Pain in Left side of neck, hand and leg.

Hello, Its been 6weeks since Im suffering from pain in left side of neck. First pain started from neck and gradually it radiated to left hand(till arm) and left leg(till foot). I've consulted a neurologist who conducted some hammer tests and others and told me that I've BRISK REFLEXES. She suggested for MRI(Brain) and gave tablets Myotop p and Vitamin D3. I've used tablets for 5days but of no use. I didn't understand why doctor suggested for Brain MRI instead of Neck MRI(spine). Not satisfied with this, I've consulted another neurologist. He told I have ISOMETRIC NECK Condition. He also gave similar kind of tablets and suggested for cervical spine MRI. Can you please advise which MRI should be done to treat my condition. My condition: No tingling.. only weakness in left side of neck, left hand,arm,leg. Unable to ride scooty as the pain increases. Also pain increases when I travel.