FRCS Otology

• 1. If a topical aminoglycoside is used, this should only be in the presence of obvious infection
• 2. Topical aminoglycosides should be used for no longer than two weeks
• 3. The justification for using topical aminoglycosides should be explained to the patient
• 4. Baseline audiometry should be performed, if possible or practical, before treatment with topical aminoglycosides

• Indication severe to profound deafness(>90dB at 2 & 4KHz) who do not receive adequate benefit from acoustic hearing aids
• Adequate hearing HA = >/ 50% Bamford–Kowal–Bench (BKB) sentence at 70 dB SPL or for children speech, language and listening skills appropriate to age
• Bamford–Kowal–Bench test speech understanding through recognition of 3 or 4 key words in each sentence
• Bilateral - children, blind/increased reliance auditory stimuli
• Trial hearing aid 3/12

• 15% progress over 5 years
• Surgery cartilage perichomdrium graft
• Surgery indications - cholesteatoma, progressive hearing loss, otorrhea, perforation, progressive chl, pain

Record electric potentials in auditory pathway in response to sound signals

• Electrocochleography 
• Auditory brain stem responses
• Cortical electrical audiometry

• Sound proof room
• Ground electrode forehead, reference mastoid, probe TM
• Wide band clicks or tone bursts using headphones
• Masking not necessary
• Ratio of amplitude of SP/AP
• Generally ratio >40% for chochlear hydrops

• Sound proof room
• Active electrode forehead
• Reference electrode ipsilateral mastoid
• Ground electrode contralateral mastoid
• Wide band clicks or tone bursts

• Sound proof room
• Ground electrode forehead
• Reference electrode both mastoids
• Active electrode vertex
• Tone bursts

• One ear headphones, both ears free field
• Phonetically balanced words Boothroyd Fry or sentence list Bamford Kowal Bench
• Asked to repeat words - spondees(2 syllable words)
• Starting level 20dB over PTA ave , then increase and decrease in 10dB

• Optimum discrimination score=highest score achieved
• Speech reception threshold=sound level at 50% score
• Half peak level=sound level of 50% ODS

• Familairisation with suprathreshold tone
• 1000Hz @ 30dB
• Hughson-Westlake up-down procedure
• 10 dB down until no response
• 5 dB up until response
• If get on 2 occasions=threshold

Technique by which non test ear is kept occupied with noise so that it cannot respond to signal in the test ear 

Interaural attenuation = drop in intensity of acoustic signal from TE to NTE

Masking level - NTE add 20dB to threshold of masking noise, increase in 10dB allotments until TE shows no change, this = masking level

• Vibrotactile thresholds
•            250   500   1K    2K   
• BC       30     60     60    80
• AC       95     115   125  130

• Stimuli =Normally clicks @ 80-85dB, <60 stim
• Recorded 20 milliseconds
• Alternating responses recorded as Gp A & Gp B, data correlating between 2 groups = response, otherwise noise
• Occur at freq 500-4000Hz

If more than 95% neuronal degeneration has occurred within 14 days then surgical exploration and decompression should be considered if imediate & complete palsy

• Tinnitus retraining therapy - white noise and counselling
• Cognitive behavioural therapy
• Sound therapy - Masking devices, neuromonics (match tinnitus pitch to music), hearing aids,Tinnitus phase out treatment(pure tone tinnitus only)
• Ginkgo biloba
• Hypnosis
• Electromagnetic stimulation - to cochlear(round window)
• Transcranial magnetic stimulation
• Ear canal magnets 
• Low power laser
• Surgery - vascular loop, stepedectomy 70-90% improvement & 1-5% deterioration, cochlear implant - 90% improvement

• Acute otitis media - grommet <1/7
• Cholesteatoma mastoidectomy <1 week
• Sharp injury explore
• Bells Palsy - Scottish Bells Palsy Study
• Mastoid surgery la,pack,explore with colleague early
• Blunt injury unknown onset -emg, explore at 3/12, if dead ear translab, if hearing mastoid and middle cranial fossa

• 20-40% inherited, chromosome 11 e.g. SDHD gene, auto dom but only shows if inherit from father
• Paragangliomas chromaffin -ve, Phaeocytochromas chromaffin +ve
• Occur MEN2a &b
• 10yr doubling time
• Screening for multiple paragangliomas, +ve fam history, functioning/metastatic tumours,<50 yrs old 
• Investigations - 24hr urinary catecholamines, MR & CT, (18F-DOPA PET, radionucleotide can be helpful)
• Treatment 90% control rate
• -Surgery - total v subtotal(if CN involved or genetic), embolisation 1 day preop(skull base), CN palsies 25-50%
• -Radio

• Fisch type A tumors can be excised by a transmeatal or perimeatal approach.
• Type B tumors require an extended posterior tympanotomy.
• Type C tumors require radical resection via a standard combined transmastoid-infratemporal or transtemporal-infratemporal approach with or without ICA trapping, preceded by external carotid artery embolization or superselective embolization. Surgery leads to therapeutic success in about 90% of patients.
• Treat large type D tumors with a combined otologic and neurosurgical approach. 
• postradiosurgery

sheehan et al 2012

• RESULTS: Overall tumor control was achieved in 93% of patients at last follow-up; actuarial tumor control was 88% at 5 years postradiosurgery. Absence of trigeminal nerve dysfunction at the time of radiosurgery (p = 0.001) and higher number of isocenters (p = 0.005) were statistically associated with tumor progression-free tumor survival. Patients demonstrating new or progressive cranial nerve deficits were also likely to demonstrate tumor progression (p = 0.002). Pulsatile tinnitus improved in 49% of patients who reported it at presentation. New or progressive cranial nerve deficits were noted in 15% of patients; improvement in preexisting cranial nerve deficits was observed in 11% of patients. No patient died as a result of tumor progression.
• control at 50 months

30db over 3 frequencies over 3 days

Autoimmune inner ear disease bilateral, HSP 70 @ 68KDa protein and , test otoblot for 68 kDa

Prognosis worse with severe loss,vertigo,,increasing age

Spontaneous recovery 30-80%

Pulsatile=synchronous with heart beat

• Vascular -  Arterial incl fibromuscular dysplasia or venous incl BIHT, jugular bulb anomalies
• Non-vascular incl Pagets(abnormal resorption/remodelling bone, frontal bossing,incrased ALP), Glomus

Hx includes head trauma, pregnancy, thyroid state, headaches, eye symptoms(carotico-cavernous fistula)

• Ix
• PTA, Long time course tympanometry
• MR,CT,doppler US

• Low flow fistulas - often resolve spontaneously
• High flow fistulas - endovascular embolisation/ligation

Abscent formamen spinosum on ct suggests persistent stapedial artery 

• Dandy criteria for benign intracranial hypertension
• Raised intracranial pressure
• CSF Pressure > 200mm H20
• Normal CSF analysis
• No intracranial mass/other pathology
• Absence of localising neurological signs

• Types
• Neuroprxia
• Axonotmesis
• Neurotmesis
• Partial transection
• Complete transection

• Facial reanimation
• Static - sling
• Dynamic - rereouting,graft

• Remove boney lining sigmoid sinus
• +/- anticoagulation

• Risk factors COM, external beam radiotherapy
• Ix - CT,MR,Arteriography if carotid involvement suspected with balloon occlusion, audiometry
• Staging - Modified Pittsburgh staging system
• Mx - Surgery & post op radiotherapy

• Lateral temporal bone resection
• - T1-2 lesions
• - pinna,EAC, TM, superficial parotid, post TMJ resected en bloc after extended cortical mastoid

• Extended temproal bone resection
• - LTBR & otic capsule, normally facial nerve, total parotidectomy
• - entire temporal bone lateral to the petrous apex is removed. The carotid artery is delineated anteriorly, and the dissection is completed between middle fossa dura superiorly, posterior fossa dura and sigmoid sinus posteriorly and jugular bulb inferiorly.

Neck SND 1-3 N0 neck

Defect reconstructed with free flap e.g. ALT

• Endochondral bone of the otic capsule undergoes remodelling with immature (woven) bone deposition
• Commonest ant stapes footplate 

• Aetiology
• Measles virus infection of otic capsule bone
• Humoral auto-immunity to type II collagen.
• Genetic mutation of collagen metabolism.

• Belfast Rule of Thumb
• - significant benefits if the average air conduction threshold (for 0.5, 1, 2 kHz) in operated ear was ≤ 30 dB or the interaural difference ≤ 15 dB.

• CSF leak
• 20% temporal bone fractures, X4 if otic capsule breached
• 10%/year risk meningitis

• IX B2 transferrin(100% specificity,95% sensitivity), CTMR
• Surgery - transmastoid/middle cranial fossa/combined

• Middle cranial fossa - craniotomy, epilepsy, hearing preservation, recommended if encephalocoele present
• If no seviceable hearing middle ear obliteration, refrain from straining, nose blowing or flying for at least a month.

• Soft band can be fitted with in a few weeks of birth
• BAHA from age 4-5

• Indications
• BC >50dB unable use conventional aids
• Single sided SNHL

• >30dB air bone gap do better with BAHA
• Bilateral BAHA for bilateral hearing loss where not greater than 20dB bc difference threasholds at 3-4KHz

Bilat BAHA for bilat CHL unable wear conventional aid & intaural difference <20dB at 3-4KHz

• Fixture failure rates of children below the age of five years and those 5-10 years are 40 and 8%, >10yrs 1%
• Skin complications 10-20% children

• >3cm - may be signs hydrocephalus, trigeminal involvement
• surgery, often minimal hearing else preservation chances slim
• Translabyrinthne approach - ID facial nerve fundus of IAM, increased preservation
• Retrosigmoid - good view lower cranial nerve
• Aim achieve complete resection but leave remnants to preserve key structures

• 2-3cm
• Surgery
• Stereotactic radiosurgery tumour control rates 75-97%, unknown late growth, sporadic intracranial malignancy related to previous higher doses

• 1-2cm
• Serial imaging
• Treatment - esp if brainstem/trigeminal impingement

• <1cm
• 80% do not grow= 

• Complications
• Catastrophic Death/severe CVA <1%
• Serious complications - PE, lower CN palsies, meningitis 2%
• Residual tumour growth rates in planned complete removal  or fragment left 1%
• Facial nerve injury related to size
• All sizes, anatomical preservation 94% with good (G1/2) facial function 86% at 1 year

• Commonest sites = intralabyrinthine & geniculate ganglion
• If sig CPA angle/middle fossa extension - resect
• Gd 4+ facial palsy resect with grafting
• Otherwise serial imaging.
• Some evidence for stereotactic radiosurgery

• Electrode implanted into brainstem via forth ventricle(foramen of Luschka) in order to stimulate dorsal and ventral cochlear nuclei
• End of electrodes in flattened paddle.
• Patient groups
• 1. NF2 - insert at time of resection
• 2. Non-NF2
• (a) Congenital cochlear abnormalities - severe
• (b) aplastic/severe hypolastic CN VIII
• (c) acquired cochlear & audiovestibular anomalies - meningitis, otosclerosis, trauma

Outcome = aid to lip reading

• Unilateral impairment
• Bilateral symmetrical impairment
• Bilateral asymmetrical impairment

• Classification
• piezoelectric or electromagnetic
• fully implanted or partially implanted

• Piezoelectric
• electric current into a piezoceramic crystal, which changes its volume and thereby produces a vibratory signal
• power output directly related crystal size
• early models benefit up to 60 dB
• inert in magnetic field
• 1. Cochlear Totally Integrated Cochlear Amplifier
• 
• 2. Envoy Esteem
• eardrum as the microphone
• sound pressure level (SPL) output close to 110 dB
• piezoelectric transducer (the driver) attached to the capitulum of the stapes
• lenticular process of the incus is removed
• battery change at 5 years
• Moderate to severe sensorineural hearing loss defined by Pure Tone Average (PTA)
• Unaided speech discrimination test score greater than or equal to 40%

• Electromagnetic hearing devices 
• electric current into a coil, thereby creating a magnetic flux that drives an adjacent magnet
• magnetic piston, is attached to one of the vibratory structures of the middle ear
• power is decreased by the square of the distance between the coil and the magnet; therefore, the coil and magnet must be close
• 1. Med-El Vibrant Soundbridge
• semi-implantable device composed of an external sound processor and amplifier, an audio processor, and an internal vibrating ossicular prosthesis
• is attached to the long process of the incus, and the magnet hugs the long axis of the stapes
• moderate to severe sensorineural hearing loss.  undergoing US clinical trial for use with conductive and mixed hearing losses.
• 
• 2. Otologics Middle Ear Transducer (partially implanted) and Carina(fully implanted)
• transducer mounted in a laser-drilled hole in the body of the incus
• 

• 3 types
• Air conduction with click stimulus (non freq specific)
• Air conduction with tone pips (freq specific) ,necessary for aiding
• Bone conduction

• Latency
• Eight nerve = 2ms
• Cochlear nucleus = 3.0
• Olive superior =4.7
• Lateral leminiscus = 5.3
• Inferior colliculus 5.9 (reduced to 5.5 with maturation)

• 6-9mths (sit up and head turn required)
• Distractor – plays with the child
• Tester – moves into position for sound presentation
• The Distractor phases out play activity
• THE Tester presents the sound
• THE child turns
• The distractor observes the response – is it valid??
• Yes it is, rewards the child with a smile, tickle, verbally
• Distractor regains the child’s attention facing forward and testing continues in this manner

• consider immediate prescribing
• children younger than 2 years with bilateral acute otitis media
• children with otorrhoea who have acute otitis media
• patients with acute sore throat/acute pharyngitis/acutetonsillitis when three or more Centor criteria are present

• Immediiate antibiotics
• are systemically very unwell
• symptoms and signs suggestive of serious illness and/or complications (particularly pneumonia,mastoiditis, peritonsillar abscess, peritonsillar cellulitis, intraorbital or intracranial complications)
• high risk of serious complications because of pre-existing comorbidity

• 201 cobalt beams
• Four collimator sizes are available, 4, 8, 14 and 18 mm
• Takes 2 years to see response
• </= 16Gy = reduced risk of complications
• Tumour control 95%
• Facial nerve dysfuntion 1%, trigeminal neuralga 3%
• Hearing preservation 50%
• , acute swelling of the tumor occurs, necessitating supportive therapies such as ventriculoperitoneal shunting, steroid administration, and seizure control

• Fractionated regimens - lower complication (evidence mixed)
• small but definite risk of malignant transformation of tumor

Comparing stereotactic radiation with microsurgery, studies show substantially less cost for radiation treatment of acoustic tumors smaller than 3 cm in diameter and comparable results in terms of postoperative outcomes, as of mean follow-up periods on the order of 5-10 years for most Gamma Knife studies and 3-4 years for LINAC based fractionated treatment studies

• Occupational
• Recreational
• Medicinal

Risk factors - renal impairement, age <5 and elderly, pre-exisitng hearing disorders, concomitant noise exposure,genetic.

• Aminoglycosides
• Streptomycin, gentamycin = vestibulotoxic
• Amikamycin, neomycin, tobramycin = cochleotoxic

• Platinum based chemotherapy
• Dose dependent
• 25-90% permanent  hearing loss

Loop diuretics - 5%

• Salicylates
• Quinine

Organophosphates/pesticides

• Testing - Extended high frequency audiometry and distortion product otoacoustic emissions
• Chemotherpay - prior, with each dose and onset of symptoms
• Aminglycosides - weekly during treatment, esp if >21 days

• Treatment
• Treat other ear disease
• Avoid loud noise exposure
• Avoid multiple vestibulotoxic medication
• Single daily dosing

N-acetyl cyteine protective in dialysis patients reciving aminoglycoside

• Steroids benefical 50mg/day 10 days
• Acyclovir no additional benefit
• Pred 95% recovery at 9/12
• Nothing 85% recovery at 9/12

• Speech discrimination >60% for ossiculoplasty
• 50% closure AB gap to 10dB, 80% in best hands

• Prosthesis
• Autograft
• Allograft(same species)
• Isograft(genetically identical individual)
• Xenograft(different species)

• Materials
• Bone
• Cartilage
• Plastics(Teflon),silastics
• Bioceramics hydroxyapetit
• Metals - steel,platinum titanium
• Ionmeric glass - neurotoxic during application

• Types
• Partial (PORP) stapes superstructure present,
• Total (TORP) stapes superstructure missing, footplate to tm/malleus handle

• Infective
• Inflammatory - cholesterol granuloma, cholesteatoma, mucocoele
• Neoplastic - Chordoma, Chondrosarcoma, Meningioma, Schwannoma (trigeminal acoustic, jugular foramen), MetastasisGlomus tumor, Nasopharyngeal carcinoma
• Vascular - Intrapetrous carotid artery aneurysm

Cholesterol granulomas are believed to be secondary to chronic otitis media. A giant cell reaction ensues, and hemoglobin is broken down to form cholesterol debris.

• Gallium-67 scanning is used to monitor the course of the disease.
• Technitium-99 scanning is more specific in the diagnosis, but findings remain positive after the course of the disease so they cannot be used to monitor therapy.

• Trans mastoid - preserve hearing and carry little risk to the facial nerve, insufficient exposure for tumor resection, includes the supralabyrinthine approach, the subarcuate approach, and the retrofacial
• Middle fossa
• Transcochlear - good exposure, dead ear, incomplete recovery facial nerve common
• Infracochlear - transcanal in the triangular space bordered anteriorly by the carotid artery, posteriorly by the jugular vein/bulb, and superiorly by the basal turn of the cochlea. Exposure is limited, limited to draining cystic lesions of the apex.
• Transethmoid-transsphenoid
• Infratemporal fossa

• Origin -
• Mondini malformation
• patent Hyrtl fissure - congenital fusion plane between the otic capsule and the jugular bulb (=tympanomeningeal fissure)
• abnormal patency petromastoid canal(normally carries subarcuate artery)
• Tegmen dehiscence

Leaks occurring following trauma or recent skull base surgery can often be treated conservatively using a pressure dressing and a lumbar drain.

• Imaging
• CT
• MR - partially empty sella suggests increased ICP

post op leaks & leaks associated with temporal bone fractures,  almost always seal in 3-4 weeks with this conservative therapy

• Surgery
• Spontaneous leaks in children with otic capsule defects, such as Mondini deformity, can often be repaired by a transcanal approach. Because rarely any hearing is present, a stapedectomy is usually performed and the oval window obliterated with soft tissue. A transcanal approach can also be used in some cases of CSF leakage due to a patent Hyrtl fissure.
• However, in most cases of spontaneous leakage, a transmastoid approach is preferred This is especially true if the exact site of the leakage is not known or suggested on imaging studies. The exposure of a mastoidectomy usually allows excellent visualization of the leakage site. The site can often be repaired with a small amount of fascia supported by Gelfoam. 
• < 1 cm tegmen defect fascial repair can be supported with a tragal cartilage graft placed between the intact bony edges and the dura.
• Occasionally, a fat or muscle graft may be needed.I
• In rare cases, the exact site of leakage is not found, and diffuse leak is observed from multiple mastoid air-cell tracts. In this situation, the mastoid may need to be obliterated with fat. Obliteration of the middle ear and eustachian tube may also be required, especially if the leakage is not limited to the mastoid.
• Leaks may occur in ears that have previously undergone canal wall down mastoidectomy. Removal of the canal wall may also be dictated by the extent of disease when the leak is associated with an active cholesteatoma. In these situations, the external ear and mastoid epithelium must be completely removed and the ear canal sewn over. Abdominal fat is then used for obliteration.
• Leaks occurring from defects of the posterior cranial fossa anterior to the sigmoid sinus present a special problem. This is the area of the basal cistern, where no arachnoid mesh is present. Leakage from this area is explosive and profuse and is not well controlled with fascia alone. A large fat graft obliterating the mastoid is usually required.
• If a leak is due to a large (>1 cm) defect in the floor of the middle fossa, the problem is best addressed with a combined middle fossa/transmastoid approach.
• Recommended repair of such large defects is with a 3-layer technique. A layer of calvarial bone is sandwiched between 2 layers of fascia

• lumbar drain. Drainage should be accomplished by draining a specific amount every hour, usually about 10 mL. Occasionally, this causes severe headache, in which case a smaller amount can be removed or the fluid can be removed less frequently (eg, 5 mL every half hour).
• lumbar drain is usually left in place for 2-3 days postoperatively. If no sign of leakage is present, it is clamped and the patient is observed for an additional 24 hours. If no further leakage is observed, the drain is then removed.

• Type I = myringoplasty
• Type II perforations with erosion of the malleus. It involves grafting onto the incus or the remains of the malleus.
• Type III  destruction of two ossicles, with the stapes still intact and mobile. It involves placing a graft onto the stapes, and providing protection for the assembly.
• Type IV tympanoplasty is used for ossicular destruction, which includes all or part of the stapes arch. It involves placing a graft onto or around a mobile stapes footplate.
• Type V tympanoplasty is used when the footplate of the stapes is fixed.Wr/Tympanoplasty.html#b#ixzz2AinmvpUI

• Micro
• Histo
• CT/MR
• Technetium bone scan
• Indium white cell scan

• Michel dysplasia 3rd week, complete labyrinthine aplasia
• Cock defect/common cavity 4th week, cochlear & vestibule = one common cavity
• Cochlear aplasia 5th week, cochlear single cavity
• Mondini dyspe of cochlear duct and sacculelasia 5-6th week, cochlear 1.5 turns, assoc widened vestibular aqueduct
• Schiebe dysplasia collapse of cochlear duct and saccule, commonest abnormality causing congenital deafness
• Alexanders dysplasia Cochlear base turn dysplasia, familial high freq SNHL

Propylene glycol

In a studyof 615patients, Leonetti et al.identified 2% of patients presenting with otalgia and a normal ENT examination having malignant tumours in the infra temporal fossa.They also concluded that MRI of the head  and neck should be requested in all patients presenting with otalgia and a normal ENTexamination.

• 0.5ml gentamtcin 40mg/ml through fine bore neadle
• lie supine 30 mins
• dizzy after 3 - 4 days for a number of weeks
• r/v 6/52
• Consider second injection at 3/12

• Malleus present ABG<20dB 80%
• PORP ABG<20dB @5yrs 61%
• TORP ABG<20dB @5yrs 37%

• Aminoglycosides-irreversable, effects can be 6/12 after rx stopped, high freq first
• Loop diuretics- predominantly cochlear, reversiable early stage
• Antineoplastic drugs - platynium assoc, irreverable,
• Salicylates- reverable,cochlear inc tinnitus
• Quinines-similar to aspirin, reverable
• Topical drugs-

• Neurogenic
• Short latency cochlear & brainstem potentials eg ECochG
• Middle latency thalamocortical potentials eg ABR
• Lond latency cortical potentials eg CERA(good threshold testing)

• Myogenic
• Tympanic acoustic reflex

difficulty in processing auditory information in CNS

• Outer hair cells functional
• Auditory info not transmitted to auditory nerve and brain faithfully
• Abscent/abnormal ABR
• PTA normal to profound loss
• Abscent stapedial reflex
• Speech reception in quiet excellent to poor
• Speech reception in noise generally poor

Otosclerosis - stapedectomy 80-90% benefit, 5%worse

• Most common overweight, child bearing age
• Headaches,dizziness,nausea,visual disturbance,pulsatile tinnitus,hearing loss,aural fullness
• MR may see empty sella, opthomalogoy opinion for papilloedema,lumber puncture CSF>250mm H2O

• Treatment
• diretics
• weight loss, wight loss surgery
• intraventricular shunt

Dx longtime base tympanometry(use old tymapnometer)

• MR brain stem
• 2 types 
• Ordinary - associated withbrain stem lesions in Guillan Mollaret triangle
• Essential - no cause

• 1/3 adults have tinnitus experience
• Habituation is the norm
• 2/3 questioned 20yrs later did not report it
• Patients with tinnitus more likely to improve with time than worsen
• 90% people get tinnitus in sound proof room

• Aspirin
• NSAID
• Aminoglycosides
• Macrolides
• Ciprofloxacin
• Quinine
• Frusemide
• Cisplatin and other cytotoxics

• CT initially
• ?neuroendocrine tumour ?dehiscent carotid/jugular

MRI with MRA & MRV

Duplex US

• Audiological
• Hearing loss (rare)
• Hyperacusis to BC sound
• -Autohony,eye movements,neck turning, foot steps,
• Pulsatile tinnitus

Vestilbular symptoms

• Of 60 patients
• 90% sound induced vestibular symptoms
• 73% pressure induced vestibular symptoms
• 67% both
• 60% autophony
• 52% conductive hearing loss(often low freq)

Weber test lateralises with a normal appearing PTA

• Normal stapedial reflexes excluding otosclerosis
• Abnormal VEMP
• CT High res 0.5mm cuts reconstructed in 90 degeree and parallel to superior canal

• Management
• Conservative
• Loud noise avoidance and ear plugs for sound induced symptoms
• Grommets for pressure induced symptoms

Surgery for disabling vestibular symptoms

• Fix gaze in neutral position (labyrinthine lesion)
• Smooth pursuit patient follows examiners fingers at 3 feet(cerebellar/brainstem lesion will produce saccadic movement)
• Gaze patient looks 30 degree left right up dpwn(midline/cerebellum)
• Saccades Patient looks back and forwards between 2 outstretched hands fingers (spinocerebellar ataxia/intranuclear opthalmoplegia)

• 1. Head shadow affect - helped by cross over aid
• 2. Sound localisation - not helped by head shadow effect
• 3. Hearing in noisey environements - helped by crossover aid if noise in good ear