Dystonic movements can augment hyperkinetic movements, especially when linked to voluntary movements.Blepharospasm is a type of dystonia characterized by the involuntary contraction of the muscles controlling the eyelids. Symptoms can range from a simple increased frequency of blinking to constant, painful eye closure leading to functional blindness.Oromandibular dystonia is a type of dystonia marked by forceful contractions of the lower face, which causes the mouth to open or close. Chewing motions and unusual tongue movements may also occur with this type of dystonia.Laryngeal dystonia or spasmodic dysphonia results from abnormal contraction of muscles in the voice box, resulting in altered voice production. Patients may have a strained-strangled quality to their voice or, in some cases, a whispering or breathy quality.Cervical dystonia (CD) or spasmodic torticollis is characterized by muscle spasms of the head and neck, which may be painful and cause the neck to twist into unusual positions or postures.Writers cramp and musicians cramp is a task-specific dystonia, meaning that it only occurs when performing certain tasks. Writers cramp is a contraction of hand and/or arm muscles that happens only when a patient is writing. It does not occur in other situations, such as when a patient is typing or eating. Musicians cramp occurs only when a musician plays an instrument, and the type of cramp experienced is specific to the instrument. For example, pianists may experience cramping of their hands when playing, while brass players may have cramping or contractions of their mouth muscles.
Tics can be either muscular (alter normal motor function) or vocal (alter normal speech) in nature and most commonly involve the face, mouth, eyes, head, neck or shoulder muscles. Tics can also be classified as simple motor tics (a single brief stereotyped movement or movement fragment), complex motor tics (a more complex or sequential movement involving multiple muscle
groups), or phonic tics (including simple, brief phonations or vocalizations).When both motor and vocal tics are present and persist for more than one year, a diagnosis of Tourette syndrome (TS) is likely. TS is an inherited neurobehavioral disorder characterized by both motor and vocal tics. Many individuals with TS may also develop obsessions, compulsions, inattention and hyperactivity. TS usually begins in childhood. Up to 5% of the population has tics, but at least 20% of boys will have developed tics at some point in their lifetimes. Tremor
A tremor can be defined as a rhythmic, back and forth or oscillating involuntary movement about a joint axis. Tremors are symmetric about a midpoint within the movement, and both portions of the movement occur at the same speed. Unlike the other hyperkinetic movements, tremors lack both the jerking associated movements and posturing.Essential tremor (ET), also known as benign essential tremor, or familial tremor, is the most common movement disorder. It is estimated that 5 percent of people worldwide have this condition, affecting those of all ages but typically staying within families. ET typically affects the hands and arms but can also affect the head, voice, chin, trunk and legs.