Hearing Hell

Superhero hearing may not be such a good thing. The condition is called Superior Canal Dehiscence Syndrome (SCD). SCD (discovered in 1998) is where the vestibular and auditory symptoms and signs can result from a dehiscence (opening) in the bone overlaying the superior semicircular canal of the inner ear. Patients with SCD will experience vertigo and oscillopsia (the motion of stationary objects) with heightened loud noises and maneuvers that change middle-ear pressure (like coughing, sneezing, and straining). Auditory consequences of this syndrome include the increased resonance of one’s own voice, hypersensitivity to bone-conducted sounds, and hearing loss. (Source: vestibular.org)
With an opening in the bone that is usually supposed to cover the semicircular canal, the fluid in the membranous superior canal can be displaced by pressure and sound. Usually there are only two points of increased pressure in the inner ear: the oval window (through which sound energy is transmitted into the inner ear) and the round window (through which sound energy is dissipated from the inner ear). SCD creates a third mobile window. Symptoms of this syndrome result from the physiological consequences. Those who are diagnosed with SCD are around 45 years old. Patients can experience it unilaterally or bilaterally. About one-third have the condition bilaterally. A common notion of this SCD is that it is due to a developmental abnormality. Studies show that approximately 1-2% of the population has abnormally thin bone overlying the superior canal. A thin layer of the canal suggests that trauma or perhaps over time the pressure of the overlying temporal lobe of the brain that leads to the onset of symptoms. (Source: vestibular.org)
Most of the time patients seek medical attention as soon as they notice the debilitating effects. Specifically, patients note that loud noises cause them to see things move and when they cough, sneeze, or strain. Sometimes patients perceive objects to be moving in the same time with their pulse. Also patients can experience a feeling of constant imbalance. (Source: vestibular.org)
Treatment options include surgical correction for those who are severely affected by SCD. The middle cranial fossa approach has been used mostly. Plugging of the canal with fibrous tissue has been shown to be more effective than canal resurfacing. Most surgeries involve going through the cranial fossa craniotomy on the affected side (surgery through the brain). The temporal lobe is retracted. The opening in the superior canal can be covered with bone wax, bone cement, or fascia; a small procedure that can fix a life altering condition. (Source: emedicine.medscape.com)