Focal dystonia is a form of dystonia that is limited to one area of the body.
Commonly described forms of focal dystonia include:
Blepharospasm: is characterized by intermittent or sustained eyelid closure. It is caused by involuntary contractions of the muscles around the eyes. It leads to excessive blinking and spasms of eye closure.
Oromandibular Dystonia: or Meige’s syndrome, affects the lower facial and jaw muscles causing involuntary opening, closing or deviation of the jaw. The tongue may be also involved.
Cervical Dystonia: also called spasmodic torticollis or ST, affects the neck muscles leading to abnormal movements of the neck and head. It is the most common form of focal dystonia.
Laryngeal Dystonia: or spasmodic dysphonia affects the vocal cords. There are two forms of laryngeal dystonia. Adductor dysphonia, which is the most common form, causes the voice to have a restricted, strangled or hoarse quality. Abductor dysphonia leads to a breathy, whispering voice.
Limb Dystonia: affects the legs, feet, arms or hands. Upper limb dystonia often appears only when performing a specific task, such as writing (Writer’s Cramp). Other task-specific or occupational dystonias include musician’s dystonia and “the yips” that affect golfers. Highly repetitive and extreme motor precision in music performance are tasks capable of inducing focal action limb dystonia. Muscian’s dystonia can occur in professional musicians using almost any kind of instrument but are more common in piano players.