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32. Meniere's Disease Investagations and treatment.pptx
- 1. Mèniére's Disease ( Investigations , differentiation from retro-cochlear lesions and treatment and vestibular rehabilitation) DR ANAND JHA 1ST YEAR RESIDENT, ENT-HNS KISTMCTH, LALITPUR
- 2. Roadmap • Investigations for Meniere’s disease • Differentiation from retrocochlear lesion • Management
- 3. Investigations 1. Assessment of cochlear function 2. Assessment of vestibular function.
- 4. Assessment of cochlear function Pure tone audiometry Flat pattern (42%) Peaked (32%) Downward sloping (19%) Rising (7%) (Belinchon et al.,2011) (AAO-HNS 1995) Stage of Meniere’s disease: Stage 1: A four tone avg of <26dB Stage 2: 26-40dB Stage 3: 41 to 70dB Stage 4: more than 70dB (Glasscock Shambough, 6th ed.)
- 5. Assessment of cochlear function Otoacoustic emission Absence of measurable OAE in frequency range affected by Meniere’s disease. Source: Scott-Brown’s Otolaryngology,Head and Neck Surgery 7th Ed
- 6. Tympanometry / Acoustic reflex • Normal tympanogram • Elicitation of acoustic reflex <60 dB patient threshold (Recruitment) • No abnormal reflex decay Assessment of cochlear function Source: Scott-Brown’s Otolaryngology,Head and Neck Surgery 7th Ed
- 7. Glycerol dehydration test • Acts as osmotic diuretic • Reduce endolymphatic pressure • Oral (usually) or IV (1.5mg/kg of 86% glycerol) • Measure Continuous transtympanic ECOG, PTA/SDS after 90min to 3 hrs of ingestion • 63% Meniere’s disease patients significant ↓ SP/AP width in 2 hours (15% change in SP/AP ratio) Moffat et al. 1992 • PTA: improvement of 15dB or more at min 3 frequencies (Aso S., 1993) • Speech audiometry: 16% increase in SDS (Aso S., 1993)
- 8. Assessment of vestibular function Calorie test • Hypoactivity of vestibule-ocular function upon calorie stimulation. • Significant calorie response reduction in 48-73.5% pt with meniere’s disease. • Complete absence of response in 6-11% (Park et al.,2005) Electronystagmography (ENG) • Reduced vestibular response in the affected ear • Irritative phase : fast phases directed toward involved ear • Paretic phase : fast phases directed toward opposite ear Source:Google image
- 9. Assessment of vestibular function Rotation chair test • Decreased gain • Abnormal phase • Asymmetry in the response Dynamic posturography • More sensitive than calorie test • 71% abnormal response • False positive – 5% (Soto et al, 2004) • Value in assessing effect of therapy Source:Google image
- 10. Assessment of vestibular function • Fistula test (hennebert sign) : fibrosis between footplate and vestibule • Tullio phenomenon: Body sway by low frequency sounds (vestibulospinal reflex) • Gait • Romberg’s test • Unterberger test: more than 45 degree rotation towards affected side
- 11. Other tests Measurement of plasma ADH levels Elevation of the plasma ADH levels in meniere's disease patients in the acute phase Aoki et al .,2005 ADH levels of meniere's disease patients • acute phase (5.80±1.37 pg/ml) • remission phase (2.26±0.41 pg/ml) (p < 0.05) In other peripheral vertigo patients • Acute phase (1.71±0.23 pg/ml) • Remission phase (1.45±0.15 pg/ml)
- 12. Metabolic and other screening tests • Full blood count • ESR • Urea, electrolytes • VDRL, TPHA • FBS, GTT • Lipid profile • TFT • Immunological assay, antibody screening
- 13. Differentiation of Meniere’s disease from retrocochlear lesions
- 14. Speech discrimination scores • Word recognition/discrimination or speech discrimination or phonetically balanced (PB) word testing • Phonetically balanced word lists used • Usually tested at 35 db above srt • Cochlear = score falls within range for given hearing loss • Retrocochlear = poor score than expected
- 15. Roll over phenomenon Speech audiogram. A—PB score in a normal person 100% at 30 dB. B—PB score in conductive hearing loss 100% at 70 dB. This curve runs parallel t o that of a normal person. C—Cochlear SNHL. PB max is at 70 dB and then attains a plateau. D—Roll over curve: PB max at 80 dB. PB scores decline as intensity increases further. Source: Scott-Brown’s Otolaryngology,Head and Neck Surgery 7th Ed
- 16. Most Comfortable Loudness(MCL) Level • Level that the listener designates as most comfortable for speech • Usually 40-50 db above srt • Determine hearing aid gain for candidates Uncomfortable loudness (UCL) level • Determine the upper hearing limit for speech • Normally 90 dB • Indicates max. Tolerable amplification • Can also establish the dynamic speech range ( ucl-srt) • Limited in recruitment
- 17. Recruitment • Abnormal loudness growth • Loudness grows more rapidly than normal at intensity levels just above threshold • Suggestive of cochlear hearing loss Measures: Alternate binaural loudness balance (ABLB) test Short increment sensitivity index (SISI) test
- 18. Alternate binaural loudness balance (ABLB) test • In pt with U/L hearing loss • A tone (1000 hz) →played alternatively to the normal and affected ear • 20 db above threshold of worse ear • Repeat at every 20 db ↑ until loudness is matched or the limit of audiometer reached • Conductive & neural deafness : initial diff is maintained through out • Cochlear lesion : partial, complete or over recruitment
- 19. Short increment sensitivity index (SISI) test • Ability to distinguish smaller changes in intensity of pure tone • Continuous tone is presented 20 db above the threshold and sustained for ~ 2 min • Every 5 sec, the tone is ↑ by 1 db and 20 such blips are presented • Conductive deafness= SISI score <15 % • Cochlear deafness = SISI score 70-100% • Nerve deafness = SISI score 0-20%
- 20. Auditory adaptation • Feature of retro-cochlear hearing loss • Normal auditory system → adapt to ongoing sound, esp near threshold → audible signal becomes inaudible • At high intensity → no adaptation • Retro-cochlear disorder → audibility may diminish rapidly owing to excessive auditory adaptation even at higher intensity levels • Tests: • Tone decay test (TDT) • Diagnostic bekesy audiometry
- 21. Tone decay test (TDT) • Measure of nerve fatigue • Normal ear - can hear a tone continuous for 60s • In nerve fatigue → stops hearing earlier • A tone, usu 4kHz, presented at 5 dB above pt’s threshold of hearing for 60s, stop hearing earlier →↑ by 5 dB, repeated till can hear for 60s Result = no of dB of decay Decay > 25dB : diagnostic of retro-cochlear lesion
- 22. Bekesy audiometry • A form of self recording audiometry • Tone freq is swept continuously from low to high over a period of several minutes • Two modes Continuous tone(c)– adaptation takes place Pulsed tone(intermittent mode)- adaptation is effectively obliterated by silent interval Adaptation = ↑ in threshold in continuous mode - ↑ in threshold in intermittent mode Width of tracing → indirect measure of recruitment
- 23. Meniere’s disease : Treatment Source: Cruz Melville da,Ménière’s disease A stepwise approach.Medicine Today,2014.
- 24. Treatment • Aim Stop vertigo Abolish tinnitus Reverse hearing loss • Spontaneous resolution rate : 60% to 80% without any therapy > 50% improve within 2 years and > 70% improve after 8 years. Source:(Glasscock – Shambaugh Surgery of the ear, 6th ed)
- 25. Treatment of Acute attack Reassurance Bed rest , hydration Inj. Prochlorperazine (Stemetil):12.5 mg I.M., 6-8 hrs Inj. Promethazine (Phenargan): 25 mg I.M., 6-8 hrs Inj. Diazepam (Calmpose): 5 mg I.V. Stat
- 26. Treatment : Prophylaxis between acute episodes
- 27. Non-surgical treatment • Reassurance Avoid tea, coffee, colas, chocolate, allergens, stress, smoking, alcohol, flying, diving, heights. • Diet: low salt (1.5 – 2 mg/day) • Diuretics: Thiazide + triamterene, Furosemide First line therapy
- 28. Non-surgical treatment • Cochlear vasodilators: Betahistine, Xanthinol nicotinate, Carbogen (5 % CO2 + 95 % O2 ), L.M.W. Dextran, Histamine drip. • Vestibular suppressants: Cinnarizine, Diazepam, Prochlorperazine, Dimenhydrinate • Dexamethasone / IgG: ↓ auto-immunity, anti-inflammatory or ion transport mechanism • Dehydration by hyperosmolar fluids
- 29. Vestibular sedatives • Augment cerebellar clamping • Delay central compensation and can make it incomplete • Elderly - ↑ unsteadiness
- 30. Vasodilators Decrease ischemia in the inner ear and better metabolism of endolymph • Betahistine ↓ asymmetric functioning of vestibular end organs ↑ Microvascular circulation Inhibition of the activity in vestibular nuclei • Well tolerated • Nausea, headache • Cochrane database review (2011) – no evidence that Betahistine is effective or ineffective in patients with ménière’s disease or syndrome Oral: 16 mg TDS, Maintenance dose: 24-48 mg
- 31. Dietary Modification and Diuretics • Salt restriction and diuresis may be the best initial therapy for meniere disease • The goal of salt restriction and use of diuretics to reduce endolymph volume by fluid removal and/ or reduced production. • Neither salt restriction nor diuretic use has had its efficacy confirmed by double- blind placebo-controlled studies. Acetazolamide • Recommended based on the localization of carbonic anhydrase in the dark cells and the stria vascularis • Not proved to be clinically more effective than use of other diuretics. (Shinkawa.,1996) (Santos et al.,1993)
- 32. Local over pressure therapy Meniett Device • Transtympanic “micropressure” treatment • FDA approved in 1999 • Applies intermittent, alternating pressure 0-20 cm H20 over 5 min, thrice daily • Requires VTI • Mechanism of vertigo reduction is unclear, but it may facilitate endolymph absorption. (Glasscock Shambough, 6th ed) • Significant decrease in vertigo symptoms for the first 3 months of therapy, but afterward similar to a placebo device (Gates et al.,2004) • Simple placement of a ventilation tube with no additional therapy has been reported to control vertigo symptoms in many patients with meniere disease. (Sugawara.,2003)
- 34. Surgical treatment • No definite criteria • Severity of symptoms • Who fail to maximal medical therapy Points to be considered before surgery • Age • Risks of surgery • Preop hearing • Status of contralateral ear • Effectiveness of central compensation
- 35. A. Hearing preservation + Balance preservation: 1. Endolymphatic sac decompression / shunting 2. Sacculotomy by puncture of footplate 3. Cochlear duct piercing via round window B. Hearing preservation + Balance ablation: 1. Chemical labyrinthectomy 2. Vestibular neurectomy 3. Vestibular end organ destruction by USG/Cryoprobe C. Hearing ablation + Balance ablation: 1. Section of VIII nerve 2. Total labyrinthectomy Surgery Historical importance
- 36. Procedures involving hearing and vestibular preservation COCHLEOSACCULOTOMY: • Cochlear-endolymphatic shunt procedure • 25% incidence of high-frequency SNHL • 10% incidence of profound deafness (Schuknecht,1991) • Alternative to labyrinthectomy in elderly patients with preexisting severe hearing loss Cochleosacculotomy Sacculotomy: Fick’s needle puncture of footplate Cody’s tack puncture of footplate
- 37. Endolymphatic Sac Surgery • Portmann ,1926 : 1st endolymphatic sac surgery • Types of procedures • Bony decompression of sac (Shambaugh) • Endolymphatic subarachnoid shunt (House) • Endolymphatic mastoid shunt (Shea) • Drainage: incision of the sac to allow drainage • Excision of the sac
- 38. How endolymphatic decompression helps in Meniere’s disease ? • Release of external compression on the sac • Neovascularization of the perisaccular region, allowing passive diffusion of endolymph • Creation of an osmotic gradient out of the sac Complications • Hearing loss • CSF leak • FN palsy
- 39. Sac shunting into mastoid Paparella technique for endolymphatic mastoid shunting
- 41. Endolymphatic Sac Surgery • RCT in Denmark, ESS vs sham cortical mastoidectomy F/u - 9 year. No significant difference in outcome-(Bretlau et al.,1989) • Cochrane review., 2010 No significant difference in outcome of ESS compared to cortical mastoidectomy or VTI
- 42. Procedures on the other ear structures • Grommet insertion • Middle ear osmotic therapy
- 43. Procedures involving hearing preservation and vestibular ablation
- 44. Chemical ablation of vestibular end organ Intratympanic Ablation • Fowler (1948) and Schuknecht (1957) established role of aminoglycoside therapy. • Streptomycin used initially • Vertigo eliminated in all patients • Profound hearing loss in all patients • Gentamicin treatment now preferred (chemical labyrinthectomy) • More vestibuloselective • Theoretical targets of therapy are • Cells of the stria vascularis • Dark cells of saccule/utricle • Higher doses destroy the hair cells of the cochlea
- 45. Intratympanic Gentamicin Many methods of delivery exist • Injection directly into RW niche • Injection through grommet • Microcatheter • Gelfoam placement • Microwick • Minipumps • Side effects can include: • Temporary imbalance or nystagmus • Hearing loss • Tinnitus
- 46. Gentamicin dosing schedule • Low dose • Weekly • Multiple daily • Titration • Profound hearing loss in 10 % (Nedzelski et al.,1993) • Side effect increase with dose and frequency • Single injection of gentamicin controlled vertigo in 41% of patients (Harner et al.,2001)
- 47. Nonablative Procedures for Meniere's Disease 1. Intratympanic Injection of Corticosteroids Mechanism: • Anti-inflammatory effect • Influence ion transport in the labyrinth • Concentrations: 2 to 24 mg/ml (12 mg/ml) • Repeat dosing : 3 month Retrospective study (n=129), John hopkins university - Satisfactory vertigo control in 91% , for 2 years or more - 63% had multiple injections At the end of the 2-year period - 70% required no further injections - 26% continued to receive intratympanic steroids - 3% went on to ablative therapy. (Boleas-aguirre et al.,2008)
- 48. Intratympanic Dexamethasone, Intratympanic Gentamicin, and Endolymphatic Sac Surgery for Intractable Vertigo in Meniere's Disease • Levent et al.,2001Ankara, Turkey • Prospective study • Dexamethasone via VTI (n=24) • Gentamicin via VTI (n=16) • ESD (n=25) • F/u 6 month • Results: • Satisfactory control of vertigo was 72%, 75%, and 52%, respectively for the ID, IG, and ESD. • Gentamicin group: 2 pts, total hearing loss. • Dexamethasone group: hearing level - same in 46% pts, 16% increase and 38% decrease
- 49. Vestibular Nerve Section • Success rate : 80-95% (Glasscock – Shambaugh surgery of the ear, 6th ed) • Approaches: • Middle fossa • Retrolabyrinthine/retrosigmoid • Transcanal • Translabyrinthine • Transcochlear • Complications • Damage to facial nerve • Damage to cochlear nerve • CSF leak (about 13%)
- 50. Middle cranial fossa approach Vestibular Nerve Section contd.. Selective transection of vestibular nerve, middle fossa approach
- 51. Middle cranial fossa approach • temporal craniotomy centered above the external auditory canal. • The middle fossa dura is elevated from the surface of the temporal bone, and the temporal lobe is retracted extradurally. • The dura of the IAC is skeletonized, with care taken not to injure the cochlea, the superior semicircular canal, or the labyrinthine portion of the facial nerve • the dura is incised, and the facial nerve is positively identified within the internal canal by electrical stimulation. • The superior vestibular nerve may be avulsed from its lateral attachments and sectioned. • The same procedure is repeated with the inferior division of the vestibular nerve, with care taken to avoid the cochlear blood supply and adjacent fibers of the auditory nerve traveling to the basal turn of the cochlea
- 52. Middle cranial fossa approach Advantage • FN & SVN separated by bill’s bar • Less injury to cochlear nerve • Minimal dural violation Disadvantage • FN injury (highest among all approach) Temporary paresis ~33% • Temporal lobe retraction Vestibular Nerve Section
- 53. Retrolabyrinthine Vestibular Neurectomy Vestibular Nerve Section contd.. Advantage • Technically simpler Disadvantages • VIIIth nerve exposed only in CP angle • Difficulty separating cochlear and vestibular fibres • Cerebellar retraction • Restricted view • CSF leak
- 54. Retrosigmoid (Suboccipital) Vestibular Neurectomy Vestibular Nerve Section contd.. Advantage Good exposure Less CSF leak Preferred by neurologists (temporal bone dissection not required) Disadvantage Poor proximity to nerve from depth of wound Retraction of cerebellum Postoperative headache
- 55. Translabyrinthine vestibular neurectomy Vestibular Nerve Section contd..
- 56. Translabyrinthine vestibular neurectomy • Nerves of the internal auditory canal are exposed. • Traction on the transected end of the superior division of the vestibular nerve (SVN) permits exposure of the inferior division of the vestibular nerve (IVN). • Transection of the nerve trunk proximal to the vestibular ganglion (VG) completes excision of vestibular neurons.
- 57. Transcochlear vestibular neurectomy Vestibular Nerve Section
- 58. Transcochlear vestibular neurectomy • Medial wall of vestibule and lateral cochlear wall are removed to expose the distal end of the internal auditory canal (IAC). • Cochlear and vestibular nerve branches are transected at their distal ends.
- 59. Procedures involving hearing and vestibular ablation
- 60. Labyrinthectomy • Useful in patients with no serviceable hearing and those who cannot tolerate intracranial procedure • Success rate ~ 98% (Glasscock – shambaugh surgery of the ear, 6th ed) • 2 approaches 1. Transcanal labyrinthectomy (oval window labyrinthectomy) → relatively non- invasive → Incomplete removal of neuroepithelium 2. Transmastoid labyrinthectomy (gold standard for surgical ablation of vestibular function) → Removal of all neuroepithelium under microscopic vision
- 62. Transcanal labyrinthectomy • tympanomeatal flap to enter the middle ear and accessing the vestibule of the bony labyrinth by removing the stapes from the oval window. • Some surgeons advocate removing bone from the promontory below the oval window toward the round window to improve visualization of the vestibue. • The saccule and utricle are identified and removed.
- 64. Transmastoid labyrinthectomy • postaurlcular incision. • mastoid cavity is opened with identification of the three semicircular canals and the facial nerve. • facial recess is shown opened, although this Is an optional part of the procedure. • three semicircular canals are blue lined and traced to their ampullated ends. • The ampullae and neuroepithelium of the three semicircular canals are exposed, along with the otolithic organs (the saccule and the utricle).
- 65. Rehabilitation therapy Vestibular rehabilitation procedure • Habituation exercises and postural control • Improve the overall balance function in both reported and objective measures • Maximizing CNS compensation • Help speed the recovery • Alleviate symptoms and improve function • Cawthorne-cooksey exercises • Tinnitus • Counseling • Hearing aids
- 66. In bed or sitting • Eye movements -- at first slow, then quick up and down from side to side focusing on finger moving from 3 feet to 1 foot away from face • Head movements at first slow, then quick, later with eyes closed bending forward and backward turning from side to side Sitting • Eye movements and head movements as above • Shoulder shrugging and circling • Bending forward and picking up objects from the ground Cawthorne-Cooksey Exercises
- 67. Standing • Eye, head and shoulder movements as before • Changing form sitting to standing position with eyes open and shut • Throwing a small ball from hand to hand (above eye level) • Throwing a ball from hand to hand under knee • Changing from sitting to standing and turning around in between Moving about (in class) • Circle around center person who will throw a large ball and to whom it will be returned • Walk across room with eyes open and then closed • Walk up and down slope with eyes open and then closed • Walk up and down steps with eyes open and then closed • Any game involving stooping and stretching and aiming such as bowling and basketball Cawthorne-Cooksey Exercises
- 68. Meniere’s disease in only hearing ear First line 1) Dietary modification (salt restriction, ↓caffeine, avoid alcohol) 2) Diuretics 3) Oral steroid Second line 1) Meniett device 2) IT corticosteroid 3) Endolymphatic sac mastoid shunt
- 69. Hearing rehabilitation • Hearing loss - Fluctuating course • Usually up to 50 DB • Hearing aid • Cochlear implant
- 70. Reference • Scott-Brown’s Otorhinolaryngology, Head and Neck Surgery, 8th ed • Scott-Brown’s Otorhinolaryngology, Head and Neck Surgery,7th ed • Glasscock – Shambaugh Surgery of the ear, 6th ed • Cummings otolaryngology head and neck surgery,5th ed
- 71. Dr. Ambalika Shakya /Meniere's disease 2021
Editor's Notes
- Stages of Meniere’s disease based on hearing levels Stage 1: A four-tone average of less than 26 dbStage 2: A four-tone average between 26 and 40 dbStage 3: A four-tone average between 41 and 70 dbStage 4: A four-tone average of more than 70 db
- Glycerol dehydration test and electrocochleography are the main diagnostic tests in current practice, while vestibular evoked myogenic potentials may be used in disease staging. Imagine techniques are not specific enough to set alone the diagnosis of Meniere’s disease, although they may be necessary to exclude other pathologies. Recently developed 3D MRI protocols can delineate the perilymphatic/endolymphatic spaces of the inner ear and aid diagnosis
- Stge 1 n 2 early reversible, stge 3 n 4 fixed not reversible
- Other, less invasive recording techniques are available as well, including the use of electrodes (e.g., the Coats leaf electrode, a gold foil–wrapped foam plug, or a tympanic membrane surface electrode) placed extratympanically in the external ear canal. The tympanic membrane surface electrode is gaining in popularity because of ease of placement and the clarity and amplitude of the responses it provides.
- The combination of glycerol dehydration test and audiometry has a high sensitivity in the diagnosis of Meniere’s disease. After a baseline audiogram is performed, the patient takes 1.5mg/kg of 86% glycerol with the same amount of water per os. Another audiogram is performed 90 minutes and 3 hours after ingestion. The test is considered positive when there is an improvement of 15 db or more in pure-tone thresholds at minimum three frequencies, or an improvement of 16% of speech discrimination scores. In addition, improvements in postural control may also be expected, and have actually been observed in as many as 70% of patients, who are undergoing the test during disease attacks. Ann Indian Acad Neurol. 2011 Jan-Mar; 14(1): 12–18. These studies suggest that distortion product otoacoustic emission could be useful in diagnostics of Meniere's disease and would be a valuable diagnostic tool as an objective examination. Otolaryngol Pol. 2003;57(5):731-7. [Evaluation of glycerol test in Meniere's disease with pure tone audiometry and distortion product otoacoustic emission].[Article in Polish]
- Glycerol dehydration test and electrocochleography are the main diagnostic tests in current practice, while vestibular evoked myogenic potentials may be used in disease staging. Imagine techniques are not specific enough to set alone the diagnosis of Meniere’s disease, although they may be necessary to exclude other pathologies. Recently developed 3D MRI protocols can delineate the perilymphatic/endolymphatic spaces of the inner ear and aid diagnosis In the earliest stage (stage I) of Ménière's disease, fluctuating hearing loss or augmented VEMPs may be attributed to a mechanical, biochemical, or some other reversible cause. However, in the latest stage (stage IV), there are permanent morphological changes in the sense organs, including loss of hair cells accompanied by collapse of the Reissner membrane onto the organ of Corti, resulting in a flat-type hearing loss with a mean hearing level of more than 70 dB. Furthermore, loss of saccular macula associated with collapse of the saccular wall onto the otolithic membrane is thought to be responsible for a depressed-type VEMP, with an IAD ratio of up to −1. Okuno and Sando4 suggested that the severity of hydrops correlates to the severity of hearing loss. In the present study, the IAD ratio of the VEMPs increased significantly according to the stage of Ménière's disease (P = .04) (Table 3). Therefore, the IAD ratio of VEMPs, like the 4-tone average of hearing, shows promise in facilitating the staging of Ménière's disease. In other words, besides the hearing test, the VEMP test provides another aid for evaluating the stage of Ménière's disease.
- Hennebert sign: False positive fistula test in Meniere’s disease due to fibrosis between stapes footplate and utricle This sign is also seen in hypermobile stapes footplate as in congenital syphilis or idiopathic. Tulio phenomenon:The activation of vestibulo-spinal responses by low frequency sound seems to be a result of the Tullio phenomenon, in which sound energy activates the vestibular end-organ. The effect of low frequency sound (LFS) on postural stability was studied in 55 healthy volunteers and in 50 patients with Meniere's disease. The sound levels ranged from 130 to 132 dB and were given at frequencies of 25, 50 and 63 Hz. The patients with Meniere's disease displayed increased body sway during stimulation. In the individual response, 26% of the patients with Meniere's disease experienced significant body sway. ullio phenomenon, sound-induced vertigo, dizziness, nausea or eye movement (nystagmus) was first described in 1929 by the Italian biologist Prof. Pietro Tullio. (1881–1941)[1][2]During his experiments on pigeons, Tullio discovered that by drilling tiny holes in the semicircular canals of his subjects, he could subsequently cause them balance problems when exposed to sound. The cause is usually a fistula in the middle or inner ear, allowing abnormal sound-synchronized pressure changes in the balance organs.[3] Such an opening may be caused by a barotrauma (e.g. incurred when diving or flying), or may be a side effect of fenestration surgery, syphilis or Lyme disease. Patients with this disorder may also experience vertigo, imbalance and eye movement set off by changes in pressure, e.g. when nose-blowing, swallowing or when lifting heavy objects. Tullio phenomenon is also one of the common symptoms of superior canal dehiscence syndrome (SCDS), first diagnosed in 1998 by Dr. Lloyd B. Minor, The Johns Hopkins University, Baltimore, United States.[4] Vestibular glycerol test: The combination of glycerol dehydration test and audiometry has a high sensitivity in the diagnosis of Meniere’s disease. After a baseline audiogram is performed, the patient takes 100 g of 95% glycerol with the same amount of water per os. Another audiogram is performed 90 minutes and 3 hours after ingestion. The test is considered positive when there is an improvement of 10 db or more in pure-tone thresholds at two or more frequencies, or an improvement of 10% of speech discrimination scores. In addition, improvements in postural control may also be expected, and have actually been observed in as many as 70% of patients, who are undergoing the test during disease attacks. Ann Indian Acad Neurol. 2011 Jan-Mar; 14(1): 12–18. Gait: wide based in cerebellar lesion Romberg’s test: positive in vit B12 def or sensory ataxia as in neurosyphilis Unterberger test: 5o steps march with eyes closed. Swaying to either side more than 45 degree indicates vestibular pathology of that side.
- Enhanced cochlea due to disruption of blood labyrinth barrier, extravasation of contrast
- Diseases and factors causing tinnitus Otologic factors-Presbyacusis, Meniere’s disease, Noise-induced hearing loss, Otosclerosis Metabolic-Hypothyroidism, Hyperthyroidism, Hyperlipidemia, Zinc deficiency, Vitamin deficiency Neurologic-Head trauma, Whiplash injury, Multiple sclerosis, Meningitis effects Pharmacologic factors-Aspirin compounds, Nonsteroidal antiinflammatory , Aminoglycosides, Heavy metals, Heterocyclic antidepressant Dental factors-Temporo-mandibular joint syndrome Psychological factors-Depression,Anxiety Herpes zoster causes pain, vertigo and hearing loss, with vesicles in the ear canal (and if accompanied by facial palsy is termed Ramsay Hunt syndrome). Meningitis due to bacteria or fungi, carcinoma, lymphoma or sarcoid can cause vestibular and cochlear dysfunction associated with other cranial nerve lesions. Vasculitides, including some ear- and eye-specific syndromes such as Cogan’s syndrome and Susac’s syndrome (retinocochleocerebral vasculopathy), and syphilis can mimic Ménière’s disease. Brainstem lesions involving the vestibular nerve root or nucleus, such as multiple sclerosis, rarely cause a similar syndrome
- Alternate binaural loudness balance Short increment sensitivity index test Most comfortable loudness level Uncomfortable loudness level Tone decay test Supra threshold adaptation test
- Phonetically balanced word testing, performance intensity curve
- Interpretation of TDT (rosenberg 1958) Normal – 0 to 5 db in 60 seconds Mild - 10 to 15 db in 60 seconds Moderate – 20 to 25 db in 60 seconds Marked – 30 db or more in 60 seconds
- Bony overhang of the round window niche is removed to allow insertion of a 3-mm, right-angle hook through the osseous spiral lamina of the basal end of the cochlea. Penetration of the tip of the hook can be monitored by movement of the stapes footplate
- The ELS is bounded superiorly by the Donaldson line, posteriorly by the sigmoid sinus, anteroinferiorly by the jugular bulb, and laterally by the descending (mastoid) portion of the facial nerve. C’mastoidectomy, skeletonisation of lat and post scc, thin layer of bone intact over vertical seg of 7th nerve.
- Even the medial layer of dura is incised to shunt the endolymph to subarachnoid space
- The planum semilunatum is located on the lateral side of the crista ampullaris of the semicircular canal. With regard to the functions of the planum semilunatum, some researchers assume the existence of secretory activity based on the microstructural features observed in isotopic experiments. In the present study, in order to confirm the existence of an immunological mechanism in the ampulla of the semicircular canal, the distribution of immunoglobulins in the semi-circular canal of guinea pigs was investigated immunohistochemically. Positivity of IgG was observed in the constituent cells of the planum semilunatum or beneath the basement membrane of the cells. It is concluded that ample IgG, which is an important constituent of the body fluids, is collected within this region. The planum semilunatum containing such ample amounts of IgG might be involved in the immunological mechanism operating in the ampullar of the semicircular canal.
- Efficacy does not seem to be affected by the delivery route
- Low dose 40mg /ml
- The middle fossa approach begins with a temporal craniotomy centered above the external auditory canal. The middle fossa dura is elevated from the surface of the temporal bone, and the temporal lobe is retracted extradurally. The dura of the IAC is skeletonized, with care taken not to injure the cochlea, the superior semicircular canal, or the labyrinthine portion of the facial nerve. An effort should be made to dissect widely around the internal canal, so that its contents will be readilyvisible after the dura is opened (see Fig. 167-8, A). It is not necessary to completely expose the labyrinthine segment of the facial nerve, although confirming its location will help with orientation. facial nerve and auditory evoked potentials, the dura is incised, and the facial nerve is positively identified within the internal canal by electrical stimulation. The superior vestibular nerve may be avulsed from its lateral attachments and sectioned (see Fig. 167-8, B). The same procedure is repeated with the inferior division of the vestibular nerve, with care taken to avoid the cochlear blood supply and adjacent fibers of the auditory nerve traveling to the basal turn of the cochlea
- Ideal retrolabyrinthine exposure requires wide decompression of the middle and posterior fossa dura. The retrosigmoid dura should be exposed for approximately 1.5 cm posterior to the sinus to allow adequate extradural retraction later in the case. The bone anterior to the sinus is removed, until the bony labyrinth is outlined, and the entire ELS is exposed. The jugular bulb is the inferior limit of dissection. Because inferior bone removal is critical to satisfactory intracranial exposure, the surgeon should make every effort to open the retrofacial air cell tract and expose the sac, until the jugular bulb is skeletonized. Care should be taken to prevent entry of bone dust into the middle ear while drilling, because this may lead to delayed fixation of the ossicular chain. The presigmoid dura and the ELS are incised parallel to the sigmoid sinus, and a flap of dura is tacked forward to expose the posterior fossa. The cerebellum is gently retracted, and the CSF of the cerebellopontine angle cistern is released by incising the arachnoid membrane. Often, the flocculus of the cerebellum must be retracted to improve visualization of the eighth nerve. The trigeminal nerve and the tentorium cerebelli should be identified superiorly for orientation; the eighth nerve complex is identified inferiorly. Because the angle of vision is parallel to the posterior face of the petrous bone, the porus acousticus is not visible.
- The retrosigmoid approach to vestibular nerve section has the advantage of a generous exposure and a direct view of the seventh and eighth cranial nerves (Figure 34-4). The procedure sigmoid sinus as the anterior limit of exposure. The posterior fossa dura is opened, and the cerebellum is retracted to expose the cerebellopontine angle and petrous ridge. The cistern is decompressed with an incision that allows the cerebellum to fall medially obviating retraction. The vestibular, cochlear, and facial nerves are identified, and then the superior and inferior vestibular nerves can be sectioned (Figure 34-5). Afterward the dura is reapproximated, and the bone flap is replaced and covered as the wound is closed.
- Translabyrinthine vestibular neurectomy. A, Nerves of the internal auditory canal are exposed. B, Traction on the transected end of the superior division of the vestibular nerve (SVN) permits exposure of the inferior division of the vestibular nerve (IVN). C, Transection of the nerve trunk proximal to the vestibular ganglion (VG) completes excision of vestibular neurons. The anterior inferior cerebellar artery (AICA) is occasionally visualized. CN VII, seventh cranial nerve; VN, vestibular nerve.
- Transcochlear vestibular neurectomy. Medial wall of vestibule and lateral cochlear wall are removed to expose the distal end of the internal auditory canal (IAC). Cochlear and vestibular nerve branches are transected at their distal ends. IVN and SVN, inferior and superior divisions, respectively, of the vestibular nerve; Tym, tympanic segment of cranial nerve VII (CN VII).
- procedure begins by elevating a tympanomeatal flap to enter the middle ear and accessing the vestibule of the bony labyrinth by removing the stapes from the oval window. Some surgeons advocate removing bone from the promontory below the oval window toward the round window to improve visualization of the vestibule (Fig. 167-5, A). The saccule and utricle are identified and removed. An attempt may be made to reach and remove the ampullae of the horizontal and superior semicircular canals, although this step requires blind manipulation with a long right-angled instrument inserted medial to the facial nerve. Augmenting this procedure by a selective section of the nerve to the posterior semicircular canal ampulla should help to prevent residual posterior canal function. To accomplish this, the bony exposure of the vestibule can be extended by drilling near the round window until the nerve to the posterior ampulla is identified and divided. Many surgeons supplement their mechanical efforts by filling the vestibule with absorbable packing soaked with an ototoxic aminoglycoside antibiotic, which enhances the likelihood of success.
- The approach begins with a standard postaurlcular incision.The mastoid cavity is opened with identification of the three semicircular canals and the facial nerve. The facial recess is shown opened, although this Is an optional part of the procedure. C, The three semicircular canals are blue lined and traced to their ampullated ends. The ampullae and neuroepithelium of the three semicircular canals are exposed, along with the otolithic organs (the saccule and the utricle).