[Pulsating tinnitus associated with high homolateral jugular bulb and aplasia of the contralateral transverse and sigmoid sinuses].

Pulsating tinnitus is uncommon in the general population. This clinical manifestation can be associated with severe intracranial pathologies and is particularly characterized by a rhythm and synchronism reflecting the heart beat. This work presents a clinical case of pulsating, subjective tinnitus associated with a high homolateral jugular bulb and marked hypoplasia of the contralateral transverse and sigmoid sinuses and the clinical-radiological examinations that made diagnosis possible (particular reference going to CT, MRI and angio-MRI). The intracranial venous drainage pattern varies and is nearly always asymmetrical. The jugular bulb is defined as "high" when its upper edge extends nearly to the level of the tympanic anulus, a condition found in 6-20% of the general population. In many cases it is found by chance as often this condition is asymptomatic. However, the pathological picture associated with pulsating tinnitus is highly complex and requires a detailed diagnostic process which some Authors have arranged in specific "flow charts". Imaging methods are essential and must be identified according to the clinical-audiological findings. The radiologist can avail himself of CT, MRI (in association with angio-MRI), Doppler ultrasound of the supraortic and transcranial branches, and digital imaging subtraction angiography. The therapeutic approach to the patient manifesting a "high" jugular bulb is surgical and makes use of such procedures as: ligature of the internal jugular vein, extracranial transposition of the bulb and, in cases of dehiscence of the limiting bone, hypotympanum repair using an autologous or homologous graft of cartilage or bone. Whichever the case, an accurate cost-benefit evaluation must be made, particularly in regard to the risks of endocranial hypertension from the reduced venous drainage, a condition which is significantly increased when concomitant abnormalities of the dural sinuses are present. In the present case, this risk was quite high because of the particular venous morphology described and the patient refused surgery. Currently the patient is under clinical-radiological observation.