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Use of the glycerin test in the diagnosis of post-traumatic perilymphatic fistulas
Use of the Glycerin Test in the Diagnosis of Post-traumatic Perilymphatic Fistulas JOELF. LEHRER, M.D., F.A.C.S.,* DONRUEC. POOLE,M.A.,% ANDBEVERLYSIGAL,M.A.*
A new application of the glycerin test in the diagnosis of post-traumatic perilymphatic fistulas is described. Temporary disappearance of abnormal responses to the fistula and Quix tests and improvement in the hearing occurred. The glycerin test was useful in confirming the diagnosis of post-traumatic perilymphatic fistula in 13 patients in whom fistulas were found at middle ear exploration.
The occurrence of surgically correctable posttraumatic perilymphatic fistulas was first reported by Fee.' These fistulas have occurred in the round window, oval window, and preformed pathways between the inner and middle ears, most notably the fissula ante fenestram. Healy et al., 2 in reporting 40 cases, stressed the importance of a history of concussion in the evaluation of patients with vertigo. The confirmation of a perilymphatic fistula in these patients rested upon the findings of an abnormal response to the fistula test, positional nystagmus and vertigo, and vestibular ataxia. Thirty-five of the 40 patients had a hearing loss. The glycerin test was described by Klockhoff and Lindblom 5 in 1966. We have found that this test, as described by Snyder, 6 is a useful procedure in patients presenting with the symptoms and signs of Meniere's disease. We have extended its use by applying it to patients suspected of having post-traumatic perilymphatic fistulas. The purpose of this report is to present the
preoperative findings with the glycerin test and other tests in 13 patients with post-traumatic perilymphatic fistulas confirmed at middle ear exploration.
METHODS All patients in our study presented with vertigo or dysequilibrium following head trauma. The evaluation included routine otoscopy, examination for spontaneous and positional nystagmus and past pointing, and the Romberg test. The Quix test, as described by Hart, 3 was used. The patient is observed for 15 to 30 seconds while standing with his feet together, eyes closed, chin up, and arms and index fingers extended. A deviation of the outstretched arms, as measured by a lateral movement of the index fingers of the patient compared to the index fingers of the examiner, is reported as a right or left Quix deviation. If a lateral sway occurred, it
Accepted for publication December 12, 1979. *Chief, Department of Otolaryngology, Holy Name Hospital, Teaneck. Associate Attending Otolaryngologist, Valley Hospital, Ridgewood, New Jersey. +Audiologist, Teaneck, New Jersey. *Audiologist, Ridgewood, New Jersey. American Journal of Otolaryngology --Volume 1, Number 3, May 1980
207
American Journal
of OtolaryngoJogy
was observed several times in order to confirm this finding. All the patients underwent a complete audiometric evaluation and electronystagmography. Fistula testing with tympanometry was performed by changing the pressure in the external auditory canal from 400 mm. of water below atmospheric pressure to 400 mm. of water above atmospheric pressure. Vertigo or dysequilibrium was indicative of an abnormal response to the fistula test as described by Kohut et al. 4 as a positive Hennebert symptom. Induced nystagmus was not noted in these patients possibly because neither Frenzel's spectacles nor electronystagmography was utilized during this examination. On a subsequent day each patient was given 1.2 ml. of glycerin per kg. of body weight orally with an equal amount of saline. The fistula and Quix tests were administered every 30 minutes after the ingestion of the glycerin over a three hour period.
RESULTS
Preoperative Findings All patients in this study presented with vertigo or dysequilibrium following head trauma. This study included nine female and four male patients with an age range from 10 to 62 years. Six patients suffered head trauma in automobile accidents. Four of these patients did not lose consciousness at the time of the trauma. Four paTABLE 1. FISTULA PATIENT
Side
Locus
1 2 3 4 5 6 7 8 9 10 11 12 13
L R L L L R L R R R R L L
F F R* R*/O F F R*/F R* R* F R* R* R*
R, right L, left. F, f i s s u l a ante f e n e s t r a m . R*, r o u n d w i n d o w . O, 0val w i n d o w .
208
Preoperative Findings
DIRECTION OF Qulx L R L L L R R R R R R L L
tients struck their head in a fall, but did not lose consciousness. One patient was assaulted and another had a car door slammed on her head. Neither of these patients lost consciousness. A history of mild head trauma was obtained in the last patient. Seven of the 13 patients had normal hearing (Table 1). Five patients had sensorineural hearing losses, and one had a conductive hearing loss. The hearing loss in each instance was in the ear with the post-traumatic perilymphatic fistula. There was an abnormal response to the fistula test in the initial diagnostic evaluation in 12 of the 13 patients. On the initial diagnostic evaluation, three patients had abnormal responses to the fistula test bilaterally (Table 1). If the response to the fistula test was abnormal on only one side, it was on the side of the post-traumatic perilymphatic fistula. The response to the Quix test was abnormal in all 13 patients and indicated the side of the fistula in 12 patients. In one patient the Quix test pointed to the ear opposite the one that had the fistula that was subsequently operated u p o n on the basis of the presence of a fluctuating sensorineural hearing loss. There was an abnormal response to the fistula test bilaterally in this patient. The Quix test was the most frequently positive test in the physical examination. The most frequent positive finding on electronystagmography was spontaneous nystagmus to the side of the fistula, which occurred in six of the 13 patients (Table 1). There was no spontaneous nystagmus in seven patients.
SIDE(S) OF + FISTULA TEST L R L L L R bilat R bilat R N L bilat
AUDIOMETRY
fL N N L N N fL N fR N fR N L
sn
co
sn sn sn sn
ENG
L nyst R rvr R n y s t N R dp L rvr L n y s t N L dp L n y s t N Not d o n e R nyst R nyst N N
N. n o r m a l f. fluctuating. sn. s e n s o r i n e u r a l . co. c o n d u c t i v e . rvr, r e d u c e d v e s t i b u l a r r e s p o n s e . dp, directional p r e p o n d e r a n c e . nyst, n y s t a g m u s .
GLYCERIN TEST IN PERILYMPHATIC F I S T U L A S
TABLE 2.
FISTULA PATIENT
Side
Locus
1 2 3 4 5 6 7 8 9 10 11 12 13
L R L L L R L R R R R L L
F F R* R*/O F F R*/F R* R* F R* R* R*
Glycerine Test Results
ABNORMAL ABNORMAL RESPONSE TO RESPONSETO FISTULA TEST FISTULA TEST DISAPPEARED R E C U R R E D (HR.) (HR.) 1 1 2 N/A N/A 1/2 1 No No N/A N/A 11/2 11/2
2 2 No N/A N/A 3 2 N/A N/A N/A N/A 3 21/2
ABNORMAL ABNORMAL RESPONSETO RESPONSETO QuIx QOlX DISAPPEARED RECURRED (HR.) (HR.) 1 1 1 1 1/2 1/2 1/2 1/2 l/2 1/2 11/2 N/A ll/2
2 2 2 2 2 3 2 1 2 3 21/2 N/A 21/2
Volume 1 Number 3 May 1980 HEARING IMPROVED ON AUDIOMETRY N/A N/A N/A Yes N/A
N/A Yes N/A N/A N/A No N/A No
R, right. L, left. F, fissula ante fenestram. R*, r o u n d w i n d o w . O, oval w i n d o w . N/A, not applicable.
Glycerin Test Although patients 4, 5, and 10 had an abnormal response to the fistula test on initial testing, there was a normal response to the fistula test on the day of the glycerin test. Patient 11 had a normal response to the fistula test on both examinations. Therefore, an evaluation of the effect of glycerin on the fistula test in these patients was not possible. Patient 12 had a normal response to the Quix test on the day of the glycerin test; therefore the effect of the glycerin on this test could not be evaluated in this patient. In the nine patients with an abnormal response to the fistula test, the ingestion of the glycerin was followed by a normal response to the fistula test in seven patients in 30 minutes to two hours (Table 2). In most of the patients there was a return of the abnormal response to the fistula test within one hour after it had disappeared. Patient 3 did not show a return of the abnormal response to the fistula test. The disappearance of the abnormal response to the fistula test did not occur until two hours after ingestion of the glycerin. The testing was terminated in three hours, and thus the recurrence of the abnormal response may have occurred after the testing period. In patients 8 and 9 the abnormal response to the fistula test persisted for three hours after the ingestion of glycerin. All 12 patients with an abnormal response to the Quix test on the day of the glycerin test were found to have a normal response to the Quix test 30 minutes to one and one-half hours after ingesting the glycerin (Table 2). In most of the
JOEL F. LEHRER ET AL.
patients the abnormal response to the Quix test recurred within one hour after it had disappeared. Two of the four patients who had a hearing loss on the day of the glycerin test showed improvement in hearing after ingesting the glycerin (Table 2). Patients 1 and 9 had normal hearing on the day of the glycerin test but had been noted to have a fluctuating sensorineural hearing loss on previous examinations. All 13 patients showed a disappearance of an abnormal response to either the fistula test or the Quix test after glycerin ingestion. Patients 4 and 7 had two perilymphatic fistulas. Patient 4 had fistulas in the round window and the oval window. Patient 7 had fistulas in the fissula ante fenestram and the round window (Table 2). All fistulas were sealed with ear lobe fat after the mucous membrane in the area of the fistula was denuded. The follow-up period ranged from three to 17 months. Vertigo or dysequilibrium was absent in all 13 patients in the postoperative period and during the follow-up period (Table 3). The abnormal response to the Quix test that had been present before the operation was no longer present in any of these patients after the surgical procedure (Table 3). The fistula test was normal in seven of eight patients in w h o m it was performed postoperatively (Table 3). The only patient with an abnormal fistula test was patient 13, who was free of symptoms for 10 months following the operation. A postoperative fistula test was not performed in this patient during this
209
American Journal Otolaryngology
TABLE 3. Postoperative Findings PATIENT
MONTHS POSTOPERATIVE
VERTIGO OR DYSEQUILIBRIUM
Quix
FISTULA TEST
HEARING OR AUDIOMETRY
N N N L co N N N N N N R sn improved N L sn
1 2 3 4 5 6 7 8 9 10 11
7 8 11 5 4 8 3 11 4 12 5
None None None None None None None None None None None
N N N N N N N N N N N
Not done N Not done N N Not done N N N N N/A
12 13
17 16
None Present*
N L*
Not done Ab
*See text for explanation. R, right. L, left. N, normal. Ab, abnormal, co, conductive hearing loss. sn, sensorineural hearing loss. N/A, not applicable.
period. She developed vertigo one year after the operation during the eighth month of pregnancy. The vertigo became more severe during delivery at which time the patient noticed a popping in her head. At that time the fistula test was abnormal bilaterally, and she again showed a Qnix deviation to the left. The seven patients with normal preoperative hearing had normal hearing after the operation. Three patients (1, 7, and 9) with a fluctuating sensorineural hearing loss had normal h e a r i n g postoperatively. Patient 11 showed improvement in preoperative sensorineural hearing loss. Patients 4 and 13 showed no change in the hearing after the operation.
tion. In patients who present with symptoms and signs compatible with Meniere's disease, the presence of head trauma requires the consideration of post-traumatic perilymphatic fistula in the differential diagnosis. An abnormal response to the fistula test is very important in the diagnosis of fistula. Indeed the glycerin test cannot be used in the differential diagnosis of Meniere's disease and post-traumatic perilymphatic fistula. In patients in whom a diagnosis of Meniere's disease is not suspected, and in whom the head trauma is not easily related to the onset of vertigo, the glycerin test is helpful in the confirmation of the diagnosis of a fistula.
References DISCUSSION
It appears that a balance between perilymph and endolymph is necessary for proper functioning of the inner ear. Patients with Meniere's disease appear to have an absolute excess of endolymph. Patients with perilymphatic fistulas may be perilymph deficient and have a relative excess of endolymph. It may be that glycerin ingestion adjusts the balance between endolymph and perilymph in patients with Meniere's disease and perilymphatic fistulas. Reduction in the absolute or relative excess of endolymph may be the reason for temporary reversals of signs and symptoms in these patients. The glycerin test appears to be a reliable aid in the diagnosis of post-traumatic perilymphatic fistulas. It is now a standard part of our evalua-
210
1. Fee, G. A.: Traumatic perilymphatic fistulas. Arch. Otolaryngol., 88:477-480, 1968. 2. Healy, G. B., Friedman, J. M., and Strong, M. S.: Vestibular and auditory findings of perilymphatic fistula: a review of 40 cases. Trans. Am. Acad. Ophthalmol. Otolaryngol., 82:44-49, 1976. 3. Hart, C. W.: The evaluation of vestibular function in health and disease. In English, G. M. (Editor): Otolaryngology. Hagerstown, Maryland, Hoeber Medical Division, Harper and Row, 1972, Vol. 1, Ch. 10. 4. Kohut, R. I., Waldorf, R. A., Haenel, J. L., and Thompson, J. N.: Minute perilymph fistulas: vertigo and Hennebert's sign without hearing loss. Ann. Otol. Rhinol. Laryngol., 88:153-159, 1979. 5. Klockhoff, I., and Lindblom, V.: Endolymphatic hydrops revealed by glycerol test: preliminary report. Acta Otolaryugol., 61:459-462, 1966. 6. Snyder, J.: Extensive use of a diagnostic test for Meniere's disease. Arch. Otolaryngol., 100:360-365, 1974. Department of Otolaryngology Holy Name Hospital 718 Teaneck Road Teaneck, New Jersey 07666 (Dr. Lehrer)
GLYCERIN TEST IN PERILYMPHATIC FISTULAS
A new application of the glycerin test in the diagnosis of post-traumatic perilymphatic fistulas is described. Temporary disappearance of abnormal responses to the fistula and Quix tests and improvement in the hearing occurred. The glycerin test was useful in confirming the diagnosis of post-traumatic perilymphatic fistula in 13 patients in whom fistulas were found at middle ear exploration.
The occurrence of surgically correctable posttraumatic perilymphatic fistulas was first reported by Fee.' These fistulas have occurred in the round window, oval window, and preformed pathways between the inner and middle ears, most notably the fissula ante fenestram. Healy et al., 2 in reporting 40 cases, stressed the importance of a history of concussion in the evaluation of patients with vertigo. The confirmation of a perilymphatic fistula in these patients rested upon the findings of an abnormal response to the fistula test, positional nystagmus and vertigo, and vestibular ataxia. Thirty-five of the 40 patients had a hearing loss. The glycerin test was described by Klockhoff and Lindblom 5 in 1966. We have found that this test, as described by Snyder, 6 is a useful procedure in patients presenting with the symptoms and signs of Meniere's disease. We have extended its use by applying it to patients suspected of having post-traumatic perilymphatic fistulas. The purpose of this report is to present the
preoperative findings with the glycerin test and other tests in 13 patients with post-traumatic perilymphatic fistulas confirmed at middle ear exploration.
METHODS All patients in our study presented with vertigo or dysequilibrium following head trauma. The evaluation included routine otoscopy, examination for spontaneous and positional nystagmus and past pointing, and the Romberg test. The Quix test, as described by Hart, 3 was used. The patient is observed for 15 to 30 seconds while standing with his feet together, eyes closed, chin up, and arms and index fingers extended. A deviation of the outstretched arms, as measured by a lateral movement of the index fingers of the patient compared to the index fingers of the examiner, is reported as a right or left Quix deviation. If a lateral sway occurred, it
Accepted for publication December 12, 1979. *Chief, Department of Otolaryngology, Holy Name Hospital, Teaneck. Associate Attending Otolaryngologist, Valley Hospital, Ridgewood, New Jersey. +Audiologist, Teaneck, New Jersey. *Audiologist, Ridgewood, New Jersey. American Journal of Otolaryngology --Volume 1, Number 3, May 1980
207
American Journal
of OtolaryngoJogy
was observed several times in order to confirm this finding. All the patients underwent a complete audiometric evaluation and electronystagmography. Fistula testing with tympanometry was performed by changing the pressure in the external auditory canal from 400 mm. of water below atmospheric pressure to 400 mm. of water above atmospheric pressure. Vertigo or dysequilibrium was indicative of an abnormal response to the fistula test as described by Kohut et al. 4 as a positive Hennebert symptom. Induced nystagmus was not noted in these patients possibly because neither Frenzel's spectacles nor electronystagmography was utilized during this examination. On a subsequent day each patient was given 1.2 ml. of glycerin per kg. of body weight orally with an equal amount of saline. The fistula and Quix tests were administered every 30 minutes after the ingestion of the glycerin over a three hour period.
RESULTS
Preoperative Findings All patients in this study presented with vertigo or dysequilibrium following head trauma. This study included nine female and four male patients with an age range from 10 to 62 years. Six patients suffered head trauma in automobile accidents. Four of these patients did not lose consciousness at the time of the trauma. Four paTABLE 1. FISTULA PATIENT
Side
Locus
1 2 3 4 5 6 7 8 9 10 11 12 13
L R L L L R L R R R R L L
F F R* R*/O F F R*/F R* R* F R* R* R*
R, right L, left. F, f i s s u l a ante f e n e s t r a m . R*, r o u n d w i n d o w . O, 0val w i n d o w .
208
Preoperative Findings
DIRECTION OF Qulx L R L L L R R R R R R L L
tients struck their head in a fall, but did not lose consciousness. One patient was assaulted and another had a car door slammed on her head. Neither of these patients lost consciousness. A history of mild head trauma was obtained in the last patient. Seven of the 13 patients had normal hearing (Table 1). Five patients had sensorineural hearing losses, and one had a conductive hearing loss. The hearing loss in each instance was in the ear with the post-traumatic perilymphatic fistula. There was an abnormal response to the fistula test in the initial diagnostic evaluation in 12 of the 13 patients. On the initial diagnostic evaluation, three patients had abnormal responses to the fistula test bilaterally (Table 1). If the response to the fistula test was abnormal on only one side, it was on the side of the post-traumatic perilymphatic fistula. The response to the Quix test was abnormal in all 13 patients and indicated the side of the fistula in 12 patients. In one patient the Quix test pointed to the ear opposite the one that had the fistula that was subsequently operated u p o n on the basis of the presence of a fluctuating sensorineural hearing loss. There was an abnormal response to the fistula test bilaterally in this patient. The Quix test was the most frequently positive test in the physical examination. The most frequent positive finding on electronystagmography was spontaneous nystagmus to the side of the fistula, which occurred in six of the 13 patients (Table 1). There was no spontaneous nystagmus in seven patients.
SIDE(S) OF + FISTULA TEST L R L L L R bilat R bilat R N L bilat
AUDIOMETRY
fL N N L N N fL N fR N fR N L
sn
co
sn sn sn sn
ENG
L nyst R rvr R n y s t N R dp L rvr L n y s t N L dp L n y s t N Not d o n e R nyst R nyst N N
N. n o r m a l f. fluctuating. sn. s e n s o r i n e u r a l . co. c o n d u c t i v e . rvr, r e d u c e d v e s t i b u l a r r e s p o n s e . dp, directional p r e p o n d e r a n c e . nyst, n y s t a g m u s .
GLYCERIN TEST IN PERILYMPHATIC F I S T U L A S
TABLE 2.
FISTULA PATIENT
Side
Locus
1 2 3 4 5 6 7 8 9 10 11 12 13
L R L L L R L R R R R L L
F F R* R*/O F F R*/F R* R* F R* R* R*
Glycerine Test Results
ABNORMAL ABNORMAL RESPONSE TO RESPONSETO FISTULA TEST FISTULA TEST DISAPPEARED R E C U R R E D (HR.) (HR.) 1 1 2 N/A N/A 1/2 1 No No N/A N/A 11/2 11/2
2 2 No N/A N/A 3 2 N/A N/A N/A N/A 3 21/2
ABNORMAL ABNORMAL RESPONSETO RESPONSETO QuIx QOlX DISAPPEARED RECURRED (HR.) (HR.) 1 1 1 1 1/2 1/2 1/2 1/2 l/2 1/2 11/2 N/A ll/2
2 2 2 2 2 3 2 1 2 3 21/2 N/A 21/2
Volume 1 Number 3 May 1980 HEARING IMPROVED ON AUDIOMETRY N/A N/A N/A Yes N/A
N/A Yes N/A N/A N/A No N/A No
R, right. L, left. F, fissula ante fenestram. R*, r o u n d w i n d o w . O, oval w i n d o w . N/A, not applicable.
Glycerin Test Although patients 4, 5, and 10 had an abnormal response to the fistula test on initial testing, there was a normal response to the fistula test on the day of the glycerin test. Patient 11 had a normal response to the fistula test on both examinations. Therefore, an evaluation of the effect of glycerin on the fistula test in these patients was not possible. Patient 12 had a normal response to the Quix test on the day of the glycerin test; therefore the effect of the glycerin on this test could not be evaluated in this patient. In the nine patients with an abnormal response to the fistula test, the ingestion of the glycerin was followed by a normal response to the fistula test in seven patients in 30 minutes to two hours (Table 2). In most of the patients there was a return of the abnormal response to the fistula test within one hour after it had disappeared. Patient 3 did not show a return of the abnormal response to the fistula test. The disappearance of the abnormal response to the fistula test did not occur until two hours after ingestion of the glycerin. The testing was terminated in three hours, and thus the recurrence of the abnormal response may have occurred after the testing period. In patients 8 and 9 the abnormal response to the fistula test persisted for three hours after the ingestion of glycerin. All 12 patients with an abnormal response to the Quix test on the day of the glycerin test were found to have a normal response to the Quix test 30 minutes to one and one-half hours after ingesting the glycerin (Table 2). In most of the
JOEL F. LEHRER ET AL.
patients the abnormal response to the Quix test recurred within one hour after it had disappeared. Two of the four patients who had a hearing loss on the day of the glycerin test showed improvement in hearing after ingesting the glycerin (Table 2). Patients 1 and 9 had normal hearing on the day of the glycerin test but had been noted to have a fluctuating sensorineural hearing loss on previous examinations. All 13 patients showed a disappearance of an abnormal response to either the fistula test or the Quix test after glycerin ingestion. Patients 4 and 7 had two perilymphatic fistulas. Patient 4 had fistulas in the round window and the oval window. Patient 7 had fistulas in the fissula ante fenestram and the round window (Table 2). All fistulas were sealed with ear lobe fat after the mucous membrane in the area of the fistula was denuded. The follow-up period ranged from three to 17 months. Vertigo or dysequilibrium was absent in all 13 patients in the postoperative period and during the follow-up period (Table 3). The abnormal response to the Quix test that had been present before the operation was no longer present in any of these patients after the surgical procedure (Table 3). The fistula test was normal in seven of eight patients in w h o m it was performed postoperatively (Table 3). The only patient with an abnormal fistula test was patient 13, who was free of symptoms for 10 months following the operation. A postoperative fistula test was not performed in this patient during this
209
American Journal Otolaryngology
TABLE 3. Postoperative Findings PATIENT
MONTHS POSTOPERATIVE
VERTIGO OR DYSEQUILIBRIUM
Quix
FISTULA TEST
HEARING OR AUDIOMETRY
N N N L co N N N N N N R sn improved N L sn
1 2 3 4 5 6 7 8 9 10 11
7 8 11 5 4 8 3 11 4 12 5
None None None None None None None None None None None
N N N N N N N N N N N
Not done N Not done N N Not done N N N N N/A
12 13
17 16
None Present*
N L*
Not done Ab
*See text for explanation. R, right. L, left. N, normal. Ab, abnormal, co, conductive hearing loss. sn, sensorineural hearing loss. N/A, not applicable.
period. She developed vertigo one year after the operation during the eighth month of pregnancy. The vertigo became more severe during delivery at which time the patient noticed a popping in her head. At that time the fistula test was abnormal bilaterally, and she again showed a Qnix deviation to the left. The seven patients with normal preoperative hearing had normal hearing after the operation. Three patients (1, 7, and 9) with a fluctuating sensorineural hearing loss had normal h e a r i n g postoperatively. Patient 11 showed improvement in preoperative sensorineural hearing loss. Patients 4 and 13 showed no change in the hearing after the operation.
tion. In patients who present with symptoms and signs compatible with Meniere's disease, the presence of head trauma requires the consideration of post-traumatic perilymphatic fistula in the differential diagnosis. An abnormal response to the fistula test is very important in the diagnosis of fistula. Indeed the glycerin test cannot be used in the differential diagnosis of Meniere's disease and post-traumatic perilymphatic fistula. In patients in whom a diagnosis of Meniere's disease is not suspected, and in whom the head trauma is not easily related to the onset of vertigo, the glycerin test is helpful in the confirmation of the diagnosis of a fistula.
References DISCUSSION
It appears that a balance between perilymph and endolymph is necessary for proper functioning of the inner ear. Patients with Meniere's disease appear to have an absolute excess of endolymph. Patients with perilymphatic fistulas may be perilymph deficient and have a relative excess of endolymph. It may be that glycerin ingestion adjusts the balance between endolymph and perilymph in patients with Meniere's disease and perilymphatic fistulas. Reduction in the absolute or relative excess of endolymph may be the reason for temporary reversals of signs and symptoms in these patients. The glycerin test appears to be a reliable aid in the diagnosis of post-traumatic perilymphatic fistulas. It is now a standard part of our evalua-
210
1. Fee, G. A.: Traumatic perilymphatic fistulas. Arch. Otolaryngol., 88:477-480, 1968. 2. Healy, G. B., Friedman, J. M., and Strong, M. S.: Vestibular and auditory findings of perilymphatic fistula: a review of 40 cases. Trans. Am. Acad. Ophthalmol. Otolaryngol., 82:44-49, 1976. 3. Hart, C. W.: The evaluation of vestibular function in health and disease. In English, G. M. (Editor): Otolaryngology. Hagerstown, Maryland, Hoeber Medical Division, Harper and Row, 1972, Vol. 1, Ch. 10. 4. Kohut, R. I., Waldorf, R. A., Haenel, J. L., and Thompson, J. N.: Minute perilymph fistulas: vertigo and Hennebert's sign without hearing loss. Ann. Otol. Rhinol. Laryngol., 88:153-159, 1979. 5. Klockhoff, I., and Lindblom, V.: Endolymphatic hydrops revealed by glycerol test: preliminary report. Acta Otolaryugol., 61:459-462, 1966. 6. Snyder, J.: Extensive use of a diagnostic test for Meniere's disease. Arch. Otolaryngol., 100:360-365, 1974. Department of Otolaryngology Holy Name Hospital 718 Teaneck Road Teaneck, New Jersey 07666 (Dr. Lehrer)
GLYCERIN TEST IN PERILYMPHATIC FISTULAS