How to recognize the signs of parkinson's disease<br>Notice any shaking or twitching. When you think of parkinson's disease, the first thing to come to mind may be tremors. These can occur anywhere on the body: a shaking finger or leg, a twitching eye, a trembling lip or chin, etc.
Ataxia is always a sign of Parkinson's disease. 
Ataxia is another word for muscle twitching, and the passage doesn't say whether or not that is always a sign of Parkinson's disease. 
( z1 signal :ARG0 ( z2 ataxia ) :ARG1 ( z3 disease :name ( z4 name :op "Parkinson's" :op "Disease" ) ) :time ( z5 always ) )