I suspect there are something else in energy drinks that could have dramatic effects on one's brain.
I usually drink one or two cups of coffee per day. I could drink more. After 7~8 cups of espresso, my hands start uncontrollably shaking, and I feel a little agitated. Those are all the symptoms I feel. Energy drinks is a completely different story. After two cans, I would have a big headache. I experimented a few times [call me crazy :)]. Every time, the headache came. So it was not a fluke, and most probably it was not caused by other factors.
I usually drink one or two cups of coffee per day. I could drink more. After 7~8 cups of espresso, my hands start uncontrollably shaking, and I feel a little agitated. Those are all the symptoms I feel. Energy drinks is a completely different story. After two cans, I would have a big headache. I experimented a few times [call me crazy :)]. Every time, the headache came. So it was not a fluke, and most probably it was not caused by other factors.