What is a characteristic facial appearance of a patient with Myasthenia Gravis?

The characteristic facial appearance of a patient with Myasthenia Gravis often includes a "mask-like" expression, sometimes described as a "snarling smile." This occurs due to muscular weakness affecting the facial muscles, leading to a reduction in facial expressions. In Myasthenia Gravis, the immune system mistakenly attacks the communication between nerves and muscles, which can affect the muscles of the face. This results in the inability to sustain facial expressions, giving the appearance of a static or "masked" face that can sometimes seem to perpetually smile or snarl due to muscle weakness around the mouth.

While some patients may exhibit other features such as drooping eyelids or facial asymmetry, the hallmark appearance involves the overall muted facial expression, which can manifest in a way that might be described as "snarling." This distinctive characteristic is an important clinical observation that can aid in the diagnosis of Myasthenia Gravis.