Gege, I'm not sure what you mean by 'up and down shaking of my left leg'. You mean you 'bounce' your leg?
Now that I think about it, I had a tic with an eye before my Parkinson's diagnosis. It's since quit and I never thought a thing about it until your post. I was dx with PD in 2001. Some of my initial symptoms were 'bouncing' my right leg plus clenching and releasing my toes on my right foot. I could make either quit, but sure enough it would gradually start again.
If you have concerns about PD, I would strongly urge you to see a movement disorder specialist (MDS) - a neurologist who specializes in movement disorders like Parkinson's disease. There is no definitive test for PD. It's basically a matter of eliminating things like stroke, brain tumor, a myriad of things that can cause tremor (if you have tremor). Then it becomes a clinical diagnosis - meaning the neuro basically observes certain physical things and if you meet the criteria for X out of Y, then the diagnosis is PD. Ex., people with PD tend to not swing their arm on the affected side as much - or they may slightly 'drag' a foot. An MDS knows what to look for.
Hope this helps, lizzy4451