Glabellar Reflex or Myerson's sign

In this medical video: This 72-year-old patient was unable to resist blinking when we tapped on the glabella. This is the glabellar reflex or Myerson's sign . It is often an early sign of Parkinson's disease, but can also be seen in early dementia as well as other progressive neurologic illness. Note the left (i.e., asymmetrical) hand resting tremor.