Dehiscence syndrome: symptoms, causes and treatment

Superior semicircular canal dehiscence syndrome (SDCSS) is a condition that affects balance. It is difficult to diagnose and is usually associated with panic attacks or other psychiatric disorders. However, this syndrome has its origins in a problem with the development of the semicircular canals, small canals located in the inner ear that help us maintain balance.

In this article we will explain the origin of dehiscence syndrome, its strange symptoms and why it presents such a complicated diagnosis.. We will also see how it can be treated with medical help.

    What is dehiscence syndrome?

    Dehiscence is defined in medicine as the spontaneous separation between two adjacent structures or tissue parts. It is generally used as a synonym for fissure.

    Dehiscence syndrome refers to dehiscence of the superior semicircular canal of the inner ear. The bone that covers this channel has a small hole. This is related to a problem in the development of the baby, it is believed that due to the lack of growth of the upper bone which makes the bone sheet very thin, this condition could worsen following a blow. But… why does this affect the balance?

    How does balance work?

    The ear is the organ of hearing but also of balance. It consists of the outer ear, the middle ear and the inner ear. The inner ear is divided into cochlea, vestibule and semicircular canals. The cochlea is responsible for receiving and transmitting auditory information and this is where the auditory nerves are located..

    The vestibule and the semicircular canals form the vestibular system. The vestibular system is responsible for maintaining the balance and posture of the body, as well as coordinating our movements and allowing us to fix our gaze on a specific point in space.

    The vestibule and circular canals have head-sensitive, fluid-filled cells called endolymph. These cells have cilia (they are like little hairs), which act as receptors, capturing the movement of liquid. and they transform it into nerve messages which they send to the brain for processing.

    This system works in a particular way, by comparing the information received from both ears. An increase or decrease in motion results in an increase or decrease in signal. For example, if we move our head to the right, the right ear will generate a stronger nerve impulse than the left. This is how the brain understands the movement of the head.

    The vestibular system is particularly sensitive. For example, when we go up to an attraction and we turn around a lot, we feel dizzy, because due to inertia, the liquid is always in motion. Even if we have stopped moving, nerve impulses are still transmitted to the brain. This causes unpleasant symptoms such as dizziness and vomiting.

      Superior semicircular canal dehiscence syndrome

      Although the cracks in the bone covering the canal are small, they cause a variety of symptoms, from mild to disabling, such as dizziness, lightheadedness, headaches, etc. Not only the variety of these symptoms, but also their consequences make their diagnosis extremely difficult.

      Many patients are diagnosed with superior semicircular canal dehiscence syndrome they report suffering from anxiety or panic attacks. If you think about it, it is clear that living with frequent headaches, persistent nausea, blurred vision, loss of balance and other debilitating symptoms, in addition to not knowing their origin, has serious effects on mood. may have a physiological explanation related to the release of catecholamines. Because of these symptoms, many SDCSS patients are referred to psychiatry.

      In reality Dr. Lloyd Minor, an otolaryngologist at Johns Hopkins, discovered this syndrome in 1995.. After that, different patients will be sent to you by psychiatry. The patients’ symptoms were actually coming from the head, but not from where they were supposed to be.

      It is believed that superior semicircular canal dehiscence syndrome is not uncommon and that between 1% and 2% of the population has a very thin bony lamina of the superior semicircular canals. As we have seen, this condition may or may not end in a crack. An estimated 33% of patients diagnosed will develop an upper auditory canal dehiscence in each ear. In 10% of people with chronic vertigo, it could be caused by SDCSS, although many of these cases are currently undiagnosed.

        The discovery of SDCSS dehiscence syndrome

        Dr. Minor was able to link this syndrome to damage found in the internal auditory canals of a group of pigeons, in which strange eye and head movements were observed. Patients also had a response to pressure and sound changes that affected the vestibular system.

        Subsequently, a study of the prevalence of temporary bone revealed a percentage of patients in whom the bone covering the superior semicircular canal was very thin. In the absence of any pathology that could explain the bone disorder, or trauma, in addition to the condition of both ears, the researchers concluded that the most likely explanation was a developmental disorder. Because the blade of bone is so thin, a sudden change in pressure or a blow can cause cracks and serious symptoms..

          Symptoms of Superior Semicircular Canal Dehiscence Syndrome

          Unfortunately, the diagnosis of superior semicircular canal dehiscence syndrome is late. It usually goes unnoticed until its symptoms worsenand go from dizziness or dizziness to disabling symptoms such as severe headaches or recurrent nausea.

          Patients are usually at least over a year old with severe symptoms or are referred by a psychiatrist who does not understand where the presenting psychological disorders are coming from and perceives a non-cerebral origin. Many patients may spend years in psychiatric treatment due to recurrent anxiety or panic attacks and it is only when, due to a change in pressure or trauma, that the symptoms of SDCSS become more serious and can then be diagnosed.

          In most cases, patients often suffer from imbalance and dizziness. However, the difference in how patients report symptoms makes diagnosis difficult and many cases go undetected. Finally, after a long wait, they can have a diagnosis. Many may have become isolated due to this condition.

          The most common symptoms are dizziness (accompanied by frequent dizziness), oscillopsia (they feel like objects are moving when they are actually still), autophony (they hear their own sounds like blinks and breaths much louder than normal), high sensitivity to loud sounds and a constant feeling of pressure, as if the ears were full.

          The psychiatric comorbidities that some patients present following their SDCSS are: anxiety, panic attacks, feeling unsteady, depression, among others. These, in addition to having a psychological explanation, could lead to the release of a large number of a type of catecholamine. Catecholamines are important neurohormones in the stress response, in high concentrations they can cause severe chest pain, palpitations and anxiety. Abnormal vestibular stimulation that occurs in the SDCSS could cause its massive release.

            Treatment of superior semicircular canal dehiscence syndrome

            To diagnose SDCSS, it is necessary to delve into the patient’s history and the symptoms he has experienced throughout his life, specifying in which situations they appear or worsen and when they occur. worsened, and whether they did so as a result of an event. concrete (a plane trip, a trauma, a visit to the dentist, etc.).

            The doctor may include several tests to confirm the diagnosis; A CT scan of the patient’s temporal bone is usually donewhere you can see if there is indeed a crack in the bone that covers the superior semicircular canal.

            Also the patient can undergo a hearing test and a PVME (evoked myogenic vestibular potential). The PVME is a recent diagnostic test used to assess the response of the vestibular organs and determine their condition. The insertion of headphones and electrodes placed at the level of the sternocleidomastoid are used to record the potentials. Patients with SDCSS are more sensitive to sound. This test can help determine the area of ​​injury to the inner ear and therefore identify if it is an upper canal dehiscence syndrome.

            In many patients, treatment involves avoiding exposure to activities that could trigger symptoms, such as high altitude climbing, boat trips, fairground attractions, etc. Additionally, physiotherapy is recommended to improve posture and balance and reduce the risk of falls.

            Patients with superior ductal dehiscence with much more severe and disabling symptoms for their daily life, they can undergo surgery to close the bony fissure. This surgery has shown good results and can alleviate or reduce the symptoms of the disease. However, sometimes after the operation the symptoms can get worse, this is usually because the patient has bilateral SDCSS and both ears need to be treated and checked.

            Bibliographic references

            • Superior semicircular canal dehiscence syndrome. About a case – Rev. Otolaryngology. Cir. Cabeza Cuello, 76 (1) Santiago (2016).

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