What could cause internal tremors above the elbow on the inner part of my left arm? i have had benign fasciculations many times before but this is different. it reoccurs every couple of min in the same spot and is not visible like external tremors?

The cause of internal tremors is often elusive but Parkinson's disease, multiple sclerosis and essential tremor are the most mentioned possible causes. Since your internal tremor remains very localized & you have no other neurological symptoms, I doubt a systemic neurological disorder & suspect an irritable superficial nerve is the cause. You could consult a neurologist for evaluation & advice.