Hypomimia in Parkinson's Disease: Understanding Facial Expression Changes

In Parkinson's disease, the control of muscle movements is lost because of a lack of the neurotransmitter (chemical messenger) dopamine. This can affect muscle movement in the face, a collection of symptoms known as hypomimia.

Identification

• Hypomimia is also known as facial masking, according to the Michael J. Fox Foundation for Parkinson's Research. It refers to the face being less expressive than usual.

Features

• Hypomimia is, according to the Mayo Clinic, part of the symptoms caused by the loss of so-called automatic movements. In the face, these include blinking and smiling; others include swinging the arms while walking.

Effects

• According to Merck Manuals, people with hypomimia may eventually develop a blank, staring facial expression, with the mouth open and the eyes unblinking.

Considerations

• Merck Manuals cautions that hypomimia can either be confused with depression or, conversely, cause people to overlook depression in a Parkinson's sufferer.

Other Facial Symptoms

• Medline Plus reports that other symptoms affecting the facial region may include trouble swallowing, drooling and tremor, along with changes in speech.