|Author||Christopher De Souza and Michael E. Glasscock|
Otosclerosis and Stapedectomy
Otosclerosis and Stapedectomy
Christopher de Souza, M.D., F.A.C.S.
Visiting Assistant Professor in Otolaryngology
State University of New York
Brooklyn, New York
Visiting Assistant Professor in Otolaryngology
Louisiana State University Health Science Center
Ear, Nose, and Throat and Skull Base Surgeon
Tata Memorial Hospital
Holy Family Hospital
Holy Spirit Hospital
Michael E. Glasscock, III, M.D., F.A.C.S.
Clinical Professor Emeritus
Department of Otolaryngology
Vanderbilt University Medical Center
New York • Stuttgart
Thieme Medical Publishers, Inc.
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New York, NY 10001
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Library of Congress Cataloging-in-Publication Data
De Souza, Chris
Otosclerosis and stapedectomy: diagnosis, management, and
complications / Christopher de Souza, Michael E. Glasscock III.
p. ; cm.
Includes bibliographical referencesand index.
ISBN 1–58890–169–6 TMP : alk. paper—ISBN
1. Otosclerosis. 2. Stapedectomy.
[DNLM: 1. Otosclerosis—surgery. 2. Otosclerosis—diagnosis. 3.
Stapes Surgery. WV 265 D467o 2004] I. Glasscock, Michael E., 1933– II.
RF270 .D47 2004
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Printed in the United States of America
TMP ISBN 1–58890–169–6
GTV ISBN 3 13 136051 8
This book is dedicated to Evi Maria, Priyanka, Tara, and Rosemarie.
The Historical Background of Otosclerosis . . . . . . .
The Pathology of Otosclerosis . . . . . . . . . . . . . . . . .
Physical Examination and Clinical Evaluation of
the Patient with Otosclerosis . . . . . . . . . . . . . . . . . .
Audiological Evaluation of the Patient with
Otosclerosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiological Imaging of Otosclerosis . . . . . . . . . . . .
Cochlear Otosclerosis . . . . . . . . . . . . . . . . . . . . . . . .
Medical Treatment of Otosclerosis . . . . . . . . . . . . . .
Hearing Aids and Otosclerosis . . . . . . . . . . . . . . . . .
Lasers in Otosclerosis . . . . . . . . . . . . . . . . . . . . . . . .
Stapedectomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Obliterative Otosclerosis . . . . . . . . . . . . . . . . . . . . .
Poststapedectomy Perilymph Fistulae . . . . . . . . . . .
Sudden Sensorineural Hearing Loss Immediately
Following Stapedectomy . . . . . . . . . . . . . . . . . . . . .
Stapedectomy versus Stapedotomy . . . . . . . . . . . . .
Bilateral Otosclerosis . . . . . . . . . . . . . . . . . . . . . . . .
Special Conditions and Complications in
Otosclerosis Surgery . . . . . . . . . . . . . . . . . . . . . . . . .
Otodystrophies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Biomechanics of Stapes Replacement . . . . . . . .
Appendix: Quiz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The ankylosis of the stapes was first described by Valsalva1 in 1735 when he
performed an autopsy on a deaf patient. In 1841, Toynbee2 reported 1659
cases of stapes fixation at autopsy. Politzer was the first to associate stapes
ankylosis with a primary disease of the labyrinthine capsule in 1893.3
There are many theories on the etiology of otosclerosis that are not in the
scope of an introduction. There are numerous sources for this information.4
Attempts to improve hearing by attacking stapes fixation in the oval window date back to 1878 when Kessel5 exposed the middle ear and attempted
to mobilize the stapes. Miot6 reported 200 cases of stapes mobilization with
results similar to those reported by Rosen7 in 1952. It was Lempert8 who
proved that it was possible to operate on the inner ear without producing a
sensorineural hearing loss. His one stage fenestration opened the door for
the successful stapes surgery that followed. Shea9 revised the stapedectomy
of Blake10 and Jack,11 and had the advantage of modern antibiotics and the
operating microscope. Shea’s great improvement over the earlier surgeons
work was his realization that to be successful, the ossicular chain must be
reconstructed, after the stapes has been removed. He accomplished this by
placing a tissue seal over the open oval window and using a prosthesis from
the long process of the incus to the tissue seal.
Over the years, there have been a number of variations on the theme of
stapes surgery. Many different prosthesis have been suggested by a variety
of otologic surgeons as the best one to use. In recent years, the stapedotomy
procedure has produced a great deal of interest.10 Lasers, both CO2 and
argon, have been employed successfully in stapedectomies as well as stapedotomies.12
Stapes surgery of either variety is successful in a high percentage of cases
regardless of the technique used. Most surgeons report closure of the airbone gap to within 10dB in over ninety percent of the cases. Dead ears occur
somewhere between .5 and 3 percent.13–15
What is as important as the surgical skill of the otologist, is the fact that
other than the fixation of the stapes, these ears are generally normal in all
other aspects. In other words, they have normal Eustachian tube function,
middle ear mucosa, and tympanic membranes.
The future always holds surprises. Perhaps in the next few years surgery
will be obsolete. With all that is occurring in the field of genetics, gene manipulation may someday be the treatment of choice.
Just think what Valsalva would think if he could walk into a modern operating room and observe a laser-assisted stapedotomy through an observation tube or better still, on a three-dimensional color television screen.
Michael E. Glasscock III
1. Valsalva AM. Opera, hoc est, tractatus de aure humana. Venice; Pitteri: 1735.
2. Toynbee, J. Pathological and surgical observations on the diseases of the ear.
Medico-Chir Tr. 1841;24:190.
3. Politzer A. Ueber primare Erkrankung der knochernen Labyrinthkapsel. Ztschr
4. Shea JJ, Shea PF, McKenna MJ. Surgery of the Ear, vol. 5. 2002;519–520.
5. Kessel J. Uber ds Mobilisieren des Stiegbugels durch Ausschneiden des Trommelfelles, Hammers und Amboss bei undurchgangigkeit der Tuba. Arch Ohrenh.
6. Miot C. De la mobilization de I’etrier. Rev. Laryng. 1890;10:49, 83, 145, 200.
7. Rosen S. Palpation of stapes for fixation: preliminary procedure to determine
fenestration suitability for otosclerosis. Arch Otol. 1952;56:610.
8. Lempert J. Improvement of hearing in cases of otosclerosis: new one-stage surgical technic. Arch Otolarnygol. 28:42, 1938
9. Shea JJ Jr. Fenestration of the oval window. Ann Otol Rhin Laryng. 1958;67:932.
10. Blake CJ. Middle ear operations. Tr Am Otol Soc. 1892;5:2, 306.
11. Jack FL. Further observations on removal of the stapes. Tr Am Otol Soc. 1893;5:3,
12. Perkins RC. Laser stapedectomy for otosclerosis. Laryngoscope. 1980;90:880.
13. Sheehy JL, House HP. Causes of failure in stapes surgery. Laryngoscope. 1962;
14. Hough JVD. Recent advances in otosclerosis. Arch Otolaryngol. 1966;83:379–390.
15. Schuknecht HF. Sensorineural; hearing loss following stapedectomy. Arch Otolaryngol. 1962;54:336–347.
Stapedectomy still remains one of the most demanding and technical surgeries. There is virtually little room for error and the first surgical effort
should be the best effort. In addition the experience garnered by earlier surgeons remains a distant dream for otological surgeons of today. For instance
Jean Bernard Causse, a pioneer in this field had performed 25,000 stapedectomies in his lifetime. For today’s surgeon this would be next to impossible
to accomplish in a single lifetime.
I have been very fortunate to have first trained with Dr. Michael Paparella
and then with Dr. Michael Glasscock. Through Dr. Paparella I received a
clear insight as to how the otosclerotic process acted on temporal bones. The
temporal bone laboratory at the University of Minnesota remains one of the
finest in the world and it was there that I received several opportunities to
look at the many temporal bones of patients who had suffered from otosclerosis. The microphotographs that appear in this book have been generously
supplied by Dr. Paparella from the temporal bone lab at the University of
Minnesota. I also had the unique opportunity to see Dr. Paparella operate
on patients suffering from otosclerosis. This served to provide me the unique
chance to translate histopathologial findings into clinical applications. Mike
Paparella has provided many students all over the world a superb understanding not only of otosclerosis but also of many other otological problems.
I am among many others who are indebted to him for this unique learning
experience. Dr. Marcos Goycoolea, who studied otosclerosis extensively,
also influenced me deeply with his observations on otosclerosis. Dr. Goycoolea wrote one of the finest chapters on otosclerosis in the book edited by
Later, I worked with Dr. Michael Glascock in Nashville at Baptist Hospital. This was the turning point in my life. It was there that I saw first hand
the vastness of Dr. Glasscock’s experience with otosclerosis. I saw virgin
stapedectomies, revision stapedectomies, re-revision stapedectomies, and
so on. I also saw many patients who were referred by other physicians to Dr.
Glasscock for surgery. Many of these had developed complications and were
sent to him for treatment. It was here that the complexity of the approach to
managing the patient suffering from otosclerosis really became apparent,
especially if the patient had undergone unsuccessful surgery elsewhere. Decision making, timing of surgery, which ear to operate on and all the debates that one reads about in textbooks were brought to life in Dr. Glasscock’s practice. It was a very edifying experience to have trained with Dr.
Glasscock and I will always remain deeply indebted to him for his willingness to share his thoughts, expertise, and experience with all those who were
unafraid to approach him. He gave me not only his professional experience
but also his warm, deep, and gracious personal friendship. To all his many
students Dr. Glasscock will always be a legend. I have a great sense of pride
and honor to assist Mike as a coauthor on this book.
I’d also like to thank Dr. C. Gary Jackson who was Mike’s partner in
Nashville. Gary has a tremendous sense of humor and keen observation.
Gary’s work was also extensive and we shared many a lively debate. I deeply
appreciated everything I learned from Gary’s wide experience.
I am deeply appreciative of the team at Thieme. J. Owen Zurhellen, Esther Gumpert, and Becky Dille, who were amazingly efficient, meticulous,
and professional. They were also very, very kind.
I’d like to thank Mr. Herman Rodrigues for all his help, time, and expertise that he generously gave to me.
Finally in conclusion it has been my observation that all authors in their
books end up thanking their families. I agree and I agree with a lot of certainity. This is so because time spent working on a book means time away
from the family. So Mommy has been instrumental in a big way because she
has been Mommy and Daddy to the children while Daddy works at being
Chris de Souza, M.D., F.A.C.S.
July 10, 2003
The Historical Background of Otosclerosis
Otosclerosis is a disorder that affects the otic capsule exclusively. The term
otosclerosis is itself actually a misnomer. It is localized otoporosis, not sclerosis of the otic capsule in its active stage. Many authors prefer the term otospongiosis because they feel this word more accurately describes the disease
in its active phase. For the purposes of convenience, the disease is described
as otosclerosis for the rest of this book.
It was Italian anatomist Valsalva who,on a postmortem examination of a
deaf patient, described ankylosis of the stapes to the margins of the oval
window. English otogist Toynbee noted osseous ankylosis in his dissection
of over a thousand temporal bones. It was Politzer who first applied the
term otosclerosis. He based this on his findings on temporal bones of patients
whom he had diagnosed to be suffering from “deafness that had previously
been attributed to chronic interstitial middle ear catarrh with secondary
stapes ankylosis.” Politzer’s discovery was confirmed by Bezold and by
Siebenmann. In 1912, Siebenmann proposed a change in nomenclature from
otosclerosis to otospongiosis. This change received support from the French
In 1950, Raymond Thomas Carhart, an audiologist, originated the term
air-bone gap. He reported the notching in bone conduction in the condition
of stapedial otosclerosis, notching that has been subsequently known as
Carhart’s notch. Carhart in 1964, and again in 1966, described audiometric
findings that were typical of stapedial and cochlear otosclerosis.
EVOLUTION OF STAPES SURGERY
In 1878, Kessel described the first successful stapes surgery. The patient, a
young man who had been diagnosed as suffering from otosclerosis, had
fallen off a wagon and struck his head on the ground. After a brief spell of
unconsciousness, the young man found that his sense of hearing had greatly
improved. The patient later died of his injuries, and Kessel was able to
study his temporal bones. He concluded that the stapes had been mobilized
and tried to duplicate this in his surgeries.
Many others attempted to emulate Kessel’s work. Boucheron in France
reported using techniques similar to that of Kessel. In 1890, Miot reported a
series of 200 stapes mobilizations without a single death or labyrinthine
OTOSCLEROSIS AND STAPEDECTOMY
complication. All this was done using gaslight and a reflector and local
Blake from Boston in 1892 and Jack in 1893 also reported good results
from stapes mobilizations. It was in 1900 at the International Congress of
Otolaryngologists in Europe that Politzer and Siebenmann condemned stapes
surgery because of its potential to cause meningitis. The result of this public
condemnation caused a complete halt to stapes surgery for the next quarter
FENESTRATION OF THE LABYRINTH
In 1916, Holmgren began a long series of operations for stapes ankylosis. He
demonstrated that by using careful sterile techniques, the labyrinth could
be safely opened. Holmgren’s assistant, Nylen, first employed the microscope for ear surgery. Holmgren was not successful, however, in maintaining an open fenestra. In 1924, Sourdille devised a procedure that he termed
tympanolabyrithopexy. This two-stage procedure began to give lasting results. Sourdille’s success lay in covering the fistula in the horizontal semicircular canal with a very thin skin of the external auditory canal.
Lempert, in 1941, found that extraction of the incus did not cause a reduction in hearing; rather, it provided him with more space to create a wider
fenestra over the ampullated end of the lateral semicircular canal. Lempert’s
was a one-stage technique.
In 1953, Rosen accidentally mobilized the stapes of a patient under local
anesthesia. The patient reported that his hearing had suddenly improved.
In 1956, Shea reported the first stapedectomy using the operating microscope. Shea sealed the oval window and placed a homograft bone implant
between the oval window and the incus; there was an immediate hearing
gain. Over time, a conductive hearing loss reappeared because of adhesions. Shea soon replaced that with a Teflon replica of the stapes.
In 1960, Shea inserted a Teflon piston into a small fenestra; thus, stapes
surgery was born. Also in that year, Schuknecht used a stainless steel wire
prosthesis placed against Gelfoam to seal the oval window.
Howard HP. The evolution of otosclerosis surgery. Otolaryngol Clin North Am.
Shambaugh GE. Definition and historical background. In: Wiet RJ, Causse JB, Shambayh GE, Causse JR, eds. Otosclerosis (Otospongiosis). American Academy of Otolaryngology—Head and Neck Surgery Foundation; Alexandria, Va; 1991;9–23.
The Pathology of Otosclerosis
Otosclerosis is a primary and exclusive disease affecting only the otic capsule and the ossicles. It is a localized disorder of bone metabolism of the otic
capsule avascular endochondral bone that is characterized by disordered
resorption and deposition of bone. Otosclerosis occurs only in the temporal
bone (Wang et al 1999).
The exact etiology of otosclerosis is not known at this time, although many
theories have been postulated. None of these theories have been proven to
be a definite cause of otosclerosis. Postulated etiologies are hereditary factors, endocrine and metabolic factors, and vascular factors.
Alterations in vascularity (either an increase or a decrease in blood supply) have been postulated by Witmaack (1930), Wolff (1950), and Mendoza
and Ruis (1966) to play a role in the etiology of otosclerosis. Intrinsic and extrinsic mechanical stresses as the result of an erect posture were once considered (Mayer 1917) as a cause of otosclerosis, because the petrous pyramid is located at the base of the skull. Because it was located at the base of
the skull, it was subjected to mechanical strains exceeding the physiological
limits of tolerance, which resulted in defects in the endochondral layer of
the bony labyrinth. It was further theorized that the stress factors appeared
during the phylogenic and otogenic development due to rotation of the
petrous bones at the base of the skull. It was thought that the cochlea moved
forward and upward and the vertical semicircular canals backward and
downward. Thus, the petrous pyramid has an almost horizontal position in
humans versus a vertical position in quadrupeds. This theory was abandoned because otosclerotic changes first appeared in the footplate of the
stapes. Fowler (1949) suggested that otosclerosis might be an expression of
a general mesenchymal hypoplasia. This was further supported by Ogilvie
and Hall (1962), who postulated that otosclerosis was a local manifestation
of osteogenesis imperfecta. In recent times viral infections and autoimmune
factors have also been postulated to trigger the otosclerotic processes.
Ruedi (1963) demonstrated shunts between the vascular system of the
otosclerotic bone and the inner ear, and suggested that venous stasis from
these shunts might be responsible for sensorineural hearing loss.
OTOSCLEROSIS AND STAPEDECTOMY
Age of Onset
It is difficult to assess the true onset of otosclerosis because the development
of histopathologic changes is gradual. Clinical otosclerosis is commonly
seen between the ages of 30 and 40 (Nager 1969), with the average age of
presentation being 33. DeJuan (1960), comparing the age of onset among
various age groups, noted that 28% of cases occurred between ages 18 and
21, 40% presented between ages 21 and 30, and 22% presented between ages
31 and 40. The clinical presentation of otosclerosis is usually that of a conductive hearing loss, which may be unilateral or bilateral. Occasionally it
may present as a sensorineural hearing loss. The onset of hearing loss is
usually between the fourth and fifth decades, with a higher prevalence in
women than men (in the ratio of 2:1). Hearing impairment reaches its maximum in the third decade and then usually remains stable (Glorig and Gallo
The prevalence of otosclerosis has been reported as 0.1 to 1.0%, with an average of 0.3% (Gordon, 1989). Autopsy studies (Konigsmark and Gorlin
1976) have found histologic otosclerosis in 5 to 18% of the general population. Jahn and Vernick (1986) stated that 10% of Caucasians develop histologic otosclerosis, and 1% go on to develop clinical otosclerosis. Shambaugh
(1961) found that histological otosclerosis was 10 times more common than
clinical otosclerosis. Friedmann (1974) and Morrison (1967), however, found
the incidence to be approximately 2%. It can therefore be seen that the exact
incidence of clinical otosclerosis is not clear and next to impossible to determine. Many authors have noted that in recent years the incidence of patients presenting with otosclerosis has fallen dramatically. The prevalence
varies in racial populations, being rare, for example, in African blacks and
There is a definite racial predisposition. Otosclerosis is more commonly
found in Caucasians. Clinical otosclerosis has been reported to be present in
1% of the population of the United Kingdom, occurring mostly among
white females (Hinchcliffe 1961). Guild (1944) reported histologic evidence
of otosclerosis in 18.5% of middle-aged white women, 9.7% of adult white
men, and only 1% of adult blacks. Cawthorne (1952) found that otosclerosis
was more prevalent in fair-haired men than in dark-haired men. The prevalence of otosclerosis is low among Asians (Altmann et al 1967; Nakamura
1968). The prevalence of otosclerosis is low among Japanese (Goto and
Omori 1957; Horiguchi 1953; Takahara et al 1959), Chinese, and Indonesians
(Nizar 1960). In a comparative study conducted in Hawaii, Joseph and
Frazer (1964) found the incidence of otosclerosis to be more prevalent in
Caucasians than in Japanese. Rosen and coworkers (1962) did not find clinical cases of otosclerosis in Sudan. Among the Todas in India, however, the
prevalence of otosclerosis was estimated at 17%. Kapur and Patt (1966) emphasized the presence of consanguineous marriages, a custom among the
THE PATHOLOGY OF OTOSCLEROSIS
Todas. Consanguinity would then appear to influence the data retrieved.
The prevalence of otosclerosis in Native Americans is extremely low across
the North American continent (Cambon et al, 1965). Wiet (1979) evaluated a
large number of Native Americans and found that only 10 had undergone
stapedectomy, of which only three had confirmed otosclerosis, a number
representing a minute fraction of the entire population examined. Tato and
Tato (1967, 1969) evaluated 5000 Native Americans and found no cases of
otosclerosis at all. When there is a racial mixture, however, otosclerosis begins to manifest itself (Goycoolea 1991).
Otosclerosis is thought to be more prevalent in women. Schmidt (1933)
quoted a female preponderance of 72.5% incidence, whereas Shambaugh
(1952) found an incidence of 68% and Cawthorne (1955) an incidence of 67%
of women who developed otosclerosis. Because otosclerosis is not a genetically sex-linked characteristic, a ratio of 1:1 would have been expected.
However, this has not been found to be true. Endocrinologic factors have
been suspected in women. Hueb et al (1991) found a higher incidence of bilateral otosclerosis in women than in men, thus prompting them to believe
that women would be more likely to seek medical advice than men. This
might possibly account for the apparent gender predisposition.
OTOSCLEROSIS AND PREGNANCY
Otosclerosis becomes evident during the childbearing years. Most authors
report otosclerosis becoming aggravated during pregnancy. Shambaugh
(1967) analyzed 475 female patients and reported that 50% did not find any
hearing impairment following pregnancies, whereas 8% noticed hearing
impairment immediately following pregnancy. In the remaining 42% of patients, hearing loss was associated with pregnancy. Thus, in Shambaugh’s
series there is a 50% chance of an association of hearing loss following pregnancy. Repeated pregnancies in the same woman, however, did not further
worsen hearing. Walsh (1954) found no evidence of a relationship between
hearing loss, pregnancy, and otosclerosis. Shambaugh (1967) estimated that
the risk of hearing loss to a woman following pregnancy is approximately 1
in 24. Elbrond and Jensen (1979) and Gristwood and Venables (1983) also
noted the association of hearing loss following pregnancy. Elbrond and
Jensen (1979) studied the hearing threshold of 144 women before and after
stapedectomy. The women were between 16 and 40 years old, and all had
undergone stapedectomy for otosclerosis. The observation period for the
women who became pregnant following stapedectomy was between 4 years
and 9 months and 5 years and 8 months. The authors observed that (1) hearing loss became greater in those who became pregnant than in those who
did not and (2) the hearing loss became significantly greater in the nonoperated ear of those patients who became pregnant following surgery. It would
thus seem that stapedectomy confers some protection from further hearing
loss following pregnancy. Although these authors note a correlation between pregnancy and the onset of hearing loss following pregnancy, they
are not clear on how this occurs. Morrison (1979) attributed this to increased
estrogen levels, which cause fragility of the lysosomal membranes, with the
OTOSCLEROSIS AND STAPEDECTOMY
consequent release of enzymes that in turn activate the otosclerotic process.
Causse and Causse (1991) postulated that the otosclerotic process is stimulated by the release of increased quantities of estrogen. The increase in estrogen levels causes the lysosomal membranes to become fragile, which in turn
leads to the rupture of the membranes with the consequent diffusion of
their enzymes, resulting in the destruction of the cochlea and its structures.
DOES OTOSCLEROSIS PRESENT ONLY AS A CONDUCTIVE
A progressive conductive hearing loss in adults is typical of the way otosclerosis presents (Chole and McKenna 2001). This is due to the fixation of the
stapedial footplate along its anterior anulus. On rare occasions, otosclerosis
can be associated with sensorineural hearing loss (Schuknecht and Kirchner
1974). This is due to cochlear otosclerosis. It is thought that some individuals may present with cochlear otosclerosis in the absence of a conductive
Temporal bone studies have shown that involvement of the endosteal
portion of the cochlea is associated with sensorineural hearing loss and diminished bone conduction hearing thresholds (Ghorayeb and Linthicum,
1978; Hueb et al, 1991). Hyalinization of the spiral ligament adjacent to the
otosclerotic foci has been shown to be associated with sensorineural hearing
loss (Antoli-Candela et al 1977; Gussen 1975; Hinojosa and Marion 1987).
Although less than 1% of the population develops clinical otosclerosis, the
finding of an otosclerotic focus upon autopsy is much more common. Histologic otosclerosis (Guild 1944) is a disease process without clinical symptoms or manifestations and can only be discovered by routine sectioning of
temporal bones (Fig. 2–1) at autopsy. Histologic otosclerosis may be seen as
an incidental postmortem finding without causing clinical symptoms. Clinical otosclerosis is otosclerosis at a site where it causes a hearing loss, which
may be conductive, sensorineural, or mixed. Histologic otosclerosis has
been reported as 8.3% and 11% in large random autopsy series.
Otosclerotic foci can sometimes be seen on high-resolution computed tomography (CT) scans of the temporal bone as areas of hypodensity of the
otic capsule or in the vicinity of the oval window (Valvassori 1993). CT scanning, however, is not reliable in detecting otosclerosis, especially when the
lesions are sclerotic (Thiers et al 1999). It is possible that future advances in
CT imaging and densitometry may be more sensitive in the detection of
these lesions. Otosclerotic lesions may also show contrast enhancement on
magnetic resonance imaging (Ziyeh et al 1997).
Otosclerosis, or otosclerotic-like lesions of the footplate and otic capsule,
has been observed in other inherited bone disorders. Otosclerosis is also
seen in some patients with osteogenesis imperfecta who commonly develop
conductive hearing loss. The lesions in the temporal bone appear similar to
THE PATHOLOGY OF OTOSCLEROSIS
Figure 2–1 (A) Photomicrograph of a human temporal
bone with histologic otosclerosis (O). This focus lies anterior to the oval window and has not resulted in any
symptoms. This is an incidental finding on autopsy, discovered accidentally, and is termed histologic otosclerosis.
(B) Magnified view of the same human temporal bone
section demonstrating histologic otosclerosis.
those of otosclerosis (Nager 1988), although some patients have lesions consisting of diminished calcification and microfractures. The bony lesions of
Paget’s disease in the otic capsule may appear similar to otosclerosis, although their distribution within the temporal bone is distinct (Fig. 2–2). Large
multinucleate osteoclasts are much more prominent in Paget’s disease than
in otosclerosis. It must be stated that the conductive hearing losses sometimes associated with Paget’s disease are not due to ossicular lesions, but
may be due to the loss of mineral density in the otic capsule (Khetarpal and
Schuknecht 1990). Paget’s disease of the bone, like otosclerosis, is a disorder
of localized bone remodeling, with osteoclastic resorption followed by compensatory increases in bone formation. Paget’s disease affects localized regions of the skeleton while sparing others; however, unlike otosclerosis, it is
not restricted to the temporal bone. Thirty percent of those suffering from
Paget’s have a family history of the disease, causing speculation about a
genetic basis of this disease. There is recent evidence from linkage studies
Author Christopher De Souza and Michael E. Glasscock Isbn 9781588901699 File size 2.7MB Year 2003 Pages 212 Language English File format PDF Category Medicine Book Description: FacebookTwitterGoogle+TumblrDiggMySpaceShare Co-authored by leading specialists, this comprehensive and current book provides a detailed and practical discussion of otosclerosis patient diagnosis, treatment, and management. The book presents a step-by-step account of stapedectomy surgery, and also covers: the pros and cons of all lasers including the latest erbium lasers and their current applications; the analysis of recent otosclerosis studies using CT scanning and audiometry as parameters; stapedectomy versus stapedotomy; frequent complications encountered in otosclerosis surgery; and much more! Key features: Walks beginners through the fundamental steps necessary to fully understand otosclerosis and stapedectomy Solutions to difficult problems encountered daily by experienced otologists Special chapters on revision and laser stapedectomy surgeries Practical quiz that helps reinforce all the salient features of the book Appealing to the novice as well as the experienced professional, this book is a key resource for any practitioner in the field – general ENT specialists, ENT surgeons, as well as medical students and otology fellows. Use this book to keep up-to-date on this important topic.