William L. Meyerhoff

Pathology of Chronic Otitis Media

A review of 800 pathological temporal bones collected from autopsy cases revealed 333 (41.6%) to have some type of otitis media; purulent otitis media (52.5%), serous otitis media (6%), mucoid otitis media (4.5%), and chronic otitis media (36.9%). The 123 temporal bones with chronic otitis media were further studied and found to have granulation tissue, cholesteatoma, cholesterin granuloma, bone changes, and fibrosis. Other findings included tympanic membrane perforation, tympanosclerosis, metaplasia of the epithelium with subepithelial glandular formation, suppuration, labyrinthitis, and evidence of complications of chronic otitis media (meningitis, subdural abscess, brain abscess, petrositis, and endolymphatic hydrops). From this study it was concluded: 1) chronic otitis media occurred quite frequently, from a histological standpoint, in the absence of tympanic membrane perforation; 2) granulation tissue in temporal bones was found much more frequently in chronic otitis media than was cholesteatoma; and 3) complications and sequelae of otitis media tended to occur more commonly secondary to granulation tissue than to cholesteatoma.

Silent otitis media

There is a traditional view that chronic otitis media and chronic mastoiditis must exist in the presence of a tympanic membrane perforation. Based on a human histopathological study of 123 temporal bones with chronic otitis media out of 333 temporal bones with all forms of otitis media pathology, only 24 patients (36 ears) had symptoms of otological disease recorded on their charts and only 19.5% of these had an associated tympanic membrane perforation. Unsuspected findings of chronic otitis media (active or inactive) are occasionally confirmed at exploratory tympanotomy. Such quiet chronic pathological findings in the middle ear have occurred in association with endolymphatic hydrops and cochlear end organ lesions suggesting the possibility that silent chronic otitis media may help explain sensorineural hearing loss, vertigo, and tinnitus for certain patients.

Endolymphatic hydrops and otitis media.

Clinical observation of patients with fluctuant sensorineural hearing loss following or occurring with chronic otitis media led to the hypothesis that endolymphatic hydrops can result from chronic otitis media. Illustrative case reports are described. This hypothesis resulted in a temporal bone study of 560 cases in which 109 temporal bones demonstrated the presence of hydrops and 194 evidenced otitis media. Seventy‐five cases demonstrated both otitis media and hydrops, of which 20 cases were selected for more detailed histo‐pathological study. An interesting finding was the presence of apical hydrops in every case of the latter group. Statistical interpretation of this data helped rule out a coincidental or chance occurrence. A discussion of this clinical relationship included the significance of subclinical (silent) otitis media as a possible cause of endolymphatic hydrops.

Complications of lumbar spinal fluid drainage.

Cerebrospinal fluid fistula is an unfortunate, yet well-recognized, complication of basilar skull fracture, skull base surgery, and neurotologic procedures. Treatment commonly involves the use of continuous lumbar drainage. A retrospective chart review of 32 consecutive patients who required placement of lumbar drain by the otorhinolaryngology and neurosurgical services from March 1988 through July 1991 was undertaken to assess possible complications. The complications found were readily separated into minor and major categories on the basis of the possibility of permanent morbidity or mortality. Minor complications, including subjective complaints of headache, nausea, vomiting, etc., were noted in 59% of patients. Major complications were observed in four of 32 patients (12.5%), including unilateral occlusion of the posterior cerebral artery and unilateral true vocal cord paralysis. Alleviation of all complications was achieved by cessation of lumbar drainage. These cases are presented with discussion of pathogenesis. These findings demonstrate the possibility of potentially serious complications that mandate close monitoring of patients who require continuous lumbar drainage.

Ototoxicity of otic drops applied to the middle ear in the chinchilla

Previous studies have shown that the application of topical otic drops to the external ear canals of animals with patent tympanostomy tubes may result in hearing impairment and cochlear hair cell loss. Otic drops are used in patients with tympanostomy tubes or tympanic membrane perforations and could have deleterious effects on the human membranous labyrinth. This report describes the inner ear damage that occurred after direct application of aminoglycoside-containing otic drops to the middle ears of experimental animals. The membranous labyrinths of 25 chinchillas were studied two days to five months after application of Cortisporin otic suspension (which contains neomycin, polymyxin B, hydrocortisone, and propylene glycol) to the middle ear cavity. Application of 0.5 ml of Cortisporin resulted in degeneration of all inner and outer hair cells throughout the cochlea, as well as severe damage to the stria vascularis. Moderate to severe degeneration of the vestibular receptor organs was also observed. The endolymphatic sacs showed dark-staining endolymph, cellular debris, and macrophages in the sac lumina, as well as increased activity of the epithelial lining.

Auditory and temporal bone abnormalities in charge association

CHARGE association is a recently described cluster of congenital defects including ocular coloboma, heart disease, choanal atresia, retarded development and/or CNS abnormalities, genital hypoplasia, and ear anomalies. Although congenital hearing loss has been reported in CHARGE association, no information regarding the underlying temporal bone disease is available in the literature to date. The authors evaluated four patients with multiple anomalies consistent with CHARGE syndrome. Two surviving patients have bilateral severe hearing loss on auditory brain stem response testing. Two patients did not survive, and their temporal bones were obtained at autopsy for histologic examination. All four temporal bones showed severe middle ear defects including ossicular deformities, absence of the stapedius muscle, absence of the oval window, aberrant course of the facial nerve, and dehiscence of the facial nerve canal. In the more severely affected case, a Mondini-type malformation of the cochlea was present, together with multiple anomalies of the vestibular apparatus. Vestibular defects also occurred in the other case; however, the cochleae were found to be normally developed.

The thyroid and audition.

Hearing loss, both congenital and acquired, can be associated in a more than happenstance manner with disorders of almost every organ system; the thyroid gland being no exception. Although the literature is replete with speculations and observations, complete understanding of the thyroid gland‐auditory system relationship is lacking. Several known syndromes, seemingly unrelated except for the association of hearing loss and thyroid abnormalities, have been described and, from the standpoint of hearing loss, may be conveniently divided into four groups: 1. non‐genetic congenital; 2. non‐genetic acquired; 3. genetic congenital; and 4. genetic delayed.

Pathology of otitis media

Otitis media is characterized by inflammation of the middle ear. The pathologic changes seen in this condition tend to occur on a continuum, progressing from acute and subacute stages to the chronic phase, in which irreversible tissue damage is observed. The earliest morphological changes involve the lamina propria of the middle ear mucosa and include increased capillary permeability, edema, and leukocytic infiltration. During the late acute to subacute stages, the mucosa also tends to show a marked increase in numbers of ciliated and secretory epithelial cells. As the inflammatory process enters the chronic phase, there is a continuing shift in the population of infiltrating leukocytes toward increasing numbers of mononuclear cells that secrete substances that facilitate tissue destruction and fibrosis. There is also development and proliferation of granulation tissue, which is intimately involved in the process of bone erosion. As granulation tissue matures, it becomes denser and less vascular—a process that leads to permanent fibrosis and formation of adhesions that may significantly compromise middle ear function. Other pathologic entities occasionally associated with chronic otitis media include cholesteatoma, cholesterol cysts and granuloma, and tympanosclerosis, all of which may contribute to irreversible alterations of middle ear structure.

Ménière's disease in children.

Approximately 3% of all patients with Menieres disease are in the pediatric age group. These children require extensive evaluation. A history of physical or acoustic trauma should be sought and an allergic work‐up should be obtained. A search for metabolic disturbances and identification of inflammatory disorders is also necessary. If a treatable etiology is identified, specific therapy should be directed toward its control. If, after careful evaluation, the etiology remains obscure, non‐specific therapy should be instituted in an effort to alleviate the symptomatology of Menieres disease. Surgical decompression of the endolymphatic sac and drainage into the mastoid cavity results in relieving the symptoms, particularly vertigo, and appears to be efficacious in patients who have failed diligent attempts at medical therapy.

Mastoiditis and brain hernia (mastoiditis cerebri).

Ten patients with brain hernia occurring as an insidious complication of chronic mastoiditis coincidentally discovered at the time of surgery are described. Four had previous surgery, six did not. A history of trauma was otherwise absent. Cerebrospinal fluid otorrhea did not occur. Our method of management is described. Pathology and pathogenesis are discussed. Three patients had pedunculated brain hernias, while seven had diffuse (fungoid) herniation. Granulation tissue appeared as an important part of the disease process. These may represent abortive attempts at brain abscess formation since the widespread use of antibiotics. Pacchionian bodies may also play a role in the pathogenesis.