Does a intermittent body twitching for several months a symptoms of brain tumor or seizure or by now other serious symptoms like numbness must occur

Ask your doctor: Twitching could be a brain tumor yes but that's probably the bad thing infections nutrition deficiencies fatigue nervousness nerve compression and on and on check with your doctor soon.

?Seizures?: I'm not sure what you are describing as intermittent body twitching, but perhaps these are seizures. If they are, then they might indeed be an indication of a brain tumor. However they don't sound like typical seizures and might be something else, related to another type of brain disease. See your doctors and have a thorough neurological workup.