Thanks for the thorough reply my friend. Are you a neurologist? You seem very knowledgeable in this matter.

I agree trouble concentrating and mood swings is possible to not be related, however since last year ALL my symptoms have become worse including those 2. The tingling is the worst. It tingles so bad that i cant speak properly without feeling so uncomfortable and out of breath.
My movements are random. I had a head tremor, hand tremor, facial tics, leg shaking, stomach jerking. (All this NOT independent of one another, meaning some come and go or all happens at same phase). Moreover, this movements serve a purpose, to REDUCE the tingling. I can stay still, but the tingling is maximum.

I went to 6 because i wasn't satisfied with the diagnosis given. I do my own self-check online on message boards, medical websites and youtube. My symptoms don't correlate. 3 of the neurologists say I have motor tics disorder, but that doesn't explain
1. my intense tingling throughout my body
2. my head tremor and leg shaking
3. Trouble speaking.... Becoming observably worse.

The last one I seen, he is a renowned movement disorder specialist, Dr Lim Shen Yang, he diagnosed me with cervical dystonia because at that time, my head tremor was the most prevalent, but also wasn't 100% sure because
1. tingling in other parts of my body
2. I can hold the movements for longer than 2 minutes.
He tried botox injection to reduce it. It reduced my head movement, but the tingling and other movements still there.

pls check this out about people's experience with mercury poisoning. They report experiencing neurological symptoms + the cognitive defects I mentioned. https://www.quora.com/What-does-it-feel-lik...rcury-poisoning