Dystonia are stiff, involuntary postures that may occur spontaneously or with intention. They may be focal (eg, blepharospasm, torticollis, "writer's cramp"), segmental (involving one or several limbs or regions) or generalized.
Note the abnormal postures and tremors in all extremities.
Writer's cramp is an example of a focal dystonia that is use-induced. Note that at first the hand posture is normal, but as the writing continues, it becomes more and more dystonic.
This woman has difficulty opening her eyes due to involuntary eyelid closure.
Also known as "wry neck", the head twists to one side. Interestingly, some dystonias respond to sensory stimulation, and it is not uncommon for a patient to be able to straighten their head using "tricks" such as touching their chin.
This is a dystonia that involves laryngeal muscles. It tends to be use-induced, although in advanced cases the change in voice is constant.
© 2018 USA Health