Patient received his MMR and Varivax vaccination this morning. Within minutes of receiving the vaccination, patient apparently did well and got up to leave. As he was walking out mom reports that she noticed his eyes were rolled back in his head and he went down.  He fell backwards on the floor in the exam room.  The nurse was present within seconds herself as she was still just about leaving the room when this occurred.  She states that she noticed him lying on the floor and his extremities were a little stiff. However, within yet another 20 seconds I was in the room 2. By this time, he was awake. He looked a little confused, but he was awake, and he responded appropriately. His pulse ox was maintained at 98 to 99% on room air. Blood pressure was initially high at 130/80 but this then settled down to 112/78.  He was alert and aware. He recognized his mom. He responded appropriately when I asked to see if he could get up. Patient not just sat up but got all the way up to standing and walked over to his mom and sat on the bench seat.  He then had a juice box without any difficulty. Blood sugars were not obtained. No labs were done. Patient came around and continued to act his normal self thereafter. I did discuss with mom father, and it appears patient had not had any breakfast before coming into the clinic this morning.  She states that he was on an empty stomach. Also, patient was able to explain to mom and described that everything that somewhat dark and black in front of him before he fell down.  Thus, based on this it sounds more like he passes out phenomena than his seizure.  In any case mom noticed very concerned about the possibility of seizure as she witnessed this stiffening of his arms. Also, she witnessed his eyes rolling back. This I have placed a referral for patient to be seen by neurology. At this time, I reassured mom that this could very well be a vaccination response to a particular vaccine or perhaps it was a pain effect or passing out.  However, mom states that patient does have high pain threshold. Regardless due to the seizure-like phenomena that was witnessed, I have elected to send patient to neurology as well for evaluation. Meanwhile I have advised that patient can go home but we will do follow-up calls today to ensure he is doing fine. Advised to call us if he should develop vomiting or emergence of any other new symptoms or concerns. Mom is to monitor him closely for the rest of the day. Mom agrees.  Thank you. 1 mom was out of the car with the patient he apparently had one episode of emesis went to a little pale and said he could not walk anymore. Thus, mom turned around and brought him right back into the clinic.  This time I evaluated him again. He answers questions appropriately. And he cried stating he was scared.  He said he felt he could not walk. Thus, at this time considering he has had the head injury with falling backwards on the clinic for, and the fact that he has had one episode of emesis, I elected to send him by nonemergent ambulance to the hospital for further evaluation. Patient has been sent to the hospital and I have called the Hospital intake stop advising them of the incident today that led to the events that followed and felt that he needed further evaluation especially considering the head injury and the vomiting now. Mom agrees with this plan as well.  Thank you