Pulsatile tinnitus must be recognized and distinguished from other types of tinnitus, as it may be curable in 70% of cases. Pulsatile tinnitus is defined as a sound synchronous with systole. It is usually heard in only one ear. Diagnosis is based on questioning, which is an essential part of the clinical examination of any patient complaining of tinnitus. Once recognized, pulsatile tinnitus requires an etiological work-up guided by a physio pathological model.
How can the cochlea ever perceive a pulsatile sound? To understand this, one needs to know that all intracranial fluids (arterial or venous blood and cerebrospinal fluid) are pulsatile and can therefore cause pulsatile sound. Pulsatile tinnitus occurs either after the appearance of a turbulent vascular flow or after the disappearance of the bony envelope (dehiscence) that normally isolates intracranial fluids from the cochlea. The radiological work-up should therefore explore these two potential mechanisms. This includes a specific brain MRI with 3 sequences (3DTOF non-injected, T2 on internal auditory canal, T1 gado MPRAGE) and a temporal CT scan.
However, unlike a large number of pathologies in which the image leads directly to the diagnosis, in the field of pulsatile tinnitus, the etiological diagnosis can only be established by concordance between the radiological image and the data from a physical examination. Why is this so? For two interrelated reasons. Firstly, because this radiological work-up may reveal “deviant” images which may or may not give rise to pulsatile tinnitus. This is the case with vascular dehiscence or stenosis, which are merely tissue remodeling without any profound structural change. Secondly, 30 % of pulsatile tinnitus do not recognize radiological visible cause. A functional test is therefore mandatory to confirm the responsibility of such a deviant image before proposing an intervention as the pulsatile tinnitus may be without cause. The physical examination should include auscultation of the entire cranial vault and cervical region in search of a murmur, which is of great value when perceived. If the patient hears the tinnitus, auscultation is followed by selective compression of the jugular vein, then of the common carotid artery ipsilateral to the tinnitus, in search of its interruption. This selective compression is a crucial functional test whenever a venous cause is suspected. By compressing the jugular vein, the tinnitus should stop. It should be pointed out that in these cases, which are the most frequent, patients have often discovered this method by their own and, to calm their tinnitus, they fall asleep by placing a pillow under their jaw: this is the “cervical wedge sign”. Finally, the examination continues with a Weber and Rinne test.
In our series, there are 32 listed causes of pulsatile tinnitus, the most frequent of which will be detailed in this workshop.