
