Researchers from University of Utah discovered that an ear fluid in patients with semicircular canal dehiscence causes dizziness and vertigo.
According to National Center for Biotechnology Information (NCBI), around 1 in 100 people have a congenital inner ear condition known as semicircular canal dehiscence, worldwide. It is a one of the superior canal dehiscence syndromes (SCDS), with major symptoms of a thinning of the bone enclosing the inner ear that can lead to vertigo in response to certain sounds. Furthermore, a person suffering from SCDS can feel the same imbalance effects of being drunk just by hearing certain tones. Now, researchers from the University of Utah, Johns Hopkins School of Medicine and the University of Mississippi discovered the mechanism behind the syndrome. The research was published in the journal Scientific Reports on July 06, 2018.
Prior to 1929, it was thought that the inner-ear balance and hearing organs are encased in solid bone. However, Italian biologist Pietro Tullio discovered that a hole in the solid bone can cause the inner ear semicircular canals to become sensitive to acoustic sounds. It further leads to rotation of eyes through an automatic reflex, which is responsible for stabilizing an image in the eye during head movements. Furthermore, wrong signals from the ear causes dizziness in the patients. The condition is similar to a feeling of drunkenness. The researchers monitored the neurons and inner ear fluid motion in toadfish to determine the mechanism responsible for sending the wrong head-motion signals to the brain. Toadfish have similar inner ear balance organs as humans. It was observed that sound generating pathological fluid mechanical waves in the semicircular canals of the ear led to effects of dizzying. Furthermore, rotating the head caused inner ear fluids to move, and eyes automatically counter rotated to stabilize the image on the retina. However, a pathological hole in the bone pumps inner ear fluid, which in turn provokes the ears to send an incorrect signal to the brain suggesting that the person is rotating his/her head when he/she is not. The researchers stated that surgery to repair the dehiscence can cure the disorder.