Minor’s syndrome (or superior semicircular canal dehiscence syndrome) is a rare otoneurological disease which affects the upper part of the inner ear and which may require an operation.
What is Minor’s syndrome?
Minor’s syndrome is a “young disease” since it was first described in 1998 by the American surgeon Lloyd Minor. “This is a disease that affects functioning affecting the vestibular and cochlear systemMore precisely, the superior semicircular canalsituated in the highest part of the inner ear, below the meninge“, explains Professor Mathieu Marx, Otologist and Otoneurosurgeon at the Pierre-Paul Riquet Hospital, Toulouse University Hospital. It is characterized by a thinning or absence of bony coverage of the roof of the superior canal (dehiscence) covering this superior semicircular canal. This disease can be unilaterali.e. only touching one ear, or bilateral, that is to say both. It may also start out one-sided and, over time, affect the other ear.
What are the symptoms of an inner ear problem?
If the disease can be asymptomatic for several yearsit can also cause many very disabling ailments on a daily basis, the intensity of which can vary from one person to another, but also from one day to the next. Among these we find:
► Hearing symptoms:
- An autophony: that is to say an abnormal perception of body sounds. “People who suffer from it complain, for example, to hear, in their skulls, their eyes moving, the cracking of their necks, the beating of their heart, their swallowing, sometimes their digestion, the sound of their footsteps while walking, their voice resonates in their head like in a cathedral…”, describes Marie-Laure Chavannes, Co-President of the SDCS Minor Association.
- A mild hearing loss but sometimes more significant (transmission deafness)
- Of the pulsatile tinnitus or permanent and/or hyperacusis or hearing hypersensitivity
- Of the sensations of pressure in the ear
► Vestibular symptoms:
- Of the dizziness or unsteadinessnotably the Tullio phenomenon: “it is a dizziness triggered by loud sounds, explains Professor Marx, accompanied by nausea, falls, discomfort or even loss of consciousness“
- Feelings of being drunk
- Involuntary eye movements:Mainly oscillopsia and nystagmus, i.e. the impression that the visual environment around is not stable“, specifies Professor Marx.
► Other symptoms:
- Great fatigue
- Concentration problems
- Memory problems
- Prioritization problems
- Brain fog
- Headaches/migraines
- Intense neck pain
- Great sensitivity to light…
What is the cause of Minor’s syndrome?
The causes of its appearance are still poorly understood.
The ear is open to the middle ear by two windows, one called the “round window”, the other “oval window”, through which sound enters and leaves. “Schematically, the sound penetrates the ear canal, vibrates the eardrum and the ossicles, which transmit these vibrations to a very thin membrane, called “oval window”, in the inner ear, explains Professor Marx. The vibrations pass through the cochlea to the “round window”. This is how hearing works. Only, in the case of Minor syndrome, the dehiscence creates a “third window” which allows part of the sound to exit towards the meninge and the brain, passing in particular through the channels responsible for the balance“. The causes of its appearance are still poorly understood. “The main hypothesis is that there is in these patients a constitutive fragility of the canalwith a dehiscence which manifests following a second event (head trauma, childbirth, etc.), specifies our expert. Another hypothesis would be that the weight and pulsation of the brain wears out the rock with age and time“.
What tests are needed to make the diagnosis?
This is the hardest part: doctors are poorly trained in this rare disease, patients can wander for years before finally being taken into care. “For some, more than 10 years passed between the start of symptoms and diagnosis.“, specifies Marie Cueff, Co-President of the SDCS Minor Association. To establish the diagnosis of Minor Syndrome, it is first necessary to eliminate other causes: neurological in particular, and other pathologies such as Ménière’s disease or otosclerosis. Then questioning specifies the symptoms suffered by the patient and directs the ENT doctor. “A hearing test detailed is carried out in order to detect possible hearing loss associated with too good perception of internal sounds via bone, adds Dr. Marx. A scanner of the rocks in sections fine, or cone beam, allows you to visualize the state of the rocks and the presence of the opening of the superior semicircular canal under the brain. Finally, different functional exploration tests can also be useful, in particular the PEO (Otolith myogenic evoked potentials), whose analysis of lowered thresholds confirms the presence of a third window in the patient“.
► Medicines are sometimes prescribed to reduce the severity of disorders, such as antivertiginous drugs, diuretics, antimigraine drugs and anxiolytics. However, the most effective remedy is surgical. There are two possible interventions, carried out under general anesthesia, chosen according to the presence of other associated fragilities, and the location of the dehiscence on the superior semicircular canal.
► Surgery via the suprapetrous route. It consists of closing the opening leading to the brain. “To do this, it requires an incision above the ear and the creation of a cranial bony flap of almost 10 cm vertically to the external ear canal, explains Professor Marx. It is thanks to this flap that the brain can be lifted, to reach the area concerned and to fill the dehiscence with small fragments of muscle and/or “bone pâté”, made by the surgeon with the brain’s own tissues and bones. patient“.
► Transmastoid surgery. “Thanks to an opening behind the ear, it consists of reaming the mastoid to reach and fill each of the two branches of the canal with a plugging, using a “bone pâté”.
► Subsequently vestibular rehabilitation is necessary with a specialized physiotherapist. It consists of restoring the balance between vision, the balance organ located in the inner ear and the feet (proprioception). “In addition, the symptoms cause great anxiety, psychologist follow-up may be essential.“, recommends Marie Cueff.
When to consider the operation?
- When symptoms become so debilitating on a daily basis that they disrupt quality of life
- When social isolation is important
- When they prevent maintaining employment, traveling, driving or having a personal, intimate and family life.
Can you fly with Minor syndrome?
“There are no contraindications to air travel, but the presence of the third window nevertheless constitutes a theoretical vulnerability factor, that is to say, travel can aggravate the condition”specifies Professor Marx.
Thanks to Prof. Mathieu Marx, Otologist and Otoneurosurgeon at the Pierre-Paul Riquet Hospital, Toulouse University Hospital, to Marie Laure Chavannes and Marie Cueff, Co-Presidents of theSDCS Minor Association