A Case Series of Isolated Smiling Tremor: What Is the Phenomenology?

Background: Five cases of tremor only upon smiling have been reported where no facial tremor is present at rest, when talking, or with full smile.

Cases: This report highlights four cases of tremor upon partial smiling, discusses the phenomenology of smiling tremor, and reviews the current literature. Four subjects with lower facial tremor present only upon smiling underwent movement disorders evaluation with video.