Case Report

Auris·Nasus·Larynx (Tokyo) 19, 51-54 (1992)

A CASE OF DELAYED ENDOLYMPHATIC HYDROPS Hidetaka KUMAGAMI, M.D. and Toshiharu SASANO, M.D. Department of Otolaryngology, School of Medicine, Nagasaki University, Nagasaki, Japan

A 30-year-old male with delayed endolymphatic hydrops was given a sac operation. An intradural portion of the endolymphatic sac was resected and the epithelial surface was examined under a scanning electron microscope. The epithelium showed fibrous degeneration and disappearance of the epithelial cells. Pathogenesis of degeneration of the endolymphatic sac is discussed. Delayed endolymphatic hydrops is a syndrome that occurs in patients who have sustained a profound hearing loss in one ear, usually from middle ear infection or head trauma, and then develops after a prolonged period of time into either episodic vertigo in the same ear or fluctuating hearing loss in the opposite ear. We experienced a case of a 30-year-old male with delayed endolymphatic hydrops who underwent an endolymphatic sac shunt operation because of episodic vertigo. The intradural portion of the endolymphatic sac (ES) was examined by scanning electron microscopy (SEM). SUBJECT AND METHODS A 30-year-old male, who showed a slow progressive hearing loss bilaterally from early childhood with the bilateral hearing loss becoming profound at school age (Fig. 1). In May 1974, at age 24, the patient had the first attack of vertigo. Then, he began to have episodic vertigo in spring and autumn. In March 1990, at age 30, he had vertigo followed by roaring tinnitus and a sensation of fullness of the right ear. The right beating horizontal nystagmus with a rotating component was seen at the time of attack and the direction of the nystagmus changed toward the left ear. Serologic test for syphilis was negative. After the attack, caloric test showed normal findings in both ears. Temporal bone film showed normal ear. From the clinical course, the affected ear was thought to be the right ear, and an endolymphatic sac shunt operation was performed in June 1990. The ES was large, separation of the sac wall was easy, and an outflow of the Received for publication July 3, 1991 51

H. KUMAGAMI and T. SASANO

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March 22, 1990

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Fig. 2. A: Normal subject. View of the whole endolymphatic sac (X 20). B: Patient. View of the whole endolymphatic sac. Note a more fibrous change compared with normal subject (X 26). C: Normal subject. Note well arranged oval epithelial cells (X 300). D: Patient. Note fibrous degeneration of the surface of the ES. No epithelial cell is found (X 300).

DELAYED ENDOL YMPHATIC HYDROPS

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endolymphatic fluid was seen with the separation of the sac wall. The surgically removed ES was fixed in 10% neutral buffered formaldehyde. The specimen was washed in phosphate buffer solution (PBS) and fixed in 2% tannic acid containing 1% glutaraldehyde for 2 hours. It was then immersed in 2% osmium oxide for 3 hours, washed throughly in PBS and dehydrated in serial ethanol, replaced by isoamyl, critical point dried and coated by AU. A JSM-35 scanning electron microscope was used for observation. RESULTS The resected intradural portion of the ES showed the disappearance of epithelial cells and the fibrous degeneration of the epithelial surface as far as specimen examined was concerned. These findings were severe changes compared with normal human epithelial surface of the ES (Fig. 2, A-D). Since the operation, the patient has shown no sign of vertiginous attack. DISCUSSION Endolymphatic hydrops was classified by ScHUKNECHT and GuLYA (1983) into symptomatic and asymptomatic types, each being subdivided into embryopathic, acquired, and idiopathic types. The acquired group was further divided into postinflammatory and posttraumatic types. Delayed endolymphatic hydrops belongs to the symptomatic acquired group. It is also known that unilateral total deafness of unknown etiology causes delayed endolymphatic hydrops (EVERBERG, 1960; OLIVEIRA and SCHUKNECHT, 1990). There is a long time lag from inner ear damage to the development of endolymphatic hydrops or to the appearance of vestibular and cochlear symptoms. For this reason, KIMURA and SCHUKNECHT (1965) and SCHUKNECHT, NORTHDROP, and IGARASHI (1968) stated that there is a great difference between animal species in the time required from the disturbance of the endolymphatic resorptive function to the onset of endolymphatic hydrops. The time required is a few weeks in guinea pigs, 3 years in cats, and a long period in humans. In our case, the first vertiginous attack began approximately 24 years after sensorineural deafness of unknown etiology. It is considered that Meniere's disease-like episodic attacks in this case are attributable to endolymphatic hydrops with normal caloric response. SEM findings of the ES resembled those of Meniere's disease in severely degenerated cases (KUMAGAMI, 1990). In animal experiments, endolymphatic hydrops was produced by cochlear deafness, and degeneration and fibrous changes in both the intradural portion and the rugose portion of the ES were also found (KUMAGAMI, 1990). In conclusion, the damage of cochlear hair cells seems to result in fibrous degeneration of the epithelial cells in the ES, then causes endolymphatic resorptive

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dysfunction in the rugose portion, and finally results in development of delayed endolymphatic hydrops after the lapse of a long period. However, further study is required in order to elucidate this hypothesis. REFERENCES EVERBERG, G.: Unilateral total deafness in children: Clinical problems with a special view to vestibular function. Acta Otolaryngol. (Stockh.) 52: 253-259, 1960. KIMURA, R. S., and SCHUKNECHT, H. F.: Membranous hydrops in the inner ear of the guinea pigs after obliteration of the endolymphatic sac. ORL 27: 343-354, 1965. KUMAGAMI, H.: Scanning electron microscopy and immunoglobulins of the endolymphatic sac in normal human subjects and sensorineural deafness. Acta Otolaryngol. (Stockh.) Suppl. 471: 1-21, 1990. OLIVEIRA, C. A., and ScHUKNECHT, H. F.: Pathology of profound sensorineural hearing loss in infancy and early childhood. Laryngoscope 100: 902-909, 1990. SCHUKNECHT, H. F., and GULYA, A. J.: Endolymphatic hydrops an overview and classification. Ann. Otol. Rhinal. Laryngol. Suppl. 106: 1-20, 1983. SCHUKNECHT, H. F., NORTHOROP, B. A., and IGARASHI, M.: Cochlear pathology after destruction of the endolymphatic sac in the cat. Acta Otolaryngol. (Stockh.) 65: 479-487, 1968.

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Dr. H. Kumagami, Department of Otolaryngology, School of Medicine, Nagasaki University, 7-1 Sakamoto-machi, Nagasaki 852, Japan

A case of delayed endolymphatic hydrops.

A 30-year-old male with delayed endolymphatic hydrops was given a sac operation. An intradural portion of the endolymphatic sac was resected and the e...
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