Relation of the Internal Ear Spaces to the Meninges

Abstract

The pathologic picture of meningitis, particularly in its relation to that of the temporal bone, is a matter of particular concern to the otologist, since in a large percentage of cases meningitis develops from otitic infection. Some of the main questions which arise in an investigation of the subject are (1) by what various pathways and methods infection may extend from the temporal bone to the meninges and intracranial structures and (2) what relation labyrinthine infection bears both to suppuration in the middle ear spaces and to infection within the subarachnoid space. Information regarding the latter point, namely, the relation of labyrinthitis to infection of the subarachnoid space, may be obtained from a study of cases in which an early stage of extension to the labyrinth from the meninges is exhibited. Observation of such cases and of cases of subarachnoid hemorrhage and intracranial tumor affords information regarding the anatomic and physiologic relation of the fluids within the labyrinth and the subarachnoid space.The late stages of labyrinthitis following meningitis, as found in deaf mutes, have been described by Siebenmann,1 Panse 2 and others.3 Extensive studies of labyrinthitis secondary to disease of the middle ear, including histologic study of the temporal bone, have been made by Fraser and Turner 4 and by Dean and Wolff.5 The more acute process in the early stages of infection has received considerable attention, both From the

Defense Mechanism of the Cochlear Aqueduct against Infection

“…Thereafter, the same invasion routes were reported from temporal bone findings in cases of subarachnoidal hemorrhages, intra cranial tumors, and meningitis by Perlman and Lindsay [12], from experience using hu man temporal bones in cases of subarachnoi dal hemorrhages and temporal bones of cats and monkeys by Paparella and Sugiura [11], and from temporal bone findings in cases of meningitis by Henneford and Lindsay [4], Igarashi et al [5], Lindsay [8], and Schu-knecht and Montandon [15]. In all of these reports, two main invasion routes were the internal auditory meatus and the cochlear aqueduct.…”

LVIII The Circulation of the Labyrinthine Fluids

“…21 Contrary to the findings in most of the laboratory animals, which have a short and wide cochlear aqueduct, in man, it is much longer and narrower. In laboratory animals the structures within the modiolus are separated from the scalae by a thin layer of compact bone.…”

LXIII Obliteration of the Endolymphatic Sac and the Cochlear Aqueduct

“…(d) On July 20,1951 (eight months) the animals auditory acuity was still within normal limits. Because of the time and work involved in conditioning these animals for auditory testing, it was decided to attempt a partial eighth cranial nerve section by an approach from the posterior fossa.…”

“…Cat 8.-(a) On Aug. 20,1950, a left destructive labyrinthotomy was performed. Auditory conditioning was accomplished during the following three months.…”