We've recently learned (confirmed by MRI) that my 2-year old son has Mondini Dyspasia in his right ear (a partially formed cochlea) and appears to have little to no hearing capability in that ear. His left ear appears to have a normal inner ear structure and displays a normal range of hearing.
While this is (obviously) something that is far in the future, I was wondering what current guidelines would suggest for him becoming a scuba diver.
Hi, BlueEyes... thanks for writing!
This is actually a fairly complex question, with no simple answer. Also, in some cases multiple congenital anomalies or syndromes may be present in the same patient, so there may be aspects of his case that are not solely related to the ear. Of course, anything I say here is a general comment and should only be read in the context of background information. Please make sure that you run all this by a pediatric ENT doctor or an otologist who has had the opportunity to examine your son.
There are several relevant issues, but remember that the Mondini dysplasia is considered a congenital anomaly of the inner ear, not the middle ear - the part of the ear that is typically associated with diving related barotrauma (injuries due to unequalized pressure changes). It is the middle ear (space behind the eardrum) that needs to be continually equalized to prevent injury. HOWEVER, inner ear injury can happen during diving, due to either a fistula (opening between the inner ear and the middle ear space), or inner ear DCS.
So the question is, is there a higher chance of a perilymph fistula (PLF, see other threads here for more about that) in the presence of a Mondini dysplasia? I don't believe that is well known, but there is at least some evidence to suggest that this may be the case. These children do have a higher incidence of leakage of cerebrospinal fluid during inner ear surgery (such as cochlear implantation), although that is a different type condition.
Also, there is the question of what his hearing level is, as Mondini patients have a wide range of hearing levels, which may change over time. If the ear is completely non-functional (which it sounds like is the case) with no residual hearing, there would be less of a concern about future injury than with an ear that has some good hearing reserve. While I haven't found any reports of a patient with a Mondini malformation and fairly good hearing experiencing worsening hearing levels with barotrauma, this can happen with other types of malformations such as the large vestibular aqueduct syndrome (LVAS). Furthermore, some patients with Mondini also have LVAS.
FURTHERMORE, there is the question of vertigo. Again, I can't tell you anything specific about your son, but even in a non-hearing ear, a fistula could lead to an episode of vertigo underwater, with all of the problems that that might entail from a dive safety point of view...
Also, even if there is no hearing in the bad ear and normal hearing on the other side, many people err on the side of caution in this situation, and avoid any activity with any risk of injury to the normal ear (such as diving), since there is less of a margin of safety. If you were to dive and go deaf in one ear, that would be a problem, but not as much as if your son were to lose hearing in his only hearing ear.
So while I'm sorry that I can't give you a definitive answer, you would probably be best not to focus on his diving with you at this point and re-evaluate the situation once he is older and that is more of a consideration. You probably don't want him growing up to expect to dive and then be disappointed! Maybe best to downplay your diving enthusiasm around him for now (I know, that's hard to do
), and then "play it by ear" in the future
I hope that this helps
feel free to PM me if you have other questions you would rather not post here.
Best,
Mike
