SEMINARS IN HEARING—VOLUME 15, NUMBER 1 FEBRUARY 1994

PERILYMPHATIC FISTULA: HISTORICAL PERSPECTIVE

R. Steven Ackley, Ph.D.,* I.K. Arenberg, M.D.,† David L. Asher, Ph.D.,‡

M.T. Browne, M.S.,§ and J. A. Drumright, M.S.**

Peri lymphat ic fistula (PLF) has been repor ted as a complication of stapedectomy surgery for over three decades.1 However, spontaneous PLF was not reported until the late 1960s,2,3 a l though disease-related PLF, i n c l u d i n g s e q u e l a of c h o l e s t e a t o m a , appeared earlier.4 Other etiologies for loss of per i lymph from the i n n e r ear inc lude head t rauma/barotrauma 5 , 6 and congenital anomalies.7 , 8 Surgical repair of fistula fre­quently stabilizes hearing, eliminates debili­tating vertigo, and may even reduce tinnitus. However, data are inconsis tent regard ing anatomy, pathophysiology, etiology, diagno­sis, and methods of repairing fistulas.

ANATOMY AND PHYSIOLOGY OF PLF ETIOLOGY

Simmons and colleagues studied surgi­cal injuries to the round window in cats.9 A t h e o r y was p r o p o s e d d e s c r i b i n g i n t r a -labyrinthine m e m b r a n e breaks to explain sensorineural hear ing loss in patients who experience popping sensation in the ear in association with hear ing loss. This concept la ter evolved in to the d o u b l e - m e m b r a n e break theory10 in which an oval or r o u n d window fistula occurs in association with an intracochlear membrane break.

T h e o r i e s p r o p o s e d by Goodh i l l a n d col leagues descr ibe m e m b r a n e breaks by explosive and implosive forces on the inner ear.11 Explosive forces enter the labyrinth by the cochlear aqueduct , lamina cribosa, or internal auditory canal. Laboratory experi­mental evidence proved the explosive route theory by demonstrat ing that cerebrospinal f lu id c o m m u n i c a t e d wi th p e r i l y m p h th rough the cochlear aqueduct.1 2 Further , after b lockage of the coch lea r a q u e d u c t inner-ear pressure remains constant despite cerebrospinal fluid (CSF) pressure changes. Addit ional exper imenta l evidence showed that India ink injected into spinal cord cere­brospinal fluid (CSF) in cats was identified in high concentrations in the cochlear aque­duc t a n d in lower c o n c e n t r a t i o n s in the internal auditory canal when CSF pressure was increased sufficiently to cause bulging or rupture of the round window membrane.1 3

CSF-perilymph exchange through the cochlear aqueduc t is deba ted in pat ients , however. Although the aqueduct appears to be patent in the fetus and young child,14 in adults it is filled with arachnoidal connec­tive tissue that may or may not prevent free flow of CSF from the subarachnoid space into scala tympani. Anson and colleagues15

conc luded that the tissue in the cochlear aqueduct is the type through which fluids of

University of Northern Colorado, Greeley, Colorado. †Swedish Medical Center, Englewood, Colorado.

Titzsimmons Medical Center. §Associates of Otolaryngology, Denver, Colorado.

Hinsdale Medical Center, Hinsdale, Illinois. Reprint requests: Dr. Ackley, Chairman, Department of Communication Disorders, University of

Northern Colorado, Greeley, CO 80639.

Copyright © 1994 by Thieme Medical Publishers, Inc., 381 Park Avenue South, New York, NY 10016. All rights reserved. 1

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

SEMINARS IN HEARING—VOLUME 15, NUMBER 1 FEBRUARY 1994

the body usually pass. O the r evidence indi­cates tha t a r achno ida l tissue funct ions to plug the duct when infection is present, as d e m o n s t r a t e d by t h e low i n c i d e n c e of labyrinthitis and deafness in cases of menin­gitis.16 Tempora l bone studies show that in as many as 90% of adults the a rachnoida l tissue does no t interfere with the patency of the duct.17 More recent evidence indicates that cochlear aqueduct patency is probably age re la ted—open in three fourths of peo­ple u n d e r age 21 a n d in only a b o u t o n e third of the elderly population.1 8

Radioactive pharmaceut ica ls and dyes have been injected into the subarachno id space to m o n i t o r CSF flow in to per i lym­phatic spaces. Ritter and Lawrence,19 using such a t echn ique , showed n o evidence of CSF flow i n t o t h e i n n e r e a r . H o w e v e r , Emmet t and colleagues20 measured radioac­tivity at oval and round window fistulas and concluded that Ritter and Lawrence failed because they allowed too much time follow­ing t racer injection before their measure­ments were made . An alternative explana­tion is that cochlear aqueduct was pa ten t in the study by Emmet t and colleagues and not so in the Ritter and Lawrence study. Con­vincing reports by Duval and Sutherland,2 1

and Asher and Sando2 2 showed that horse­radish peroxidase tracers injected into CSF of guinea pigs are t ransmit ted to the scala t ympan i t h r o u g h t h e c o c h l e a r a q u e d u c t a n d a long c o c h l e a r a n d ves t ibular ne rve fibers.

Car lborg a n d Farmer 2 3 d e m o n s t r a t e d that inner-ear fluid pressures were primarily affected by blockage of the cochlear aque­duct. Using a sensitive pressure transducer, t hey d e m o n s t r a t e d t h a t w h e n c o c h l e a r a q u e d u c t was left p a t e n t CSF p r e s s u r e c h a n g e s were quickly (within 5 seconds) t r a n s m i t t e d to p e r i l y m p h ; however , with b locked cochlear a q u e d u c t 10 to 20 min­utes passed before pressure equi l ib ra t ion be tween these fluids was achieved. T h u s , pa ten t cochlear aqueduc t in chi ldren and m o s t a d u l t s p r o v i d e s a m e c h a n i s m for explosive r u p t u r e of a window m e m b r a n e th rough increased CSF pressure, accompa­nying physical exertion, transmitted to scala tympani.

STAPEDECTOMY AND PLF

In 1955, Shea performed the first stape­dectomy. This surgical p r o c e d u r e involves open ing the vestibule of the inner ear and creat ing a temporary per i lymphat ic fistula unti l a stapes prosthesis is placed and the oval window is closed. If the oval window is inadequately closed or later reopens , peri­lymph escapes into the middle ear. Repor t of PLF following s t apedec tomy descr ibed symptoms of t innitus, vertigo, nausea, and v o m i t i n g r e l a t e d to oval w i n d o w fis tula a r o u n d the stapes prosthesis.1 O t h e r studies r e p o r t s imilar symptoms assoc ia ted with posts tapedectomized patients, and surgical c o m p l i c a t i o n is r e p o r t e d to o c c u r in as many as 7% of cases.24

CONGENITAL DEFECT AND PLF

C o n g e n i t a l r o u n d w i n d o w a n d oval window malformations present with or with­out a fistula may predispose the pat ient to PLF. A review of cases of meningitis related to congenital PLF was repor ted by Parsifer and Birken,25 who described several patients with r e p e a t e d episodes of meningi t i s a n d with repor ted ear anomalies such as stapes defect a r o u n d which per i lymph was drain­ing. In patients present ing with meningit is and severe sensor ineural hea r ing loss, the possibility of PLF is to be considered. Reilly7

repor ted that 26% of chi ldren with congen­ital middle-ear defect had peri lymph fistula. Weber and coworkers8 r epor ted that 81.3% of PLF cases h a d c o n g e n i t a l m i d d l e - e a r defect, with malformed stapes occurr ing in 60% of cases.

Seltzer a n d McCabe2 6 c o n c l u d e d tha t congenital ear anomalies were rare (2%). It was, h o w e v e r , n o t e d t h a t s o m e f o r m of Mondini 's malformation was present in 8% of pat ients . A high rate of r ecu r r ing peri­lymph fistulas was observed in these patients.

STAPES GUSHER AND CONGENITAL DEFECT

"Stapes gusher" occurs when perilymph pours into the middle ear after open ing the 2

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

HISTORICAL PERSPECTIVE—ACKLEYET AL.

vestibule surgically. The leak in these cases may occur because of CSF flow from the internal auditory canal or pa ten t cochlear aqueduct . Glasscock27 in a review of stapes gusher cases de te rmined that the internal auditory canal is the probable source of per­ilymphatic leaks. Shea28 and Goode2 9 pro­pose that the site for stapes gushers is the cochlear aqueduct . In patients with congen­ital s tapes fixation a n d elevated perilym­phatic pressure, "gusher" results when the stapes is removed, causing first a conductive h e a r i n g loss t h a t p r o g r e s s e s to a sen­so r ineu ra l loss, a cco rd ing to G o o d e . H e p r o p o s e d tha t the sensor ineura l h e a r i n g loss may result from chronically high peri­lymph pressure, or perilymphatic hydrops. To prevent stapes gushers dur ing surgery, Shea r e c o m m e n d s m a k i n g a s tapes foot­plate hole to determine if a profuse amount of fluid will leak out.

SPONTANEOUS PLF AND CONGENITAL DEFECT

A p p a r e n t s p o n t a n e o u s fistulas have been associated with exertion and trauma. In a review of PLF in chi ldren, Grundfast and Bluestone showed a predisposing con­genital malformation of the oval or round window as a cause in spontaneous PLF.30 In children with unilateral sensorineural hear­ing loss of unknown cause who develop a loss in the only hearing ear, congenital mal­fo rmat ion lead ing to PLF is likely.31 A 4-year-old child was described31 who bumped his head on a couch and immediately expe­r i e n c e d b u z z i n g t i n n i t u s in b o t h e a r s . During surgical exploration, the patient was found to have both oval and round window fistulas with a malformation of the stapes. Chi ldren who have ana tomic defects may no t need significant t rauma for a perilym­phatic fistula to develop.

TRAUMA

Seltzer and McCabe stress the need for early surgical intervention in young patients who have a known prior hear ing loss, and

t hen e i ther a progress ion in the h e a r i n g loss or a new hearing loss in the better ear.26

This is r ecommended because of the high incidence of PLF observed in their series. PLF should be included in the differential diagnosis in children with unexplained uni­lateral sensorineural hearing loss, especially with history of head trauma, vertigo, or sus­pected ear deformity.32

Traumatic ear fistulas can result from temporal bone injuries.2 Blunt head t rauma may cause temporal bone fracture, but pen­etrat ing ear t rauma, acoustic t rauma, and barotrauma are also implicated in PLF etiol­ogy.33,34 O n s e t of PLF is n o t necessa r i ly immediate , however. In fact, cochlear and vestibular problems are repor ted to repre­sent the largest group of delayed complica­tions of head injuries,35 with main causes of PLF resulting from stapedial footplate sub­luxa t i on or f r ac tu re after h e a d t r a u m a . Patients who present with vertigo and hear­ing loss following head t rauma should be explored for PLF.5,36

Middle-ear exp lora t ions often fail to reveal a fistula of the window membranes ; ra ther , fistulas of the lateral semicircular canal are repor ted to occur in as many as 25% of PLF cases.5 Blunt blows to the ear can produce PLF, such as striking the ear with hand slaps, which may cause tympanic mem­brane perforations as well. The mechanism causing this type of fistula is implosive.37

Pene t r a t i ng injuries of the t e m p o r a l bone , gunshot wounds, Q-tip insertion, and surgical i n t e rven t ion may all po ten t ia l ly cause PLF. Round window fistulas may be caused by flying a n d diving b a r o t r a u m a , and are attributed to forceful movement of the stapes while achieving middle-ear infla­t ion t h r o u g h Valsalva maneuver . 3 8 High-intensity acoustic t rauma or blast can cause a PLF with or without a tympanic membrane perforation. Narula and Marks present two cases of PLF due to acoustic trauma.39 The f i rs t p a t i e n t was e x p o s e d to 130 dBA through a te lephone headset, while the sec­o n d p a t i e n t was e x p o s e d to 118 dBA of music through a loudspeaker.

PLF may b e i n i t i a t e d by e x p l o s i v e forces such as sneezing, coughing , laugh­ing, a n d b e n d i n g over. T h e s e t r auma t i c 3

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

SEMINARS IN HEARING—VOLUME 15, NUMBER 1 FEBRUARY 1994

events may cause a r u p t u r e of the r o u n d window m e m b r a n e or the annular l igament of t h e s t apes footplate . 5 , 3 7 , 3 8 Se l tze r a n d McCabe identified PLF of this type in 24% of their series.26 Surgical repair of traumatic PLF is r ecommended , with the incidence of meningitis in such cases as high as 25%.40,41

SYMPTOMS

Symptoms associated with PLF include h e a r i n g loss, t inn i tus , aura l fullness, a n d vestibular symptoms ranging from debilitat­i n g v e r t i g o to s l i g h t d i s e q u i l i b r i u m . 4 2

Sudden or fluctuating hear ing loss is report­ed in over 80% of patients. Vertigo or dis­equ i l ib r ium occurs in m o r e t han 7 5 % of pat ients , a n d 60% of PLF pa t ien ts r e p o r t tinnitus.42 Hear ing loss varies from sudden, p r o f o u n d deafness to n o r m a l p u r e - t o n e sensitivity with fluctuating speech discrimi­na t ion scores.26 Pat ients may also p re sen t with modera te hear ing loss and low speech d i s c r i m i n a t i o n ab i l i ty , a n d f l u c t u a t i n g s p e e c h d i s c r i m i n a t i o n may b e t h e on ly hea r ing - re l a t ed symptom in over 20% of PLF cases.26 Normal hear ing and good word discr iminat ion ability are also r epo r t ed in PLF cases.4 3 Such cases r e p o r t e d l y of ten p r e sen t with conduct ive h e a r i n g loss a n d concomitant ossicular damage. O t h e r con­duct ive losses r e p o r t e d in PLF cases a re exp la ined by Goodhi l l ' s theory, in which t h e h e a r i n g loss is c a u s e d by p e r i l y m p h backsplash causing decreased energy from the middle ear to the inner ear, resulting in a conductive hear ing loss.44

Vestibular symptoms include t rue verti­g o , d i s e q u i l i b r i u m , l i g h t h e a d e d n e s s , mo t ion in to le rance , a n d combina t ions of these symptoms. Seltzer and McCabe found that in their pat ient series of over 100 ears some repor t ed initial severe episodic verti­g o t h a t d e c r e a s e d w i t h t i m e . 2 6 O t h e r p a t i e n t s r e p o r t e d an i nc rease in ve r t igo w i t h p h y s i c a l e x e r t i o n o r s t r a i n i n g . P e r s i s t e n t d i s e q u i l i b r i u m is a c o m m o n compla in t in PLF pat ients , as is in termi t ­tent dizziness. However, in termi t tent dizzi­ness may be difficult to diagnose, especially in chi ldren; and , cases of bilateral disease

a re r e p o r t e d l y g r e a t e r t h a n 5 0 % of PLF c h i l d h o o d cases, m a k i n g this age g r o u p especially at risk for p e r m a n e n t inner-ear damage.4 5

Vertigo is the only present ing sign of a pa t ient with fistula r epor t ed by Koltai and Galos,4 6 who suggest tha t fistula causes a change in the endolymphat ic space of the vestibular labyrinth by decompress ing the perilymphatic space. When the fistula is sur­g ica l ly c l o s e d , a n o r m a l f l u id b a l a n c e b e t w e e n e n d o l y m p h a n d p e r i l y m p h may then exist so symptoms disappear.

Tinnitus is also a highly variable symp­tom in PLF patients. It is r epor t ed in PLF patients without measurable hear ing loss,47

a n d it is p e r h a p s t h e m o s t c o m m o n l y r e p o r t e d a u d i t o r y s y m p t o m . T i n n i t u s desc r ip t ions r a n g e from r o a r i n g to h igh-p i t c h e d noise occu r r i ng in te rmi t t en t ly to constantly in over 60% of PLF cases.26

Although hear ing loss, pressure, tinni­tus , a n d ve r t igo a r e t h e s y m p t o m s m o s t c o m m o n to PLF as well as M e n i e r e ' s dis­ease, the two diseases can be distinguished. Patients with Meniere ' s disease often have f luctuat ing hea r ing , disabl ing vert igo, ear pressure, and distracting tinnitus, while PLF patients have stable hear ing loss, nondebil i-tating vertigo, mild ear fullness, and tinni­t u s . 48,49,50 H o w e v e r , Swift51 d e s c r i b e s a p a t i e n t with classic M e n i e r e ' s s y m p t o m s who had a PLF of the r o u n d window discov­ered dur ing surgery, suggesting that many Men ie r e ' s pa t ien t s m igh t actually be PLF cases. Swift repor ted the symptom of aural fullness as helpful in de te rmin ing which ear to exp lo re in 2 5 % of cases wi thou t o t h e r localizing signs.

DIAGNOSING PLF

Several signs, symptoms, a n d tests are used in d iagnosing PLF. In an a t t empt to d iagnose a fistula, aud iomet r i c evaluat ion including positional audiometry, electronys-t a g m o g r a p h y ( E N G ) , E N G f i s tu la tes t , Hennebe r t ' s sign and symptom, Tullio test, glycerin test ing, Quix test ing, eyes-closed t u r n i n g test, x-ray e x a m i n a t i o n , a n d case history are useful.36 4

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

HISTORICAL PERSPECTIVE—ACKLEYET AL.

A u d i o m e t r i c tes t ing in PLF pa t i en t s may show any type of hearing configuration including high-frequency, low-frequency, or flat audiometric loss and poor to excellent w o r d d i s c r i m i n a t i o n sco re s . T h r e s h o l d audiometry performed in various positions, including the horizontal position with the affected ear up, has been suggested.53 Such pos i t i on ing m i g h t allow air to e n t e r t he m e m b r a n o u s labyrinth when vertical, and interferes with stapes vibration, thus reduc­ing thresholds , whereas in the hor izonta l position the cochlea refills with perilymph and hear ing improves. The procedure may be sensitive to the site of the fistula because oval window fistulas correlate with 500-Hz threshold change and r o u n d window PLF correlates with 8000-Hz threshold change dur ing positional audiometry.54 The proce­d u r e has p a r t i c u l a r p r o m i s e w h e n air is seen in the cochlea on x-ray. Thin sectioned laminography may show air aspirated into the cochlea or semicircular canal.30 In theory, air might enter the vestibule in an implosive manner , and the round window membrane would r u p t u r e , s imul taneous ly re l ieving pressure and minimizing hear ing loss fol­lowing intracochlear membrane break.30

A repor t by Nishioka and Yanagihara55

descr ibed the p resence of air bubbles in experimental perilymph fistula as an expla­nation for inner ear morphology. Gibson56

described the condition of "dry cochlea" in p a t i e n t s wi th PLF as s y m p t o m a t i c , a n d other experimental studies corroborate this report.57,58

ENG fistula testing may provide useful information if a positive result is obtained, but does no t rule out a fistula if a negative result is obtained.59 Localization of a fistula may also be determined using the ENG fis­tula test as suggested by Koltai and Galos.46

Positive pressure applied to a patient 's right ear p roduced right beating nystagmus and vertigo, and round window fistula was con­f i rmed surgically. T h e fistula test is also he lp fu l in t h e d i f f e ren t i a l d i agnos i s of patients who have symptoms and signs simi­lar to Ménière 's disease but are suspected of having a fistula.58

Fistula test without ENG was described by DeWeese and Saunders4 using a Politzer

bag to increase ear canal pressure. Response of sudden vertigo frequently indicated PLF, especially in cases where cholesteatoma was suspected of eroding through the horizon­tal semicircular canal wall.

H e n n e b e r t testing may reveal H e n n e -b e r t ' s s ign o r s y m p t o m . T h i s d e s c r i b e s ei ther a visually observed deviation of the eyes with manual application of positive or negative pressure to the external auditory canal or a subjective sense of disequilibri­um. The procedure is positive in as many as 90% of PLF cases.52 When the procedure is positive for both ears, bilateral PLF may be confused with syphilis. An objective Henne­bert 's sign was seen relatively rarely in Potter and Conner ' s patients, yet when observed it was associated with oval window fistula.52

These investigators r ecommend tests for fis­tula and Henneber t ' s sign and, when posi­tive, exploratory tympanotomy is indicated.52

Tullio phenomenon , or disequilibrium induced by sound, has been identified in some PLF patients.60,61 Test procedures vary, al though presentation of intense, high- and low-frequency pure tones or narrow bands of noise for several seconds is used success­fully in PLF diagnosis.62

Glycerin testing is advocated because patients with PLF may have a deficiency of per i lymph and a relative excess of endo-lymph, which would there fore dehydra t e f avorab ly a n d i m p r o v e h e a r i n g . 4 8 , 5 0 In patients where Ménière 's disease is not sus­pected and head t rauma may have caused the symptoms, glycerin testing is helpful in diagnosing fistula.

L e h r e r a n d c o l l e a g u e s 5 0 s u g g e s t vestibular testing for PLF evaluation, includ­ing Quix test for body deviation. This is per­fo rmed by having the pa t i en t s tand with feet together, eyes closed, chin raised, and arms and index fingers extended. A gradual sway in a lateral direction is a positive result. Single ton devised an eyes-closed t u r n i n g test in which pa t i en t s a t t e m p t to walk a straight line with eyes closed, then on com­mand turn quickly either right or left 180° and stop with subsequent instability noted.47

He stated that patients with a positive eyes-c losed t u r n i n g test will ident ify t h e ea r involved by falling toward the affected side. 5

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

SEMINARS IN HEARING—VOLUME 15, NUMBER 1 FEBRUARY 1994

E N G t e s t i n g m a y r e v e a l p o s i t i o n a l a b n o r m a l i t i e s in o n e o r m o r e p o s i t i o n s characterized by lack of latency, long dura­tion, slow or no fatiguability, and no t neces­sarily with the affected ear down.3 6 Spon­taneous nystagmus was seen to beat to the o p p o s i t e s ide of t h e af fec ted ea r in t h e majority of PLF cases in the pat ient sample described by Singleton.47 Bithermal caloric testing has not proven as useful in demon­s t r a t i ng a s y m m e t r i e s b e t w e e n ves t ibu la r labyrinths. Experimental caloric testing pro­duces variable slow-phase velocity and pro­longed duration.6 3

Electrocochleography (ECoG) is useful in i d e n t i f y i n g e n d o l y m p h a t i c h y d r o p s (ELH) secondary to PLF.56,57,58 Summat ing potential is enhanced in more than 50% of active PLF cases,58 but findings fail to differ­ent ia te PLF cases from ELH pat ients with classic Ménière 's disease.57

SITE OF PLF

PLF may be more common in left ears than in right ears.33,64 Goodhill attributes this f i nd ing to s tud ies of t he t e m p o r a l b o n e where he theorizes that the patency of the cochlear aqueduct is inversely proport ional to the size of the lateral sinus, and in the temporal bones studied there were smaller sinuses and larger cochlear aqueducts on the left side.33 Oval window PLF is m o r e com­monly repor ted than r o u n d window fistula or fistulas of both window membranes . More than half of PLF cases occur at the oval win­dow and most are attributed to spontaneous and traumatic causes.26 The most c o m m o n area of perilymph leak from the oval window region, not associated with prior ear surgery, is the fissula ante fenestram.65

Round window PLF, though less com­m o n t h a n oval window PLF, may have a h i g h e r i n c i d e n c e of d e f o r m i t y . S u c h defects , a l o n g with c o n g e n i t a l t y m p a n i c cavity anomaly, are r e p o r t e d in over 30% of cases . 8 R o u n d w i n d o w n i c h e may b e a b n o r m a l in over 9 0 % of cases a n d t h e m e m b r a n e is frequently in a m o r e vertical o r i e n t a t i o n t h a n n o r m a l . 4 7 F i s t u l a s o c c u r r e d in b o t h window m e m b r a n e s in

9% of the pat ients described by Seltzer and McCabe.2 6

Yaniv a n d T r a u b s tud ied h e a d injury patients who had fistulas of the lateral semi­circular canal.5 They repor ted that patients wi th h e a d in ju r i e s w h o also e x p e r i e n c e vest ibular a n d coch lea r symptoms shou ld be explored after 10 days for the possibility of a f i s t u l a . If a w i n d o w f i s tu l a is n o t o b s e r v e d , t h e l a t e ra l s e m i c i r c u l a r c ana l should be explored . If a window fistula is repaired and symptoms persist, then explo­ration of the lateral semicircular is indicat­ed. They repor ted the following case:

Patient was initially operated on 12 days after injury. At that stage his hearing was 30 dB. A fistula discovered in the round win­dow was closed. Postoperatively his vertigo improved slightly, but his hearing deterio­rated to 55 dB. Six weeks later he under­went surgery again. The round window was found to be intact. [Surgery] was performed and a fracture which was found along the lateral semicircular canal with perilymph leakage was closed. Two days postoperatively he was free of vertigo, and three weeks later his hea r ing improved to 30 dB, but improved no further.5

T h e s e r e s e a r c h e r s e m p h a s i z e t h a t , a l though the incidence of lateral semicircu­lar canal fistulas is probably h igher in their series because of the severity of injuries they see, pa t ien ts with vest ibular a n d coch lea r symptoms following head t rauma may have fistulas of the lateral semicircular canal.

TREATMENT OF PLF

P e r i c h o n d r i u m , s u b c u t a n e o u s tissue, and fat are used for grafting, while gelatin s p o n g e is o f t en u s e d to s u p p o r t t h e grafts.26,36,50 Vein a n d t ragal p e r i c h o n d r a l grafts have also b e e n used.5 2 T h e grafting material of choice may depend on where the fistula is and whether it is necessary to remove the stapes to view the fistula.47 Seltzer and McCabe prefer to use subcutaneous areolar tissue because it drapes bet ter than fascia, per ichondral tissue, or other material.26

Failures of p a t c h i n g are often at t r ib­u t e d to fat graf ts . Ove r ha l f t h e fistulas 6

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

HISTORICAL PERSPECTIVE—ACKLEYET AL.

r e p a i r e d with fat grafts fail a n d fistulas recur.47 Per ichondr ium is seen as superior to fat a n d shou ld be rout ine ly used as a p a t c h i n g material.3 6 , 4 7 , 5 0 In i t ia l r e p a i r of PLF us ing fat r e su l t ed in 69% of recur ­rences of fistulas in the series repor ted by Seltzer and McCabe.26 Four of 10 graft sites using fat failed in the series of Potter and Conner , while vein and tragal per ichondral grafts were no t associated with refistuliza-tion.52 No patching material is seen as per­fect a c c o r d i n g to Seltzer a n d McCabe. 2 6

They repor t a failure rate of 15% for areo­lar tissue, 1 1 % for per ichondral tissue, 11% for fascia only, and 10% for prosthesis and fascia.

P r e p a r a t i o n of the graft site may be more impor tant than the type of seal cho­sen.36 The graft site must be exposed suffi­ciently and enough gelatin sponge must be placed over the grafting material to keep it in place dur ing the postoperative period.36

Singleton suggests that when packing the ear t ightly with Gelfoam adhesive b a n d s may form be tween the e a r d r u m a n d the g ra f t m a t e r i a l . 4 7 H e n o t e d t h a t t h e s e patients exper ienced vertigo with pressure movement of the tympanic membrane . The apparent sensorineural hearing loss experi­enced by these pat ients d isappeared after the bands connecting the eardrum and the tissue graft were cut. To prevent formation of adhesions between the d rum and graft, S i n g l e t o n r e c o m m e n d s c o v e r i n g t h e Gelfoam packing with Gelfilm sheet.

Surgical r e p a i r of PLF may have an u n a n t i c i p a t e d resul t . Pa t i en t s who have symptoms of hydrops secondary to elevated perilymph rather than endolymph pressure may be less symptomat ic because of the presence of a fistula.52 With spontaneous or surgical c losure of the fistula, symptoms may increase and recurring PLF may devel­op. This might explain the rare case where surgical closure of the PLF causes symptoms to become worse. Suppor t ing this theory, Goode suggests that the peri lymph hyper­tension may be a cause of ear disease that p r e s e n t s s im i l a r l y to e n d o l y m p h a t i c hydrops.29 Pathologic changes show a shift of Reissner's m e m b r a n e toward the organ of Corti.29

Results are good in controlling vertigo after fistula r epa i r . Sel tzer a n d McCabe report improvement in 95% of patients with vestibular symptoms by e l iminat ing dizzi­ness or d e c r e a s i n g it sufficiently to n o t interfere in daily living.26 All surgically con­firmed cases of PLF reported by Yaniv and Traub 5 were without symptoms of vertigo a n d dizziness postsurgical ly . Halvey a n d Sade6 6 r e p o r t e d comple t e e l imina t ion of vertigo in 69% of patients, but unsteadiness persisted in 36%. Potter and Conner52 report­ed elimination of vertigo in 80%. Vertigo and d isequi l ibr ium were cu red in all pa t ien ts described by Lehrer and colleagues.49,50

W h e n h e a r i n g loss occurs fol lowing PLF, surgery provides the best chance of res tor ing hearing.36,49 ,50 S p o n t a n e o u s PLF may heal without surgical intervention, but in many cases pe rmanen t cochlear damage may occur unless t r e a t m e n t is p rompt . 5 1

Hearing improved following surgery in 22% of patients repor ted by Halvey and Sade,66

while 56% showed no change and 22% had g r e a t e r h e a r i n g loss. Al thaus 6 4 r e p o r t e d improved hearing in 34% and greater post­surgical hea r ing loss in 27%. Seltzer and McCabe 2 6 r e p o r t e d improved h e a r i n g in 49% with 23% of those with a speech recep­tion threshold (SRT) better than 35 dB and speech discrimination ability better than 80%. They found poore r postoperative hear ing in 1 1 % and stabilized hear ing in 40%. As h i g h as 80% of p a t i e n t s have i m p r o v e d h e a r i n g fo l l owing c l o s u r e of t h e P L F , al though few improve to normal hearing.5

A common treatment in cases of trau­matic or sudden hearing loss where PLF is suspected is a trial medica l m a n a g e m e n t consisting of bed rest, head elevation, and avoiding straining to allow for spontaneous healing.36 If symptoms or hear ing become worse, or if no change occurs in the first 4 weeks, t h e n exp lora to ry t y m p a n o t o m y is advised.36,49,50 E m m e t t a n d Shea37 cau t ion tha t pa t i en t s with t r aumat ic PLF may be symptomat ica l ly i n d i s t i n g u i s h a b l e f rom patients with tympanic membrane perfora­tion, who may have symptoms of hea r ing loss, t inn i tus , uns t ead ines s , a n d ver t igo . However , b e c a u s e a h i g h p e r c e n t a g e of t raumatic PLF cases also involve ea rd rum 7

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

SEMINARS IN HEARING—VOLUME 15, NUMBER 1 FEBRUARY 1994

perforation (64% according to Emmett and Shea) surgical repair of both window mem­branes should always be considered when tympanic membrane perforation occurs fol­lowing trauma. Althaus64 recommends bed rest and head elevation if the main post­traumatic symptom is sudden sensorineural hearing loss. If after 1 week there is no improvement in hearing, exploratory tym­panotomy is advised.

SUMMARY

More than 200 medical references describe PLF in clinical cases and in labora­

tory animal models . Fewer than half a dozen authors deny PLF as a pathologic entity. Laboratory experimental evidence of PLF is convincing. Mystery surrounding the disorder focuses not on its existence, but rather on the challenge to clinicians to identify patients with PLF as diagnostically distinct from patients with classic Meniere's disease.

ACKNOWLEDGMENTS

The au thors acknowledge Cadwell Labs, Inc., Colorado Hearing Foundation, NIH (BRSG) Grant 5-35367, and R. F. Krug.

REFERENCES

1. Lewis, M.L. (1961). The inner ear compli­cations of stapes surgery. The Laryngoscope, 71, 377-384.

2. Fee, G.A. (1968). Traumatic perilymphatic fistulas. Archives of Otolaryngology, 88, 477-480.

3. Ruben, R.J., & Yankelowitz, S.M. (1989). Spon­taneous perilymphatic fistula in children. American Journal of Otology, 10(3), 198-207.

4. DeWeese, D.D., & Saunders, W.H. (1973). Textbook of otolaryngology. St. Louis: C.V. Mosby, p. 361.

5. Yaniv, E., & Traub, P. (1988). Traumatic perilymphatic fistulae of the lateral semicir­cular canal . Journal of Laryngology and Otology, 99(4), 393-397.

6. Brawley, B.W., & Kelly, W.A. (1967). Treatment of basal skull fractures with and without cerebrospinal fluid fistulae. Journal of Neurosurgery, 26(1), 57-61.

7. Reilly, J.S. (1989). Congenital perilymphat­ic fistula: A prospective study in infants and children. Laryngoscope, 99(4), 393-397.

8. Weber, P.C., Perez, B.A., & Bluestone, CD. (1993). Congenital perilymphatic fistula and associated middle ear abnormalities. Laryngoscope, 103(2), 160-164.

9. Simmons, F.B., Burton, R.D., & Beatty, D. (1962). Round window injury: Auditory, behavioral and electrophysiological conse­quences in the cat. Transactions of the American Academy of Ophthalmology and Otolaryngology, 66, 715-722.

10. Simmons, F.B. (1979). The double-mem­brane break syndrome in sudden hearing loss. The Laryngoscope, 89, 59-64.

11. Goodhill, V., Brockman, S.J., Harris, I., et al. (1973). Sudden deafness and labyrin­

thine window ruptures. Annals of Otology, Rhinology, and Laryngology 82, 2-12.

12. Beentjes, B.I.J. (1970). On the pressure of the endolymphatic, the perilymphatic, and the cerebrospinal fluid, with data on the endolymphatic membranes. Experiments on cats and guinea pigs. Henkes Holland, N V—Hearlemn, pp. 1-68.

13. Harker, L.A., Norante, J.D., & Rye, J.H. (1974). Experimental rupture of the round window m e m b r a n e . Transactions of the American Academy of Ophthalmology and Otolaryngology, 78, 448-452.

14. Bast, T.H., & Anson, B.J. (1949). Temporal bone and the ear. Springfield, Illinois, (73).

15. Anson, B.J., Donaldson, J.A., & Warpeha, R.L. (1965). The vestibul and cochlear aqueducts: Their variational anatomy in the adult human ear. The Laryngoscope, 75, 1203-1223.

16. Crowe, S.J. (1930). Pathologic changes in meningitis of the internal ear. Archives of Otolaryngology, 11, 537.

17. Palva, T., & Dammert, K. (1969). Human cochlear aqueduct . Acta Otolaryngology (Supplement), 86, 1503-1515.

18. Wtodyka, J. (1978). Studies on cochlear aqueduc t , patency. Annals of Otology, Rhinology, and Laryngology, 87, 22-28.

19. Ritter, F.N., & Lawrence, M. (1965). A his­tological and expe r imen ta l study of cochlear aqueduct patency in the Human Adult. The Laryngoscope, 75, 1224-1233.

20. Emmett, J.R., Staab, E.V., & Fischer, N.D. (1977). Perilymph fistulas secondary to gunsho t wound. Localizat ion with a radioactive pharmaceut ical . Archives of Otolaryngology, 103(2), 98-102. 8

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

HISTORICAL PERSPECTIVE—ACKLEYET AL.

21. Duval , A.J., & S u t h e r l a n d , C.R. ( 1 9 7 2 ) . Cochlear transport of horseradish Peroxidase. Annals of Otology, Rhinology, and Laryngology, 81, 705-713.

22. Asher, D.L., & Sando , I. (1981) . Perilym­phatic communicat ion routes in the audito­ry and vestibular System. Otolaryngology and Head and Neck Surgery, 89, 822-830.

23. Carlborg, B., & Farmer, J.C. (1983). Effects of hyperosmolar solutions on the labyrin­t h i n e f lu id p r e s s u r e s . Annals of Otology, Rhinology, and Laryngology, 3(92), 2-9.

24. H e m m e n w a y , W.G. , H i l d y a r d , V . H . , & Black, F.O. (1968). Poststapedectomy peri­lymph fistulas in the Rocky Mountain area: T h e i m p o r t a n c e of n y s t a g m o g r a p h y a n d audiometry in diagnosis and early tympan­o tomy in prognos is . The Laryngoscope, 77, 1687-1715.

25. P a r s i f e r , S.C., & B i r k e n , E.A. ( 1 9 7 6 ) . R e c u r r e n t m e n i n g i t i s s e c o n d a r y to id io­p a t h i c oval window CSF leak. The Laryn­goscope, 86, 1503-1515.

26. S e l t z e r , S., & M c C a b e , B.F. ( 1 9 8 6 ) . Perilymph fistula: T h e Iowa experience. The Laryngoscope, 96(1), 37-49.

27. Glasscock, M.E. (1973). The Stapes gusher. Archives of Otolaryngology, 98, 82 -91 .

28. Shea, J.J., & Konishi, S. (1971). Complica­tions of the stapedectomy operat ion. Annals of Otology, Rhinology, and Laryngology, 72, 1109-1123.

29. Goode , R.L. (1981). Per i lymph hyper ten­s ion a n d t h e i n d i r e c t m e a s u r e m e n t of coch lea r p ressu re . Laryngology, 91, 1 1 0 6 -1712.

30. Grundfast, K.J., & Bluestone, C D . (1978). Sudden or fluctuating hear ing loss and ver­tigo in ch i ld ren d u e to per i lymph fistula. Annals of Otology, Rhinology, and Laryngology, 87(6 Pt 1), 761-771.

31. P a s h l e y , N .R . , & S h a p i r o , R. ( 1 9 7 8 ) . Spontaneous peri lymphatic fistula. Journal of Otolaryngology, 7(2), 110-118.

32. Petroff, M.A., Simmons, F.B., & Winzelberg, J. (1986). Two emerg ing peri lymph fistula " s y n d r o m e s " in c h i l d r e n . Laryngoscope, 96(5), 498-501.

33. G o o d h i l l , V. (1980) . T r a u m a t i c f is tulae. Journal of Laryngology and Otology, 94(1), 123-128.

34. Pul len, F.W. (1992). Per i lymphat ic fistula induced by barotrauma. American Journal of Otolaryngology, 13(3), 270-272.

35. Healy, G.B., Fr iedman, J.M., & DiTroia, J. (1978). Ataxia and hear ing loss secondary to pe r i l ympha t i c fistula. Pediatrics, 61(2), 238-241.

36. Weider , D J . (1992). T r e a t m e n t and man­a g e m e n t of pe r i l ympha t i c fistula: A New Hampshi re experience. American Journal of Otolaryngology, 13(2), 158-166.

37. Emmett , R., & Shea, J.J. (1980). Traumatic pe r i lymph fistula. Laryngoscope, 90, 1 5 1 3 -1520.

38. P a r e l l , G.J. , & B e c k e r , G . D . ( 1 9 8 5 ) . Conse rva t ive m a n a g e m e n t of i n n e r e a r b a r o t r a u m a resu l t ing from scuba diving. Orolaryngology and Head and Neck Surgery, 93(3), 393-397.

39. Narula, A., & Marks, N.J. (1985). Acoustic t r a u m a a n d p e r i l y m p h fistula. Journal of Laryngology and Otology, 99(9), 909-911.

40. El jamel , M.S., & Foy, P.M. (1991) . Non­traumatic CSF fistulae: Clinical history and management . British Journal of Neurosurgery, 5(3), 275-279.

41 . T o m , L.W. , B i l a n i u k , L. , & R o a , R.A. (1992). Recurrent meningitis and a congen­ital perilymph fistula. Ear, Nose, and Throat Journal 71(7), 287-290.

42. Glasscock, M.E., Hart , M.J., Rosdeutscher, J. D., & Bhansali, S. A. (1992). Traumatic per­ilymphatic fistula: How long can symptoms persist? A follow-up report . American Journal of Otolaryngology, 13(4), 333-338.

43. Love, J.T. Jr., & Waguespack, R.W. (1981). Per i lymphat ic fistulas. Laryngoscope, 91(7), 1118-1128.

44. Goodhi l l , V. (1967) . T h e conduct ive loss p h e n o m e n o n in p o s t s t a p e d e c t o m y pe r i ­l y m p h f i s tu l a s . The Laryngoscope, 77, 1179-1190.

45. P a r n e s , L .S . , & M c C a b e , B.F. ( 1 9 8 7 ) . Per i lymph fistula: An i m p o r t a n t cause of d e a f n e s s a n d d i z z i n e s s in c h i l d r e n . Pediatrics, 80(4), 524-528.

46. Koltai, P.J., & Galos, R. (1986). Vertigo and p e r i l y m p h fistula. Ear, Nose, and Throat Journal, 65(6), 264-266.

47. Singleton, G.T. (1986). Diagnosis and treat­men t of perilymph fistulas without hear ing loss . Otolaryngology and Head and Neck Surgery, 94(4), 426-429.

48. Lehrer, J.F., Poole, D.C., & Sigal, B. (1980). Use of the glycerin test in the diagnosis of p o s t - t r a u m a t i c p e r i l y m p h a t i c f i s t u l a s . American Journal of Otolaryngology 1(3), 207-210.

49. Lehrer , J.F., & Poole, D.C. (1986). Vertigo from perilymphatic fistulas [letter] . Journal of the American Medical Association, 256(8), 1002-1003.

50. Lehre r , J .F., Quara ish i , A.U., Poole , D.C. ( 1 9 8 7 ) . T h e r o l e of e n d o l y m p h a t i c sac surgery in the m a n a g e m e n t of secondary e n d o l y m p h a t i c h y d r o p s a s soc i a t ed wi th perilymphatic fistulas: Preliminary observa­tions. American Journal of Otology, 8, 93-95 .

51 . Swift, A.C. (1985). O to r rhoea as a present­ing feature of a spontaneous round window rupture in a pat ient with Meniere 's disease. Journal of Laryngology and Otology, 99(10), 1009-1010. 9

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.

SEMINARS IN HEARING—VOLUME 15, NUMBER 1 FEBRUARY 1994

52. Pot ter , C.R., & Conner , G.H. (1983) . Hydrops following perilymph fistula repair. Laryngo&ope, 93(6), 810-812.

53. Fraser, J.G., & Flood, L.M. (1982). An audiomet r ic test for fistula. Journal of Laryngology and Otology, 96, 513-520.

54. Hazell, J.W., Fraser, J.G., & Robinson, P.J. (1992). Positional audiometry in the diag­nosis of perilymphatic fistula. American Journal of Otology, 13(3), 263-269.

55. Nishioka, I., & Yanagihara, N. (1986). Role of air bubbles in the perilymph as a cause of sudden deafness. American Journal of Otology, 7(6), 430-438.

56. Gibson, W.P.R. (1990). Electrophysiology in surgically, confirmed perilymphatic fistula. Third International Symposium on Inner Ear Surgery. Snowmass, CO, Feb. 1990.

57. Ackley, R.S. (1984). Electrocochleographic and histopathological observation of experi­mental perilymphatic fistula in guinea pigs. Doctoral thesis. University Microfilms International, Ann Arbor, MI.

58. Arenberg, I.K., Ackley, R.S., Ferraro, J., & Muchnik, C. (1988). ECoG results in peri­lymphatic fistula: Clinical and experimental studies. Otolaryngology and Head and Neck Surgery, 99(5), 435-443.

59. Daspit, C.P., Churchill, D., Linthicum, F.H.

(1980). Diagnosis of perilymph fistula using ENG and impedance . Laryngo&ope, 90, 217-223.

60. Arenberg, I.K., Ackley, R.S. (1988 Feb.) Perilymphatic fistula and endolymphatic hydrops. Presented at Prosper Meniere Society Midwinter Meeting. Aspen, CO.

61. Fox, E.J., Balkany, T.J., & Arenberg, K. (1988). The Tullio phenomenon and peri­lymph fistula. Otolaryngology and Head and Neck Surgery, 98, 88-89.

62. Ackley, R.S. (1988 Feb.). Experimental peri­lymphatic fistula: ECoG and histology. Presen ted at Prosper Meniere Society Midwinter Meeting. Aspen, CO.

63. Young, Y.H., Nomura , Y., & Hara , M. (1992). Caloric irregularity in experimen­tally induced perilymphatic fistula. European Archives of Otorhinolaryngology, 249(3), 181-184.

64. Althaus, S.R. (1981). Perilymph fistulas. Laryngo&ope, 91(4), 538-562.

65. Williams, D.C., Keene, M.H. (1986) . Perilymph leak from the fissula ante fenes¬ tram. Journal of Laryngology and Otology, 100 (6), 707-710.

66. Halvey, A., Sade, J. (1983). The perilymph fistula. American Journal of Otology, 5(2), 109-112.

10

Dow

nloa

ded

by: U

nive

rsite

Lav

al. C

opyr

ight

ed m

ater

ial.