Opinion – Luciano Melo: Tinnitus, in most cases, is caused by changes in brain activity

Maria sleeps sheltered by thin walls, ineffective in blocking out the sounds of the neighborhood. Every night, grudgingly, she monitors her footsteps, coughs, leftover conversations, and all sorts of embarrassing, beeping noises from her vicinity. In her nightly ritual, she tossed and turned in bed, naively hoping to find a comfortable position and some silence.

Thereza has similar problems. But she carries the burden with her, all the time, everywhere, and always worse at night. She has heard a ringing in her left ear, incessant, for years.

For medicine, tinnitus is the hearing of a sound that does not have an external source, it is a child of the body. The vast majority are caused by changes in brain activity, initiated after some hearing loss. These changes are selective, affecting brain areas related to hearing and attention. However, tinnitus can rarely be the result of real noise, for example, when caused by continuous twitching of muscles that are supposed to stabilize the eardrum.

Surveys carried out in different countries indicate that 10% to 25% of adults suffer from this problem. However, only a small number of those affected are deeply bothered by the disorder. This is the case with Thereza: “the wheezing impairs my concentration at work and in conversations. But I would even put up with it, if the noise gave me a break at bedtime”, as she often said.

The characteristics of the disturbing sound, such as frequency and amplitude, are not decisive for the cause of so much annoyance, but for brain functioning. Recent studies point out that brain centers involved in controlling attention and emotions work exaggeratedly in those who are so bothered. Thereza was all focused on her symptom and was disgusted. She was submerged in the problem.

Much to your dismay, almost all tinnitus has no cure. And it wasn’t for lack of trying, many drugs were used in various experiments, but the results were disappointing.

Unfortunately, it took a long time for her to clarify that there was something atypical about her symptoms, an extremely relevant fact, unnoticed in consultations, but an indication of being a candidate for a cure.

Thereza heard a pulsating murmur, coinciding with her heartbeat. She was probably hearing a circulatory problem. Let me explain: there is no sound produced by the normal blood movement in our circulatory vessels. However, when there is an obstruction, the flow of blood occurs in a whirlwind, an audible phenomenon.

With this great suspicion the doctor pressed her neck lightly. Such an action made the buzz momentarily disappear. The maneuver interrupted blood flow through the jugular veins, part of the body’s circulatory system responsible for receiving all the blood that passed through the brain. The blockage also prevented noisy circulation at some intracranial site. No movement, no noise. MRI scans pointed to the venous structure to blame: a small vessel near the left ear was narrowed. The cause of the blood turmoil, the source of Thereza’s tinnitus, was found.

The solution was very technological. Locate a small tube inside the strangulated ductus venosus. The execution had its risks, but Thereza accepted the challenge. She didn’t have the option to change her body like Maria would have to change her house. Now he is doing well, he no longer thinks about the rhythm of the tinnitus.

References:
1. Shahsavarani S, Schmidt SA, Khan RA, Tai Y, Husain FT. Salience, emotion, and attention: The neural networks underlying tinnitus distress revealed using music and rest. Brain Res. 2021 Mar 15;1755:147277.
2. Bauer CA. Tinnitus. N Engl J Med. 2018 Mar 29;378(13):1224–31.
3. Kandeepan S, Maudoux A, Ribeiro de Paula D, Zheng JY, Cabay JE, Gómez F, et al. Tinnitus distress: a paradoxical attention to the sound? J Neurol. 2019 Sep;266(9):2197–207.
4. Cortese J, Eliezer M, Guédon A, Houdart E. Pulsatile Tinnitus Due to Stenosis of the Marginal Sinus: Diagnosis and Endovascular Treatment. Am J Neuroradiol. 2021 Dec 1;42(12):2194–8.