A rare case of a high-riding jugular bulb

The superior border of the jugular bulb normally lies below the hypotympanum of the middle-ear cavity. However, in rare cases, the jugular bulb may extend upwards, elevating the floor of the hypotympanum and presenting in the middle-ear space with a thin or absent bony septum. This anomaly is known as a high-riding jugular bulb. A jugular bulb is also considered high-riding if it extends superior to the level of tympanic annulus, or within 2 mm of the internal auditory canal (IAC). Symptoms of a high-riding jugular bulb include tinnitus and conductive hearing loss.

A 26-year-old male presented with progressive hearing loss, ear fullness and tinnitus on the right ear in the last 4 months. In the medical history there were two times of grummet insertion in the right ear because of the effusion. The otoscopy of his right ear showed a scarred tympanic membrane without effusion. The pure tone audiometry of the right ear revealed a mild mixed hearing loss with an air bone gap (20 dB). Tympanometry showed type A tympanogram with absent stapedial reflexes on the right side. Given these findings, with a probable diagnosis of otosclerosis, we elected to proceed with an exploratory tympanotomy. Upon elevating the right tympanomeatal flap a bony mass which restricts the tympanic membrane movement has been found. By trying to dissect this mass a severe bleeding has occurred immediately. Because of this finding we had to abort the procedure. The local area of bleeding was covered by fascia and fibrin glue. The tympanomeatal flap was folded back. Silicon sheets and tamponade were put in the external auditory canal. The high- resolution CT scan of the temporal bone shows a dehiscence of the right jugular bulb with contact to the tympanic membrane.

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Publication History

Article published online:
10 June 2020