About six percent of the general population has what they consider to be "severe" tinnitus. That is a gigantic number of people ! Tinnitus is more common with advancing age. In a large study of more than 2000 adults aged 50 and above, 30.3% reported having experienced tinnitus, with 48% reporting symptoms in both ears. Tinnitus had been present for at least 6 years in 50% of cases, and most (55%) reported a gradual onset. Tinnitus was described as mildly to extremely annoying by 67%.(Sindhusake et al. 2003)
Additional conditions that can cause pulsatile tinnitus include arterial bruit, abnormal passages or connections between the blood vessels of the outermost layer of the membrane (dura) that covers the brain and spinal cord (dural arteriovenous shunts), or conditions that cause increased pressure within the skull such as idiopathic intracranial hypertension (pseudotumor cerebri). Sigmoid sinus dehiscence may be associated with pseudotumor, but this connection has not been firmly established. It possible that cases of pulsatile tinnitus associated with pseudotumor may be caused by an undiagnosed SSWA. Head trauma, surgery, middle ear conductive hearing loss, and certain tumors can also cause pulsatile tinnitus. Obstructions within in the vessels that connect the heart and brain can also cause pulsatile tinnitus.
The researchers next tested whether tinnitus could be reversed in noise-exposed rats. The animals received VNS paired with various tones other than the tinnitus frequency 300 times a day for about 3 weeks. Rats that received the treatment showed behavioral changes indicating that the ringing had stopped. Neural responses in the brain's auditory cortex returned to their normal levels as well, indicating that the tinnitus had disappeared.
Pulsatile tinnitus is generally caused by abnormalities or disorders affecting the blood vessels (vascular disorders), especially the blood vessels near or around the ears. Such abnormalities or disorders can cause a change in the blood flow through the affected blood vessels. The blood vessels could be weakened from damage caused by hardening of the arteries (atherosclerosis). For example, abnormalities affecting the carotid artery, the main artery serving the brain, can be associated with pulsatile tinnitus. A rare cause of pulsatile tinnitus is a disorder known as fibromuscular dysplasia (FMD), a condition characterized by abnormal development of the arterial wall. When the carotid artery is affected by FMD, pulsatile tinnitus can develop.
This well-designed study found that using CBT alongside elements of standard therapy can help patients with tinnitus of varying severity. However, the differences in outcomes between the two groups were quite small, and this technique can only help manage tinnitus rather than curing it, as some papers implied. Also, the patients in the study were followed for only 12 months, so it is unclear whether this approach can help in the longer term.
Tinnitus that's continuous, steady, and high-pitched (the most common type) generally indicates a problem in the auditory system and requires hearing tests conducted by an audiologist. Pulsatile tinnitus calls for a medical evaluation, especially if the noise is frequent or constant. MRI or CT imaging may be needed to check for a tumor or blood vessel abnormality.