I’ve had Bell’s palsy and though the condition resolved, I still notice some residual symptoms. It would bear to keep this in mind especially when diving.
When I first developed the condition, I was surprised to speak to so many people who volunteered that they had suffered this problem and recovered without any outward signs. Briefly the condition is a facial weakness/paralysis that comes on spontaneously. The cause is really unknown. In my case it occurred on a weekend and for a moment I entertained the thought of a stroke. After some tense weeks the facial weakness resolved. At this point my motor strength is full and the face is symmetrical except when I am fatigued. Then there is enough residual to notice an asymmetry.
As to diving, I began lessons and qualified as an advanced open water diver in the PADI course over the summer. As I became more experienced I noticed that there were problems clearing/equalizing my left ear. Presently I hold my nose and after the right side opens, I quickly swallow and the left side then opens up. After the dive, I have the feeling of fullness and increased bone conduction which subtly affects my hearing. I have puzzled over this and cleaned my ears to no avail. Finally I looked up the anatomy and realize that the Eustachian tube opens by a muscle. That same muscle is controlled by the facial nerve (Bell’s palsy). So it is the mild subtle residual weakness in the nerve which makes the left side equalize more slowly.
A word to all divers who have had Bell’s palsy, perhaps this will reassure and allow you to compensate better. It took a while for me to reach this “aha!!” moment.