The House-Brackmann score is a standardized clinical grading system used to assess the degree of facial nerve damage. Developed in 1985 by Drs. John W. House and Derald E. Brackmann, it provides a common language for healthcare professionals to classify the severity of facial paralysis. This system allows for an objective way to document a patient’s function and track changes over time.
The Six Grades of Facial Function
The House-Brackmann system is composed of six grades, ranging from normal function to complete paralysis. Grade I signifies normal facial function in all areas, with no discernible weakness. A person with a Grade I score has perfect symmetry at rest and during movement, with full and effortless motion of the forehead, eyes, and mouth.
Grade II indicates a mild dysfunction. At this level, there is still normal tone and symmetry when the face is at rest, but a slight weakness becomes noticeable upon close inspection during movement. A person might have good to moderate forehead movement and can achieve complete eye closure with minimal effort, though a slight asymmetry may be visible when smiling. Very slight, barely perceptible involuntary facial movements, known as synkinesis, may also be present.
Grade III is considered moderate dysfunction. There is an obvious, but not disfiguring, difference between the two sides of the face, and some abnormal, involuntary movements are noticeable. While at rest, the face may still appear symmetrical. However, achieving complete eye closure or a full smile requires significant effort, and forehead movement is diminished.
Grade IV represents a moderately severe dysfunction, where the weakness is obvious and can be disfiguring. A key distinction for this grade is the inability to close the eye completely, alongside an asymmetrical mouth movement with maximum effort and no forehead movement. At this stage, the face has lost its normal symmetry even at rest, and involuntary movements are often more pronounced.
Grade V is classified as severe dysfunction, with only barely perceptible facial motion. The face is asymmetrical at rest, and there is no movement in the forehead. Eye closure is incomplete, and any movement of the mouth is slight and asymmetrical. Grade VI indicates total paralysis, with a complete absence of facial movement on the affected side.
How the Score is Determined
A clinician determines the House-Brackmann score through a careful physical examination of the face. The assessment involves observing the patient’s facial symmetry and muscle tone while the face is at rest. The practitioner looks for any drooping of the eyebrow, corner of the mouth, or other asymmetries that indicate a lack of underlying muscle tone.
Following the observation at rest, the patient is asked to perform a series of specific voluntary movements. These requests include raising the eyebrows to test the frontalis muscle, closing the eyes both gently and tightly to assess the orbicularis oculi muscle, and smiling or showing the teeth to check the zygomaticus muscles. The patient will also be asked to pucker their lips and puff out their cheeks. A significant part of the assessment is noting the presence and severity of synkinesis, as these involuntary linked movements are a factor in distinguishing between the moderate grades.
Conditions Assessed with the Score
The House-Brackmann scale is used across a variety of medical conditions that result in facial paralysis. Its most frequent application is in cases of Bell’s palsy, an idiopathic condition characterized by sudden, temporary facial weakness.
Beyond Bell’s palsy, the grading system is also applied to other causes of facial nerve damage. This includes Ramsay Hunt syndrome, which is caused by a shingles outbreak affecting the facial nerve. It is also used to assess facial function after surgical procedures, such as the removal of an acoustic neuroma or other tumors located near the facial nerve. Additionally, patients who have experienced facial trauma that results in nerve injury are evaluated using this scale.
Prognosis and Recovery Implications
The initial score assigned shortly after the onset of paralysis can offer some insight into the potential for recovery; a lower grade at the outset is often associated with a better prognosis and a faster recovery time. For instance, studies have shown that patients with a score of Grade III or lower tend to recover more quickly than those with higher scores.
The score is not a permanent label but a dynamic measurement that is reassessed at different points during the recovery process. Tracking changes in the grade helps doctors determine if a patient’s condition is improving, staying the same, or worsening, which can inform treatment decisions. This provides an objective measure of progress.