There are various potential etiologies, ranging from neurologic to psychiatric to cardiovascular. You could be experiencing a simple partial (focal) seizure. Stress is the most common trigger. Others include fever/infection, fatigue, dehydration, caffeine, alcohol, medications, and flashing lights (e.g., playing video games). Many times, these small seizures are a warning that a bigger seizure is coming. Hence, it is important that you see your doctor for further workup and evaluation. This may include laboratory tests (e.g., electrolytes, including serum glucose) as well as other tests (e.g., EEG).
Hi, Brad. It could be from what is well known enough to even be in Urban Dictionary:
"gamers twitch
Involuntary, muscle spasm particularly in the hand, arm, or leg caused by quick movements. Generally results from playing too many video games."
https://www.urbandictionary.com/define.php?term=gamers%20twitch
Don't freak out, some people like to mention all the worst things that can happen. But the above is probably where the problem is. There is currently an epidemic of neck, back. arm and hand problems being caused by the constant use of video games, cell phones, and computers. To use them often requires terrible postures, such as neck craning, and if you repeat them a lot you can get problems. Go see your doc if you're concerned enough, but try not playing video games for a week and if it goes away you'll have your answer.