------------------------------------------------------------------------------ TITLE: ENDOLYMPHATIC HYDROPS SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: June 12, 1991 RESIDENT PHYSICIAN: Bruce A. Scott, M.D. FACULTY: Chester L. Strunk, M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. ------------------------------------------------------------------------------ "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." I. History - An excessive accumulation of endolymph in the labyrinth causing symptoms such as vertigo, tinnitus, and deafness A. Prosper Meniere - 1861 - first to associate clinical triad with pathology of the labyrinth B. Knapp - 1871 - compared Meniere's to ocular glaucoma C. Portmann - 1920's - hypothesized role of endolymphatic sac in ear fluid volume dynamics, resorption, and pressure regulation; buildup of excess endolymph, most likely caused by deficient resorption of endolymph in the ELS and duct, leading to "endolymphatic hypertension;" designed first drainage procedure. D. Dandy - 1920's - selective vestibular nerve sectioning via suboccipital posterior fossa approach E. Hallpike and Cairns - 1938 - first histologic findings of "hydrops" of the endolymphatic system F. House, Fisch, Glasscock - 1962 - vestibular nerve sectioning via middle fossa approach G. Kimura and Schuknecht - 1965 - created endolymphatic hydrops by destroying the sac and duct H. Stahle and Arenberg - 1976 - first valve implant II. Subtypes A. Syphilitic Hydrops 1. Result of congenital or acquired syphilis 2. Temporal bone studies have confirmed endolymphatic duct obstructed or obliterated by microgamma and fibrous tissue 3. Progressive hydrops and degeneration of the labyrinth structures results 4. Treatable etiology and FTA-ABS should be drawn on all patients as part of workup B. Delayed Hydrops 1. Nadol and Wolfson (1975) described simultaneously a clinical entity characterized by Meniere's type vertigo arising in a previously deafened ear 2. May occur as delayed manifestation of previous insult to the inner ear 3. Prognosis for resolution of vertigo is good C. Autoimmune 1. Approximately 50% of patients with immuno-mediated inner ear disease manifest hydrops 2. Typically have bilateral disease, middle age, females > males 3. Systemic immune disease, arouse suspicion, although causal relationship not yet proven 4. Immune laboratory tests should be obtained when suspect 5. Treatment a. Low salt diet, diuretic, vestibular suppressant b. Steroid - Prednisone 80 mg x 30 days - Taper to maintenance (5mg/day) for weeks or months to maintain hearing and resolve vertigo c. Consider cytotoxic drugs D. Idiopathic - Meniere's Disease III. Etiology A. Endolymphatic volume control 1. Secretory function residing in the stria vascularis of the auditory labyrinth and the dark cell areas of the vestibular labyrinth 2. Resorbtive function of the endolymphatic sac B. Temporal bone studies on Meniere's patients have confirmed hydrops - Rauch, et al 1989 - Yazawa, et al 1990 C. Specific factors remain a mystery - Autoimmune - Congenital - Allergic - Vascular - Viral - Traumatic - Dietary - However, the underlying pathology (endolymphatic hydrops) and mechanism (endolymphatic hypertension) has been well described. Damage to the stereocilia hair cell bundle as a direct result of increased pressure within the endolymphatic system has been shown as well as uncoupling of the tectorial membrane and growth, collapse, or rupture of the membranes of the inner ear compartments D. Schuknecht - Fluctuating nature of hearing loss and episodic vertigo is attributed to ruptures of the distended membranous labyrinth which lead to contamination of the perilymph with neurotoxic concentrations of potassium E. Shea argues that effect not due to pressure from hydrops 1. Some temporal bones of patients with Meniere's don't show Hydrops 2. Changes in endolymphatic fluid pressures occur to slowly to explain sudden changes in symptomatology 3. Suggests symptoms attributed to loss of the ion pump and DC potential in the organ of corti. Hydrops may explain gradual hearing loss. IV. Incidence A. Prevalence From 2,400,000 to 7,000,000 new cases by rough estimate based on study in Sweden. Great Britain estimates five out of 1000 patients who consult a general practitioner. Stahle in 1978 estimated 50 cases per 100,000 population B. Occur in adults 30-60 years, most common onset 41-50, followed by 51-60 and 31-40 age groups. Slight male predominance. No racial tendencies. Recent study of 91 patients has shown 14% of cases could be classed as familial with different modes of inheritance. C. Bilateral disease 1. Reports range from 2.3 to 78% 2. Rate probably approximately 30% - Temporal bone studies (Yazawa, 1990) - Pillsbury - Schuknecht V. Clinical Manifestations A. Progressive hydrops caused by impaired resorption and all pathological changes and functional disorders are consequential B. Classic Meniere's: Fluctuating fullness, fluctuating tinnitus, fluctuating sensorineural hearing loss - As above intensify, an attack of vertigo follows C. Vertigo 1. Acute rotatory Episodic (free between episodes) Mild to incapacitating Increases with movement Lasting minutes to hours (unsteadiness may remain for several days) May be accompanied by profuse perspiration, nausea and vomiting Can awaken patient with acute attack (this may be characteristic) 2. Can not diagnose without definitive spells with good health between 3. Adjunctive spells - not considered true episodes Moments of motion intolerance Positional vertigo Falling or momentary ataxia on cornering D. Hearing Loss 1. Sensorineural with fluctuations; progressive 2. Early - occurs immediately preceding, during, and for a variable time after episodes, returns to normal 3. Later - degree of fluctuations less marked; fails to return to normal and eventually permanent 4. Audiogram - usually lower and middle frequencies a. Speech discrimination initially preserved, then decreases/fluctuates (may occur independent of PTA change), eventually declines b. Recruitment with intolerance of loud sounds (almost all) c. Diplacusis binauralis dysharmonica (invariably present) - immediately before and after d. Site of lesion testing suggests cochlear lesion E. Tinnitus 1. Present in some form in 98.6% of patients - Increased loudness or change pitch first sign of attack 2. Early - intermittent, occurring just before and during attack 3. Shortly becomes constatn, increasing intensity during attack 4. Variable - usually low roar or buzzing (less often high pitched or hissing) VI. Diagnosis A. Complete history and physical examination including: 1. Complete otoneurologic with CN, especially nystagmus 2. Corneal reflex 3. Nasopharyngoscopy 4. Fistula test 5. Listen for bruits in head and neck 6. PMH - head trauma, ear infections, endocrine deficiencies, CVD, allergies, medications, excess smoking/alcohol/dietary indiscretions B. Baseline studies 1. CBC 2. VDRL/FTA-ABS 3. TFT's 4. Lipid Profile 5. Five hour glucose tolerance 6. C-spine 7. CT-MRI C. Audiogram 1. Fluctuating 2. Pure tone average 3. Speech discrimination 4. Recruitment (pinpoint site of lesion) 5. Tone decay (R/O retrocochlear lesion) 6. ABR D. Vestibular 1. Calorics a. Can be normal early b. Increased sensitivity by simultaneous bithermal calorics (80% diagnostic vs. 50%) c. Affected ear decreased as compared to normal side 2. ENG battery - During attack may be spontaneous nystagmus with direction changing components E. Special Testing 1. Osmotic tests a. Glycerol 180cc 50% glycerin and water, or 1.5gm/kg in saline with lemon PTA and discrim before and three hours after Greater chance of (+) with mean loss > 70 db and with increased age but more side effects (nausea, headache) b. Urea 25gms in 100-200cc juice, test before and two hours after c. PTA shift more than 15 dB in at least one frequency (250-4000 Hz) d. Speech discrimination improved by at least 12% 2. Furosemide a. 20 mg IV b. Test before and one hour after c. Increase maximum velocity of caloric nystagmus beyond the normal range d. More sensitive than glycerol test VII. Treatment - Criteria for Reporting Results A. Vertigo "Control" means absence of definitive spells for 10 times the average interval between the spells before treatment (+/- adjunctive spells) B. Deafness 1. "Hearing improved and serviceable" Sustained PTA or SRT of 30dB or > and discrimination of 80% or > when one or both was not so before 2. "Hearing improved but not serviceable" Sustained increase in speech frequencies of an average of 15dB or more (SRT > 30%) with a discrimination score improved 20% or >. 3. "Hearing worse" 15dB or > loss in average speech frequencies or 15% or > decrease in discrimination score that was 80% or less 4. "Hearing unchanged" <15dB change in average speech frequencies and < 15dB change in discrimination score C. Classifications (AAOO Classification) 1. Class A - Vertigo controlled - hearing improved 2. Class B - Vertigo controlled - hearing unchanged 3. Class C - Vertigo controlled - hearing worse 4. Class D - Uncontrolled vertigo D. Any medical or surgical therapy is always suspect because the natural history of the disease is so variable VIII. Treatment A. Medical - Reassurance, counseling, pharmacotherapy for acuteepisodes - Able to carry out normal social and work life 1. Acute Episodes Treatment depends on severity of symptoms, especially nausea and vomiting a. Bed rest and sedation b. Antihistimines and antiemetics (meclizine, diphendydramine, phenothiazines) c. Psychosedatives and vestibular suppressants (valium, phenobarbital, thorazine) d. Anticholinergics (atropine, scopolamine) e. Vasodilators (nicotinic acid, histamine, CO2) f. Neuroleptics (innovar), psychotropics (droperidol), narcotics (fentanyl) g. Hypobarics (-70cm water, 30 mins., without ME equalization) h. Osmotic diuretics (glycerine, urea, isosorbide) 2. Quiescent periods - none proven a. Diet control, alcohol, smoking, identify allergens b. Vitamins c. Diuretics (benzthiazides, cholrthalidone, K- sparing, furosemide, urea, isosorbide) - helpful with control of vertigo, but recent study (Corvera 1989) showed no beneficial effect on long term hearing d. Vasodilators e. Antihistamines f. Sedative, psychotherapeutic drugs g. Anticholinergics h. Desensitization with histamine phosphate 3. 85% of Meniere's patients get better a. 60% with complete remission b. End-point in hearing and balance varies with point of remission c. Tinnitus may be residual d. Concerned with the other 15% - salvage attempted with surgical approaches 4. Streptomycin Therapy a. Overview Safest form of selectively ablating vestibular formation while preserving hearing Effect greatest on vestibular sensory hair cells initially (before cochleotoxic effect) b. Indications 1. Unilateral hearing ear effected 2. Bilateral disease < 50 years old c. Method 1. 2.3 gms/day x 2-3 weeks 2. Auditory damage preceded by tinnitus 3. Follow ice-water calories daily and audiograms d. Complications Continuation beyond end-point of vestibular ablation with cochleotoxic effect. B. Surgical 1. Indications a. Failed adequate trial of medical treatment b. Recurrent bouts of vertigo c. patient's mental attitude toward the disease d. Economic factors - need to restore working ability in shortest possible time 2. Destructive Procedures a. Eliminate the neural input from the peripheral vestibular system by destroying the sensory or neural component. Relies upon central compensation to achieve orientation. Relief of symptomatic vertigo should be 100%. (If not resolved must examine visual system, proprioception, cerebellum, reticular formation.) b. Unilateral disease with hearing poor or non-serviceable PTA > 60 dB, discrimination < 50% c. Labyrinthectomy Eliminate sense organ Transtympanic or transmastoid approaches 2-6 days hospitalization for recovery and compensation d. Complications CN VII injury CSF leak Inadequate ablation and persistent vertigo 3. Selective procedures - Vestibular nerve section a. Eliminates transmission of abnormal (and normal) stimuli b. Indications 1. Useful in cases of previous incomplete labyrinthectomy 2. Indicated in young, healthy, Meniere's cripple with serviceable hearing 3. Sac decompression failures c. Approaches 1. Suboccipital posterior cranial fossa (Dandy) 2. Middle fossa (House) 3. Retrolabyrinth transmastoid (Silverstein) 4. Extradural approach, easier separation between cochlear and vestibular nerve trunks Complications - unsteadiness, transient VII paralysis, total SNHL, wound infection, CSF leak - Smyth - VNS Vertigo no % given - none recurred into Class D Hearing 17% primary - 48% at 10 yrs compared to worst pre-op audio 62% 88% compared to best preop - Low morbidity, somewhat effective, doesn't eliminate further surgical options. d. Results: Primrose, et al 1986 1. Vertigo a. No statistical significance at 1 year compared to shunt procedures b. Statistically better control at 5 and 8 year follow-ups 2. Hearing a. No difference as compared to sac surgery b. Gradual deterioration in most cases 3. Tinnitus a. No difference from sac surgery b. Generally poor control Silversteine/Norrell (26 pts) - RLVNS Vertigo 85% Hearing 30% worse e. Complications/Summary 1. Increased risk to CN VII Transient paralysis in 26% 2. CSF leak, meningitis, cerebral infection 3. Deafness: 10% even in skilled hands (vs. approximately 1% for sac surgery) 4. Neuroma development 5. Greatly increased skill and neurosurgical backup needed 4. Preservative Procedures Generally less effective than ablative procedures Success rate 50-70% a. Endolymphatic sac surgery 1. Indicated in patients with hearing (servicable) ears 2. Transmastoid approach Sac identified after skeletonization of the dura covering the sigmoid portion of the lateral sinus and posterior fossa 3. Shunted medially into subarachnoid space or laterally into mastoid cavity 4. Problems a. Identifying the sac may be difficult b. Site of obstruction in the endolymphatic system may be proximal to the sac c. Encapsulization of shunt with blocked drainage d. Hearing loss e. Shunt failure/recurrence of vertigo f. CSF leak g. Injury to sigmoid sinus 5. Thomsen 1981 - Placebo surgery with only mastoidectomy and exposure of sac - similar results as shunted patients (preservation of hearing, relief of vertigo) 6. Shunts of some benefit because endolymph reaccumulates so slowly (Shea 1989) 7. Results - Smyth (21 pts) - sac exposed, pedicle soft tissue graft Vertigo 86% primary; 71% at 10 years. Hearing 14% worse 58% worse compared to worst 45% worse 75% worse compared to best. Low morbidity - Huang/Lin (339 pts) - mastoid drainage techniques compared (incision, Silastic sheet, penrose drain, Arenberg valve) - symptoms tended to recur in 2-4 years. No significant difference in results between the types. Vertigo 79.7%. Hearing 16.7% mildly worse (no dead ears) - Miller (24 pts) - mastoid shunting Vertigo 87%; Hearing 16.7% mildly worse (no dead ears) - Schuknecht (90 pts) - cochleosacculotomy (Avoids problem with fibrous encapsulation, fistulize, the cochlea duct into the perilymphatic space with stab through round window); Vertigo 70%; Hearing 45% worse (15dB loss or more) - Arenberg (300 pts) - unidirectional valve; Vertigo 93.7% (primary) 87.3% (overall); Hearing Class A or B:73%; Class C: 26.8% compared to worst preop; 12.2% compared to best preop - Glasscock (77 pts) - with Arenberg shunt Vertigo 49%; b. Endolymphatic sac decompression Expose sac but don't shunt (Shambaugh) Wide removal of bone around sac Others incise sac and probe the interior, no shunt (Portman) c. Ultrasound - Radiation of the labyrinth 1. Destructive ultrasound delivered to vestibular labyrinth 2. Round window technique a. Transtympanic approach b. Probe placed in round window niche and directed superiorly through basal turn of cochlea into vestibule c. Risks damage to basal end hair cells No hearing loss in upper turns where speech frequencies located d. Ultrasound destruction of the cristae ampullaris is monitored by checking nystagmus response - Initially, irritative, toward operated ear; Reverses (paralytic nystagmus), away from ear 3. Lateral canal technique a. Delivered through lateral and posterior semicircular canals b. Via transmastoid approach with thinning of the labyrinth bone c. Probe directed toward ampullae Unsatisfacotry control with only lateral canal application, thus also apply to posterior 4. Short term control 80-85% (1-1.5 yrs), long term control 50-60% 5. Complications a. SNHL - Estimated at approximately 25% b. Facial nerve paralysis with lateral canal approach Heat generated by probe colse to the nerve Ear pain/facial pain indicates potential damage to nerve -> reduce power or stop. d. Cryosurgery 1. Introduced by Wolfson (1968) Later modified technique to localize effect and minimize cochleotoxic effect, short application 2. Mastoidectomy approach - "Blue line" the lateral SCC 3. Destroy vestibular function by application to lateral canal as with ultrasound above Cryoprobe cooled to -78oC Six applications of 2 mins each 4. Results Horowitz 1989 2 yrs (n=69) 10 yrs (n=40) Class A 4 (6%) 0 Class B 37 (54%) 15 (37%) Class C 8 (11%) 9 (20%) Class D 20 (29%) 16 (41%) Tinnitus rarely controlled 5. Complications Those of mastoidectomy (1-10%) Thermal damage to CN VII or cochlea (0-11%) e. Cochlear Dialysis - Morris and Morrison, 1989 1. Techniques Tympanotomy approach, expose round window, aspirate perilymph and replace with dialysis fluid (1.31 gm mannitol in 5% dextrose to 100ml) Repeat dialysis instillation 5 times 2. Results a. Vertigo Complete control - 11/30 Substantial control 5/30 Insignificant control - 13/30 Worse - 1/30 No immediate post-operative improvement in vertigo b. Hearing Improved - 8/30 Unchanged - 14/30 Worse - 8/30 c. Tinnitus unchanged d. 30% have gone on to require labyrinthectomy or neurectomy e. Started with "worse" patients, failed other conservative therapy f. Streptomycin Therapy - perfusion into labyrinth Shea 1989 1. Technique Mastoidectomy approach, create bony opening in lateral SCC, 30 gauge needle inserted, inject 1 ml of 300 micrograms of streptomycin in lactated ringers solution with 20 mg of methlyprednisolome IM 1 gm streptomycin concurrently (increase effect) Closure with fascia and Gelfoam 2. Theory a. Destroy vestibular receptors (vestibular hair cells) b. Reduce production of endolymph (+ pressure) to slow effect on hearing 3. Results - 1-3 yrs f/u a. Vertigo: Improved - 11/12 Same/Worse - 1/12 b. Hearing: Improved - 9/12 Same/Worse - 3/12 c. Fullness: Improved - 12/12 d. Tinnitus: Improved - 8/12 Same/Worse - 4/12 - Smaller new dose gets same benefit with less effect on hearing -------------------------------------------------------------------------------- BIBLIOGRAPHY 1. Corvera, J and Corvera G. "Long-term Effect of Acetazolamide and Chlorthalidone on the Hearing Loss of Meniere's Disease." The American Journal of Otology. March 1989;10(2):142-145. 2. Hicks, GW et al. "Delayed Endolymphatic Hydrops: A Review of 15 Cases." Laryngoscope. August 1988;98:840=845. 3. Horowitz, M et al. "Cryosurgical Treatment of Endolymphatic Hydrops." The Journal of Laryngology and Otology. May 1989;103:481-484. 4. Hughes GB et al. "Autoimmune Endolymphatic Hydrops: Five-year Review." Otolaryngology-Head and Neck Surgery. March 1988;88(3):221-225. 5. Linthicum, FH et al. "Hydrops Due to Syphilitic Endolymphatic Duct Obliteration." Laryngoscope. May 1987;97:568-574. 6. Morris, AW and Morrison, GAJ. "Cochlear Dialysis for Meniere's Disease: An Update." The American Journal of Otology. March 1989;10(2):148-149. 7. Morrison AW. "Predictive Tests for Meniere's Disease." The American Journal of Otology. January 1986;7(1):5-9. 8. Primrose, WJ et al. "Vestibular Nerve Section and Saccus Decompression: An evaluation of Long-Term Results." The Journal of Laryngology and Otology. July 1986;100:775-784. 9. Rauch, SD et al. "Meniere's Syndrome and Endolymphatic Hydrops: Double blind Temporal Bone Study." Ann Otol Rhinol Laryngol. 1989;98:873-883. 10. Schuknecht, HF. "Endolymphatic Hydrops: Can It Be Controlled?" Ann Otol Rhinol Laryngol. 1986;95:36-39. 11. Shea, JJ. "Perfusion of the Inner Ear With Streptomycin." The American Journal of Otology. March 1989;10:150-155. 12. Smith WC and Pillsbury HC. "Surgical Treatment of Meniere's Disease Since Thomsen." The American Journal of Otology. January 1988;9:39-43. 13. Thomsen, J et al. "Placebo Effect in Surgery for Meniere's Disease." Archives of Otolaryngology. 1981;107:271-277. 14. Wright, JW and Hicks GW. "Valved Implants in Endolymphatic Sac Surgery." The American Journal of Otology. July 1987;8(4):307-312. 15. Yazawa, Y and Masaaki, K. "Bilateral Endolymphatic Hydrops in Meniere's Disease: Review of Temporal Bone Autopsies." Ann Otol Rhinol Laryngol. 1990;99:524-527. ----------------------------------END----------------------------------------