Is hearing loss multifactorial and does superior semicircular canal dehiscence be a contributing factor?
User rating for this question
Hello Doctor, thank you taking my question. About a year ago my two year old grandchild was diagnosed with hearing loss. What started as a mild hearing loss on the left ear at birth is now a severe and permanent loss in both ears. A genetic link was found and a CT scan also revealed semi circular canal dehiscence in both ears. She now wears hearing aids. My question is, can the findings of the superior semicircular canal dehiscence be a contributing factor to the hearing loss, it was never explored further by her ENT. Yes, the genetic factor exists, there is no denying this. But I have also read that sometimes conditions such as hearing loss are caused by a combination of genetic mutations and non-genetic factors. I believe these conditions are said to be “multifactorial”. I have read that sometimes, it is not possible to tell if a mutation is the cause of a condition, or just a coincidence. Apparently, people who have multifactorial conditions often are born into families with no other affected members, which is the case for us. Thank you for your time and attention, XXXXXXX
Posted Tue, 7 Jan 2014 in Ear, Nose and Throat Problems
Answered by Dr. Sriram Nathan 1 hour later
Brief Answer: Hearing loss is always multifactorial Detailed Answer: hello and welcome to health care magic, I am Dr Sriram Nathan, an ENT surgeon and Let me complement you in being so involved and having a good understanding on the problem facing your grandchild. You are right in assuming that hearing loss is multifactorial. In fact in any case of hearing loss, although the insult may be one or two, the factors causing the hearing loss may be many. A Bony dehiscence of the superior semicircular canals can cause hearing loss even in adults along with vertigo and in fact can also explain the initial findings as seen in your grand child such as the conductive hearing loss and also the OAE results. In many cases a mild conductive hearing loss can lead to severe hearing loss which might even happened in your grand child. In addition to the genetic factor which could have accelerated the process of course. Now you must also understand that this is just a possibility, no one can concretely say that this is what happened. Everyone reacts to situations in their own different way and there is no maths in human body. Even a mutation even if it present in no way means that the person will be affected by a problem. This is what we call the genotype and phenotype which essentially means that though if you have a mutation there is a risk, it is not necessary that you will develop the problem associated with the mutation. The development of problem associated with the mutation depends on several factors which are the interplay between the agent (mutation), host (our body) and environment (both internal and external). Hope what I am trying to explain is clear to you a little. What I am further trying to explain is that the Bony dehiscence of the superior semicircular canals could have played a role in the present situation of your grand child but no one can be sure of the exact role and the extent of the same. In addition to this since you have diagnosed this condition you must also consider these: 1. The dehiscence may cause vertigo or further problems in the future so you must have a follow up with scans every year and manage whenever necessary 2. In your grandchild's situation I would advice you to reconsider taking up cochlear implantation which is the best bet for her recovery of hearing loss and also for her future language development. 3. If the hearing does not get better you must know that the language also will not develop so you must always make sure she gets the best in aids and always wear them so that the at least some language development can be salvaged 4. The investigation for cause may turn out to be an exercise in futility but it is important for proper treatment and also to prevent such mishaps in future. Hope this has shed some light in your plight and If you have any more doubts you can always get back to me regards Dr Sriram Nathan
Follow-up: Is hearing loss multifactorial and does superior semicircular canal dehiscence be a contributing factor? 16 hours later
Thank Dr XXXXXXX for your quick reply. In your professional experience have you seen this type of hearing loss improve? Is there a chance that the semi circular dehiscence would heal itself therefore improve the hearing loss? Any additional help or advice would be greatly appreciated. I know you suggested cochlear implantation but my grandmotherly instinct tell me that there is a better way. She is doing well with her hearing aids and has a vocabulary of about 40-45 words at two years of age, although she doesn't always pronounce them correctly, but that could partly be her young age. Her comprehension is very good and follows instructions really well. Thanks again and Happy Holidays!
Answered by Dr. Sriram Nathan 4 hours later
hello again, I do not want to raise your hope much but if the nerves have got weakened then it is unlikely that they will improve. like I mentioned before, the dehiscence may or may not have a relation to her hearing loss and in many cases may not even effect her directly. It is known more to cause giddines rather than hearing loss. I have seen thousands of kids with such loss but unfortunately never seen them improve on thier own but my word is not absolute anyway. There is always hope but as a doctor I would again impress upon you the benefits of cochlear implant as your grand child can have a better shot at language development because of this. Hope you would reconsider as hearing aids alone will never reach the efficacy of implants. apart from implant you must constantly use the aids and always try to talk to her and give extra attention to her language development. There is usually no force stronger than will right? Try also to teach her sign and lip reading and make sure she stays otherwise sharp and keen. Hope this helps and hope your perseverance bears fruit happy holidays to you too regards Dr Sriram Nathan