Friday, August 22, 2014
MG and hyperacusis
I`m a 21 year old male and the neurologist recently told me that i may have myasthenia gravis. I`ve been suffering from feeling off-balance for 10 months and being exhausted sometimes and my symptoms used to randomly disappear for a day,two or even weeks and come back. my hearing tests and caloric testing were completely normal.
I notice that i`m very sensitive to sounds especially from the phone. Is there muscles in the ear that get affected from MG and possibly cause that?
There are muscles in the ear that are responsible for dampening sound (the stepedius muscle), but that would be very selective involvement to just involve this little muscle. Myasthenia could theoretically affect the muscles of the ear, like the stapedius and the tensor tympani, that regulate how much sound the eardrum can process. Hyperacussis is possible, although I have never heard a patient complain of this in my practice. Hearing loss can also occur in the context of myasthenia due to muscle weakness that allows for middle ear fluid collection through eustachian tube dysfunction. Fatigue may be a symptom of myasthenia. Imbalance is also usually not a symptom of myasthenia without leg weakness.
Robert W Neel, IV, MD
Assistant Professor of Neurology
College of Medicine
University of Cincinnati