Various head issues

Some background
Around 4 years ago i had a large tumor removed from inside my spinal column. It was located approx between my shoulderblades, was benign and was removed successfully. I have been having yearly MRI scans and my surgeon says its not coming back and healing very well.

Two years after this i had a gastric bypass to help lose weight i had put on because i couldn't exercise or even walk any distance for around 5-6 years (yes it took them that long to diagnose my tumor).

I have to have a B12 injection every three months because of the bypass surgery. I also need a testosterone injection every three months because of an issue with my pituitary gland.

Medication i currently take:
Oxycontin 40mg twice a day.
Pregabalin 150mg Twice a day.
Duloxetine 60mg twice a day.
Omeprazole 20mg once a day.
Forceval multivitamin/mineral supplement (for gastric bypass)

Current Issue
Recently (past 12 months) I have had various issues with my head.
Bad vision my eyes are always crossing giving me double vision which i can correct be concentrating. I am also seeing occasional flashes or i often thing something has gone by me very quickly in my peripheral vision.

I have bad ringing in my ears, which i assumed was tinnitus but my left ear often vibrates painfully when people speak.

The back of my head where it connects to my neck is incredibly stiff and i often have a lot of pain from there - the ache is constant.

Throat. I am always losing my voice when trying to have conversations - people have commented on it several times. My throat will feel incredibly sore but soon is okay again, I am assuming this has something to do with my acid reflux which i suffer from badly (i often wake up unable to breath with water pouring out of my nose, or i can feel liquid in my breathing (when i fully exhale i can hear liquid bubbling) this happens maybe once a month.

I had a few MRI Scans from various hospital departments (Ear, Nose & Throat etc) One of the scans was picked up by a endocrinologist because it showed dark spots on my brain, he noted that while they were expected at my current age (48) there seemed to be more than usual and because of my previous tumour he thought it should be looked into.

This brings me to my question here - could someone tell me what the following letter actually means;

Quote:

I am in receipt of Ian's MRI of the brain which only showed some small vessel ischaemic changes without any significant abnormality. He also had an MRA which has only shown an abnormal variant end of the left vertebral artery and Hyperplastic right vertebral artery. No other significant abnormality has been reported. I have already reffed him on to various colleagues and I have not offered him another appointment. Should you wish for me to see him again, do feel free to refer him back.

I have no idea what those two artery items are, could someone tell me? Of course I will go see my GP asap but I would like some idea of whats going on before i meet him.

Thank you!

Various head issues