your history looks like sinus involvement, but you say your ent doctor has ruled out any pathology. there, so there are two options, either you see some other ent doctor or you can take an opinion from a neurologist.
I hope that helps you ,
as mentioned by you, that your father has undergone the lumbar spine surgery, then what surgery he has undergone for? Also, this is more like the irritation to the sensory and motor functions of the nerve. Also, what were his symptoms before the Surgery?
I will advice to undergo physical...