Metastatic involvement of the eighth cranial nerve: a temporal bone study

A total of 251 temporal bones belonging to 130 patients who had malignant disease were revised for evidence of metastatic involvement of the VIIIth nerve within the internal auditory meatus. Twenty-one bones from 14 cases, were recovered, found positive for secondary implication of the VIIIth nerve and included in the study. The pathologic findings of 21 temporal bones with metastatic involvement of the VIIIth nerve are reported and correlated with the clinical history, autopsy findings and pathologic changes in the inner ear. It was concluded that a generalized insight has been developed regarding the magnitude of metastatic [secondary] involvement of the VIIIth cranial nerve which may be more prevalent than realized. Diagnosis of VIIIth nerve involvement by metastatic disease may contribute clues to the prognostic evaluation of the patient's status. Five pattern of implicating the VIIIth nerve by metastatic malignancies within the internal auditory canal are recognized and reported

Toxic labyrinthine reaction: a human temporal bone study

The study material included 240 temporal bones with various pathological conditions involving the middle ear, internal auditory meatus and otic capsule in addition to 40 normal temporal bones to serve as controls. The bones were examined for histomorphologic changes in the inner ear and its fluid content. A significant correlation has been shown between the intralabyrinthine eosinophillic reaction and many of the pathological categories included in the study. It was concluded that speculation were inferred relating the toxic labyrinthine reaction to the immune mechanisms of the inner ear, to the development of secondary endolymphatic hydrops and to the modalities of hearing loss in otitic and meningitic conditions. The pathogenesis of intralabyrinthine eosinophilic exudate was hypothesized and pathophysiology of the consequent hearing loss was discussed

Histomorphometric mapping of melanocytes in the inner ear: a study of human temporal bones

The inner ear in 100 human temporal bones of various age groups was mapped out for ten different locations on each bone, using semiquantitative histomorphometric measures to assess the distribution of pigmentary cells in the labyrinth in the various age groups. The mean pigmentary intensity of the various inner ear location in the various age groups was assessed and tabulated. It was concluded that possible functional correlations to the different pigmentary distributions are suggested. A chronological alteration in pigmentary pattern was shown and was related to the development of the inner ear and to the developmental period during which hearing function is established. Pigment was detected in the subepithelial space of the round window niche and is explained by the migratory ability of the melanocyte