Chapter 31 – Functional facial and tongue movement disorders

Functional movement disorders (FMDs) affecting the eyelids, tongue, and other facial muscles are often underrecognized because their phenomenology has not been fully characterized. Nevertheless, these disorders are more common than previously thought. In this chapter we will discuss the phenomenology as well as the clinical and instrumental diagnosis of facial FMDs. Facial FMDs should be considered when a patient exhibits any combination of the following features: (1) fixed unilateral facial contractions, especially with lower lip, with or without ipsilateral jaw involvement, of maximal severity at onset; (2) inconsistent features such as changes in side and pattern during or between examination; (3) associated somatoform or nonphysiologic sensory or motor findings; (4) reduction or abolition of facial spasm with distraction; (5) response to suggestion or psychotherapy; (6) rapid onset and/or spontaneous remissions; and (7) normal neurologic examination. Supportive features are young age, female gender, and associated medical conditions such as depression, headaches, facial pain, fibromyalgia, or irritable-bowel syndrome. Finally, the differential diagnosis with the organic counterparts will be also addressed, particularly with respect to blepharospasm, oromandibular dystonia, and hemifacial spasm.