Congenital deformity of the internal auditory meatus and labyrinth associated with cerebrospinal fluid fistula

Association of spontaneous anterior fossa CSF rhinorrhea and congenital perilymphatic fistula in a patient with recurrent meningitis

A case of recurrent meningitis associated with spontaneous cerebrospinal fluid (CSF) rhinorrhea and left sensorineural hearing loss in a 4-year-old boy was found to be due to simultaneous congenital defects. High resolution CT examination clearly showed an anterior fossa defect and an inner ear malformation, including demineralization in the region of the footplate of the stapes, and thus provided clear guidance for the surgeon.

Cochlear implants for congenital deformities

There have been few accounts of multi-channel cochlear implants in patients with congenital structural deformities of the inner ear which are associated with severe and sometimes progressive deafness. These malformations can now be recognized easily on 2 plane thin section high resolution CT studies which are mandatory for the pre-implantation assessment. However, no attempt seems to have been made to describe which of these malformations would be suitable for an implant or for which would this procedure be contra-indicated. True Mondini deformity of both the cochlea and dilated vestibular aqueduct type would appear suitable for a multi channel implant, but this type of implant should not be used for a primitive otocyst, severe labyrinthine dysplasia or the characteristic X-linked deformity.

X-linked deafness, stapes gushers and a distinctive defect of the inner ear

The association of X-linked mixed deafness with stapes gusher has been recognized for 20 years, and imaging studies by polytomography have shown dilatation of the lateral end of the internal auditory meatus (IAM) in some cases. We have made genetic linkage studies in 7 pedigrees in whom deafness was inherited in an X-linked manner. All patients had a full range of audiometric and vestibular function tests. Thin section high resolution CT in two planes was used to assess the state of the middle and inner ears. We found a distinctive inner ear deformity in some of the deaf males characterised not only by a wide bulbous IAM but more importantly, by deficient or absent bone between the lateral end of the IAM and the basal turn of the cochlea. We believe that this results in a communication between the subarachnoid space in the IAM and the perilymph in the cochlea, leading to perilymphatic hydrops and a "gusher" if the stapes is disturbed. Moreover, some of the obligate female carriers seem to have a milder form of the same anomaly associated with slight hearing loss. Genetic studies on some of the deaf males with apparently normal inner ear anatomy suggest a different locus on the X chromosome and hence a different pathogenesis for the deafness.

Recurrent meningitis in children due to inner ear abnormalities

Recurrent meningitis in children is not only a potentially life threatening condition, but often involves the child in the trauma of repeated hospital admissions and multiple and invasive investigations to try and find an underlying cause. Symptoms and signs of CSF rhinorrhoea or otorrhoea are infrequent in these patients. Unilateral deafness may be difficult to diagnose in the young child. Full ENT examination may be normal. We report seven cases of children with recurrent meningitis in whom inner ear abnormalities were only indicated as the site of entry of infection by hypocycloidal tomography or high resolution CT scanning of the temporal bone. Subsequent tympanotomy confirmed the site of the CSF leak as the oval window in the majority of cases; packing the vestibule with muscle halted further attacks in these patients.

Congenital cerebrospinal fluid fistulae of the petrous temporal bone

Spontaneous cerebrospinal fluid fistulae from the subarachnoid space into the middle ear cavity may be classified as perilabyrinthine or translabyrinthine. The very rare perilabyrinthine group, through bony defects close to but not involving the labyrinth, usually have normal hearing initially. The commoner translabyrinthine group are nearly always associated with anacusis, severe labyrinthine dysplasia and a route via the internal auditory meatus. The labyrinthine deformity is more severe than the type classically described by Mondini, and evidence of a dilated cochlear aqueduct in these cases is also unconvincing.

The Mondini defect in Turner's syndrome. A temporal bone report

The histopathology of the right temporal bone of a 47 year old deaf woman with Turner's Syndrome (gonadal dysgenesis) is described. The appearances are of the Mondini deformity, the cochlea consisting of a single basal turn with a bulbous apical dilatation. The organ of Corti was absent. The remainder of the bony labyrinth save for the cochlear aqueduct was normal. The patient's death was due to a cerebral astrocytoma. Previous reports concerning the co-existence of gonadal dysgenesis, congenital deafness and non-gonadal neoplasia are discussed.

Ear deformities associated with the Klippel-Feil syndrome

Congenital spinal fusion, constituting the Klippel-Feil anomaly, has long been known to be associated with severe deafness in many patients. Ten such cases are described, with audiometric and tomographic assessment of the ear lesions. Of the 20 ears examined, 12 showed evidence of severe hearing loss and of these, 11 had evidence of significant inner ear dysplasia on tomography. Middle and external ear abnormalities were also demonstrated. The significance of these findings and the relation to other syndromes is discussed.