Are you on cycle? If so what are you using? There are numerous things that can cause these problems from just as simple as not eating correctly to a leasion on the brain. If you have had no trauma i.e.(bumped head, car accident etc.) and you are off cycle then I would not be to concerned unless the problem keeps occurring... If you are on cycle you may have some bad shit. You may just not be eating right or you could have strained a neck muscle. Also if you are adding muscle in areas not used to having muscle you may be pinching a vein or artery that supplies blood to the brain. All in all go to the doc better to be safe then sorry.
AREA 51, HE IS I, AND I AM HIM!