Neuromuscular Reeducation in Facial Palsy

Original Editor - Claudia Karina

Top Contributors - Claudia Karina, Jess Bell, Wendy Walker, Kim Jackson, Tarina van der Stockt, Claire Knott and Lucinda hampton  

Introduction

The loss or decrease in facial movements, expressions, and functions such as eating, drinking or talking have a negative impact on the psychosocial well-being of people with neuromotor facial disorders, thus affecting all aspects of an individual's quality of life.

The incomplete recovery of a facial disorder, specifically facial palsy, produces sequelae that interfere with facial expressions and, therefore, affect self-esteem and social interaction. The most common are:

• Asymmetry
• Muscle contracture
• Muscular facial weakness
• Synkinesis

It is very important to implement an efficient treatment that reduces the presence of sequelae. Neuromuscular facial re-education (NMR) has been shown to be the most effective treatment because it enables recovery of symmetrical movement in the face and eliminates or reduces problems in the patient's facial functions.

Basic Concepts

Facial Movement System

Facial movements, expressions, and functions are the result of a combination of different muscle contractions.

The facial muscles are small and, unlike skeletal muscles in the rest of the body, have no fascial encasement or tendons binding them directly to the bones. Thus, their origin and insertion are able to move freely. They also lack internal sensory receptors that provide them with intrinsic proprioceptive feedback.

Influence of Emotions on the Rehabilitation Process

Facial expressions result from either:

• Brain activity involving the motor cortex (i.e. cortical behaviour)
  • Usually voluntary
• The activity of a network of subcortical nuclei and parts of the brain-stem (i.e. subcortical behaviour)
  • Usually a reaction to something (e.g. shock, laughter, sneezing)

It has been proposed that because emotions can generate specific facial muscle contractions to achieve an expression (e.g. a smile), it is possible that facial muscle activities may actually create or enhance emotions. It is known that psychological distress affects the relationship between impairment and disability in patients with facial palsy. Thus, the "presence of a marker of positive affect predicts greater response to therapy to increase lip corner movement with smiling in individuals with a facial neuromotor disorder." Thus, it may be beneficial to retrain the muscles that are responsible for certain expressions, rather than focusing on the restoration of facial movement (i.e. an impairment level).

Useful Tools for the Rehabilitation Process

Because there is little intrinsic information about facial muscle posture and movement, it is difficult to achieve a specific voluntarily movements of the facial muscles without some feedback, such as using a mirror or surface EMG biofeedback. This feedback enables the patient to modify muscle activity by increasing or decreasing muscle contraction.

The activation of the facial muscles alone is not, however, sufficient to recover facial expressions. Thus, it is important to incorporate facial exercises that focus on emotions and expressions into a rehabilitation programme - i.e. ask the patient to remember a time when she / he was very happy when practising a smile, in order to activate the "positive affect marker, the orbicularis oculi contraction in association with smiling".

Neuromuscular Facial Re-Education

Neuromuscular facial re-education is the: "process of relearning facial movement using specific and accurate feedback to (1) facilitate facial muscle activity in functional patterns of facial movement and expression and (2) suppress abnormal muscle activity interfering with facial function." It is based on patient education and the use of extrinsic feedback to achieve re-education or physical learning.

As mentioned above, facial muscles lack intrinsic feedback information (i.e. they do not have internal sensory receptors) and a variety of muscle synergies can be created by small contractions of a single muscle. Thus, exercise rehabilitation should be done "delicately through neuroplasticity" in order to reduce the risk of creating abnormal patterns of movement (i.e. synkinesis).

The physiotherapist must educate patients to ensure that they are aware of their motor dysfunction and can recognise the patterns they want to achieve (i.e. the correct pattern of muscle activation) and those they wish to avoid (i.e. abnormal pattern of muscle activation). This may reduce the patient's risk of facial palsy sequelae, particularly when combined with extrinsic biofeedback, which allows patients to modify muscular activity by:

• Increasing muscle activation in muscles that must move, but do not move
• Decreasing muscle activation in muscles that do not have to move, but do move

Evaluation of Treatment Approaches

Evidence supports the use of assessment tools that can guide the physiotherapist in the process of determining the specific goals of treatment for each patient based on the signs and symptoms or sequelae. The most commonly used assessment tools are:

• Facial grading system (FGS)
• Facial disability index (FDI)
• House–Brackmann Scale
• Photoshop method

Treatment Categorisation

Van Swearingen has classified patients with facial neuromotor disorders into four treatment-based categories:

1. Initiation
2. Facilitation
3. Movement control
4. Relaxation

Initiation (i.e. Acute Phase)

Characteristics

• Moderate-marked asymmetry at rest (e.g. drooped face)
• Marked asymmetry with voluntary movement or other spontaneous expressions and functions
• They do not have abnormal movement (i.e. synkinesis)
• Facial functions, such as eye closure / blinking, eating, drinking, talking, are difficult for this group
• Contraction of the affected side very little or absent

Treatment

• Active-assisted exercises
  • The patient starts the movement with the help of his hand and performs small range movements to prevent the unaffected side from acting (i.e. avoid contraction of the unaffected side, so the unaffected side does not over-power the affected side)
• Massage and stretch for affected side
  • Improves blood flow in soft tissue
• Education
  • Explain the usual process of recovery and educate about the signs that indicate recovery

Facilitation (≥ Six Months of Impairment)

Characteristics

• Medium-moderate asymmetry at rest
• The patient can start a movement, but the asymmetry is noticeable if movement continues
• Little or no synkinesis
• Primary movement problems are:
  • Insufficient eye protection to due difficulty closing / maintaining closure
  • Some problems with eating, drinking, and rinsing the mouth - typically mild
• There is usually less psychosocial distress than is apparent during the initiation phase as symptoms are less severe

Treatment

1. Active-assisted exercise: the patient initiates the movement to where the unaffected side does not act. Once the patient manages to improve this, he can perform active-resisted exercise
2. Education: the patient must understand the importance of performing the exercises accurately and must be able to identify the signs that indicate that he is performing abnormal movement patterns to correct them or return to the physiotherapist to avoid reinforcing synkinesis

The patients in the facilitation category initiate facial movement, so active and resistive exercises to increase facial movement excursion are appropriate. Education includes emphasizing the importance of ac- curate exercise practice over quantity and an awareness of signs of some typical abnormal movement patterns (synkinesis) that may develop with the increasing move- ment. The recognition of any synkinetic movement may indicate the need to return for a therapy visit to avoid continued exercise with synkinesis reinforcing undesir- able patterns of facial movement.

Movement control or Group 3

Characteristics

• little asymmetry at rest: generated no longer by weakness but by contraction or retraction of soft tissues
• synkinesis: noticeable involuntary movement of a facial region when performing any movement or facial expression
• abnormal movement patterns during facial functions: difficulty keeping the eye open while talking, yawning or eating and eating biting the inside of the cheek

Treatment

1. Thermotherapy
2. Massage and stretching for facial retraction
3. For short term: create movements and facial expressions without synkinesis. This can be achieved by making small movements or accepting very few synkinetic movements until correct
4. For long-term: guide the patient to re-learn to isolate muscle contractions and thus decrease the activation of abnormal patterns of movement (While the patient relearns the appropriate patterns of activation, he will be reclassified in the facilitation group for their rehabilitation process.)

Relaxation or Group 4

Characteristics

• voluntary movements are produced 50% by the unaffected side; this generates contracture or tension of the soft tissue of the affected side
• marked facial asymmetry at rest but accompanied by spontaneous spasms that occur more frequently and amplitude while there is more effort to perform a movement, due to this fact, the movement will be restricted by the patient as a protection strategy for the next spasm

Treatment

1. Thermotherapy
2. Relaxation exercises: Jacobson's relaxation technique 
3. Alternating rhythmic movements
4. Muscle inhibition techniques: sustained stretching or cross friction massage

Suggested exercises

Due to the multifactorial nature with which facial movements occur, the repetition of maximal movements as a rehabilitation program does not have great efficacy in the recovery of movement patterns in the patient with facial movement disorders.

Evidence suggests performing exercises that keep the center of the face from moving sideways during exercise. In this way the affected side would be integrated during muscular activation without having changes in its length and therefore the simultaneous activation of both facial sides during the facial activity that is requested would be achieved. it also proposed a program at home with 3 to 5 facial centering exercises of 5 to 10 repetitions twice a day, using a biofeedback tool

Exercises to recover mid-cheek lift

Activation of the upper portion of the levator muscle of the lips and orbicular of the lips(zygomatic muscle group); and medial portion of the orbicular muscle of the eyes.

1. suck the cheeks between the teeth
2. wrap your lips
3. make sustained‘‘f’’ sound
4. blowing through a straw

Because these muscles accompany other facial expressions and functions, such as smiling, speech sounds, whining and facial expressions of disgust and perplexity. It is also suggested to practice the following exercises.

1. blowing while eyebrows come together as if thinking
2. blowing and transitioning to a '' fffff '' sound, alternating
3. make the sound '' fffff '' and add a smile
4. blow and add a smile

(smile instruction has to be said to remember a very happy moment to add emotional aspects for expression recovery)

Exercises for recovering the eye closure

The main goal will be to recover the integration and coordination of the downward movement of the eyeball (relaxation of the superior rectus muscle) with the descent of the upper eyelid (relaxation of the levator muscle, innervated by III cranial nerve) with the contraction of the orbicular muscle of the eyes (who inhibits the rectus superior so that the eyeball descends). In a summarized way if the orbicular muscle of the eye contracts, the eyeball will descend together with the eyelid by the action of inhibition on the upper rectus muscle and by relaxation of the levator muscle of the upper eyelid, Therefore, if the orbicular muscle of the eyes is weak, all the synergy is affected and the sign of Bell appears

The proposed strategies for this aim are:

1. look down- close your eyes- continue to look down
2. squint eyes- look down-close eyes