Harold F. Schuknecht

Atrophy of the stria vascularis, a common cause for hearing loss.

Atrophy of the stria vascularis is a genetically determined deafness of aging characterized by a bilateral symmetrical sensori‐neural hearing loss showing flat audiometric patterns and excellent speech discrimination. The temporal bones of individuals exhibiting this type of hearing loss were studied by serial sections and surface preparations for light microscopy and by electron microscopy. The atrophic changes are most severe in the apical regions of the cochleas and involve the marginal, intermediate and basal cells in that order of severity. It seems probable that atrophy of the stria vascularis causes some deficiency in the quality of endolymph throughout the cochlear duct, regardless of the location of the atrophy. Typically all other structures of the cochlear duct are normal, and the sense organ when stimulated within its sensitivity range is capable of normal stimulus coding, thus accounting for the usually excellent speech discrimination.

The pathology of sudden deafness

Pathological studies were performed on eight temporal bones, of which six were from in- dividuals with unilateral sudden deafness and two from one individual with bilateral sequential sudden deafness. The hearing losses were profound in four ears, severe in three ears and moderate in one ear. At the time of onset of the sudden deafness two reported having headcolds, one had acute pharyngitis, two had pneumonia and two complained of headache. Vertigo as an associated symptom was severe in one case and mild in two cases. The principal pathologi- cal changes consisted of atrophy, in varying com- binations and severity, of the organ of Corti, tec- torial membrane and stria vascularis. These patho- logical alterations were judged to be more like those occurring in labyrinthitis of known viral etiology than those following experimentally induced vascular lesions in animals. There are many known causes for deafness of sudden onset. A partial listing would in- clude: bacterial labyrinthitis, viral labyrinthi- tis (mumps, measles), ototoxic drugs, tem- poral bone fracture, inner ear concussion, noise, surgical injury, otitic barotrauma, in- ner ear hemorrhage (leukemia), macroglobu- hernia, occlusion of the posterior inferior cerebellar artery (lateral medullary syn- drome), multiple sclerosis, carcinomatous en- cephalomyelitis, glioma of the pons, metas- tatic neoplasms, vestibular schwannoma, Me- nieres disease and severe cochlear otosclero- sis. These causes for sudden deafness are abundantly documented in the literature. There are also many cases of sudden deaf- ness in which the etiology is not so obvious.

Cochleosacculotomy for meniere's disease: Theory, technique and results

A series of 51 patients with intractable vertigo from Menieres disease were treated by a surgical procedure termed cochleosacculotomy. In this operation a right‐angled pick is introduced through the round window membrane and advanced 3 mm in the direction of the oval window. This passage carries the pick through the cochlear partition causing a fracture‐disruption of the osseous spiral lamina and cochlear duct. Within the time limits of this study (mean 4.32 months) 88% were relieved of disabling vertigo. Hearing losses of more than 20 dB occurred in 23% of the patients. Profound hearing losses occurred in two patients, one of which was associated with postoperative otitis media.

Results of tympanoplasty and mastoidectomy at the massachusetts eye and ear infirmary

The primary objectives of surgery for chronic suppurative disease of the ear are the elimination or arrest of disease and the preservation or improvement of auditory function. The concept is not new, for even the earliest otologists1 performed temporal bone surgery with the hope of preserving the sound transmitting mechanism of the middle ear. Before the availability of antibiotic drugs for the control of bacterial infection, it was not always prudent to compromise the removal of diseased tissues for the sake of preserving function. It was observed, however, that good thresholds of hearing sometimes occurred even though the ossicles and tympanic membrane were partly or completely destroyed by disease or surgery. These cases were the result of fortuitous patterns of healing in which the function of the ossicular system or the phase difference at the oval and round windows was preserved. Tympanoplasty tries to achieve these goals without compromising the desired end result of a safe, dry, and asymptomatic ear.

Human cochlear changes in noise induced hearing loss

The temporal bone histopathological findings in 14 ears with noise induced hearing loss are presented. The morphological changes consist mainly of hair cell loss, which is more severe in the 9 mm to 13 mm region of the cochlear duct. Within the area of maximum hair cell loss, there is a greater loss of outer hair cells than of inner hair cells. There is a good correlation between the permanent auditory threshold shifts and the spatial location of the sensory lesion according to the anatomical frequency scale.

Experiences with type iv tympanomastoidectomy

Type IV tympanoplasty was performed on 72 patients having advanced suppurative disease of the middle ear and mastoid with total loss of the middle ear sound transmission system. The principal features of the method consist of a postauricular wide‐field mastoideetomy, canalplasty, meato‐plasty, Type IV tympanoplasty with cutaneous exteriorization of the footplate and mastoid obliteration. The method achieved a postoperative bone‐air gap of 30 db or less in 59 percent of cases with a 15 percent incidence of recrudescence requiring some further surgery

Clinical and experimental results with focused ultrasound

Focused ultrasound was applied at the lateral semicircular canal in 19 patients and at the round window in 12 patients, all of whom had intractable vertigo caused by Menieres disease. Postoperatively, the vertigo was relieved or diminished in 75% of the lateral canal cases and in 25% of the round window cases. The results indicate that the lateral canal approach may have some therapeutic value, but the treatment is arduous for the patient and the risk of facial palsy is always nettlesome. Utilizing similar techniques, ultrasound irradiation was given to the lateral canals of 6 squirrel monkeys and to the round windows of 15 cats. After survival times of up to 3 months, light microscopic studies of the temporal bones of these animals show no morphological changes which can be attributed to the ultrasound irradiation. In general, these findings are in concert with the reports of other investigators and show that selective ablation of the vestibular sense organs cannot be achieved by current techniques of ultrasound irradiation. It seems doubtful that prolonged relief of vertigo can be expected to occur without a more complete morphological ablation of the vestibular sense organs than is possible with the current methods of ultrasound treatment.

Facial nerve and stapes anomaly: A case report†‡

A 17‐year‐old white female presented with a unilateral conductive hearing loss which had been present since birth. The external auditory canal and tympanic membrane appeared to be normal, and the manubrium was mobile.