Endolymphatic hydrops after fenestration: a temporal bone study with implications on the function of the utriculo-endolymphatic valve.

A temporal bone specimen demonstrating endolymphatic hydrops 13 years after fenestration of the lateral semicircular canal is presented. Fibro-osseous tissue extending from the lateral semicircular canal and reaching the vestibule produced fixation of the membranous wall of the utricle to the bony wall. Fixation and retraction of the utricule appears to have resulted in a permanently open utriculo-endolymphatic valve leaflet.

Surgical trauma to the lateral semicircular canal with preservation of hearing.

Surgical trauma to the lateral semicircular canal (LSC) is a rare complication which does not always result in cochlear damage. The authors present six such cases, discuss the histopathological findings of one case, and review 12 previous reports. Transient cochlear depression with normalization of function within 6 weeks of trauma occurred in most instances.

The endolymphatic sac in the Mondini disorder.

The endolymphatic sacs are described in temporal bone specimens from a 31-year-old man with bilateral Mondini disorder. The ducts and sacs are thin-walled, cyst-like structures with complete absence of loose vascular perisac tissue, and are directly apposed to the bone of the vestibular aqueduct. Histological evidence of severe bone erosion is present in these specimens and is most marked in the intermediate and distal portions of the vestibular aqueduct.

The fate of an ossicular allograft in tympanoplasty.

Correction of ossicular defects in tympanoplasty most commonly involves the use of commercially available prostheses or preserved allograft ossicles. Incus autografts and tragal cartilage autografts are also used by many surgeons. Presculptured preserved allograft ossicles have not been used widely, but are used almost exclusively by our clinic.

Vascular mechanisms in Meniere's disease.

Normal venous drainage of the vestibular organs through the vein of the paravestibular canaliculus (PVC) may be crucial to inner ear fluid mechanics. It is proposed that increased venous pressure, with resultant venous insufficiency of the vestibular organs, may result in endolymphatic hydrops unless collateral venous circulation develops. Certain variations in pattern of venous drainage where the vestibular organs drain predominantly through the PVC vein may be a predisposing factor.

Sudden deafness associated with bilateral Reissner's membrane ruptures.

A histologic study of sudden deafness resulting from rupture of cochlear membranes, first in the left ear, and then, three years later, in the right ear, in a patient with vertebro-basilar arteriosclerosis is reported. Two healed ruptures were demonstrated on the right side, one in the hook portion of the cochlea, and one in the area of the promontory. The latter was adherent to the saccule, distorting it inferiorly.

Vascular mechanisms in Meniere's disease. Theoretical considerations.

Unimpeded venous drainage of the vestibular organs via the paravestibular canaliculus (PVC) vein is crucial to inner ear fluid mechanisms. With increased venous pressure, insufficient drainage may result in endolymphatic hydrops, unless collateral veins develop. Different mechanisms cause venous insufficiency in different cases of Meniere's.

Mucormycosis of the temporal bone.

Mucormycosis of the temporal bone is described in a 60-year-old female with uncontrolled diabetes mellitus whose symptoms related to cranial nerve palsies and hearing loss, following spread of infection from the nasopharynx. The infection spread along the eustachian tube and tensor tympani muscle to the base of the skull, involving the internal carotid artery with mycotic thrombosis and rupture. Subsequent spread occurred from this area predominantly along nerve pathways and as mycotic emboli in blood vessels of the labyrinth and middle ear.

Middle and inner ear changes in congenital rubella.

Temporal bone changes in a 14-month-old female infant with congenital rubella are described. The inner ears showed cochleo-saccular degeneration, with more severe involvement of the right side. Perivascular round cell infiltration was demonstrated in the base of the cochlea, stria vascularis, and superior ampullary cribriform region, consistent with viral infection.

Sudden hearing loss associated with cochlear membrane rupture. Two human temporal bone reports.

Cochlear membrane ruptures occurred in the left temporal bones of two patients--one was a result of barotrauma caused by flying and was associated with sudden deafness, tinnitus, and some vertigo and the second occurred in a patient with profound deafness in a previously normal-hearing ear. Both occurred as ruptures of Reissner's membrane at the junction of the ductus reuniens with the cecum vestibulare portion of the cochlear duct. With healing, a balloon-like structure formed from the rupture site into the adjacent vestibule, resulting in a secondarily ruptured saccule duct in one case and in collapse of the saccule in the second case.

Temporal bone findings in rhabdomyosarcoma with predominantly petrous involvement.

Temporal bone rhabdomyosarcomas are rare tumors that occur almost exclusively in children. They arise most commonly in the middle ear, from which they extend through the mastoid and petrous portions of the temporal bone, eventually invading the cranium. We report the histopathologic findings of a rhabdomyosarcoma with anterior and medial displacement, predominantly involving the petrous bone.

Saccule otoconia displacement into cochlea in cochleosaccular degeneration.

Eight human temporal bones from five patients demonstrated varying degrees of cochleosaccular degeneration. Otoconial debris, with tissue reaction, was demonstrated within the ductus reuniens and cochlear duct, as far distal as the middle of the ascending basal limb. Saccule degeneration could be the primary lesion in cochleosaccular degeneration related to heredity or aging, with cochlear changes secondary to the presence of displaced otoconia.

Endolymphatic hydrops with absence of vein in paravestibular canaliculus.

Unilateral endolymphatic hydrops is described associated with absence of the vein in the paravestibular canaliculus (PVC), and with decreased vascularity of the vestibular aqueduct and endolymphatic sac. The venous return from the vestibule was normal as far as the junction of the branches forming the PVC vein. At this junction, a blind venous loop was formed with no continuation of venous drainage through the PVC.

Histological evidence of specialized microcirculation of the endolymphatic sac.

A specialized type of blood vessel is demonstrated within the dense soft tissue areas of the vestibular aqueduct and vascular channels of the surrounding bone, including the paravestibular canaliculus (PVC). The vessel wall is formed by the collagen-smooth muscle bundles of these areas. The lumen of these vessels is irregular, and segments appear to be closed by apposition of the bundles.

Round window niche melanocytes and webby tissue. Possible collateral route of vascular and perilymph circulation.

Two hundred thirteen human temporal bones were studied for characteristics of the round window niche. In 163 specimens melanocytes were found within the attachments of the round window membrane and in the niche, most prominently at the level of the cochlear aqueduct opening. Sixty-two specimens demonstrated discrete webby foci within the lining of the niche, 16 of which completely or partially covered the tympanic surface of the round window membrane, unassociated with fibrous tags or adhesions, and in some cases contained congested vascular channels and melanocytes.

Melanocyte system of the endolymphatic duct and sac.

One hundred fourteen human temporal bones from 64 individuals were studied for the presence of melanized melanocytes about the endolymphatic duct and sac. Specimens were from Caucasians (104), Orientals (6) and Negroes (4). Of the specimens from people above nine years of age 79% demonstrated melanized melanocytes about the endolymphatic duct and sac, as well as occasionally about blood vessels in the adjacent bone.

Nonotosclerotic ankylosis of the stapedial footplate.

A woman with a long history of chronic otitis media had a stapedectomy after a surgical diagnosis of otosclerosis. In the histologic study of the temporal bones, done after her death four years later, the main portion of the stapes footplate was present but fractured and no otosclerosis was present. New celluluar bone which simulated otosclerosis filled the anterior oval window niche and was continuous with the middle ear surface of the footplate fragments.

Pathogenesis of Bell's palsy. Retrograde epineurial edema and postedematous fibrous compression neuropathy of the facial nerve.

The pathogenesis of Bell's palsy is presented as retrograde epineurial compression edema with ischemia of the facial nerve. Although the etiology is unknown, an attractive theory is vasospasm, from any cause, along any facial nerve branch, with the chorda tympani, perhaps, the usual primary involvement. Retrograde vascular distension and edema, within the epineurium of the bony facial canal, compresses the nerve from outside its perineurial sheath.

Atypical ossicle joint lesions in rheumatoid arthritis with sicca syndrome (Sjögren syndrome).

Atypical incudomalleal and incudostapedial joint changes were found in a 55-year-old woman with long-standing rheumatoid arthritis and sicca syndrome (Sjögren syndrome). Available audiograms taken at 37 and 42 years of age demonstrated slight bilateral high-frequency loss of hearing. The ossicular joint changes involved dissolution of disk material together with proliferation of synovial-type elements of the disk and articular surfaces, with formation of pannus-like tissue.

Inner ear pathologic features following mumps infection. Report of a case in an adult.

Temporal bone studies in an adult with a moderately severe, bilateral sensorineural hearing loss revealed bilateral cochlear changes 13 years after mumps infection. The organ of Corti was completely absent in the greater part of the superior horizontal basal limbs, with occasional hair cell loss throughout the rest of the cochlea. The outer sulcus cell area was degenerated.

Sudden deafnfess of vascular origin: a human temporal bone study.

Temporal bone changes are described in a 57-year-old man who had sudden onset of dizziness and unilateral deafness two months before death. The patient suffered from hypertension, and congestive and renal failure. At autopsy, subarachnoid hemorrhage with punctate cortical hemorrhages and arteriolar thickening involved the right superior cerebellar hemisphere.

Labyrinthine otosclerosis and sensorineural deafness. Pathologic findings of the spiral ligament.

In severe labyrinthine otosclerosis, spiral ligament changes occur predominantly adjacent to the stria vascularis, and consist of a decrease or loss of the capillary-perilymph system. It is suggested that this results in increased concentrations of metabolic products in the cochlear fluids that can no longer be absorbed effectively. If vascular shunts form they might represent collateral channels, with the flow of blood from the cochlea into the otosclerotic focus, bypassing the deficient capillary network in the spiral ligament.