Hemifacial spasm (HFS) is a rare movement disorder that causes involuntary muscle contractions on one side of the face. It typically starts with painless but annoying twitching around one eye. Over ...

Hemifacial spasms happen when a blood vessel puts excess pressure on a facial nerve, per the National Institute of Neurological Disorders and Stroke (NINDS). They can also be caused by external nerve ...

Hemifacial spasm affects muscles on one side of the face. Laryngeal dystonia causes spasms in the voice box (larynx). It can affect voice quality, leading to hoarseness or interruptions in sound. It ...