what if C5-C6 disks got reduction?

Hi,

My is 62 yrs old. He is suffering from head rotation and feeling like eyes rotaion. Feeling like rotation in stomach. And he gets 1 or 2 vomitings also. When he bends down which causes compression on spinal disks, he gets this kind of problem. He got it 2 years ago also, and cured by some medicines that time. It came again. So i rushed him to hospital where he gets treatment for diabetic monthly and there he got X-ray for neck and it says,

C5 and C6 disks got reduction.
Rest are normal.

So he was suggested to consult a nuero surgen and he prescribed some medicins.
They gave him relief for 5days.
He got it again now with the same problems.

Could any body explain what kind of problem it is. how to go forward?

Thanks,
Ganesh