WHAT DOES THE EAR DO?
1.)HEARS - CONVERTS INTO NEURAL ACTIVITY 2.) GIVES US EQUILIBRIUM IN A GRAVITY FIELD 3.) DETECTS MOVEMENT
WHAT MAKES UP THE OUTER EAR?
PINNA EAR CANAL (External Auditory Meatus)
HAIR AND WAX GLANDS LAY IN THE ____ 1/3RD OF THE OUTER EXTERNAL AUDITORY MEATUS (EAR CANAL)
OUTER AND MIDDLE EAR PATHOLOGY CAUSES which type of HEARING LOSS?
WHAT MAKES UP THE MIDDLE EAR CLEFT?
EAR DRUM OSSICLES EUSTACHIAN TUBE MASTOID
WHAT IS EXOSTOSES?
BONY GROWTH IN TO THE EAR CANAL, CAUSING (EVENTUAL) CONDUCTIVE HEARING LOSS. THIS IS BECAUSE COLD WATER STIMULATES BONY GROWTH IN THE INNER 1/3 OF THE E.A.M. COMMON IN SURFERS.
THE EAR DRUM VIBRATES IN A ____ _____.
THE EAR DRUM IS ATTACHED TO THE ____
THE ROUND WINDOW IS AT THE FAR END OF THE ______. IT MOVES IN AND OUT OPPOSITE THE _____. IT ALLOWS FOR FLUID CONDUCTANCE OF SOUND WAVES.
COCHLEA Oval window
WHAT IS CHOLESTEATOMA?
A form of otitis media characterised by in-growth of skin into the middle ear where it is destructive to middle ear bones and other structures.
HOW LONG DOES IT TAKE FOR SKIN CELLS TO MIGRATE TO THE OUTER EAR?
ABOUT 3 WEEKS
WHERE DO SKIN CELLS START IN THE EAR CANAL?
The skin of the ear drum and canal all originates from the region of the umbo (the most depressed part of the Tympanic Membrane) and then migrates radially in all directions across the drum and out into the canal.
WHAT ARE THE COMPLICATIONS OF CHOLESTEATOMA?
MENINGITIS BRAIN ABSCESSES DESTRUCTION OF FACIAL NERVE VERTIGO DEAFNESS NECK DAMAGE OTHER?
WHAT ARE THE CHARACTERISTICS OF CHOLESTEATOMA?
CONDUCTIVE HEARING LOSS FOUL SCANTY GREEEN DISCHARGE PAINLESS OFTEN PRESENTS WITH COMPLICATIONS IE: -VII PARALYSIS - SEE SLIDE
HOW MANY PEOPL HAVE OTOSCLEROSIS?
1 IN 10. ONLY 1 IN 100 PRESENT WITH SYMPTOMS. COMMONEST CAUSE OF CONDUCTIVE HEARING LOSS IN ADULTS (CAUCASIAN)
WHAT IS OTOSCLEROSIS?
A hereditary disorder causing progressive deafness due to overgrowth of bone in the inner ear.
WHAT IS THE SURGICAL TREATMENT FOR OTOSCLEROSIS?
1.) It is possible to improve hearing by removing the stapes bone and replacing it with a micro prosthesis - a stapedectomy, or 2.) creating a small hole in the fixed stapes footplace and inserting a tiny, piston-like prosthesis - a stapedotomy.
WHAT ARE THE TREATMENTS FOR GLUE EAR?
GROMMETS ETC ETC SEE SLIDES
THE ORGAN OF CORTI IS WHAT?
A structure in the cochlea of the inner ear which produces nerve impulses in response to sound vibrations. The organ of Corti is the structure that transduces pressure waves to action potentials.
HIGH FREQUENCY HEARING LOSS GETS WORSE AS YOU GET _____.
CONSONANTS ARE ____ FREQUENCY SOUNDS.
PATIENTS WHO HAVE PRESBYACUSIS CANNOT HEAR _____.
WHAT IS Presbycusis?
Presbycusis (also spelt presbyacusis, from Greek presbys “elder” + akousis “hearing”), or age-related hearing loss, is the cumulative effect of aging on hearing. It is a progressive bilateral symmetrical age-related sensorineural hearing loss. The hearing loss is most marked at higher frequencies.
WHAT IS THE SPEECH BANANA?
A FLAT AREA ON AN AUDIOGRAM IN WHICH ALL SPEECH SOUNDS SIT.
NAME SOME IATROGENIC CAUSES OF DEAFNESS?
DRUGS: -GENTAMYCIN (AMINOGLYCOSIDES) -LOOP DIRURETICS - FERUSOMIDE -CHEMOTHERAPY - CISPLATIN/CARBOPLATIN -OTHERS SURGICAL TRAUMA
WHAT IS AN ACOUSTIC NEUROMA?
NEITHER ACOUSTIC NOR A NEUROMA! A SCHWANNOMA. COMPRESSES COCHLEAR NERVE SEE OTHERS COMPRESSION OF RESPIRATORY CENTRES, PRESSES ON BRAINSTEM (CEREBELLAR PEDUNCLE)
DEFINE LIMITS OF STABILITY.
HOW FAR ONE CAN MOVE THE CENTRE OF GRAVITY WITHOUT REQUIRING A CORRECTION.
A HALLUCINATION OF MOVEMENT.
WHAT IS NYSTAGMUS?
A DISORDER OF OCULAR POSTURE, CHARACTERISED BY RHYTHMIC, JERKING MOVEMENTS.
WHICH IS THE MOST IMPORTANT INPUT TO MAINTENANCE OF BALANCE?
A MIX OV VISION, VESTIBULAR APPARATUS AND PROPRIOCEPTION.
THE SEMICIRCULAR CNALS ARE RESPONSIBLE FOR WHAT?
The semicircular ducts provide sensory input for experiences of rotary movements. They are oriented along the pitch, roll, and yaw axes.
WHAT IS BPPV (BENING PAROXYSMAL POSITIONAL VERTIGO)
The most common and most curable form of Vertigo. the vertigo lasts for seconds only and is provoked by specific positioning manoeuvres. It is a disease that commonly starts without warning (idiopathic) but it also commonly follows head trauma. Interestingly it may also follow other causes of vertigo - Meniere's Disease and Vestibular Neuritis.
WHAT IS LABRYNTHITIS?
Inflammation of the labyrinth or inner ear. Causes acute vestibular failure.This failure is characterised by a rapid onset of vertigo which may be very severe and associated with nausea, vomiting, pallor, sweatiness and diarrhoea (vegetative symptoms).
WHAT IS THE CRISTA?
The crista ampullaris is the sensory organ of rotation located in the semicircular canal of the inner ear. The function of the crista ampullaris is to sense angular acceleration and deceleration.
WHAT IS THE MACULAE?
A portion of the utricle (cul-de-sac), which forms the macula of utricle (or utricular macula), which receives the utricular filaments of the vestibulocochlear nerve. The macula of utricle allows a person to perceive changes in longitudinal acceleration (in horizontal directions only). 3 layers.
GIVE THE PERIPHERAL CAUSES OF VERTIGO.
BPPV MENIERES VESTIBULAR NEURITIS LABRYNTHITIS
GIVE THE CENTRAL (BRAIN) CAUSES OF VERTIGO.
MIGRAINE MULTIPLE SCLEROSIS POSTERIOR CIRCULATION STROKE
WHAT IS THE DIX-HALLPIKE MANOEUVRE?
The Dix–Hallpike test or Nylen–Barany test is a diagnostic maneuver used to identify benign paroxysmal positional vertigo (BPPV). https://www.youtube.com/watch?v=vRpwf2mI3SU
WHAT IS THE EPLEY MANOEUVRE?
The Epley maneuver or repositioning maneuver is a maneuver used to treat benign paroxysmal positional vertigo of the posterior or anterior canals.It works by allowing free floating particles from the affected semicircular canal to be relocated, using gravity, back into the utricle, where they can no longer stimulate the cupula, therefore relieving the patient of bothersome vertigo.
IN BPPV NYSTAGMUS IS PRIMARILY ____, THOUGH SOME ______ MOVEMENT IS ALSO OBSERVED.
BPPV IS A DISEASE OF ____ONLY. (NO ____ SYMPTOMS)
WHAT IS THE BRANDT DAROFF MANOEUVRE?
Exercise for BPPV.
WHAT ARE THE EXCLUDING AND SUPPORTIVE TESTS OF MENIERES DISEASE?
WHAT IS A VESTIBULAR NERVE SECTION?
A vestibular nerve section is a destructive procedure used for Ménière’s disease. The vestibular branch of the vestibulo-cochlear nerve is cut in one ear to stop the flow of balance information from that ear to the brain. The brain can then compensate for the loss by using only the opposite ear to maintain balance. This means the labrynth is CUT OFF.
FC TABLE FORM FOR VESTIBULAR DISEASES
FC TABLE FORM FOR VESTIBULAR DISEASES
.This needs doing - see lecture slide.
WHAT IS MIGRAINE ASSOCIATED VERTIGO?
Vestibular dysfunction in parallel with other symptoms of migraine.
WHAT ARE THE RED FLAGS FOR ACUTE VERTIGO?
What are the functions of the paranasal sinuses?
1.) Lightening the weight of the head 2.) Humidifying and heating inhaled air 3.) Increasing the resonance of speech 4.) Mechanical protection in the event of facial trauma
WHAT ARE THE RED FLAGS FOR ACUTE VERTIGO?
Beware 'red flags' such as: 1.)hearing loss 2.) new-onset headache AND central neurological signs: -gait ataxia -down-beating or other atypical nystagmus. These suggest more serious causes of vertigo and should prompt rapid specialist referral.
Which is the largest of the paranasal sinuses?
Which is the first paranasal sinus to develop?
Which paranasal sinus houses the infraorbital nerve?
The maxillary sinus - provides sensation to the cheek area (approx).
The Frontal sinus is housed in the ____ bone.
Anterior Ethmoid cells in the frontal sinus move up after the age of ___.
The sphenoid sinus is formed from the ____ ______ ____.
Nasal embryonic lining.
The Ethmoid sinus grows and pneumatizes until the age of ___.
What is the Basal lamela?
A thin barrier between anterior and posterior ethmoid air cells in the ethmoid sinus.
When the maxillary sinus is fully developed (after 18 YO), it lays ____ the nasal cavity.
The most anterior Ethmoid air cells is called the ____
Ager nasi (see spelling)
What is the largest ethmoid bone.
The Ethmoid Bullae.
The middle turbinate, with an ethmoid air cell trapped inside, is called _______.
What is the function of the Eustachian tube
Pressure Regulation Protection Clearance
What's a Haller cell?
Haller cells are also known as infraorbital ethmoidal air cells or maxilloethmoidal cells. They are extramural ethmoidal air cells that extend into the inferomedial orbital floor and are present in ~20% (range 2-45%) of patients
How long is the Eustachian tube in adults?
31-38mm in adults, 18mm (average) in infants.
Most of the increase in length of the Eustachian tube takes place before the age of ____.
SIX - This will come up!
Why do see less middle ear infections in children after the age of six?
This is related to the development of the Eustachian tube and subsequent improvements in clearance, reducing the likelyhood and duration of infections.
See table on Eustachian tube in anatomy lecture and write up cards.
This needs doing. 29/10/14
What is the Lamina Papyracea?
Bone plate which forms the lateral surface of the labyrinth of the Ethmoid bones. It is also a VERY thin and easily damaged barrier between the nasal cavity and the orbit.
The Stylomastoid Foramen ins the termination of the ____ ____ and contains the ____ _____ and the ______ artery. On OSCE Skulls it is number ___.
Termination of the facial nerve Contains the Facial nerve and the Stylomastoid Artery NUMBER 39 on skulls (OSCE)
Which nerve is completely exposed in children, and yet protected in adults (related to Ear anatomy)?
The Facial Nerve. This can be damaged in surgery if you are not careful!
Why do we have pinni?
To aid in hearing high frequency sounds.
Learn parts of the Tympanic membrane
8 of them
Between the Tympanic membrane and the oval window, sound intensifies x ___.
The change in movement from a forward-back at the TM to a rocking at the Foot of the stapes improves efficiency of sound conduction by a factor of about ____.
The middle ear improves sound conduction by about ___ times.
Transduction to neuronal activity from the vibrations within the cochlea is only from the ___ chamber (of 3).
The three segments of the path of the facial nerve are the ?
Cranial cavity (soft) Bony Extracranial (non bony)
What are the 5 branches of the Facial nerve?
TEN ZULUS buggered MY CAT Temporal, zygomatic, Buccal, Mandibular, Cervical
How do you test the zygomatic branches of the facial nerve?
Obicularis Oculi - Ask to screw your eyes shut!
How do you test the Temporal branch of the facia nerve?
Ask patient to raise eyelids.
How do you test the Cervical branches of the facial nerve?
Ask to tense neck "as if were a man shaving"
In a contrast CT scan, what type of structure will show up better?
What is a Bells Palsy?
Idiopathic Facial Nerve palsy - have to rule out everything else first.
The frequency range of human hearing is related to what?
The length and width of the EAM.
What is the smallest muscle in the body?
Stapedis muscle, supplied by the facial nerve. It's role is to dampen down the noise/movement of the stapes.
Learn the Walls of the "box" arond the middle ear
See anatomy lecture from 28th.
Taste to first 2/3 of the tongue is supplied by the?
What are the two BASIC types of cholesteatoma?
Congenital and Acquired.
What is primary acquired Cholesteatoma associated with?
This is associated with a defect in the pars flaccida.
What is secondary acquired Cholesteatoma associated with?
This is associated with a defect in the pars tensa.
What is Tertiary acquired Cholesteatoma associated with?
Arising behind an intact tympanic membrane after previous ear surgery has implanted epithelium into the middle ear e.g after grommet insertion.
Which two parts of the ear drum are weaker than the others?
There are two areas of the ear drum that are weaker than the others: the pars flaccida and the postero-superior quadrant of the pars tensa.
What two processes are important aspects of the formation of cholesteatoma?
1.)The process of skin migration from the UMBO of the tympanic membrane. 2.) The concept of negative pressure effect on skin migration.
In Cholesteatoma, Discharge is classically ___, ____, and ________. Pain is ______.
Discharge is classically scanty, green and foul smelling. Pain is notably absent.
What are the middle ear complications of Cholesteatoma?
1.Conductive hearing loss as the ossicles are eroded 2.Facial palsy as the bone covering the facial nerve is destroyed
What are the Inner ear complications of Cholesteatoma?
1.Sensorineural hearing loss 2.Vertigo 3.Labyrinthitis 4.Petrositis or inflammation of the petrous temporal bone
What are the Mastoid and posterior Fossa complications of Cholesteatoma?
1.Mastoiditis with subperiosteal abscess (behind the ear). 2.Meningitis 3.Cerebellar abscess 4.Sigmoid sinus thrombosis
What are the Middle Fossa complications (superior to middle ear) of Cholesteatoma?
1.Meningitis 2.Temporal lobe abscess 3.Extradural abscess 4.Subdural abscess (uncommon)
What are the complications anterior and inferior to the ear, of Cholesteatoma?
1.Abscesses can form in the sternocleidomastoid or in the Zygomatic region
What is the usual management type for Cholesteatoma? Which two are most common?
Surgery: 1.Atticotomy. Used when the disease is limited to the attic region i.e. is relatively small 2.Modified radical mastoidectomy. Used when the disease extends backwards into the mastoid system.
What are the risks of surgery for Cholesteatoma?
1.Facial paralysis - temporary or permanent 2.Worsening of hearing loss or even dead ear 3.Taste disturbance - because the corda tympani travels through the middle ear and may be damaged during surgery. This is fairly common. 4.Recurring discharge after surgery. This is due to failure of the ear to heal or recurrence of the original disease
What is the cause of Eustachian tube dysfunction in glue ear?
1.) nasopharyngeal infection (usually within the adenoids) 2.) Infective rhinitis. Note that it is not the size of the adenoid that is relevant but its state of health. In adults unilateral glue ear may be associated with nasopharyngeal carcinoma (especially in patients of Chinese origin).
What % of glue ear resolves without treatment?
Hearing loss is a major feature of Glue Ear. What does this lead to?
1. Educational delay 2. Speech problems 3. Emotional delay 4. Intellectual delay
What are the management options for glue ear?
1 Watchful waiting 2 Grommets 3 Grommets and adenoidectomy 4 Hearing aid
What are the complications of Grommet insertion?
"cocky dudes produce tympanic farts" 1 Complications of anaesthetic. Grommet insertion is performed under general anaesthesia in children 2 Discharge10% of ears with grommets discharge. This is usually curable with a short course of ear drops but rarely the grommet may have to be removed 3 Perforation. A permanent hole may remain in the ear drum after the grommet falls out (6-9 months after insertion). 4 Tympanosclerosis. A chalky deposit is sometimes found in the ear drum after the grommet has come out. It is of no relevance usually. 5 Failure. Not really a complication but sometimes the grommet doesn't stay in long enough to allow resolution of the problem. Further grommets are required in about 20%.
What are Grommets?
Grommets are ventilation tubes that are placed in the tympanic membrane to hold it open.
Describe the pathophysiology of benign paroxysmal positioning vertigo.
In BPPV the otoconia attached to the macula of the Utricle become displaced into the endolymph.While floating in the endolyph o fthe Utricle they cause no problems but when they become trapped in the semi-circular canals they induce nystagmus and vertigo of short duration following turns of the head or body.
In BPPV, Otoconia usually go to which semi-circular canal?
The posterior! 94%
What do we THINK happens (in terms of pathophysiology) in Menieres disease?
One theory of Meniere's disease has it that the function of the endolymphatic sac is impaired and that there is a relative build-up of endolymph within the endolymphatic space. This is sometimes referred to as endolymphatic hydrops. These can expand, and finally rupture, causing an ionic disequilibrium between the endolymph and the prilymph, leading to hearing loss and vertigo.
The perilymph is high in _____. The endolymph is high in ______.
The perilymph is high in Sodium. The endolymph is high in Potassium.
What are the triad of symptoms that characterise Menieres disease? What else may a patient describe?
The triad of symptoms that characterize Meniere's Disease are: hearing loss, tinnitus and vertigo. To this triad is usually added 'aural pressure' but it's presence is variable. In a typical attack the patient will describe a sensation of 'fullness' or 'pressure' in one ear. Some time later they will notice tinnitus and then hearing loss. These symptoms herald the onset of vertigo.
What are the essential investigations required for the exclusion or confirmation of Menieres disease?
1.) Pure Tone Audiogram. This typically shows a fluctuating low frequency hearing loss. Later in the disease the hearing loss becomes permanent and progressive. 2.) MRI of the posterior cranial fossa and Internal Acoustic Meatus. This is done to rule out acoustic neuroma. 3.) FBC, Glc, TFT are done to exclude systemic diseases.
What is the treatment for Menieres disease?
1.)Salt restriction. 2.) Betahistine TID everyday as prophylaxis. 3.) Antiemetic during attacks only. 4.) Surgery - conservative and destructive. Betahistine (Serc) is the only medication that has any evidence of success in preventing attacks. This evidence is not very robust. Antiemetics are used only during attacks.
What are the surgical options for the treatment of Menieres disease?
If the hearing is good then conservative options are tried: 1.) Grommet. Nobody really knows why this works but it does in a large proportion of patients. 2.) Gentamicin instillation. Here gentamicin is instilled into the middle ear via a temporary grommet. It passes in to the inner ear and destroys balance function while sparing hearing - mostly. 3.) Saccus decompression. In this operation the endolymphatic sac is opened to drain endolymph out. 4.) Vestibular nerve section. While this aims to preserve hearing function it is nonetheless a major operation. Destructive options are limited. The main one is labyrinthectomy. In this operation the function of the inner ear is totally destroyed by drilling out the inner ear.
What is the difference between conservative and destructive surgical options (with regards to the ear)?
Surgical options are divided into those that spare hearing function (conservative) and those that destroy it (destructive).
What is the difference between Vestibular Neuritis and Labrythitis?
The two diseases are distinct in that labyrinthitis involves the whole labyrinth (and causes vertigo and sensory deafness and tinnitus) while vestibular neuritis causes only vertigo.
What is the difference in presentation between BPPV, say, and Labrynthitis?
The duration of vertigo. In BPPV, only seconds, in Labrynthitis, very prolonged indeed.
What is Otalgia?
Pain in the ear is either from ear disease, or it is ____.
Which nerves supply sensation to the skin and the mucosa of the ear?
a. CN V The Trigemminal b. CN VII The Facial c. CN IX The Glossopharyngeal d. CN X The Vagus e. C2 and C3 Cervical roots 2 and 3
Which structures can cause referred pain in the ear? THINK "T's"!
1.) Tonsil Tonsillitis, tonsil carcinoma 2.) Tongue Tongue carcinoma 3.) Teeth Tooth abscess 4.) TMJ (temporomandibular joint)TMJ dysfunction 5.) Throat Carcinomas in larynx and pharynx 6.) The neck Arthritis
What are the potential causes of Facial Palsy? "Bells Rammed Traumatically Toward Infected Others"
1. Bell's Palsy. This accounts for more than half of cases. By definition it is of unknown aetiology and the diagnosis can only be made after a search for other cases. Current research suggests that it is of viral origin - probably herpes simplex type 1. 2. Ramsay Hunt Syndrome. Herpes Zoster Oticus is it's proper name and this tells you the cause. In this condition a herpetic rash is seen on the pinna or soft palate in addition to the facial palsy. Hearing loss and vertigo may also be present. 3. Trauma. Most commonly due to surgical accident in parotidectomy, middle ear surgery or surgery on the internal acoustic meatus. It may occur after head injury especially where there has been a fracture of the temporal bone. 4. Tumour. Facial or vestibular schwannomas and malignancy of the parotid (such as mucoepidermoid tumour or adenoid cyctic carcinoma) are the main causes here but both are rare causes of facial weakness. Note that benign parotid tumours such as pleomorphic adenoma do not cause facial paralysis. 5. Infection. Acute suppurative otitis media, cholesteatoma and malignant otitis externa may all cause this. 6. Others. Sarcoid, MS, CVA, Guillian-Barre syndrome, HIV.
What causes Neuroporaxia?
Caused by local compression and is recoverable when the pressure is relieved
What causes Axonotmesis?
Axonal integrity is disrupted but endoneural sheaths preserved. Distal degeneration of the nerve occurs. Return to normal function is possible.
What causes Neurotmesis?
Destruction of axon and support cells. Significant recovery is unlikely.
Why can you movey our forehead with an UMN lesion, but not a LMN lesion?
If the patient has a CVA that affects the areas above the VII nucleus (upper motor neurone) the forehead will still have movement because it will have input from the opposite cortex. This is not the same for lower motor neurone weakness. The Facial Nerve contains only lower motor neurones. If the nerve is damaged then there is ipsilateral weakness in all of the facial divisions.
Diseases that affect the outer or middle ear cause _____ loss and those that affect the cochlea or cochlear nerve cause ________ losses.
Diseases that affect the outer or middle ear cause conductive loss and those that affect the cochlea or cochlear nerve cause sensorineural losses.
There are a few diseases that can cause both types of deafness - name some.
(e.g. otosclerosis, cholesteatoma and acute suppurative otitis media).
Define sensorneural hearing loss.
Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve (cranial nerve VIII), the inner ear, or central processing centers of the brain. Sensorineural hearing loss can be mild, moderate, or severe, including total deafness.
Name 4 ototoxic drugs.
1.) Aminoglycosides (gentamicin, neomycin) - irreversible 2.) Loop diuretics (furosemide, bumetamide) - largely reversible 3.) Chemotherapeutic agents (cisplatin, carboplatin) - irreversible 4.) Aspirin - reversible
vestibulotoxic drugs cause ______ ____.
cochleotoxic drugs cause ______.
What is an acoustic Neuroma?
This is a badly named tumour as it is in reality a schwannoma and seldom occurs on the cochlea nerve (usually it arises on the superior vestibular nerve). So really it should be called a vestibular schwannoma. Causes sensoineuronal hearing loss.
Acoustic neuroma usually arises on which nerve?
Superior Vestibular nerve.
What do you know about acoustic neuroma? Why is it dangerous?
The tumour is benign but is situated in the bony internal auditory meatus and as it expands it grows towards the brain stem. Hence, although it is benign it can be extremely dangerous by virtue of its position and causes death by brain stem compression.
The characteristic sign of an acoustic neuroma is signs that are ____.
UNILATERAL (one side)!
What is the treatment for acoustic neuroma?
1.) Conservative. The tumour is slow growing and in patients with other disease there may be no need to remove it. 2.) Surgery. This requires a major neurosurgical procedure with it's attendant risks 3.) Radiosurgery. This is relatively new to the UK but is a relatively non-invasive treatment
What is congenital hearing loss?
This is deafness present at birth and is distinct from hereditary deafness (where a deafness may or may not be present at birth).
List causes of congenital hearing loss.
1.)Toxoplasmosis 2.) Rubella 3.) CMV 4.) Herpes 5.) Syphilis 6.) Neonatal hypoxia 7.) Rhesus incompatibility
What is Presbyacusis?
Presbyacusis is the decline in hearing thresholds that is associated with age. Note that age does not cause it. In the cochlea both the outer and inner hair cells of the organ of Corti are affected. This is especially so at the basal turn of the cochlea where high frequency sound is detected. This means that the patients get a high frequency hearing loss. As time passes the hair cells further up the cochlea are affected and progressively lower frequencies are lost.
High frequency sound is detected in the ___ ____.
Low frequency sound is detected in the ___ _____ __ ___ ______.
thin apex of the cochlea
What is the management of Presbyacusis?
Sensorineural hearing loss of this type is irreversible so the patient requires assessment as to the degree of disability and provision of a hearing aid and hearing rehabilitation.
In a normal patient, what would you expect from Webber and rinne tests?
Weber: Central Rinne: L: AC (air conduction)>BC(bone conduction) R: AC>BC
In a patient with Conductive hearing loss on the right what would you expect from Webber and rinne tests?
Weber - RIGHT Rinne: L: AC>BC R: BC>AC
In a patient with Conductive hearing loss on the left what would you expect from Webber and rinne tests?
Weber - left Rinne: L: AC>BC R: BC>AC
Weber Central Rinne: L: AC>BC R: AC>BC Means what?
Sensory deafness R, sensory deafness L (of the same degree) OR Normal
Weber Central Rinne: L: BC>AC R: BC>AC Means what?
Conductive hearing loss R, conductive hearing loss L (of the same degree)
Weber: To left Rinne: L: BC>Ac R: AC>BC Means what?
Conductive loss L, normal R OR Sensory deafness R, conductive hearing loss L (greater degree than R)
Weber: To left Rinne: L: BC>Ac R: BC>AC Means what?
Conductive loss R, greater conductive loss L
Weber: To left Rinne: L: AC>BC R: AC>BC Means what?
Sensory deafness R, normal L.
Weber: To Right Rinne: L: BC>AC R: AC>BC Means what?
Dead ear L, normal R. Wait, What!? Surely, if BC>AC on the left then Weber should lateralise that side also! This is a special situation. The left ear is dead – it has no hearing at all so that AC vibrations do not register. However, when a tuning fork is placed behind that ear the patient says they can hear it (ie BC>AC). This is because they are hearing it in the opposite ear. Vibrations pass across the skull easily and stimulate the opposite cochlea, which is working well. If such a situation arises then a masking noise is placed into the non-test ear (ie the Right one). When this is done it will not pick up vibrations from the opposite side of the head and the patient will not hear AC or BC on the left.
Still need to cover balance sections, pictures, normal eardrums (sides), parts of anatomy and all of the sinus stuff.
To do by end of week.
What are the three major inputs to balance? Where are they coordinated?
Visual input (70%) Proprioception (15%) Vestibular system (15%) Co-ordinated in the brainstem, and with additional cerebellar input maintains balance.
What is vertigo?
The Hallucination of movement. This is the cardinal symptom of disease of the vestibular system.
What is the pharmacological treatment for Menieres disease?
Betahistine 16mg TDS - Not to be overly used. Thiazide diuretics
What is the Annulus?
A thickened ring of collagen at the periphery of the pars tensa. It DOES NOT surround the pars flaccida. It sits in a bony groove in the tympanic bone. Basically - a thickening of the middle fibrous layer of the tympanic membrane.
What is the attic?
This is a term that is used to loosely describe the space in the middle ear that lies above the level of the tympanic membrane. In HEALTH - contains the head of the malleus and the body of incus, together with their suspensory ligaments.
Which is the most lateral of the three ossicles?
What is contained within the middle ear space?
This is WITHIN the TEMPORAL bone. It contains the ossicles, facial nerve, corda tympani and air.
What are the three main regions of the middle ear?
1.) Epitympanum (above eardrum) 2.) Hypotympanum (below eardrum) 3.) Mesotympanum (level with eardrum)
What is the Epitympanum?
This is the region of the middle ear above the level of the eardum.
What is the Hypotympanum?
This is the part of the middle ear below the level of the eardrum.
What is the Mesotympanum?
This is the part of the middle ear that is level with the ear drum.
Which nerve is vulnerable in ear disease?
The Facial nerve (CN VII)
What are the superior relations of the middle ear?
1.) Meninges of middle cranial fossa. 2.) Temporal lobe of brain
What are the inferior border relations of the middle ear?
1.) SCM Muscle 2.) Jugular Vein
What are the medial anatomical relations of the middle ear?
1.) Cochlea 2.) Semicircular canals 3.) Facial nerve
What are the posterior anatomical relations of the middle ear?
1.) Mastoid 2.) Meninges of posterior cranial fossa 3.) Cerebellum 4.) Sigmoid sinus
What is the "point" of the middle ear?
Amplification of sound (Approx. 20 times) Prevents reflection of sound waves from fluid filled ears
The membranous labyrinth contains ____.
In Menieres/Alcohol consumption, what changes in the endolymph?
The composition or specific gravity of endolymph is changed.
Which nerves supply the inner ear?
The superior Vestibular Nerve The Inferior Vestibular Nerve The Cochlear Nerve
Which nerve supplies the cochlea?
The cochlear nerve
The utricle, some of the saccule, the lateral semicircular canal and the superior semicircular canal are all supplied by which nerve?
The superior vestibular nerve.
Which nerve supplies the posterior canal of the cochlea?
The Inferior Vestibular nerve.
Which artery supplies the utricle, superior canal and lateral canal?
The anterior vestibular artery.
Which artery supplies the posterior canal of the inner ear?
The posterior vestibular artery.
The anterior vestibular artery and posterior vestibular artery are branches of the ___ ____ _____. This is derived from the ___ ____ ______ _____.
Common Cochlear Artery The Anterior inferior cerebellar artery.
What is the Internal Auditory Meatus?
The IAM is a bony conduit in the petrous temporal bone, through which the vestibular, cochlear and facial nerves leave the posterior fossa.
The neuroepithelium within the membranous labyrinth of the ear contains what type of cells?
The neuro epithelia are bathed in ___ rich ____
Potassium rich endolymph.
On vestibular neuroepithlial cells, one "cilia" is much longer than the others - what is this called?
When cilia move in the labyrinth of the inner ear move towards the Kinocilium, what happens to the firing rate of the cell, and why?
The firing rate increases. This is because The links connecting cilia are pulled open when the cilia are pulled towards the kinocilium. This opens channels, causing potassium from the endolymph surrounding the "cilia" to flood into the cell, causing depolarisation, and subsequent firing.
What closes the channels between cilia in the labryinth?
Calcium flooding into the cells, activating myosin filaments which subsequently close intracellular spaces.
What is meant by the term "tonic discharge"?
This refers to the fact that the cilia cells of the neuroepithelium in the labyrinth are constantly firing - inputs only change the RATE of fire.
Hair cells are contained within the ___ and the ____, and the Cristae within the _____ ______.
Utricle and Saccule. The semicircular canals.
The maculae are responsible for changing ___ ____ into neural activity.
What is the name given to crystals of calcium carbonate that give the gel layer of the labyrinth mass and inertia?
The lateral semicircular canals are in the ___ ____.
The left posterior semicircular canal is in the same plane as the _________ ____ _____.
Right superior semicircular canal.
In all functional pairs (regardless of orientation), a head movement raising the neural activity in one canal will ___ the neuronal activity of its functional pair.
When cilia bend AWAY from the Kinocilium, firing rate _____.
The wiring of the eye muscles to the ear means that you can do what?
You can keep your eyes fixed on a target when your head is moving.
What causes the first phase of jerk nystagmus?
Failure of firing rate of one lateral canal causes weakness in associated muscles. This causes the eye to drift in one direction AKA the first phase of jerk nystagmus.
In ear disease the nystagmus is directed ___ from the diseased ear.
When examining the pinna, you should look at what?
1.) Site/Size/Shape 2.) Scars behind Pinna 3.) Scars in front of pinna 4.) Preauricular pits, cysts and discharge 5.) Lesions on the pinna
When examining the E.A.M, what should you look for?
1.) Wax 2.) Bony growths 3.) Signs of skin infection or dermatitis
What is a drum perforation?
A hole in the eardrum. They generally have a smooth edge and are round or kidney shaped. Some traumatic perforations are linear with ragged edges.
What is a central perforation?
These are holes in the pars tensa. They all have a margin of eardrum around them (that's important!)
What's a marginal perforation? Where are they normally found?
This is a perforation that DOES NOT have a margin or annulus surrounding it. They usually lie in the posterior half of the eardrum.
What is an attic perforation?
These are holes in the attic region - mostly marginal also.
What is Myringoslcerosis?
Chalky white patches in the ear drum, forming as a result of damage to the drum - of little relevance.
A Herpetic rash seen on the pinna or soft palate in ADDITION to facial palsy is indicative of what?
Ramsay Hunt Syndrome (Herpes Zoster Oticus)
Facial or vestibular schwannomas, and malignancy of the parotid are rare causes of what?
How are patients examined for proptosis?
Periorbital changes can be assessed in a well-lit room:
Note the direction of the proptosis. Look down at the patient from above and behind, so that you are looking at their eyebrows and the nose below. Observe the proptosed eye and whether it is displaced forward or to the side. Intraconal lesions tend to push the globe directly forwards, whereas extraconal lesions push it to one side.
Establish how severe it is. This can be assessed formally using a Hertel exophthalmometer which uses a system of small mirrors to visualise the corneal apices against a scale. Although less accurate, one can also measure these, using a clear plastic ruler, by placing it at the lateral canthus (where the upper and lower lids meet) and holding it parallel to the patient's nose. A difference of 2 mm between the two eyes is significant.
Note whether it is reducible.
Ascertain whether it is pulsatile.
Establish what degree of chemosis is present.
Ascertain how immobile the eye is.
Look for lid swelling, engorged conjunctival and episcleral vessels and lagophthalmos/incomplete lid closure. Palpate the orbit for any tenderness or masses and examine the regional lymph nodes. If you suspect a high-flow lesion, listen to the globe over the closed eyelid with a stethoscope.
How do we test for loss of red saturation and what is the relevance of this sign?
To test for red desaturation, cover the patient’s weaker eye (if there is one) and ask him or her what color object you are holding. Typically, a red-topped dilating drop bottle can be used for this test. Then, ask the patient to cover the other eye and describe the color relative to the fellow eye.
Optimally, you should ask the patient to quantify the percentage of red desaturation. For example, if the patient says an object looks 100% red with the stronger eye and 70% red with the weaker eye, record that the patient has a 30% red desaturation in the weaker eye.
Relevance: Sign of OPTIC NERVE DAMAGE. If spotted early, it's reversible.
A Subperiosteal abscess of the orbit is a complication of which other disease process?
Otitis media/Mastoiditis. It's a RARE complication!
Whatr would a hole at this site be called?
An Attic Perforation.
What can you see here?
An attic pocket.
What would a hole at this sit be called?`
A Central perforation.
What condition is this?
Say what abnormalities you can see here.
Crust in the attic, with a cholesteatoma below it.
What is this?
Say what the arrow is pointing to.
What is this? And which side is it?
This is a normal RIGHT ear drum.
What is this? Which side?
Otitis MEDIA in the LEFT Ear.
Name the diferent perforation sites.
A. Attic perforation
B. Antero-superior central perforation
C. Antero-inferior marginal perforation
D. Posterior marginal perforation
E. Postero-inferior central perforation
If this were a hole, what would you call it?
Post marginal perforation.
If the green patch were a hole, what would it be called?
This would be a posterior perforation.
Which test is this? What would you expect in health?
Rinnes test - checking for conductive hearing. In health, Air Conduction>Bone Conduction.
What is the nickname given to the yellow patch, and what does it signify/represent?
The Speech banana. This is the range in which spoken words are heard.
If the green patch were a hole, what would it be called?
This would be a subtotal central perforation.
What procedure has been carried out here? What are the reason for this being done?
Vestibular nerve section. Reason: Severe Menieres Disease.
Which test is this? What is the result in health?
This is Webers test. In health, sound should be centralised.
Name the blanks.
What is this?
Delayed onset facial palsy implies a __________.
Delayed onset facial palsy implies a neuropraxia.
Immediate facial palsy suggests _____.
Immediate facial palsy suggests neurotmesis.