Parkinson’s disease is a central nervous system disorder that affects movement. Some people with Parkinson’s disease may experience hypomimia, which is known as facial masking or masked face.

Hypomimia affects facial expression, making it difficult to express emotions or use the facial muscles as normal. Basic facial movements, such as raising an eyebrow or smiling, may be difficult.

The symptoms of facial masking can vary from person to person, depending on the severity of the condition. The physical symptoms may cause people to experience other issues, such as difficulty expressing themselves or maintaining interpersonal relationships. Some treatments may improve the range of motion of the muscles.

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Parkinson’s disease is a central nervous system disorder that causes difficulties with movement, balance, and coordination.

It occurs when nerve cells in the brain that produce chemical messengers, such as dopamine and norepinephrine, become damaged.

Losing these chemical messengers impairs functions in the nervous system, causing various symptoms.

The National Institute on Aging notes that people typically first develop symptoms at about the age of 60 years. About 5–10% of cases are early onset, with symptoms presenting before the age of 50 years.

The symptoms of Parkinson’s disease generally begin slowly and worsen over time. As the disease progresses, a person may struggle with everyday skills, such as talking or walking.

Facial masking is one of the most common symptoms of Parkinson’s disease as it progresses. A study in the European Journal of Neurology found that it may occur in up to 70% of people with Parkinson’s disease.

Parkinson’s disease can cause stiffness and slowness in the muscles that a person uses to move around. It can also cause these effects in other muscles, such as the facial muscles.

When the condition affects the facial muscles, it can become difficult to form simple expressions, and a person may struggle to smile, raise the eyebrows, or move the lips.

As a result, a person with Parkinson’s disease may have an expressionless or “masked” face.

Facial masking reduces facial expression, and it can affect communication because humans use facial cues to interpret emotional states and intention while talking.

Other effects of Parkinson’s disease may combine with facial masking to make the issue worse. For example, speech changes, such as speaking at a lower volume, alongside the inability to smile, may falsely indicate sadness.

Facial masking can develop as the loss of motor function progresses. As with other symptoms, it may appear gradually.

There are numbered degrees of severity with this symptom:

  • 0: normal expression and function
  • 1: slight symptoms
  • 2: noticeable loss of facial movement
  • 3: moderate loss of facial movement, present most of the time
  • 4: more severe loss of facial movement or immobilization of the face that is mostly present

It may become difficult for the person to show emotion either spontaneously or upon request. Research in the Journal of the Neurological Sciences reported that the participants with Parkinson’s disease regularly had difficulty showing expression and emotion.

These difficulties get worse as the symptoms progress, and the person may only be able to smile briefly, if at all. The eyebrows and cheeks may also become difficult to move, and blinking may slow down and become infrequent.

Facial masking may come with more severe Parkinson’s symptoms, too.

Researchers have identified a link between facial masking and more severe symptoms of Parkinson’s. In the study, people with facial masking sometimes had severe motor symptoms, such as rigid movement and slow speed when talking and moving. They also had more severe axial and orofacial symptoms, including difficulty swallowing, speech issues, and extra saliva.

Although the study did not find a connection between more severe facial masking and higher cognitive impairment, other studies have reported this link. For instance, research in Frontiers in Neurology found that people with dementia had more significant symptoms of facial masking than those who did not.

The severity of symptoms varies depending on how the condition progresses and responds to treatment.

Facial masking results from Parkinson’s disease. The nerve endings that produce dopamine become damaged or deteriorate. These cells cannot produce chemical messengers, such as dopamine, resulting in diminished control of motor function.

Along with symptoms such as low speaking volume and difficulty forming words, facial masking makes it difficult to communicate effectively.

Research in Parkinson’s Disease notes the social aspect of this issue, pointing out that facial masking can cause stigma and dehumanization because other people can struggle to pick up on emotional or nonverbal cues. It can affect a person’s quality of life by making them feel isolated and lonely.

Some treatments for Parkinson’s disease, such as medications for movement symptoms, should reduce facial masking. Medications such as amantadine (Gocovri) and anticholinergic drugs may reduce involuntary movements and ease muscle rigidity.

The main therapy for Parkinson’s disease is levodopa (Sinemet), which the body uses to make dopamine. A 2020 study found that levodopa improved symptoms of facial masking. However, doctors may recommend combining it with another drug to ease its possible side effects.

Other medications to increase dopamine or other chemicals in the brain include:

  • dopamine agonists
  • catechol-o-methyl transferase (COMT) inhibitors
  • monoamine oxidase-B (MAO-B) inhibitors

Other therapies may also help with facial masking. For example, physical therapy may help with muscle rigidity and tremors.

Another option is speech pathology. A speech and language pathologist can suggest exercises to alleviate symptoms of facial masking and help with other symptoms, such as trouble swallowing.

Lee Silverman voice treatment (LSVT) is a technique that may help people with Parkinson’s speak more clearly or at a louder volume. The process uses voice and articulation exercises, in addition to other behaviors that engage with the act of speaking.

Direct communication may improve the social aspect of facial masking. Explaining the condition and how it affects the face may help friends and family better understand the issue. A person may find that clearly communicating how they are feeling and inviting others to ask questions about their emotional state help improve communication.

Parkinson’s disease has four main symptoms:

  • tremors in the hands, arms, legs, and jaw or head
  • slow movements
  • stiffness in the limbs or torso
  • difficulties with balance and coordination

Other symptoms can include:

The exact symptoms that a person experiences and the rate at which they progress will vary in each case.

The early symptoms tend to be subtle, and some people may mistake them for the normal symptoms of aging. Symptoms may begin on one side of the body or affect just one limb. As the disease progresses, they may affect both sides of the body and become more severe.

Facial masking in Parkinson’s disease can be a troublesome symptom. Alongside physical symptoms, it may affect socializing or relationships if others do not understand the symptoms.

It is advisable to talk with a doctor about possible treatments in each case. Medications for movement should also help with facial masking. Some forms of therapy may help a person increase their range of motion or slow the progression of Parkinson’s disease.