25 yo male with increasing neck pain, perceived atrophy in neck & arms accompanied by twitching (fasciculations) perceived weakness, no clinical weakness. clean mri of c-spine & brain. negative for syrinx, vitamin e, b12, b6, b1, d, mag all normal?

For peace of mind and reassurance consult a neurologist with a special interest in neuromuscular disorders at a department of neurology at a university hospital near you. Bring records of all imaging & lab results.

Seek a second opinion from a Neuromuscular Specialist. Have an EMG study of your neck and arms if not done previously. Many conditions have been ruled out, but other possibilities need consideration.