435
UNILATERAL COMPLETE APLASIA OF THE INNER EAR WITH ASSOCIATED TRACHEOESOPHAGEAL FISTULA: REPORT OF A CASE STEVEN
F.
ISENBERG,
MD
BY INVIT"nox
LAVERNE B. TUBERGEN, MD INDIANAPOLIS, INDIANA
A use of unilateral complete aplasia of the petrous apex and Inner ear assoctated with H· type tracheoesophageal fistula is reported. Polytomography, computerized axial tomography, and plain film radiography confirmed the presence of this rare variant of Inner ear aplasia. This patient, who has normal fadal nerve function, Is, to our knowledge, the first reported use of a nonthalidomide, Micheltype aplasia since the original report of Michel more than a century ago. Unilateral complete inner ear aplasia associated with tracheoesophageal fistula has not been preYiously reported. IN 1863, Michel' reported a case of bilateral complete bony and membranous aplasia of the inner ear. In his description of an autopsy performed on an 11-yearold deaf mute, Michel described the absence of the mastoid and inner ear. The petrous pyramid was reduced in size bilaterally, and no opening for the eighth cranial nerve was identified. Through a 2-mm gap the facial nerve WclS traced between the petrous and occipital bones to exit via the stylomastoid foramen. The external meatus was closed by an intact tympanic membrane, and the middle ear was normal except for the absence of a stapes.
Submitted for publication Sept 12, 1978. From the Department of Otolaryngology, Indiana University School of Medicine, Indianapolis. Presented at the 1978 Annual Meeting of the American Academy of Otolaryngology, Las Vegas, Sept 10U.
Valvassori et al2 reviewed 50 cases in which abnormalities appeared in tomograms. He classified seven ears as "aplastic." He defined these as "aplasia of all inner ear structures, with only a simple undifferentiated cavity being present." Jorgensen! reported a case of Michel's deformity (bilateral aplasia) in an infant with marked external deformity secondary to thalidomide taken by the mother the first month of gestation. Microscopically, the middle ear demonstrated absence of the oval window and foot plate on the left and absence of the stapes on the right. On the right side was total aplasia of the inner ear with no trace of cavitation; on the left was a smoothwalled spherical cavity with primordia of a membranous labyrinth and end-organ. The seventh and eighth nerves were absent bilaterally. The following case report differs significantly in description from any previously reported'·3 in the literature.
CASE REPORT
A 6-year-old white girl was examined at the Department of Otolaryngology, Indiana University Medical Center, because of a sensorineural hearing loss that had occurred one month previously. The patient had no additional complaints. The patient's mother had noticed no difference in the patient's hearing, but had noticed occasional weakness in the right upper extremity, especially in the evening, with some question of tremor. This, combined with the occurrence of sudden
Olo/aryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
436
ISENBERG AND TUBERGEN
hearing loss, prompted admission of the patient to the ENT Service with neurosurgical consultation. The patient had been the product of a fullterm vaginal delivery. Birth weight was 2.98 kg. She was the fourth child in eight pregnancies, and the mother recalled a "difficult perinatal period." The mother denied taking any medications except penicillin for bronchiectasis. After delivery the mother was started on thyroid supplementations after a diagnosis of hypothyroidism. No thyroid function tests were available to document this condition. On the day of birth, the patient was transferred to the James Whitcomb Riley Children's Hospital with a tracheoesophageal fistula demonstrated on barium swallow. The following day, the patient underwent repair of a fistula at the level of n. A fistula was identified and closed. Twenty days postoperatively, repeated aspiration prompted a repeat barium swallow, which demonstrated an additional fistula in the cervical area. Reexploration revealed an additional H-type fistula at the level of C6. This defect was repaired and the patient was discharged without problems. Periodic esophageal dilations and gastrostomy closure were uneventful. Physical examination at the time of admission showed the patient had an occipitofrontal circumference of 56 em, placing her in the 98th percentile. Pupils showed slight anisocoria, with the left 1 to 2 mm greater than the right but both reactive. The external ear appeared normal and the seventh nerve was intact. The tympanic membrane on the left was normal; the right had a slight decrease in mobility, but had normal landmarks. Results of cerebellar testing and the additional neurologic examination were normal. The hospital course included a normal electronystagmogram (ENG) and EEG. Audiometrically, no measurable hearing was recorded on the right side, but normal pure-tone thresholds and 100% discrimination were found on the left. An ipsilateral left acoustic reflex was present. There were no contralateral reflexes, and the patient demonstrated a flat, type B tympanogram on the right side. On routine radiographs (Fig 1 and 2), differences were noted in comparing the anatomy of left and right petrous bones. The arcuate eminence was absent on the right petrous (Fig 1, top), as was labyrinthine anatomy on that side. The right petrous ridge was flat, and the petrous apex on the right side was located a greater distance than normal from the midline. The internal acoustic meatus and labyrinthine
R
Fig 1.-Routine radiographs of skull coned down to area of petrous pyramid. Top, Caldwell view. Note well-developed left petrous pyramid showing prominent arcuate eminence (larger arrowhead) and labyrinthine structures below this point in body of petrous pyramid. Apex of petrous pyramid (smaller arrowhead) on right side is located at greater distance from midline compared with left side. Right petrous ridge is flat. Bottom, Submentovertex view. Anterior and posterior margins of porus acousticus interna on left side are well seen (arrowheads). Internal auditory canal ends laterally at vestibule (v). These structures are absent on right side. Tympanic cavities (tl are readily identified bilaterally.
vestibule were absent from radiographic visualization in the submentovertex view (Fig 1, bottom). Thin-section tomography (Fig 2, top) demonstrated a low profile and flat appearance of the petrous ridge on the right side. The right internal meatus was visualized as a short, narrow channel placed inferiorly and medially, probably conveying the facial nerve. Semicircular canals and cochlear turns were displayed on the left (Fig 2, top right), but were absent on the right (Fig 1, bottom). In the middle ear, some displacement in position of the malleus and incus was noted on the right, as well as absence of the round window (Fig 2, bottom). With computerized axial tomography, obvious absence of the otic capsule structure is noted in the right petrous (Fig 3).
Oto/aryngol Head Neck Surg 87:435-439 (july-Aug> 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
UNILATERAL COMPLETE APLASIA
437
Fig 2.-Anteroposterior thin-section tomographic views of both ears. Top left and right, Level of malleus and cochlea. Scutum (a), malleus (b). petrous ridge (c). porus acousticus interna (d). Note flat petrous ridge on right side with no inner ear structures, which should be visualized below point "c." Compare with left side, where apical and midturns of cochlea and geniculate ganglion fossa are readily identifiable. Also note small and inferior medially displaced opening of bony canal (d) on right side, which is probably conveying facial nerve. Bottom left and right, Level of incus and vestibule. Right incus (e), short process of left incus (f), left arcuate eminence (g), lefr round window (h). Note horizontally oriented right incus (e). which was noted with nght malleus also. On left side, superior and horizontal semicircular canals converging at vestibule are well seen below arcuate eminence (g). Round window and short process of incus are also identified. None of these inner ear structures, not even a simple cavitary lucency, are seen on right side.
DISCUSSION
If a common developmental"accident" is to explain the association of the temporal bone defect with the tracheoesophageal fistula, then the time of appearance of the laryngotracheal groove should more or less synchronize with a certain event in the development of the petrous temporal.
The first indication of the developing ear can be found in an embryo approximately 22 days old as bilateral thickenings of the surface ectoderm to each side of the rhombencephalon. These thickenings, the otic placodes, invaginate rapidly and form the otic vesicle. Balinsky. gives an excellent description of a chain of inductions:
Otolaryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
438
ISENBERG AND TUBERGEN 3. The otic vesicle, as a tertiary inductor, induces formation of the cartilaginous capsule.
Two other embryologic points are pertinent to the discussion of internal ear aplasia. First, there is a direct causal relationship between the otic vesicle (derived from otic placode) and the development of the ear capsule. Balinsky.s with reference to the work of lewis,S states that if the ear vesicle is removed, the ear capsule does not develop, and if a foreign ear vesicle is transplanted in the tail bud stage, the local mesenchymal cells may aggregate around it and produce an additional cartilaginous capsule, For the petromastoid complex alone, up to 14 centers of ossification in capsule have been described, usually as being initiated in the fifth intrauterine month. Secondly, the middle ear, derived from the brachial apparatus, is not related to development, or directly to lack of development, of the inner ear.
Fig 3.-Head at level of petrous pyramid. Top, External auditory canals curving slightly forward and end ing at tympanic cavity (arrowheads) are well visualized. On left side is oval bony densily representing otic capsule structures, which is absent on right. Bottom , level approximately 1.5 cm more cephalad. Otic capsule structures represented by oval bony density and attic mastoid antrum lateral and posterior to it are well seen on left side. On right side, attic and mastoid antrum are small, although well aerated . Otic capsule structures are absent on th is side.
"I
1. The primary inductions-The roof of the archenteron (gut) consisting of presumptive chordomesoderm-induces development of the hindbrain. 2. The hindbrain, as a secondary inductor, stimulates development of the otic vesicle (in conjunction with the direct action of the mesoderm on the presumptive ear ectoderm),
Interestingly, the ventral portion of the archenteron, which serves as the primary inductor of the otic vesicle, is the primary inductive influence on the formation of the trachea . Myers6 reported a case of bilateral partial aplasia of the inner ear with ossicular anomaly, congenital tracheoesophageal fistula, cleft lip, and cleft palate. He theorized an embryologic arrest of the ingrowing mesoderm between the third and 12th weeks of development in the tracheoesophageal fistula, and the concomitant development of the inner ear suggested a development accident common to the several organs. Altmann? pointed out several factors essential for development of the ear based on work done on amphibians. The anlagen of the ear must be properly positioned to bring the chordal mesoderm under the prospective inner ear ectoderm during gastrulation; revising the neural folds brings the hindbrain in relation to the ear ectoderm. Altman theo-
Oto/aryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
UNILATERAL COMPLETE APLASIA
rized that inner ear malformations may be caused by formation of the otic placode at a greater distance from the neural tube than normal at the somite stage of II to III. These abnormal inductive forces may have arisen from the mesoderm. In the case presented here, perhaps an abnormal influence from the primary inductor, the archenteron, gave rise to an aplasia of the inner ear dorsally, and a tracheoesophageal fistula ventrally. Among other theoretic considerations is the possibility that the two developmental accidents did not occur simultaneously. Perhaps the inner ear exists in this patient as a nonossified cartilaginous capsule, radiographically lucent. The aplasia in this patient was unilateral and complete. Unlike the cases described by Valvassori et all and Iorgensen.! there was no evidence of even a simple cavitary lucency as described in their patients. Additonally, this patient, like that of Michel, had an intact facial nerve.
SUMMARY A case of unilateral, complete aplasia of the petrous apex and internal ear, associated with an H-type tracheoesophageal fistula, is reported. Polytomography, computerized axial tomography, and plain
439
film radiography confirmed this occurrence as a rare variant of inner ear aplasia. Theoretic considerations are presented in an effort to explain this developmental accident. This appears to be the first recorded case of unilateral complete aplasia with tracheoesophageal fistula.
REFERENCES
1. Michel EM: Memoire sur les anomalies congenitales de I'oreille intern. Gaz Med Stresb 3:55-56, 1663.
2. Valvassori GE, Naunton RF, Lindsay JR: Inner ear anomalies: Clinical and histopathological considerations. Ann Otol 76:929-936, 1969. 3. Jorgensen MD: Thalidomide induced aplasia of the inner ear. J Laryngol 78:1095-1101, 1964.
4. Balinsky BI: An Introduction to Embryology, ed 4. Philadelphia, WB Saunders Co, 1975, pp 367-370.
5. lewis WH: On the origin and differentiation of the otic vesicle in amphibian embryos. Anat Rec 1:141-145, 1907. 6. Myers EN, StoolS, Weltschew A: Congenital anomaly of the middle and inner ear. Laryngoscope 8:344-351, 1966. 7. Altmann F: The Inner ear in genetically determined deafness. Acta Otolaryngol, suppl 167, 1964, P 39.
Otolaryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
UNILATERAL COMPLETE APLASIA OF THE INNER EAR WITH ASSOCIATED TRACHEOESOPHAGEAL FISTULA: REPORT OF A CASE STEVEN
F.
ISENBERG,
MD
BY INVIT"nox
LAVERNE B. TUBERGEN, MD INDIANAPOLIS, INDIANA
A use of unilateral complete aplasia of the petrous apex and Inner ear assoctated with H· type tracheoesophageal fistula is reported. Polytomography, computerized axial tomography, and plain film radiography confirmed the presence of this rare variant of Inner ear aplasia. This patient, who has normal fadal nerve function, Is, to our knowledge, the first reported use of a nonthalidomide, Micheltype aplasia since the original report of Michel more than a century ago. Unilateral complete inner ear aplasia associated with tracheoesophageal fistula has not been preYiously reported. IN 1863, Michel' reported a case of bilateral complete bony and membranous aplasia of the inner ear. In his description of an autopsy performed on an 11-yearold deaf mute, Michel described the absence of the mastoid and inner ear. The petrous pyramid was reduced in size bilaterally, and no opening for the eighth cranial nerve was identified. Through a 2-mm gap the facial nerve WclS traced between the petrous and occipital bones to exit via the stylomastoid foramen. The external meatus was closed by an intact tympanic membrane, and the middle ear was normal except for the absence of a stapes.
Submitted for publication Sept 12, 1978. From the Department of Otolaryngology, Indiana University School of Medicine, Indianapolis. Presented at the 1978 Annual Meeting of the American Academy of Otolaryngology, Las Vegas, Sept 10U.
Valvassori et al2 reviewed 50 cases in which abnormalities appeared in tomograms. He classified seven ears as "aplastic." He defined these as "aplasia of all inner ear structures, with only a simple undifferentiated cavity being present." Jorgensen! reported a case of Michel's deformity (bilateral aplasia) in an infant with marked external deformity secondary to thalidomide taken by the mother the first month of gestation. Microscopically, the middle ear demonstrated absence of the oval window and foot plate on the left and absence of the stapes on the right. On the right side was total aplasia of the inner ear with no trace of cavitation; on the left was a smoothwalled spherical cavity with primordia of a membranous labyrinth and end-organ. The seventh and eighth nerves were absent bilaterally. The following case report differs significantly in description from any previously reported'·3 in the literature.
CASE REPORT
A 6-year-old white girl was examined at the Department of Otolaryngology, Indiana University Medical Center, because of a sensorineural hearing loss that had occurred one month previously. The patient had no additional complaints. The patient's mother had noticed no difference in the patient's hearing, but had noticed occasional weakness in the right upper extremity, especially in the evening, with some question of tremor. This, combined with the occurrence of sudden
Olo/aryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
436
ISENBERG AND TUBERGEN
hearing loss, prompted admission of the patient to the ENT Service with neurosurgical consultation. The patient had been the product of a fullterm vaginal delivery. Birth weight was 2.98 kg. She was the fourth child in eight pregnancies, and the mother recalled a "difficult perinatal period." The mother denied taking any medications except penicillin for bronchiectasis. After delivery the mother was started on thyroid supplementations after a diagnosis of hypothyroidism. No thyroid function tests were available to document this condition. On the day of birth, the patient was transferred to the James Whitcomb Riley Children's Hospital with a tracheoesophageal fistula demonstrated on barium swallow. The following day, the patient underwent repair of a fistula at the level of n. A fistula was identified and closed. Twenty days postoperatively, repeated aspiration prompted a repeat barium swallow, which demonstrated an additional fistula in the cervical area. Reexploration revealed an additional H-type fistula at the level of C6. This defect was repaired and the patient was discharged without problems. Periodic esophageal dilations and gastrostomy closure were uneventful. Physical examination at the time of admission showed the patient had an occipitofrontal circumference of 56 em, placing her in the 98th percentile. Pupils showed slight anisocoria, with the left 1 to 2 mm greater than the right but both reactive. The external ear appeared normal and the seventh nerve was intact. The tympanic membrane on the left was normal; the right had a slight decrease in mobility, but had normal landmarks. Results of cerebellar testing and the additional neurologic examination were normal. The hospital course included a normal electronystagmogram (ENG) and EEG. Audiometrically, no measurable hearing was recorded on the right side, but normal pure-tone thresholds and 100% discrimination were found on the left. An ipsilateral left acoustic reflex was present. There were no contralateral reflexes, and the patient demonstrated a flat, type B tympanogram on the right side. On routine radiographs (Fig 1 and 2), differences were noted in comparing the anatomy of left and right petrous bones. The arcuate eminence was absent on the right petrous (Fig 1, top), as was labyrinthine anatomy on that side. The right petrous ridge was flat, and the petrous apex on the right side was located a greater distance than normal from the midline. The internal acoustic meatus and labyrinthine
R
Fig 1.-Routine radiographs of skull coned down to area of petrous pyramid. Top, Caldwell view. Note well-developed left petrous pyramid showing prominent arcuate eminence (larger arrowhead) and labyrinthine structures below this point in body of petrous pyramid. Apex of petrous pyramid (smaller arrowhead) on right side is located at greater distance from midline compared with left side. Right petrous ridge is flat. Bottom, Submentovertex view. Anterior and posterior margins of porus acousticus interna on left side are well seen (arrowheads). Internal auditory canal ends laterally at vestibule (v). These structures are absent on right side. Tympanic cavities (tl are readily identified bilaterally.
vestibule were absent from radiographic visualization in the submentovertex view (Fig 1, bottom). Thin-section tomography (Fig 2, top) demonstrated a low profile and flat appearance of the petrous ridge on the right side. The right internal meatus was visualized as a short, narrow channel placed inferiorly and medially, probably conveying the facial nerve. Semicircular canals and cochlear turns were displayed on the left (Fig 2, top right), but were absent on the right (Fig 1, bottom). In the middle ear, some displacement in position of the malleus and incus was noted on the right, as well as absence of the round window (Fig 2, bottom). With computerized axial tomography, obvious absence of the otic capsule structure is noted in the right petrous (Fig 3).
Oto/aryngol Head Neck Surg 87:435-439 (july-Aug> 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
UNILATERAL COMPLETE APLASIA
437
Fig 2.-Anteroposterior thin-section tomographic views of both ears. Top left and right, Level of malleus and cochlea. Scutum (a), malleus (b). petrous ridge (c). porus acousticus interna (d). Note flat petrous ridge on right side with no inner ear structures, which should be visualized below point "c." Compare with left side, where apical and midturns of cochlea and geniculate ganglion fossa are readily identifiable. Also note small and inferior medially displaced opening of bony canal (d) on right side, which is probably conveying facial nerve. Bottom left and right, Level of incus and vestibule. Right incus (e), short process of left incus (f), left arcuate eminence (g), lefr round window (h). Note horizontally oriented right incus (e). which was noted with nght malleus also. On left side, superior and horizontal semicircular canals converging at vestibule are well seen below arcuate eminence (g). Round window and short process of incus are also identified. None of these inner ear structures, not even a simple cavitary lucency, are seen on right side.
DISCUSSION
If a common developmental"accident" is to explain the association of the temporal bone defect with the tracheoesophageal fistula, then the time of appearance of the laryngotracheal groove should more or less synchronize with a certain event in the development of the petrous temporal.
The first indication of the developing ear can be found in an embryo approximately 22 days old as bilateral thickenings of the surface ectoderm to each side of the rhombencephalon. These thickenings, the otic placodes, invaginate rapidly and form the otic vesicle. Balinsky. gives an excellent description of a chain of inductions:
Otolaryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
438
ISENBERG AND TUBERGEN 3. The otic vesicle, as a tertiary inductor, induces formation of the cartilaginous capsule.
Two other embryologic points are pertinent to the discussion of internal ear aplasia. First, there is a direct causal relationship between the otic vesicle (derived from otic placode) and the development of the ear capsule. Balinsky.s with reference to the work of lewis,S states that if the ear vesicle is removed, the ear capsule does not develop, and if a foreign ear vesicle is transplanted in the tail bud stage, the local mesenchymal cells may aggregate around it and produce an additional cartilaginous capsule, For the petromastoid complex alone, up to 14 centers of ossification in capsule have been described, usually as being initiated in the fifth intrauterine month. Secondly, the middle ear, derived from the brachial apparatus, is not related to development, or directly to lack of development, of the inner ear.
Fig 3.-Head at level of petrous pyramid. Top, External auditory canals curving slightly forward and end ing at tympanic cavity (arrowheads) are well visualized. On left side is oval bony densily representing otic capsule structures, which is absent on right. Bottom , level approximately 1.5 cm more cephalad. Otic capsule structures represented by oval bony density and attic mastoid antrum lateral and posterior to it are well seen on left side. On right side, attic and mastoid antrum are small, although well aerated . Otic capsule structures are absent on th is side.
"I
1. The primary inductions-The roof of the archenteron (gut) consisting of presumptive chordomesoderm-induces development of the hindbrain. 2. The hindbrain, as a secondary inductor, stimulates development of the otic vesicle (in conjunction with the direct action of the mesoderm on the presumptive ear ectoderm),
Interestingly, the ventral portion of the archenteron, which serves as the primary inductor of the otic vesicle, is the primary inductive influence on the formation of the trachea . Myers6 reported a case of bilateral partial aplasia of the inner ear with ossicular anomaly, congenital tracheoesophageal fistula, cleft lip, and cleft palate. He theorized an embryologic arrest of the ingrowing mesoderm between the third and 12th weeks of development in the tracheoesophageal fistula, and the concomitant development of the inner ear suggested a development accident common to the several organs. Altmann? pointed out several factors essential for development of the ear based on work done on amphibians. The anlagen of the ear must be properly positioned to bring the chordal mesoderm under the prospective inner ear ectoderm during gastrulation; revising the neural folds brings the hindbrain in relation to the ear ectoderm. Altman theo-
Oto/aryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
UNILATERAL COMPLETE APLASIA
rized that inner ear malformations may be caused by formation of the otic placode at a greater distance from the neural tube than normal at the somite stage of II to III. These abnormal inductive forces may have arisen from the mesoderm. In the case presented here, perhaps an abnormal influence from the primary inductor, the archenteron, gave rise to an aplasia of the inner ear dorsally, and a tracheoesophageal fistula ventrally. Among other theoretic considerations is the possibility that the two developmental accidents did not occur simultaneously. Perhaps the inner ear exists in this patient as a nonossified cartilaginous capsule, radiographically lucent. The aplasia in this patient was unilateral and complete. Unlike the cases described by Valvassori et all and Iorgensen.! there was no evidence of even a simple cavitary lucency as described in their patients. Additonally, this patient, like that of Michel, had an intact facial nerve.
SUMMARY A case of unilateral, complete aplasia of the petrous apex and internal ear, associated with an H-type tracheoesophageal fistula, is reported. Polytomography, computerized axial tomography, and plain
439
film radiography confirmed this occurrence as a rare variant of inner ear aplasia. Theoretic considerations are presented in an effort to explain this developmental accident. This appears to be the first recorded case of unilateral complete aplasia with tracheoesophageal fistula.
REFERENCES
1. Michel EM: Memoire sur les anomalies congenitales de I'oreille intern. Gaz Med Stresb 3:55-56, 1663.
2. Valvassori GE, Naunton RF, Lindsay JR: Inner ear anomalies: Clinical and histopathological considerations. Ann Otol 76:929-936, 1969. 3. Jorgensen MD: Thalidomide induced aplasia of the inner ear. J Laryngol 78:1095-1101, 1964.
4. Balinsky BI: An Introduction to Embryology, ed 4. Philadelphia, WB Saunders Co, 1975, pp 367-370.
5. lewis WH: On the origin and differentiation of the otic vesicle in amphibian embryos. Anat Rec 1:141-145, 1907. 6. Myers EN, StoolS, Weltschew A: Congenital anomaly of the middle and inner ear. Laryngoscope 8:344-351, 1966. 7. Altmann F: The Inner ear in genetically determined deafness. Acta Otolaryngol, suppl 167, 1964, P 39.
Otolaryngol Head Neck Surg 87:435-439 (July-Aug) 1979 Downloaded from oto.sagepub.com at UNIV REGINA LIBRARY on June 8, 2016
