MRI arranged - need some advice

I saw my doctor today and we have finally got an MRI arranged - private so I have to pay for it, however, it is peace of mind that I can get it done.

I would like to ask though - he did another neuro test - tested my reflexes which were fine, tested my sensation of touch, checked my pupillary reaction to light - all were fine.  He tested my strength and said there was no weakness.

However, he said I have muscle spasm in my neck which could be causing the pain and pins and needles down my arms.  

I would like to know the likelihood of them finding something nasty like a tumor  - I have passed the neuro tests thus far, he does say I have carpal tunnel in one arm (my mouse arm, which I know because i have had pain while typing and numbness in my middle finger joint), I am shaky a lot too especially first thing in the morning.  I have had myoclonic twitching in my neck/head for a couple of months, and a constantly fast heart rate since April but my strange malaise feeling started in Feb.

I have had some brain fog and changes in the strength of my speech, also a little trouble getting food down, however there have been no other characteristic symptoms of nasties.

I would like to know, if anyone can shed some light, the likelihood of it being something nasty.