Pulsatile tinnitus, which is the sensation of a sound in one or both sides of the ear that is similar to the rhythm of the heartbeat, has a basic pathological mechanism related to abnormal intracranial and extracranial vascular structures, and the location of the lesion is mostly not in the ear. Electrical auscultation is predominantly low frequency, usually not exceeding 800 Hz; the loudness of tinnitus varies according to the severity of the lesion. There may be venous, arterial, and other vascular abnormalities in the classification, with the first two predominating; the vast majority are permanently curable.
First of all, arterial tinnitus is most commonly caused by arteriovenous fistulas caused by skull base meninges, hemangiomas, or trauma, commonly known as “vascular short circuit”. Patients themselves feel it as pulsatile tinnitus. In clinical examination, the murmur can be heard around the eyes, behind the ears, and in the neck with a stethoscope, but the murmur cannot be diminished or disappeared by squeezing the neck with the hand; therefore, this kind of tinnitus can be identified as arterial.
Venous tinnitus is basically caused by the structural variation of the cerebral venous sinuses. Commonly, there is a narrowing of the junction area between the transverse sinus and the sigmoid sinus, a narrowing of the jugular venous foramen segment of the sigmoid sinus combined with a high or thick jugular venous bulb, and a large diverticulum of the sigmoid sinus. When these structural abnormalities cause increased blood flow and turbulence, a local murmur is formed, which is then transmitted to the cochlea via the bony structures at the base of the skull, and pulsatile tinnitus occurs. Because of the slow venous blood flow, even if there is a murmur, its loudness is not too loud, so it cannot be heard locally with a stethoscope; however, if you squeeze the jugular vein in the neck with your hand, the murmur (or tinnitus) will be significantly reduced or disappear; this is the most typical feature of venous pulsatile tinnitus.
What tests are done after suffering from pulsatile tinnitus?
1. Go to the otolaryngologist first and listen to the murmur in the neck, in front of and behind the ears, and around the eyes with a stethoscope;
2. Squeeze the position of the internal jugular vein under the jaw, and if the tinnitus disappears, it is a venous murmur.
3. doing a tinnitus matching test to understand the frequency and loudness of the tinnitus.
4. doing MRA or CTA of the brain and neck vessels, and brain MRV or CTV to see if there are any abnormalities in the structure of the vessels.
5. an ophthalmologic examination of the fundus, preferably with a photographic examination to see if there is edema.
6, when financially available, additional MR or CT plain plus enhanced examinations of the brain and neck to exclude the possibility of tumor growth and other diseases.
7. if there are symptoms or discomfort in other parts of the body, then seek examination by relevant professional doctors.
8. If the diagnosis is still difficult, then use invasive cerebrovascular DSA imaging, which is the best way to diagnose.
What to do after the cause of pulsatile tinnitus is determined? There are only two choices: treatment or conservative.
Therefore, I recommend that treatment should be considered when the following conditions occur.
1. The tinnitus is so loud that it seriously affects life and even causes anxiety or depression.
2. The examination confirms that the primary lesion causing the tinnitus is very serious, such as arterial stenosis is so severe that it is about to be blocked causing cerebral infarction; or arteriovenous fistula is about to cause cerebral hemorrhage; if the venous sinus stenosis is too severe, there will be edema in the fundus, which may be secondary to fatal cerebral venous sinus thrombosis and intracranial hypertension.
As far as treatment is concerned, since there are no drugs available for pulsatile tinnitus, if the above two are not available, pulsatile tinnitus, at least currently, is not life-threatening and can be observed for a long time, except that the nasty tinnitus will reduce the quality of life; however, it needs to be reviewed regularly at the hospital every year, and when it is severe, it is expected to choose the treatment in time, so as not to miss the disease. When treatment is needed, the most effective way is to do interventional embolization or stent shaping of abnormal blood vessels; secondly, open surgery is also possible, but it requires more advanced technology and is difficult, so it is not recommended.
Interventional treatment mainly involves intravascular stenting of the narrowed artery or vein to restore the shape of the normal vascular cavity so that the murmur will not form and the tinnitus can and will disappear. In the case of arteriovenous fistulas and diverticulae, a special small spiral ring is used to occlude them so that the blood flow cannot pass through these abnormalities and instead flows to the normal channels, and the tinnitus is eliminated and other accompanying symptoms are corrected.
Some patients may have bilateral venous sinus stenosis at the same time, in which case they will have pulsatile tinnitus on one or both sides. Since the transverse sinuses are anatomically connected via the sinus sink, only the more severe side of the stenosis is treated; of course, after the stenting of the more severe side, pressure measurements in the transverse and sigmoid sinuses on the other side are done.
Many netizens are concerned about the effect of interventional treatment for venous sinus pulsatile tinnitus; my personal experience and feeling is that the technical problems of interventional stenting have been basically solved, and in nearly 100 cases done, the tinnitus has completely disappeared within a few days after the operation; the longest follow-up is now 6 years, and there has been no recurrence. The risks of surgery are theoretically always present, but there have been no adverse events so far. The procedure requires antiplatelet agents for 2-3 months and warfarin anticoagulation for 6 months; there have been no significant drug side effects either. Regarding the cost, the cost of treatment for simple venous pulsatile tinnitus is around 40,000 to 50,000 yuan; whether the medical insurance can reimburse is mainly determined by the local medical insurance department.
After stentoplasty for venous sinus stenosis, it is advisable to have a lumbar puncture to measure the intracranial pressure if there is any swelling of the head or blurred vision, or at the 3-month review. Normally, the cranial pressure should not be higher than 200 mmH2O; if it is high, the stenosis may recur and a brain DSA is needed to determine whether there is restenosis in the stent. We have not encountered the problem of stent restenosis or blockage; if intracranial hypertension has already occurred before surgery, the postoperative recovery will take some time; it is better to do a lumbar puncture regularly to determine the degree of the disease and then choose the appropriate symptomatic treatment.