Menieres disease

menieres disease and its management

1. MENIERE’S DISEASE Dr. Rajendra Singh Lakhawat Department Of Otorhinolaryngology and Head & Neck Surgery SMS Medical College and Hospital, Jaipur, India

2. Prosper Menière (18 June 1799 – 7 February 1862) was a French doctor who first identified that the inner ear could be the source of a condition combining vertigo, hearing loss and tinnitus, which is now known as Ménière's disease (MD) Menière, P. Mémoire sur les lésions de l’oreille interne donnant lieu à des symtômes de congestion cérébrale apoplectiforme. Gaz . Med. Paris 16 , 597–601 (in French) (1861).

3. INTRODUCTION MD is a complex, multifactorial disease of the inner ear that causes spontaneous episodes of VERTIGO (the sensation that you or your environment is spinning), FLUCTUATING HEARING LOSS , tinnitus (a ringing noise in the ears) and AURAL FULLNESS (a feeling of pressure in the ear).

4. Core hypotheses for Menie`re’s disease

5. The connection between the inner ear and three nerves and a sectional view of the cochlea.

6. The membraneous labyrinth contains endolymph and the bony labyrinth contains perilymph, both in the vestibule and in the cochlea. The vestibule includes two otolith organs (the saccule and the utricle), which are sensitive to linear acceleration, and three semicircular canals, which are sensitive to rotational acceleration (head rotation). The spiral ganglions and the Scarpa ganglions contain bipolar neurons connected to sensory cells in the cochlea and the vestibular apparatus, respectively.

7. The cochlea consists of the scala vestibuli and scala tympani, which are filled with perilymph, and the scala media, which is filled with endolymph. The key sensory organ is the organ of Corti , which contains the inner hair cells, the outer hair cells and supporting cells. The stria vascularis produces endolymph. The endolymphatic duct and sac are thought to be involved in the reabsorption and regulation of endolymph.

8. VIDEO SUMMARY OF MD

9. A characteristic feature often observed in MD is endolymphatic hydrops (EH), which is an excessive accumulation of endolymph in the cochlea and the vestibular system in the inner ear. A potential explanation for the accumulation of endolymph is disturbed fluid homeostasis The cause of EH and the relationship between EH and MD are still unclear. Recent evidence suggests that EH has a causal relationship with MD, but that it requires additional cofactors to become symptomatic.

10. Migraine is considered to be one of the most important cofactors in MD In most patients, the clinical symptoms of MD present after a considerable accumulation of endolymph has occurred. Thus, EH can be symptomatic or asymptomatic, whereas MD is by definition associated with symptoms. MD can be unilateral or bilateral. Unilateral MD refers to MD with symptoms arising from only one ear, although this does not exclude the possibility that the other ear has asymptomatic EH.

11. Its diagnosis is complex Classification methods have evolved over time and are often based on a combination of several symptoms The diagnostic criteria for MD defined by the American Academy of Otolaryngology–Head and Neck Surgery (AAOHNS) in 1995. This classifies MD into different subtypes: certain, definite, probable and possible MD. The diagnosis of certain MD requires the confirmation of EH by histopathology of the temporal bone taken after death

12. AAO-HNS DIAGNOSTIC CRITERIA 1995 Certain Menière’s disease Definitive Menière’s disease plus histopathologic confirmation Definite Menière’s disease Two or more definitive spontaneous episodes of vertigo lasting 20 minutes or longer Audiometrically documented hearing loss on at least one occasion Tinnitus or aural fullness in the treated ear Other causes excluded

13. Probable Menière’s disease One definitive episode of vertigo Audiometrically documented hearing loss on at least one occasion Tinnitus or aural fullness in the treated ear Other causes excluded Possible Menière’s disease Episodic vertigo of the Menière type without documented hearing loss, or sensorineural hearing loss fluctuating or fixed, with disequilibrium but without definitive episodes Other causes excluded

14. Cochlear and vestibular Meniere’s disease defined by the AAOO in 1972 Cochlear Meniere’s disease (MD), or MD without vertigo, is characterized solely by a fluctuating and progressive sensorineural deafness with all auditory test results typical of MD . Many patients notice a fullness in the ear coincident with a sudden drop in hearing. Some patients subsequently develop the definitive dizzy spells and the qualifying term cochlear is discarded.

15. Vestibular MD, or MD without deafness , is characterized solely by the definitive spells of vertigo . This is more difficult to diagnose as there is no objective finding between spells. The diagnosis may be accepted on the exclusion of other diseases. Some patients subsequently develop deafness and the qualifying ‘vestibular’ is dropped.

16. 2015 proposed criteria of Meniere’s disease Criteria proposed by the Classification Committee of the Barany Society, the Japan Society for Equilibrium Research, the European Academy of Otology and Neurotology, the Equilibrium Committee of the American Academy of Otolaryngology–Head and Neck Surgery and the Korean Balance Society Definite Meniere’s disease At least two spontaneous episodes of vertigo , each lasting from 20 minutes to 12 hours Audiometrically documented low-frequency to medium-frequency sensorineural hearing loss in one ear , defining the affected ear on at least one occasion before, during or after one of the episodes of vertigo Fluctuating aural symptoms (hearing, tinnitus or fullness) in the affected ear Not better accounted for by another vestibular diagnosis

17. Probable Meniere’s disease At least two episodes of vertigo or dizziness, each lasting from 20 minutes to 24 hours Fluctuating aural symptoms (hearing, tinnitus or fullness) in the affected ear Not better accounted for by another vestibular diagnosis

18. Epidemiology The prevalence of MD was estimated as 0.27% in the United Kingdom A study in the United States reported an estimated prevalence of 0.19% In earlier studies, the estimated prevalence varied from 17 to 513 cases per 100,000 MD is regarded as a disease of middle age. The mean age of onset of MD peaks at 40–50 years; 10% of patients with MD had a disease onset at ≥65 years of age

19. Cumulative age distribution of onset of symptoms in patients with Meniere’s disease. The mean age at onset of symptoms was estimated to be 44.0 years on the basis of data from 1,035 patients in Finland

20. Mechanisms / pathophysiology MD is a complex, heterogeneous disorder in which numerous underlying factors interact, including anatomical variations in the temporal bone, genetics, autoimmunity, migraine, altered intralabyrinthine fluid dynamics and cellular and molecular mechanisms.

21. Histopathology

22. Endolymphatic hydrops EH is characterized by an accumulation of fluid (endolymph) , leading to an expansion of the endolymphatic space. The progression of Meniere’s disease is associated with the advancement of EH. The thin membrane bordering the endolymph and the perilymph is flaccid. When a rupture of the membraneous labyrinth and subsequent collapse of the endolymphatic space is observed at some point in the inner ear, EH is usually observed in other parts inside the inner ear.

23. One of the earliest and most important findings IS that of gross distension of the endolymphatic system in the inner ear in patients with MD. Studies assessing the distribution of EH in specimens obtained after death from patients with MD revealed the universal involvement of structures of the inferior parts of the inner ear (the saccule and the cochlea), with less-frequent involvement of the superior sections (the utricle and the semicircular canals)

24. Exaggerated narrowing of the isthmus of the endolymphatic duct is a histopathological feature more commonly observed in the temporal bone of patients with MD. it remains unclear whether EH results from the overproduction or under-resorption of endolymphatic fluid. Histopathological evaluation of the diseased cochlea shows distension of the scala media with ballooning of Reissner’s membrane into the scala vestibuli

25. damage to ganglion cells rather than damage to sensory hair cells is directly associated with the initiation and progression of symptoms. the scarcity of samples from patients with confirmed clinical MD has propelled the scientific community to develop animal models to study the pathogenesis of this disease.

26. Experimental models of MD Guinea pig models of EH mirror the human condition in that a vast decrease in the diameter of the eighth cranial nerve occurs, suggesting that MD is primarily a neuronal pathology. these studies have shown that EH causes a profound loss of spiral ganglion cells in the apical region of the cochlea ; the magnitude of the loss is correlated with the severity of EH. These studies suggest that early functional or biochemical disturbances lead to progressive cochlear and vestibular dysfunction , but the exact mechanisms are currently unknown

27. Quantitative studies show a topographical pattern of spiral ganglion cell loss (that is, starting at the apex of the cochlea and moving towards the base); this pattern mirrors the progression of EH (apex to base) . Targeting neurotoxicity might be a promising avenue for the treatment of MD. For example, systemic treatment with riluzole (a glutamate release inhibitor) and dimethyl sulfoxide (a free radical scavenger) slowed hearing loss in the surgical model of MD in guinea pigs

28. One other potential mechanism of EH progression is linked with the vasopressin type 2 receptor (V2R), a water channel protein regulated by vasopressin that controls fluid homeostasis in the inner ear. Some studies have shown that patients with MD have increased plasma levels of vasopressin as well as increased V2R mRNA expression in the endolymphatic sac

29. Clinical symptoms Symptoms can evolve during the course of the EH disease, either spontaneously or as a response to treatment. Although hearing loss is correlated with the extent of EH in most patients, this relationship is complex as hearing can be relatively well preserved despite prominent EH. The association of tinnitus and vertigo with EH is not evident owing to insufficient data.

30. The occurrence of recurring episodes of spontaneous vertigo is the main feature of MD and it is present in 96.2% of patients ( Paparella and Mancini, 1985). Vertigo is the most disabling symptom , commonly described as spinning, exacerbated by head movements, and accompanied by nausea, vomiting, and sweating. Spells of vertigo last several hours , and when they subside patients complain of unsteadiness for several days . These spells are often preceded by tinnitus, aural fullness, and a decrease in hearing in the affected ear. Some patients report sudden falls with no previous warning or provocative factor, and without vertigo, loss of consciousness, or other neurologic symptoms. These episodes are named otolithic crises of Tumarkin

31. Hearing loss is associated with vertigo attacks in 77% of patients (Lopez- Escamez et al., 2014) The basilar membrane is wider and softer in the apex than in the base of the cochlea. As a consequence, distension of the membranes in EH start within the apex , as does hearing loss. Hearing loss associated with MD thus begins with low frequencies . The threshold of low-tone and middle-tone hearing can indirectly reflect the severity of EH in the cochlea. It is fluctuating in the first years.

32. as the disease progresses, hearing worsens with each crisis and it does not return to the previous level. Eventually, deafness becomes permanent and no longer fluctuates. Lermoyez’s syndrome is a rare phenomenon in some patients with MD. It consists of a transient improvement of hearing during the onset of a vertigo attack . Tinnitus may also improve. A possible explanation for Lermoyez syndrome is the movement of endolymph from the cochlea towards the semicircular canals, resulting in a reduction of EH in the cochlea, but an increase in EH in the semicircular canals

33. Some patients report a previous history of hearing loss, often since childhood, preceding the onset of the episodes of vertigo. Tinnitus may be the initial symptom of MD, preceding the full picture by months. It is commonly described as low-pitched, as a harsh, roaring, machine-like sound or a hollow seashell sound . At the onset of the disease, tinnitus is intermittent and appears during the attacks in 83% of patients and disappears afterward

34. Vertigo in MD arises because of the abnormal excitability or cessation of sensory input from the affected ear as a result of fluid disturbance in the inner ear Once initiated, vertigo attacks persist for up to several hours. The rupture of Reissner’s membrane or the membranous labyrinth has been suggested as a cause of vertigo attacks mediated by the leakage of high-potassium endolymph into the perilymph, which can depolarize and activate auditory nerve fibres into pathological firing

35. drop attacks or Tumarkin attacks — a sudden fall without loss of consciousness that can be potentially life-threatening — are caused by disorders of the otolith organs in the utricle and the saccule. Serious drop attacks occur in 6% of patients with MD and some milder types of drop attack in 72% of patients with MD Drop attacks are generally difficult to treat compared with the typical vertigo attacks, but can resolve spontaneously

36. Disease progression. Initial symptoms include only one of the typical features (vertigo, hearing loss, tinnitus or aural fullness) Symptoms often start with vertigo (in 41.2% of patients) with or without tinnitus and aural fullness, whereas hearing loss as the sole symptom occurs considerably less frequently (in 15% of patients). MRI has shown that EH can progress during the disease course and its severity is correlated with the deterioration of cochlear, saccular and horizontal semicircular canal function. Considering the frequency of EH in asymptomatic and symptomatic ears , it is thought that symptomatic MD is always preceded by asymptomatic EH

37. Of all the symptoms of MD, hyperacousis (an increased sensitivity to certain frequency or volume ranges), drop attacks, tinnitus and moving difficulties have been associated with increased aural pressur e. Drop attacks seem to be associated with gait difficulties, intense tinnitus and anxiety Nausea associated with vertigo was most common among patients with a long history of disease

38. FUNCTIONAL TESTS PURE-TONE AUDIOMETRY The AAO-HNS established a hearing staging system, according to the pure-tone thresholds at 0.5, 1, 2, and 3 kHz obtained in the audiogram. Audiometrically documented fluctuating low-tone unilateral SNHL is the key to the diagnosis of MD when facing patients with an episodic vestibular syndrome. With follow-up, it is easy to document fluctuation when recovery is appreciated, thus supporting the diagnosis of MD.

39. A shift in pure-tone thresholds for bone conduction by at least 30 dB hearing level at each of two adjacent frequencies below 2000 Hz is required for unilateral MD. The low frequencies (250 and 500 Hz) are typically affected at the earlier stages

40. Staging should be applied only to cases of definite or certain Menie`re’s disease

41. ELECTROCOCHLEOGRAPHY ( ECoG ) ECoG is a neurophysiologic technique in which an auditory evoked potential is obtained in response to brief sound stimuli and recorded by an intratympanic or extratympanic ( noninvasive ) electrode. The cochlear microphonic and the summating potential (SP) are generated by the hair cells of the organ of Corti , whereas the compound action potential (AP) of the auditory nerve represents the summed synchronized response of many individual nerve fibers . Testing parameters include latencies and amplitudes of SP and AP, and SP/AP amplitude ratio, and area under the curve of SP/AP ratio.

42. Changes in the SP response can reflect pressure differences between the scala media and the scala vestibuli, indicating excessive fluid pressure, thus deforming the basilar membrane toward the scala tympani, so that enhanced-amplitude SP is thought to reflect EH . SP/AP ratio is the most common parameter for diagnosis of EH. Increases in SP amplitude with an enlarged SP/AP ratio and a prolongedAPlatency shift have been observed in patients with MD (Ge and Shea , 2002; Ferraro and Durrant , 2006)

43. When hearing thresholds reach 60 dB, EcoG cannot be used . ECoG has been performed for determining hearing outcome (Moon et al., 2012) and to monitor the response to intratympanic steroid therapy (Martin-Sanz et al., 2013a).

44. Electrocochleography in a patient with left Meniere’s disease. The SP/AP ratio is normal in the asymptomatic ear (right ear (R); that is, 0.250 (trial I) and 0.222 (trial II) (norm <0.42); part a ), whereas those of the symptomatic ear (left ear (L)) are higher (0.729 (trial I) and 0.776 (trial II); part b ). This finding suggests that an abnormal electrical potential is generated by the symptomatic inner ear, which might be an indication for endolymphatic hydrops. Two consecutive trials (I and II) confirm the reproducibility

45. Vestibular testing CALORIC TESTS Bithermal caloric irrigation with computerized electronystagmography or videonystagmography has been the main laboratory test to evaluate vestibulo -ocular reflex (VOR) function. Caloric tests assess horizontal semi-circular canal function , with the percentage of unilateral caloric weakness or canal paresis as the main outcome measure. Unilateral vestibular hypofunction on caloric testing is observed in up to 75% of unilateral MD patients (Wang et al., 2012), a normal bithermal caloric response has been reported in up to 50% of patients in some series.

46. VIDEO-HEAD IMPULSE TEST ( vHIT ) This is a video-oculography device that allows assessment of the VOR at high frequencies during HIT. The equipment may provide an objective measurement of VOR gain when head impulses are performed in the plane of each of the six semicircular canals. It has been reported that 67% of patients with MD show a reduced VOR gain in at least one semicircular canal when the six canals are tested; the posterior semicircular canal of the affected ear is the most frequently involved canal ( Zulueta -Santos et al., 2014).

47. VESTIBULAR-EVOKED MYOGENIC POTENTIALS (VEMPS) These are otolith-mediated, middle-latency reflexes that are recorded from sternocleidomastoid ( cVEMPs ) or infraocular ( oVEMPs ) electromyography in response to high-intensity auditory stimuli (air conduction) or high-frequency vibratory stimulation (bone conduction). Air conduction is preferred for cVEMPs , while bone conducted vibration is mostly used in oVEMPs . VEMPs show a biphasic waveform with a positive and a negative peak.

48. It is widely accepted that cVEMPs evaluate the integrity of the sacculus and the inferior vestibular nerve, whereas oVEMPs primarily evaluate contralateral utriculus and superior vestibular nerve. Patients with unilateral MD usually show abnormalities in VEMPs with reduced or absent responses , although at the initial stage an augmented response is sometimes registered. The sensitivity and specificity of VEMPs in diagnosing MD are as low as 50% and 49%, respectively.

49. Visualization of endolymphatic hydrops using MRI and intratympanic gadolinium-based contrast agent . after the intratympanic administration of an eightfold diluted gadolinium-based contrast agent (GBCA). The diluted solution is injected, usually intratympanically , through the tympanic membrane. Because the GBCA moves into the perilymph , but not into the endolymph, the perilymph looks white and the endolymph looks black . The image shows a profoundly enlarged endolymphatic space (EH) in the cochlea (thin arrows) and the vestibule (thick arrows) in the inner ear of a patient with Meniere’s disease.

50. Visualization of endolymphatic hydrops using MRI and intravenous gadolinium-based contrast agent A The affected ear has an enlarged endolymphatic space (endolymphatic hydrops; black) within the white perilymph, which contains GBCA, in the cochlea (thin arrows) and the vestibule (thick arrows). b | The unaffected ear shows no or only a very small endolymphatic space.

51. MENIERE’S DISEASE: MEDICAL AND SURGICAL MANAGEMENT

52. MANAGEMENT The goal of the management of MD is to provide relief during acute attacks of vertigo, to prevent recurrent attacks and to eliminate the progressive damage to hearing and vestibular function in the affected ear. the elimination of the progressive damage to hearing and vestibular function has proved elusive.

53. Treatment of acute vertigo attacks Several drugs are used to reduce the asymmetry in neuronal input to the brainstem during vertigo attacks. Drugs that are used to treat motion sickness are useful for acute attacks of MD. Centrally acting antihistamines with anticholinergic effects have the dual effect of suppressing the vestibular system while also acting as anti-emetics. dimenhydrinate has the shortest onset , meclizine is the least sedating and promethazine is the most sedating but is available as a rectal suppository, which is useful if vomiting prevents the use of oral medication.

54. Benzodiazepines (for example, diazepam, lorazepam and clonazepam) are also often used for their γ‑ aminobutyric acid (GABA) agonist effect. GABA is the main central inhibitory neurotransmitter, therefore agonists cause a decrease in neuronal firing throughout the brain and in the vestibular nuclei. Daily use should be avoided because it can result in addiction and withdrawal symptoms. In this class, lorazepam has the fastest onset and its duration best matches that of the typical MD vertigo attack.

55. Prophylactic treatments Because attacks cannot be aborted once initiated , the preventio n of MD vertigo attacks provides the most effective relief of vertigo. Some medical and surgical treatments have the potential to slow the progression of hearing loss and vestibular injury; however, this has not yet been unequivocally proven for any therapy. As MD is a multifactorial disorder, no single treatment will provide relief in all patients. The first step in medical management is to delineate correctable factors that might be contributing to the attacks.

56. Management of risk factors: A rigorous search for vascular risk factors should be undertaken and treatment should be initiated. In people <50 years of age, migraine is the most common cofactor of MD. Drugs that are prophylactic in migraine, such as topiramate, calcium channel blockers (verapamil, nimodipine, flunarizine and lomerizine ), β-blockers and acetazolamide can be used

57. In patients >50 years of age, traditional vascular risk factors , such as hypertension, increased levels of cholesterol or a history of stroke or myocardial infarction, can be managed medically with antihypertensive drugs , including diuretics, calcium channel blockers and β-blockers, along with low doses of aspirin and statins.

58. Preventive treatment The main goal of preventive treatment is to improve patients’ quality of life. This may be achieved by reducing the frequency, duration, and severity of vertigo spells. Preventive treatment includes lifestyle and dietary modifications , pharmacologic therapy, and in some cases surgical procedures

59. Lifestyle and dietary modifications Patients with MD are counseled to follow a regular daily routine, and avoid triggers such as stress, barometric pressure change, fatigue, or sleep deprivation . Alcohol, coffee, and tobacco are traditionally restricted , although the efficacy of these measures has not been demonstrated in randomized controlled trials ( Luxford et al., 2013).

60. The most important dietary recommendation is a high water intake and a very low sodium diet. Sodium restriction is supported by the hypothesis that an increase of endolymphatic pressure can lead to the rupture of membranes in the scala media. An increase in water intake is presumed to reduce the severity of MD symptoms by decreasing the systemic AVP arginine vasopressin level ( Naganuma et al., 2006).

61. Betahistine This drug is broadly used worldwide, except for the USA, since it has not been approved by the US Food and Drug Administration. Betahistine is a structural analog of histamine. The mechanism of action of the drug appears to depend mainly on its action on H3 receptors mediated by two metabolites, amino-ethyl-pyridine and hydroxy-ethyl-pyridine

62. Experimental studies in animals demonstrate that betahistine improves labyrinthine microcirculation by vasodilation of the arterioles of the stria vascularis , and also in the posterior semicircular canal ampulla. Betahistine would reduce endolymphatic pressure by achieving a reduction in the production of, and an increment in the re-absorption of, endolymph

63. Diuretics Diuretics are commonly used in MD patients, especially in the USA, where they are the primary mode of therapy. Diuretics act by diminishing sodium reabsorption at different sites in the nephron, thereby increasing urinary sodium and water loss. Reduction of extracellular volume is supposed to decrease endolymphatic pressure and volume , either by increased drainage of endolymph or a reduction in its production at the stria vascularis . Thiazides, such as hydrochlorothiazide , are the most frequently used diuretics in patients with MD

64. Steroid therapy The mechanism of action of corticosteroids in MD is not limited to their anti-inflammatory and immunosuppressive effects in the cochlea, including the stria vascularis . They can increase labyrinthine circulation and improve inner-ear function through ion or water transport mechanisms influencing cochlear fluid homeostasis (Fukushima et al., 2004; Alles et al., 2006; Otake et al., 2009; Nevoux et al., 2015).

65. Intratympanic delivery results in significantly higher inner-ear levels of steroids as compared with systemic administration. Moreover, intratympanic delivery avoids the well-known adverse effects of systemic administration. Compared with gentamicin therapy, the main advantage of intratympanic corticosteroids is the absence of risk of hearing loss. Furthermore, this is a low-cost and safe technique. Residual tympanic perforation is the main risk.

66. High-dose dexamethasone (16 mg/mL) appears to provide better outcome than a lower dosage (4 mg/mL). When first-line treatment fails to control vertigo, it is a common practice to administer intratympanic corticosteroids if the patient still has functional hearing.

67. Intratympanic gentamicin therapy (IGT) The aminoglycoside antibiotics are used in the management of MD at low dosage to produce a partial vestibular ablation. The aim of IGT is to obtain a long-lasting, nonfluctuating, peripheral vestibular hypofunction capable of being centrally compensated . As compared with systemic administration, intratympanic therapy has many advantages: it is an office-based procedure that avoids toxicity in the contralateral ear or other organs and yields a higher concentration of drug in the inner ear.

68. GUIDELINE FORCONSERVATIVE TREATMENT OF MD Lifestyle modifications and medical therapy are able to control vestibular symptoms in most patients, although they have no effect on progression of hearing loss or tinnitus. 1. low-sodium diet (around 1800 mg/day) and high water intake (2000 mL/day), considered as baseline therapy 2. betahistine 24 mg/8 hours for at least 6 months 3. prednisone 1 mg/kg for 15 days if multiple episodes of vertigo with longer duration are observed in consecutive weeks or a sudden drop in hearing level is found. If no response is observed, prednisone is stopped in 4 weeks

69. 4 . intratympanic gentamicin , if there are six episodes in the last 3 months. The most studied dosage is 0.3–0.5 mL gentamicin sulfate using a concentration of 26.4 mg/ mL. It can be repeated up to four times. Gentamicin should not be used in patients with bilateral disease, since they can develop bilateral vestibular hypofunction and persistent vestibular ataxia.

70. Stepwise approach to conservative management of Menie`re’s disease based on the number of episodes of vertigo and hearing thresholds

71. OTHER TREATMENT MODALITIES Endolymphatic sac surgery Semicircular canal occlusion Vestibular neurectomy Labyrinthectomy Cochlear implantation Transtympanic ventilation tube insertion Hearing aids

72. Endolymphic Decompression Surgical decompression of endolymph for meniere's was first described by Portmann in 1926 more than a decade before the earliest histologic evidence of the existence of endolym phatic hydrops. It has been a controversial subject. It is thought that this procedure relieves a supposed high endolymphatic pressure by means of drainage into the mastoid or into the subarachnoid space. Although several case series report vertigo control between 60% and 80%.

73. Transmastoid endolymphatic sac surgery. A, Mastoidectomy is performed with identification of the tegmen, sigmoid sinus, antrum, facial nerve. horizontal semicircular canal, and posterior semicircular canal. The facial nerve, sigmoid sinus, and horizontal canal are skeletonized to allow wide exposure of the posterior fossa dura. B, The bony covering of the posterior fossa dura is removed between the sigmoid sinus and the posterior canal. C, The superior edge of the endolymphatic sac is identified; it usually lies at or below Donaldson's line, which extends posteriorly along the plane of the horizontal canal and bisects the posterior canal.

74. Paparella technique for endolymphatic mastoid shunting. A T-shaped piece of silicone is coiled and placed into a lateral incision in the endolymphatic sac to create a drainage path to the mastoid cavity

75. Endolymphatic-subarachnoid shunt . A, After exposing and opening the lateral wall of the endolymphatic sac, the medial wall of the sac is incised to open the lateral prolongation of the basal cistern. Dissection in the cistern is carried out bluntly to avoid venous injury. B, A silicone ( Silastic ®) shunt is inserted to maintain drainage path between the endolymphatic sac and the basal cistern. The lateral endolymphatic sac should be carefully closed with a fascia graft to prevent cerebrospinal fluid leak.

76. Vestibular Neurectomy The earliest approach was the retrosigmoid , with the first large series by Walter Dandy in the 1930s. The middle fossa approach to the internal auditory canal and superior vestibular nerve was developed by William House in the early 1960s, and was later modified to include inferior vestibular nerve section. The middle fossa and retrosigmoid approaches remain the most commonly performed today.

77. Vestibular nerve section has a complete vertigo control rate of about 85 to 95% with 80 to 90o/o of patients maintaining their preoperative hearing immediately postoperatively. The procedure offers much greater vertigo control rates than endolymphatic shunt procedures, but is also a more invasive and technically challenging procedure. Vestibular nerve section bas been argued to have a lower risk of hearing loss when compared with gentamicin injection.

78. R e t rosi g m o i d approach to vestibular nerve section . The cerebellum is retracted m ed i a ll y giving a view of the superior and inferior vestibular nerves. A, The posterior fossa is exposed and nerves a r e i d e nt i f ie d . B, The superior vestibular nerve is separated from the more anterior facial nerve. C, The superior vestibular nerve has been sectioned.

79. S u r geon's view from the head of the table during the middle fossa approach to a vestibular nerve section. A right-sided procedure is shown with anterior toward the left. A, View of the middle fossa after the bone flap has been removed and the temporal lobe has been elevated. B, A diamond bur is used to thin the bone over the internal auditory canal between the arcuate eminence and geniculate ganglion.

80. C, The internal auditory canal is opened revealing the facial nerve (anterior) and the superior vestibular nerve (posterior), which are separated by Bill's bar laterally. The superior vestibular nerve is carefully separated from the facial nerve in preparation for sectioning.

81. The risk of facial paresis is higher using a middle fossa approach than with the suboccipital approach causing many to abandon this technique in recent years. Labyrinthectomy is the most destructive procedure in the treatment of Meniere's as it destroys both hearing and vestibular function. Ideal candidates for labyrinthectomy are those who have no hearing and have failed more conservative treatments, such as gentamicin injection. Despite its morbidity, the procedure has a higher rate of vertigo control than vestibular neurectomy and has been reported to improve quality of life in 98% of patients

82. There are rwo approaches: transcanal and transmastoid . Transmastoid is more popular. The transcanal approach involves exposing the middle ear through a tympanomeatal flap. The incus and stapes arc removed to expose the oval window. A hook is then inserted into the vestibule to remove the neuroepithelium. The limitation of the transcanal approach is the poor access it yields to the posterior canal, located medial to the facial nerve; thus, complete ablation may not be achieved. The limited exposure also makes the procedure more technically difficult than the transmastoid approach.

83. Transcanal labyrinthectomy

84. Transmastoid labyrinthectomy . A, The approach begins with a standard postauricular incision. B, 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. D, The ampullae and neuroepithelium of the three semicircular canals are exposed, along with the otolithic organs (the saccule and the utricle). Neuroepithelium removed

85. An Interesting fact Dr. William House had developed a surgical treatment to relieve the symptoms of Meniere's disease. Astronaut Alan Shepard, the first American in space, and 5 th man to walk on moon, developed the disease and consulted House for a fix. Without it, he couldn't fly to the moon. In 1971 The astronaut called Dr. William House when he was en route to the moon and three quarters away from moon, to thank Dr. House

86. Differential diagnoses of Meniere’s disease

87. CEREBELLAR INFARCTION About 25% elderly patients suffering from acute isolated vertigo have a cerebellar infarction. Clinical features: vertigo and vomiting, ipsilateral limb ataxia. Facial hemianesthesia and contralateral body anesthesia .

88. Vestibular Migraine A. At least five episodes with vestibular symptoms, lasting 5 minutes to 72 hours B. Current or previous history of migraine with or without aura C. One or more migraine features symptoms with at least 50% of the vestibular episodes: (1) headache with at least two of the following characteristics: one-sided location, pulsating quality, moderate or severe pain intensity, aggravation by routine physical activity (2) photophobia and phonophobia (3) visual aura D. Not better accounted for by another vestibular or ICHD diagnosis

89. Vestibular Paroxysmia Patients suffered from a minimum of five vertigo attacks and fulfilled one criterion of each category (A)–(E): A. Vertigo attacks (rotatory as well as to and fro vertigo) with short duration (seconds to minutes), which ceased spontaneously B. Vertigo triggers: Attacks occurred while in rest , were induced by a specific head and/or body position, or by a specific change of head and/or body position C. Accompanying symptoms: Attacks were accompanied by at least one of the following additional symptoms: unsteadiness of stance and/or gait, lateralized tinnitus , decreased hearing function or subjective sensory irritations, such as a feeling of pressure within or around one ear D. Additional criteria: The diagnostic procedures revealed a neurovascular compression of the eighth cranial nerve on MRI scans , E. Exclusion: Any other possible pathology or disease explaining the symptoms had to be excluded

90. Superior Semicircular canal dehiscence Due to thinning or absence of bone overlying SCC. Vertigo torsional vertigo triggerd by vibrations , pressure , and loud sound Tinnitus : complain of tinnitus on moving the eyes horizontally and hearing of internal body sounds of chewing etc. HL : low freq. CHL . BC become better than 0 dB . Autophony : pt. own voice seems unusually loud.

91. Cogan syndrome Rare autoimmune d/o Non syphilitic Interstitial keratitis, sudden onset meniere’s like symptoms, life threatening aortic insufficiency. Diagnosis :

92. SUSAC SYNDROME Autoimmune rare d/o Impaired brain function (encephalopathy) BRAO (retinopathy) and blockage of cochlear vessels HL at low freq. and tinnitus and vertigo Periodic episodes of vertigo and dizziness

93. VKH Chronic inflammation of melanocytes B/L diffuse uveitis Hearing loss tinnitus and vertigo Vitiligo and alopecia Meningo encephalopathy

94. GLYCEROL TEST Glycerol is a dehydrating agent. When given orally, it reduces endolymph pressure and thus causes an improvement in hearing. Patient is given glycerol (1.5 mL/kg) with an equal amount of water and a little flavouring agent or lemon juice . Audiogram and speech discrimination scores are recorded before and 1–2 h after ingestion of glycerol. An improvement of 10 dB in two or more adjacent octaves or gain of 10% in discrimination score makes the test positive. There is also improvement in tinnitus and in the sense of fullness in the ear. The test has a diagnostic and prognostic value.

95. THANK YOU