XXXX involving the temporal bone: histopathologic aspects.

@entity1 @entity18300 @entity2172 @entity18299 @entity73 @entity425 @entity2103 @entity1463 @entity4237 @entity1274
@entity18300 is a rare, potentially lethal, autosomal recessive, progressive @entity18299 with characteristic facial and skeletal features. The temporal bone changes include a marked increase in overall size, extensive @entity1463 , narrowing of the external auditory canal, and severe constriction of the internal auditory meatus, fallopian canal, eustachian tube, and @entity2172 . Attenuation of the bony canals of the 9th, 10th, and 11th cranial nerves, reduction in size of the internal carotid artery, and severe obliteration of the sigmoid sinus and jugular bulb also occur. Loss of hearing, generally bilateral, is a frequent symptom. It often manifests in early childhood and initially is expressed as sound conduction impairment. Later, a @entity1274 and @entity4237 function often develop. @entity73 is another feature occasionally present at birth. In the beginning, a unilateral intermittent @entity425 may occur which eventually progresses to a bilateral permanent facial paresis. The histologic examination of the temporal bones from a @entity1 with @entity18300 explains the mechanisms involved in the progressive impairment of sound conduction and loss of cochlear, vestibular, and @entity2103 . There is a decrease of the arterial blood supply to the brain and an obstruction of the venous drainage from it. The histopathology reveals the obstacles to decompression of the @entity2172 , ossicular chain, internal auditory and facial canals, and the risks, and in many instances the contraindications, to such procedures. On the other hand, decompression of the sigmoid sinus and jugular bulb should be considered as an additional life-saving procedure in conjunction with the prophylactic craniotomy recommended in all adult @entity1 .
