Arch. Otorhinolaryngol. 221, 285-288 (1978)
Archivesof Oto-Rhino-Laryngology 9 Springer-Verlag 1978
Clinical Reports/Klinische A rbeiten Diving Injuries to the Inner Ear O. I. Molv~er 1, E. Natrud 1, and S. Eidsvik 2 1 Department of Otolaryngology, University Hospital, Trondheim, Norway 2 Norwegian Navys Diving School, Bergen, Norway
Summary. Two skin divers and 7 SCUBA divers, all men, aged 2 1 - 3 3 years, are presented. The injury occurred at shallow depths and difficulties with pressure equilibration to the ears were a common complaint. Vertigo and hearing losses. When a perilymph fistula is suspected and decompression sickness can be in the round, the other in the oval window. The latter patient also had a perforated ear drum on the same side, but his hearing normalized after surgical repair of the fistula and perforation. The others suffered lasting sensorineural high tone losses. When a perilymph fistula is suspected and decompression sickness can be ruled out, surgery within two days is recommended if bed rest does not prove effective. Key words: Inner ear damage -- Diving.
The risk of middle ear damage during diving is well-known. During recent years also our knowledge about inner ear damage resulting from diving has increased. Goodhill [4] described some of the possible mechanisms, and Farmer [2] recently reviewed the problem. Beside inner ear barotrauma with labyrinthine bleeding and possible membrane ruptures, cases with perilymph fistula are reported with increasing frequency [2-5, 8]. Other reasons for inner ear damage during diving may be noise, decompression sickness, air embolism, or bubble formation in the labyrinth as a counter diffusion phenomenon. Fourteen cases from Norway have been published before [7, 8]. Material
Recently we have gathered 9 similar cases from different parts of Norway, all men, aged 21-33 years. See Table 1 for survey and Table 2 for therapy and results. Offprint requests to: O. I. Molv~er, Norwegian Underwater Institute Box 6, N-5034 Y. Laksev~tg, Norway
0302-9530/78/0221/0285/$
01.00
286
O. I. Molv~er et al.
Table 1. Survey of the material Diver No/type
Type of dive Depth (m)
Difficulties with pressure equilibration
Vertigo
Sensorineural hearing loss (side)
Diagnosis
1. Sportdiver (trainee)
SCUBA/7
+
+
L
2. Sportdiver 3. Sportdiver 4. Fire brigade diver 5. Fire brigade diver 6. Professional diver 7. Navy diver 8. Skin diver
SCUBA/25 SCUBA/18 SCUBA/shallow
+ ? +
+ + +
R R
R
Oval window fistula. Tympanic membrane rupture (see text) Inner ear barotrauma Inner ear barotrauma Inner ear barotrauma
SCUBA/shallow
+
R+L
Inner ear barotrauma
SCUBA/shallow
+
+
SCUBA/20 Underwater polo/4 Plunged into pool
+ ?
+
R R
Inner ear barotrauma Inner ear barotrauma
+
L
Round window fistula
9. Skin diver
L
Inner ear barotrauma
SCUBA: Self Contained Underwater Breathing Apparatus
Table 2. Therapy and results Diver No.
Therapy
Result
1
Surgical repair. Antibiotics (our ward) Bed rest
Complete restitution (see text) Residual sensorineural high tone loss (75 dB at 8 kHz) Residual high tone loss (40 dB) Residual high tone loss (65 dB at 6 kHz) Residual high tone loss (R: 65 dB at 4 kHz L: 80 dB at 6 kHz) Residual high tone loss (75 dB at 8 kHz) Residual high tone loss (80 dB at 4 - 6 kHz) (11 years after the dive) Residual high tone loss (75--70 dB at 6--8 kHz) Residual high tone loss (45 dB at 8 kHz)
2
(our ward) 3 4 5
6 7
8 9
Bed rest (elsewhere) Nasal decongestant (elsewhere) Nasal decongestant (elsewhere) Bed rest (our ward) Nihil
Nihil. Advised to stop diving (elsewhere) Surgical repair (elsewhere)
Diving Injuries to the Inner Ear
287
Illustrative Case History A 21-years-old man attending a course for sport divers experienced severe difficulties with pressure equilibration to the middle ears during descent. At 6 m depth he got an unpleasant feeling in his left ear and experienced acute vertigo forcing him to surface. The vertigo lasted for only a couple of minutes whereafter he dived once more. This time he could not equalize the pressure to his right middle ear, but reached 7 m depth before surfacing. He suspected perforation of his left ear drum and was admitted to our ward on the same day. We found a round, central perforation with a diameter of 2 mm in the rear upper quadrant of his left tympanic membrane, clear fluid in his left middle ear and right-sided hematotympanon. Audiometry showed small, bilateral conductive losses with an additional light sensorineural loss (40 dB at 8 kHz) on the left side. Good correspondence between pure tone and SRT. No vertigo or nystagmus. In spite of bed rest with elevated head and antibiotics, both the conductive and sensorineural losses on the left side increased during the following 3 days and reached 75 dB at 6 kHz. Simultaneously, the hearing in the right ear normalized. A perilymph fistula was suspected and the ear explored surgically. Perilymph leakage from the oval window was found and the fistula was closed with fat. Also the ear drum perforation was repaired. Postoperatively his hearing normalized gradually.
Discussion A c c o r d i n g to F a r m e r [2], a case of perilymph fistula in the oval window resulting from diving was not published so far. The case reported above is the second of that type we have operated in our ward. The first one was a skin diver [5]. V a c u u m pumping (1.5 torr) of the middle ear did not d a m a g e the anular ligament or the m e m b r a n e o f the round window in 55 temporal bones enclosed in paraffin wax [9]. Nevertheless, none of the two divers with perilymph fistula operated in our w a r d had been exposed to hydrostatic pressures exceeding 1 atmosphere. Consequently, we feel that an "explosive" force through the canaliculus cochleae must work together with the low middle ear pressure to produce a perilymph fistula. L a m k i n et al. [6] have shown in guinea pig experiments that when the difference between the ambient and middle ear pressure was great, either cochlear bleeding or t y m p a n i c m e m b r a n e rupture occurred. In accordance with this, we have observed a number o f inner ear injuries resulting from diving without rupture of the ear drum. Cases of drum rupture without audiological signs of inner ear damage are not rare either. The explanation m a y be that when the ear drum bursts early, the pressure difference is equalized before it reaches the size or duration necessary to d a m a g e the inner ear. In blast injury to the ear Silox et al. [11] observed that the hearing loss was greater when the ear drum remained intact than when it broke. This m a y partly be explained b y the fact that the part of the blast energy required to tear the t y m p a n i c m e m b r a n e will never reach the inner ear. The case reported above is to our knowledge the first one published with the combination of t y m p a n i c m e m b r a n e rupture and perilymph fistula in the oval window resulting from diving. This diver most likely had sea water in his middle ear and the risk of infectious labyrinthitis must have been high. Also, one would expect the great salinity o f the
288
O. L Molv~er et al.
sea water to exert deleterious osmotic effects on the inner ear when a perilymph fistula was present. Nevertheless, the hearing normalized. The explanation may be that the perilymph pressure and flow was great enough to prevent sea water from penetrating to the inner ear. If decompression sickness can be ruled out in a diver with inner ear barotrauma, he should be put to bed with elevated head and avoid noise and anything that can raise the central venous, cerebrospinal fluid and perilymphatic pressure. If his sensorineural hearing loss and/or vertigo does not subside in the course of two days, a perilymph fistula should be suspected. The therapy is then surgery in order to confirm the diagnosis and close a possible fistula. Hyperbaric oxygen therapy is controversial in cases of inner ear barotrauma. The high tone range is always most affected in these cases. Morgenstern et al. [10] found that oxygen diffusion from the middle ear through the fenestra in guinea pigs amounted to 15% of the oxygen consumption of the first turn of cochlea when pO 2 in the middle ear reached 400 mmHg. During hyperbaric oxygen therapy pO 2 is more than five times that value. Hence, it is realistic to expect a considerably greater O2-diffusion to the damaged basal part of the cochlea. French authors [1] have achieved good results with such therapy, but Farmer et al. [3] maintain that it is not recommendable because it exposes the diver to the same stress that provoked the damage. This m a y be avoided by performing a prophylactic myringotomia.
References 1. Appaix, A., Demard, F.: Oxygtnothtrapie hyperbare et surditts brutales de perception. Rev. Laryngol. Otol. Rhinol. (Bord.) 11-12, 951-972 (1970) 2. Farmer, J. C.: Diving injuries to the inner ear. Ann. Otol. Rhinol. Laryngol. 86, Suppl. 36 (1977) 3. Farmer, J. C., Thomas, W. G.: Vestibular injury during diving. Ftrsvarsmedicin 9, 396--403 (1973) 4. Goodhilt, V.: Sudden deafness and round window rupture. Laryngoscope 81, 1462--1474 (1971) 5. Gundersen, T., Molv~er, O. I.: Hearing loss resulting from perilymph fistula. Acta Otolaryngol. (Stockh.) 85, 324-327 (I978) 6. Lamkin, R., Axelsson, A., McPherson, D., Miller, J.: Experimental aural barotrauma. Electrophysiological and morphological findings. Acta Otolaryngol. (Stockh.) Suppl. 335 (1975) 7. Molv~er, O. I.: Acute sensorineural hearing loss during diving. Minerva otorinolaringol. 22, 216-222 (i972) 8. MolvEer, O. I., Eidsvik, S.: Dykking og skade av det indre oyret. Tidsskr. Nor. L~egeforen. 98, 263--265 (1978) 9. Molv~er, O. I., Vallersnes, F. M., Kringlebotn, M.: The size of the middle ear and the mastoid air cell system measured by an acoustic method. Aeta Otolaryngol. (Stockh.) 85, 24-32 (1978) 10. Morgenstern, C., Kessler, M.: Oxygen consumption and oxygen distribution in the inner ear. Arch. Otorhinolaryngol. (N.Y.) 220, 159-162 (1978) 11. Silox, L. E., Schenek, H. B.: Blast injury of the ears. Arch. Otolaryugol. 39, 4t3--420 (1944) Received July 21, 1978
Archivesof Oto-Rhino-Laryngology 9 Springer-Verlag 1978
Clinical Reports/Klinische A rbeiten Diving Injuries to the Inner Ear O. I. Molv~er 1, E. Natrud 1, and S. Eidsvik 2 1 Department of Otolaryngology, University Hospital, Trondheim, Norway 2 Norwegian Navys Diving School, Bergen, Norway
Summary. Two skin divers and 7 SCUBA divers, all men, aged 2 1 - 3 3 years, are presented. The injury occurred at shallow depths and difficulties with pressure equilibration to the ears were a common complaint. Vertigo and hearing losses. When a perilymph fistula is suspected and decompression sickness can be in the round, the other in the oval window. The latter patient also had a perforated ear drum on the same side, but his hearing normalized after surgical repair of the fistula and perforation. The others suffered lasting sensorineural high tone losses. When a perilymph fistula is suspected and decompression sickness can be ruled out, surgery within two days is recommended if bed rest does not prove effective. Key words: Inner ear damage -- Diving.
The risk of middle ear damage during diving is well-known. During recent years also our knowledge about inner ear damage resulting from diving has increased. Goodhill [4] described some of the possible mechanisms, and Farmer [2] recently reviewed the problem. Beside inner ear barotrauma with labyrinthine bleeding and possible membrane ruptures, cases with perilymph fistula are reported with increasing frequency [2-5, 8]. Other reasons for inner ear damage during diving may be noise, decompression sickness, air embolism, or bubble formation in the labyrinth as a counter diffusion phenomenon. Fourteen cases from Norway have been published before [7, 8]. Material
Recently we have gathered 9 similar cases from different parts of Norway, all men, aged 21-33 years. See Table 1 for survey and Table 2 for therapy and results. Offprint requests to: O. I. Molv~er, Norwegian Underwater Institute Box 6, N-5034 Y. Laksev~tg, Norway
0302-9530/78/0221/0285/$
01.00
286
O. I. Molv~er et al.
Table 1. Survey of the material Diver No/type
Type of dive Depth (m)
Difficulties with pressure equilibration
Vertigo
Sensorineural hearing loss (side)
Diagnosis
1. Sportdiver (trainee)
SCUBA/7
+
+
L
2. Sportdiver 3. Sportdiver 4. Fire brigade diver 5. Fire brigade diver 6. Professional diver 7. Navy diver 8. Skin diver
SCUBA/25 SCUBA/18 SCUBA/shallow
+ ? +
+ + +
R R
R
Oval window fistula. Tympanic membrane rupture (see text) Inner ear barotrauma Inner ear barotrauma Inner ear barotrauma
SCUBA/shallow
+
R+L
Inner ear barotrauma
SCUBA/shallow
+
+
SCUBA/20 Underwater polo/4 Plunged into pool
+ ?
+
R R
Inner ear barotrauma Inner ear barotrauma
+
L
Round window fistula
9. Skin diver
L
Inner ear barotrauma
SCUBA: Self Contained Underwater Breathing Apparatus
Table 2. Therapy and results Diver No.
Therapy
Result
1
Surgical repair. Antibiotics (our ward) Bed rest
Complete restitution (see text) Residual sensorineural high tone loss (75 dB at 8 kHz) Residual high tone loss (40 dB) Residual high tone loss (65 dB at 6 kHz) Residual high tone loss (R: 65 dB at 4 kHz L: 80 dB at 6 kHz) Residual high tone loss (75 dB at 8 kHz) Residual high tone loss (80 dB at 4 - 6 kHz) (11 years after the dive) Residual high tone loss (75--70 dB at 6--8 kHz) Residual high tone loss (45 dB at 8 kHz)
2
(our ward) 3 4 5
6 7
8 9
Bed rest (elsewhere) Nasal decongestant (elsewhere) Nasal decongestant (elsewhere) Bed rest (our ward) Nihil
Nihil. Advised to stop diving (elsewhere) Surgical repair (elsewhere)
Diving Injuries to the Inner Ear
287
Illustrative Case History A 21-years-old man attending a course for sport divers experienced severe difficulties with pressure equilibration to the middle ears during descent. At 6 m depth he got an unpleasant feeling in his left ear and experienced acute vertigo forcing him to surface. The vertigo lasted for only a couple of minutes whereafter he dived once more. This time he could not equalize the pressure to his right middle ear, but reached 7 m depth before surfacing. He suspected perforation of his left ear drum and was admitted to our ward on the same day. We found a round, central perforation with a diameter of 2 mm in the rear upper quadrant of his left tympanic membrane, clear fluid in his left middle ear and right-sided hematotympanon. Audiometry showed small, bilateral conductive losses with an additional light sensorineural loss (40 dB at 8 kHz) on the left side. Good correspondence between pure tone and SRT. No vertigo or nystagmus. In spite of bed rest with elevated head and antibiotics, both the conductive and sensorineural losses on the left side increased during the following 3 days and reached 75 dB at 6 kHz. Simultaneously, the hearing in the right ear normalized. A perilymph fistula was suspected and the ear explored surgically. Perilymph leakage from the oval window was found and the fistula was closed with fat. Also the ear drum perforation was repaired. Postoperatively his hearing normalized gradually.
Discussion A c c o r d i n g to F a r m e r [2], a case of perilymph fistula in the oval window resulting from diving was not published so far. The case reported above is the second of that type we have operated in our ward. The first one was a skin diver [5]. V a c u u m pumping (1.5 torr) of the middle ear did not d a m a g e the anular ligament or the m e m b r a n e o f the round window in 55 temporal bones enclosed in paraffin wax [9]. Nevertheless, none of the two divers with perilymph fistula operated in our w a r d had been exposed to hydrostatic pressures exceeding 1 atmosphere. Consequently, we feel that an "explosive" force through the canaliculus cochleae must work together with the low middle ear pressure to produce a perilymph fistula. L a m k i n et al. [6] have shown in guinea pig experiments that when the difference between the ambient and middle ear pressure was great, either cochlear bleeding or t y m p a n i c m e m b r a n e rupture occurred. In accordance with this, we have observed a number o f inner ear injuries resulting from diving without rupture of the ear drum. Cases of drum rupture without audiological signs of inner ear damage are not rare either. The explanation m a y be that when the ear drum bursts early, the pressure difference is equalized before it reaches the size or duration necessary to d a m a g e the inner ear. In blast injury to the ear Silox et al. [11] observed that the hearing loss was greater when the ear drum remained intact than when it broke. This m a y partly be explained b y the fact that the part of the blast energy required to tear the t y m p a n i c m e m b r a n e will never reach the inner ear. The case reported above is to our knowledge the first one published with the combination of t y m p a n i c m e m b r a n e rupture and perilymph fistula in the oval window resulting from diving. This diver most likely had sea water in his middle ear and the risk of infectious labyrinthitis must have been high. Also, one would expect the great salinity o f the
288
O. L Molv~er et al.
sea water to exert deleterious osmotic effects on the inner ear when a perilymph fistula was present. Nevertheless, the hearing normalized. The explanation may be that the perilymph pressure and flow was great enough to prevent sea water from penetrating to the inner ear. If decompression sickness can be ruled out in a diver with inner ear barotrauma, he should be put to bed with elevated head and avoid noise and anything that can raise the central venous, cerebrospinal fluid and perilymphatic pressure. If his sensorineural hearing loss and/or vertigo does not subside in the course of two days, a perilymph fistula should be suspected. The therapy is then surgery in order to confirm the diagnosis and close a possible fistula. Hyperbaric oxygen therapy is controversial in cases of inner ear barotrauma. The high tone range is always most affected in these cases. Morgenstern et al. [10] found that oxygen diffusion from the middle ear through the fenestra in guinea pigs amounted to 15% of the oxygen consumption of the first turn of cochlea when pO 2 in the middle ear reached 400 mmHg. During hyperbaric oxygen therapy pO 2 is more than five times that value. Hence, it is realistic to expect a considerably greater O2-diffusion to the damaged basal part of the cochlea. French authors [1] have achieved good results with such therapy, but Farmer et al. [3] maintain that it is not recommendable because it exposes the diver to the same stress that provoked the damage. This m a y be avoided by performing a prophylactic myringotomia.
References 1. Appaix, A., Demard, F.: Oxygtnothtrapie hyperbare et surditts brutales de perception. Rev. Laryngol. Otol. Rhinol. (Bord.) 11-12, 951-972 (1970) 2. Farmer, J. C.: Diving injuries to the inner ear. Ann. Otol. Rhinol. Laryngol. 86, Suppl. 36 (1977) 3. Farmer, J. C., Thomas, W. G.: Vestibular injury during diving. Ftrsvarsmedicin 9, 396--403 (1973) 4. Goodhilt, V.: Sudden deafness and round window rupture. Laryngoscope 81, 1462--1474 (1971) 5. Gundersen, T., Molv~er, O. I.: Hearing loss resulting from perilymph fistula. Acta Otolaryngol. (Stockh.) 85, 324-327 (I978) 6. Lamkin, R., Axelsson, A., McPherson, D., Miller, J.: Experimental aural barotrauma. Electrophysiological and morphological findings. Acta Otolaryngol. (Stockh.) Suppl. 335 (1975) 7. Molv~er, O. I.: Acute sensorineural hearing loss during diving. Minerva otorinolaringol. 22, 216-222 (i972) 8. MolvEer, O. I., Eidsvik, S.: Dykking og skade av det indre oyret. Tidsskr. Nor. L~egeforen. 98, 263--265 (1978) 9. Molv~er, O. I., Vallersnes, F. M., Kringlebotn, M.: The size of the middle ear and the mastoid air cell system measured by an acoustic method. Aeta Otolaryngol. (Stockh.) 85, 24-32 (1978) 10. Morgenstern, C., Kessler, M.: Oxygen consumption and oxygen distribution in the inner ear. Arch. Otorhinolaryngol. (N.Y.) 220, 159-162 (1978) 11. Silox, L. E., Schenek, H. B.: Blast injury of the ears. Arch. Otolaryugol. 39, 4t3--420 (1944) Received July 21, 1978
