If you have balance and hearing problems or ear pressure sensitivity, you may have superior canal dehiscence syndrome, or SCDS.
SCDS is a rare inner ear condition. It happens when there’s an abnormal opening in the bone over the superior semicircular canal, a structure that regulates balance.
At UPMC, our specialists provide comprehensive care for a wide range of problems, including SCDS. We help manage SCDS with lifestyle changes, hearing aids, and surgery.
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What Is Superior Canal Dehiscence Syndrome?
Doctors define SCDS as an inner ear disorder in which there’s a hole in the bone covering the superior semicircular canal. This fluid-filled tube helps you balance.
Here's how it works: Your inner ear consists of a system of passages and canals. Within that system, two “window” openings are responsible for moving sound and air pressure in your ear.
SCDS begins when a third window forms and redirects the pressure in this inner ear system. (The word “dehiscence” means the opening up of a previously closed structure.)
This window forms when the bony covering of the semicircular canal near the top of the inner ear doesn’t exist or is too thin. Without that covering, the extra opening leads to balance, vision, and hearing problems.
You may hear SCDS called superior semicircular canal dehiscence or canal dehiscence condition.
How common is superior canal dehiscence syndrome?
SCDS itself is rare.
It's important to separate two different conditions:
- Having a dehiscence — You have an opening or thin spot in the bone.
- Having the syndrome — You have symptoms caused by the dehiscence.
Imaging studies suggest anywhere from about 1% to 9% of the population have some degree of thinning or opening over the superior semicircular canal. But only a small fraction of these people ever develop noticeable symptoms of SCDS.
Some doctors believe there may be more people with SCDS. Because the symptoms mimic signs of other diseases, the condition may be under-diagnosed.
What causes superior canal dehiscence syndrome?
Doctors don’t always know the causes of semicircular canal dehiscence in adults.
For some people, symptoms seem to build up slowly. The thin or open area of bone may be present from birth but only become noticeable later in life. Most patients are diagnosed in their 50s or 60s, though symptoms can appear earlier, especially after a head injury or a significant pressure event.
Theories about how SCDS develops include:
- A pause in bone development early in life, leaving the covering over the canal thin or incomplete from birth.
- Head trauma.
- Thinning of the bone as part of aging.
There may also be a connection between SCDS and different kinds of pressure that affect the body.
Events that might trigger SCDS include:
- Changes in barometric pressure.
- Diving.
- Flying.
- Giving birth.
- Physical trauma like a fall or car crash.
What triggers superior canal dehiscence syndrome symptoms, and what complications can occur?
Common triggers of superior canal dehiscence syndrome
SCDS symptoms can be caused by:
- Exposure to loud noise at work.
- Pressure changes, as in scuba diving.
- Sneezing or coughing.
- Surgery.
- Trauma such as a fall or car crash.
Complications of superior canal dehiscence syndrome
SCDS can lead to other problems, including:
- Anxiety.
- Brain fog.
- Depression.
- Headaches.
- Isolation to avoid loud noises.
- Overall reduced quality of life.
How can I reduce risks of superior canal dehiscence syndrome?
There are no known modifiable risk factors that cause SCDS to develop in the first place — the thin or open area of bone is typically present from early in life. However, once you have SCDS, certain things can trigger or worsen your symptoms.
You can reduce your risks by:
- Avoiding extreme pressure changes.
- Keeping up with doctors’ appointments so you can manage your condition.
- Wearing ear protection if you’re around loud noises.
What Are the Signs and Symptoms of Superior Canal Dehiscence Syndrome?
Symptoms of SCDS can be confusing. Even in one person, they may vary dramatically from day to day.
Another confusing issue is that there are no symptoms that are specific to SCDS. Because you have one or more of the symptoms below doesn’t necessarily mean you have SCDS. You could have another inner ear condition.
If you have SCDS, it may gradually get worse over the years. You may not notice increasing symptoms. Or if a child grows up with SCDS, they may accept the symptoms as normal and not realize they have a problem.
Symptoms of SCDS fall into two main categories:
- Auditory (hearing)
- Vestibular (balance)
Auditory symptoms of superior canal dehiscence syndrome
Auditory (hearing) problems include:
- Aural fullness — A feeling that your ear is full or clogged, or that you can’t “pop” your ears.
- Autophony — Hearing internal body sounds more loudly, like creaking joints, pulse, and breathing.
- Hyperacusis — An increased sensitivity to sounds, to the point where normal noises feel painful.
- Low-frequency conductive hearing loss — The inability to hear deeper or bass sounds.
- Tinnitus — A ringing, buzzing, or roaring sound in the ear.
Vestibular dysfunction symptoms of superior canal dehiscence syndrome
Vestibular (balance-related) problems often happen after loud sounds or changes in pressure.
They include:
- Disequilibrium — Chronic unsteadiness.
- Nystagmus — Involuntary eye movement.
- Oscillopsia — When objects in your visual field appear to move rapidly.
- Vertigo — A type of dizziness where you feel your surroundings are spinning.
Other symptoms of superior canal dehiscence syndrome
They include:
- Brain fog.
- Headache.
- Migraines.
- Nausea, caused by vertigo or nystagmus.
- Tiredness.
When should I see a doctor about my superior canal dehiscence syndrome symptoms?
You should see a doctor as soon as you notice any of the symptoms of SCDS. The sooner you get treatment, the sooner your quality of life will improve.
Your primary care provider (PCP) may refer you to an otolaryngologist, also known as an ear, nose, and throat (ENT) specialist. You may also see an audiologist, or hearing specialist.
They may be able to rule out other conditions that have similar symptoms to SCDS.
How Do You Diagnose Superior Canal Dehiscence Syndrome?
SCDS is difficult to diagnose because its symptoms overlap with many other conditions.
The most similar conditions include:
- Otosclerosis —Stiffening of a tiny ear bone that can also cause hearing loss.
- Vestibular migraine — A common problem that can also cause sound and motion sensitivity.
- Persistent postural-perceptual dizziness (PPPD) — A chronic imbalance disorder.
- Patulous Eustachian tube dysfunction — A disorder in which the tube stays open too much.
- Perilymphatic fistula — Another type of abnormal opening in the inner ear.
- Enlarged vestibular aqueduct syndrome —An inner ear structural condition.
- Intracranial hypertension.
- Temporomandibular joint (TMJ) dysfunction.
- Meniere’s disease.
- Other rare inner ear openings, such as cochlea-carotid or cochlea-facial dehiscence.
- Post-concussive syndrome.
- Near-dehiscence syndrome — Condition in which the bone is very thin but not fully open.
Your doctor may ask you questions that seem strange but can point to a diagnosis of SCDS.
According to the SCDS Society, these questions include:
- “Can you hear your eyes move?”
- “Do you get dizzy when you have a bowel movement?”
- “Does blowing your nose make you feel like you are spinning?”
A positive answer to questions like this may lead to a diagnosis of SCDS. Of course, your doctor will ask about your medical history and do a physical exam. They will order tests to help diagnose SCDS and to rule out other conditions.
Tests to diagnose superior canal dehiscence syndrome
- CT scan — To look at the opening in the bone that covers the superior semicircular canal. It is typically the gold standard of testing for SCDS.
- Hearing test — To get an overall sense of how your ears are working.
- Vestibular myogenic evoked potential (VEMP) test — Small sensors are placed on your neck and under your eyes to pick up tiny, automatic muscle reflex responses to loud clicking sounds or tones played through headphones. In SCDS, these reflexes are often easier to trigger than normal, which helps confirm the diagnosis.
Superior canal dehiscence syndrome outlook
The good news is that SCDS is treatable.
If your SCDS is mild, the techniques below may be enough to manage your symptoms.
If you have a more severe condition, surgery can decrease or relieve your symptoms.
How Do You Treat Superior Canal Dehiscence Syndrome?
The goal of treatment is to reduce your SCDS symptoms and improve your quality of life. If you have SCDS, you may consult with an audiologist and an otolaryngologist.
Treatment options for superior canal dehiscence syndrome may take several different forms.
Lifestyle changes for superior canal dehiscence syndrome
In some cases, simply avoiding situations that induce symptoms (like places with a lot of loud noises) can help manage discomfort. Wearing earplugs may help. You may also be able to work with a physical therapist who specializes in balance issues.
Surgery for superior canal dehiscence syndrome
Surgical options include:
- Plugging the opening with bone or connective tissue — Surgeons get to your inner ear through an opening in your skull or behind the ear.
- Resurfacing the opening — This technique covers the hole without completely closing it.
Doctors are currently working to develop less-invasive techniques to treat SCDS.
Hearing aids for superior canal dehiscence syndrome
Hearing aids are also an option for people who have hearing loss associated with SCDS.
How effective is treatment?
Most people benefit from treatment for SCDS. Talk to your doctor about which options are best for you.
How long does it take to recover after surgery for superior canal dehiscence syndrome?
Recovery from SCDS surgery may take up to six weeks. You may experience dizziness and vertigo in the days after the surgery. These side effects should diminish as your brain adjusts.
What questions should I ask my provider about superior canal dehiscence syndrome?
- Can I manage my SCDS without surgery?
- Is it possible I have another inner ear condition?
- Is my condition mild or severe?
- Should I see a specialist — and if so, what kind?
- What’s the best form of treatment for my SCDS?
- Will my SCDS get worse with age?
Why Choose UPMC for Superior Canal Dehiscence Syndrome Care?
At UPMC, our ear, nose, and throat specialists provide comprehensive care for a wide range of problems, include SCDS.
We offer:
- A team approach — From diagnosis to treatment, our multidisciplinary team of experts offers world-class support. Our ENT doctors, audiologists, speech pathologists, and neurosurgeons provide specialized care for your specific symptoms.
- A wealth of experience — Our hearing and ENT specialists have years of experience in treating the most challenging cases.
- In-house testing — We offer testing for auditory issues including hearing, balance, swallowing, and sleep problems.
