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Biomedical subjects

A Belal

Publications and source records attributed to A Belal.

At least 37 records · Page 2Linked to original sources
PubMed1983

Pathology as it relates to ear surgery II. Labyrinthectomy.

Five human temporal bones and three surgical VIIIth nerve biopsies from patients who had previously undergone labyrinthectomy, five months to ten years before examination, were studied by light and electron microscopy. Post-labyrinthectomy dizziness could be explained on the bases of inadequate surgical removal of the vestibular sense-organs, neuroma formation in the vestibule, and high regenerative potential of the vestibular nerve. Post-labyrinthectomy pressure sensation and tinnitus are most probably due to cochlear endolymphatic hydrops and need cochlear neurectomy. The severe atrophy in the sensorineural structures of the cochlea was not associated with retrograde degeneration of the cochlear nerve central axons. This may be of significance in the artificial electrical stimulation of the cochlear nerve in deaf patients.

Adult↗
PubMed1982

Torps and porps: a transmission and scanning electron microscopic study.

TEM and SEM were used to evaluate the fate of eleven Plasti-pore prostheses left in the human middle ear for periods varying from seven to 34 months. It was evident that Plasti-pore is a relatively inert material based on its clinical performance, absence of gross fibrous tissue reaction from the middle ear, and the unchanged physical characteristics of the prosthesis. Micro-disintegration of the TORPs and PORPs was suggested by the consistent foreign body reaction invading their structure, and the presence of particulate-like matter inside the giant cells. However, micro-disintegration did not affect the physical characteristics of the prosthesis and seem to have little bearing on their clinical performance. The question of the long-term performance of Plasti-pore remains to be answered.

Adult↗
PubMed1982

Poststapedectomy dizziness. A histopathologic report.

Long-term disabling dizziness is a rare but serious postoperative complication of stapedectomy. The temporal bone collection of the Ear Research Institute in Los Angeles includes 117 bones from patients who underwent unilateral or bilateral stapes operations. Of them, nine patients (8 percent) complained of severe long-term postoperative dizziness. Histologic examination of the temporal bones revealed a pathologic condition in the peripheral vestibular system of seven patients; the remaining two patients showed normal maculae, cristae, and vestibular nerve. Pathologic conditions found were suppurative labyrinthitis in one case, endolymphatic hydrops in two cases, fibrous adhesions in the utricle in two cases, and a bone fragment in contact with the saccule in one case. An undiagnosed inferior vestibular nerve schwannoma was present in one case of unilateral stapedectomy that was followed by constant unsteadiness. Because there are many causes of poststapedectomy dizziness, a complete neurotologic evaluation is indicated in every case for a specific diagnosis.

Adult↗
PubMed1982

Acoustic tumor surgery with preservation of hearing. A histopathologic report.

The goals of acoustic tumor surgery are total tumor removal, intact facial nerve function, and preservation of hearing. the middle fossa approach offers the opportunity to achieve these goals in selected cases. This article presents the findings from the temporal bones of two patients who had undergone middle fossa removal of an acoustic tumor, nine and ten years before their deaths. Hearing was preserved in one case and lost in the other. The patient with profound postoperative deafness showed severe degenerative changes and ossification in the membranous labyrinth. This was explained on the basis of internal auditory artery occlusion. The goals of acoustic tumor surgery are discussed in light of the histopathologic findings in these two cases. the middle fossa approach is advocated as the best available to achieve these goals in intracanalicular tumors.

Audiometry↗
PubMed1981

Human vestibular nerve morphology and labyrinthectomy.

Surgical labyrinthectomy leads to extensive and degenerative changes in the membranous labyrinth and is often followed by fibrosis and ossification of the vestibule and neuroma formation. After labyrinthectomy the distal processes of the vestibular nerve degenerate, but the nerve trunk within the internal auditory canal, including Scarpa's ganglion, does not show an obvious loss of neurons. Electron microscopic examination of the cells of Scarpa's ganglion revealed many changes similar to those of chromatolysis, indicating increased cell metabolism and probable regenerative changes. Many nerve fibers appeared to be in the process of regeneration. Some ganglion cells were fibrotic and showed ultrastructural features similar to those of cells that had undergone atrophy but survived in a sublethal state.

Adult↗
PubMed1981

Rhinitis medicamentosa: electron microscopic study.

The deleterious effect of decongestant drops on the rabbit respiratory nasal mucosa was studied with the aid of the electron microscope. The cilia were severely damaged, with the appearance of virus-like particles. The epithelium showed characteristic morphological details suggestive of oedematous infiltration. The tunical blood vessels revealed ultrastructural changes of their endothelial lining and basal lamina indicative of increased permeability.

Animals↗
PubMed1981

Surgical anatomy and pathology of the round window.

A study of the surgical anatomy and pathology of the round window was performed on a total of 292 serially sectioned temporal bones. The surgical approach to the round window is discussed with consideration of the anatomical findings. In the pathological study obliteration of the round window niche occurred as a congenital anomaly, in otosclerosis, chronic otitis media and as an end result in suppurative labyrinthitis. Clinical reports seem to indicate that obliteration of the window is associated with significant hearing loss, contrary to the findings in experimental animals. In chronic otitis media the round window is a pathway for spread of infection to the labyrinth, but also the finding of perilymphatic precipitates to the window in some ears suggests that certain inflammatory products may enter the scala tympani through the round window and so lead to high tone sensorineural hearing loss.

Adolescent↗
PubMed1980

Pathology of congenital syphilitic labyrinthitis.

An alarming increase in the incidence of syphilitic labyrinthitis has prompted us to review the pathology of this condition. The temporal bones of two patients with congenital syphilis of the ear were studied histopathologically. They showed diffuse osteitic changes in the otic capsule associated with severe hydrops and degeneration of the membranous labyrinth. The posterosuperior wall of the external auditory canal as well as the auditory ossicles showed numerous connective tissue filled spaces surrounded by thin bony trabeculae. These lesions probably represent healed luetic osteitis. There was severe degeneration of the sensorineural structures in the cochlea. A finding of particular interest was the infiltration and fibrous obliteration of the ductus endolymphaticus in both cases. The significance of these findings in relation to the pathophysiology and treatment of syphilitic labyrinthitis is emphasized.

Bone Resorption↗
PubMed1980

Pathologic significance of Meniere's symptom complex. A histopathologic and electron microscopic study.

Histologic and ultrastructural findings in the temporal bones of a patient clinically diagnosed as having unilateral Meniere's disease are presented. The patient underwent two endolymphatic subarachnoid shunt operations that failed to relieve symptoms and a middle fossa vestibular nerve section that completely relieved episodic vertigo and stabilized hearing in the ear operated upon. Histopathologic examination of the temporal bones showed no endolymphatic hydrops in either ear. The maculae and cristae on the side operated upon showed severe degenerative changes attributed to vestibular neurectomy. The cochleograms of the operated and contralateral ears showed degeneration of the sensorineural structures in the basal two turns of the cochlea. No apparent cause for the fluctuant hearing loss was found in the cochlea or the cochlear nerve of the involved ear. Light and electron microscopic studies of the vestibular nerve excised at the time of vestibular neurectomy showed that most of the nerve fibers and ganglion cells were essentially normal. Collagen tissue deposition was increased in some areas of the endoneurial space. Most myelinated nerve fibers in these areas had degenerated. Although these changes may be partly due to artifacts and partly due to aging, they probably are the result of a pathologic process affecting the vestibular nerve. These findings suggest that a revised approach to the etiology, pathogenesis, and treatment of Meniere's symptom complex is indicated.

Female↗
PubMed1980

Pathologic correlates of electronystagmographic tracings.

Electronystagmographic tracings were correlated with the histopathologic findings in the peripheral vestibular system of 66 temporal bones of 34 patients who complained of dizziness. Although some findings (e.g., spontaneous nystagmus, unilaterally reduced caloric response, and directional preponderance) seemed to have doubtful value in localizing vestibular system disease, other findings indicated a peripheral site of the vestibular lesions. Bilaterally reduced or bilaterally absent caloric responses were consistently associated with pathologic changes in the peripheral vestibular system. Similarly, a unilaterally absent caloric response consistently indicated peripheral disease. On the other hand, positional nystagmus and bilaterally equal caloric responses seemed to indicate the absence of a peripheral site of disease in the vestibular system. Although there is no reliable way to differentiate end organ from vestibular nerve lesions, the latter were more commonly associated with positional nystagmus and absence of a caloric response. The direction of nystagmus beating correlated with the side of the diseased peripheral site in two of four patients with spontaneous nystagmus, in five of seven with positional nystagmus, and in all with unilateral reductions in or absence of caloric responses. Electronystagmographic findings in the present study seemed to reflect diffuse rather than localized pathologic changes in the peripheral vestibular system.

Adolescent↗