My cat is exhibiting very worrisome behavior over the past week. His right lip is getting stuck up randomly with all the whiskers on that side spread out. He's trying desperately to fix it by shaking his head violently and losing his balance in the process, pawing at the right side of his face and flinching his tongue towards the right lip. He also seems just overall weaker/lethargic, though he is eating all his food and drinking lots of water.
I took him to the vet and had his blood work and urine analysis done. Vet said nothing is wrong with his teeth (he's had his teeth cleaned under anesthesia 4 months ago, and part of his gum fixed where it had come loose). Some things came back higher than normal: liver enzyme and BUN, and HCT was lower than 4 months ago, though still in range.
Any ideas what is wrong, or what to do? Vet said to wait a month and redo his bloodwork and urine analysis to see progression,and to monitor for any other signs of neurological problems but it's breaking my heart to see him struggling when his lip gets stuck
Thank you for your help!