My father is 58 years old, and for some time now he has shown signs of:'
-ringing in ears
These symptoms have only worsened and progressed farther over the past few years, but whenever my dad visits a doctor the doctor only says, "oh, you're fine." I was thinking it could be spinal muscular atrophy, bulbospinal muscular atrohy or amyotropic lateral sclerosis, but at my request my father was tested for those diseases and the results were negative.
Is there a way an MRI or other test would fail to detect those diseases, or are there any other possible diagnosis I could be missing?