Parkinson’s disease affects the control of movement throughout the body. This includes the facial muscles that are used to express emotion.

When the movements of the face are rigid or slow to respond, it can result in a mask-like expression that appears to lack emotion. This is known as facial masking, stone face, or Parkinson’s masked face. The scientific term for masked face is hypomimia.

Hypomimia is a common symptom of Parkinson’s disease. It’s included in the Unified Parkinson’s Disease Rating Scale as a characteristic that can range from slight to severe.

The face contains 42 individual muscles. These muscles are used, often unconsciously, to display happiness, sadness, confusion, contentment, and many other emotional states.

If you have Parkinson’s masked face, your facial motor control isn’t working as they usually would. This causes a disconnect between what you’re thinking, saying, or feeling with how your face appears to others.

A person with Parkinson’s masked face may seem uninterested or uncaring, even when the opposite is true. They may also look angry, sad, or completely free of emotion.

Parkinson’s disease can also affect the movements that control your voice, giving you a flat, low monotone. This together with masked face can make it hard to communicate what you’re feeling and thinking.

Parkinson’s disease affects the brain cells that make dopamine. Dopamine helps control muscle movements, and without enough dopamine, the regulation of movement is impaired. This affects the face as well as other movements throughout the body.

Parkinson’s disease can affect the facial movements in several important ways by causing:

  • Rigid, stiff muscles. Muscle stiffness can make it hard or impossible to smile or raise your eyebrows.
  • Bradykinesia (slowed movement). Bradykinesia reduces your visible facial responses. This can make it difficult to accurately show visual responses during a conversation.
  • Fewer autonomic movements. Facial movements, such as blinking, smiling, and laughing can occur involuntarily in response to emotions or other stimuli rather than by deliberate control. These autonomic responses may be significantly impaired in Parkinson’s disease.
  • Apathy. Depression and a lack of emotional responses can affect facial expressions.

Parkinson’s disease is a chronic, progressive condition. There are five different stages of Parkinson’s when certain symptoms may appear or worsen. Masked face can manifest as an early symptom in stage 1.

Masked face severity can progress and worsen as Parkinson’s takes hold. According to the Unified Parkinson’s Disease Rating Scale, masked face symptoms are categorized from slight to severe. Each masked face stage includes the symptoms of the previous stages, plus new ones. Here is a breakdown of each stage:

  • Slight. In this stage, you may blink less often than usual.
  • Mild. This stage includes minimal masked facies (the distinctive facial expression associated with a particular medical condition) and less movement in the lower face, including mouth movements and spontaneous smiling. People with mild hypomimia still have the ability to keep their lips closed.
  • Moderate. The moderate stage has an increase in masked facies. The lips are held in a parted position for some of the time when the mouth is at rest.
  • Severe. There’s an increase in masked facies, and the lips are parted most of the time when the mouth is at rest.

There are no specific medications for treating masked face. However, treatments for Parkinson’s disease can help reduce masked face, as well as other symptoms of this condition.

Some medications used to treat Parkinson’s disease focus on increasing dopamine activity in the brain. Some examples of these medications include carbidopa and levodopa.

Levodopa is one of the main medications used to treat Parkinson’s. It is a natural chemical that converts to dopamine in the brain. It is often paired with carbidopa, which helps levodopa work more efficiency and prevents certain side effects like nausea and vomiting.

Together, carbidopa-levodopa can be given as an:

  • oral medication (Levodopa or Lodosyn)
  • inhalant (Inbrija)
  • infusion that is administered through a feeding tube directly into the small intestine (Duopa)

Other medications for rigidity, as well as facial exercises and physical therapy, may also be recommended to treat masked face.

Participating in activities that you love or feel passionate about may help improve your facial expressions. This includes creative pursuits, such as singing, dancing, or watching movies and plays.

Masked face (hypomimia) is a common symptom of Parkinson’s disease. Masked face may start as early as stage 1 of this disease. It may get progressively more pronounced as Parkinson’s continues to worsen.

There’s no specific treatment for masked face. However, Parkinson’s medications, such as those that enhance dopamine levels in the brain, can help with this symptom. Participating in creative and physical activities can also help.