DR RV ANAND SENIOR NEUROLOGIST SAI NEUROCLINIC MANDAVELI HOW IS PARKINSON DISEASE FIRST IDENTIFIED? person may notice decrease in size of letters while writing.their signatures may not be legible.somtimes it is associated with shaking..friends may notice slowness in walking, decreased volume of speech.they may also speak fast. they can have increased salivation.thier face can lack expression. some people will have behavioural disturbances in sleep several years before the onset of parkinson disease.it is called as REM SLEEP BEHAVIOURAL DISORDER