- 1 DSM-III
- 2 DSM-IV
- 2.1 Disorders
- 2.2 Differential Diagnosis
- 3 DSM-5
In DSM-III, this category is called Stereotyped Movement Disorders
- Transient Tic Disorder
- Chronic Motor Tic Disorder
- Tourette's Disorder
- Atypical Tic Disorder
- Atypical Stereotyped Movement Disorder
Differential Diagnosis of Tics
A tic is defined as an involuntary rapid movement of a functionally related group of skeletal muscles or the involuntary production of noises or words. Tics should be distinguished from other movement disturbances.
Choreiform movements are dancing, random, irregular, nonrepetitive movements.
Dystonic movements are slower, twisting movements interspersed with prolonged states of muscular tension.
Athetoid movements are slow, irregular, writhing movements, most frequently in the fingers of toes.
Myoclonic movements are brief, shocklike muscle contractions that may affect parts of or a whole muscle, but not entire muscle groups.
Hemiballismic movements are intermittent, coarse, jumping, and unilateral movements of the limbs.
Spasms are stereotypic, slower, and more prolonged than tics, and involve groups of muscles.
Hemifacial spasm consists of irregular, repetitive, unilateral jerks of facial muscles.
Synkinesis consists of movements of the corner of the mouth when the individual intends to close the eye, and its converse.
Dyskinesias, such as tardive dyskinesia, are silent, oral-buccal-lingual, masticatory movements in the face and choreoathetoid movements in the limbs.
The term "stereotyped movement," which is here used as a diagnostic term, refers to a voluntary, brief or prolonged habit or mannerism that often is experienced as pleasurable.
General medical conditions or effects of a substance
Tic Disorders must be distinguished from other types of abnormal movements that may accompany general medical conditions (e.g., Huntington's disease, stroke, Lesch-Nyan syndrome, Wilson's disease, Sydenham's chorea, multiple sclerosis, postviral encephalitis, head injury) or may be due to the direct effects of a substance (e.g., a neuroleptic medication). Choreiform movements are dancing, random, irregular, nonrepetitive movements. Dystonic movements are slower, twisting movements interspersed with prolonged states of muscular tension. Athetoid movements are slow, irregular writhing movements, most frequently in the fingers and toes, but often involving the face an neck. Myoclonic movements are brief, shocklike muscle contractions that may affect parts of muscles or muscle groups but non synergistically. Hemiballismic movements are intermittent, coarse, large-amplitude, unilateral movements of the limbs. Spasms are stereotypic, slower, and more prolonged than tics and involve groups of muscles. Hemifacial spasm consists of irregular, repetitive, unilateral jerks of facial muscles. Synkinesis involves an involuntary movement accompanying a voluntary one (e.g., movement of he corner of the mouth when the person intends to close the eye). This differentiation is further facilitated by considering the presence of features of the underlying general medical condition (e.g., characteristic family history in Huntington's disease) or a history of medication use.
When the tics are a direct physiological consequence of medication use, a Medication-Induced Movement Disorder Not Otherwise Specified would be diagnosed instead of a Tic Disorder. In some cases, certain medications (e.g., methylphenidate) may exacerbate a preexisting Tic Disorder, in which case no additional diagnosis of a medication-induced disorder is necessary.
Tics must also be distinguished from stereotyped movements seen in Stereotypic Movement Disorder and Pervasive Developmental Disorders. Differentiating simple tics (e.g., eye blinking) from the complex movements characteristic of stereotyped movements is relatively straightforward. The distinction between complex motor tics and stereotyped movements is less clear-cut. In general, stereotyped movements appear to be more driven and intentional, whereas tics have a more involuntary quality and are not rhythmic.
Tics must be distinguishable from compulsions (as in Obsessive-Compulsive Disorder). Compulsions are typically quite complex and are performed in response to an obsession or according to rules that must be applied rigidly. In contrast to a compulsion, tics are typically less complex and are not aimed at neutralizing the anxiety resulting from an obsession. Some individuals manifest symptoms of both Obsessive-Compulsive Disorder and a Tic Disorder (especially Tourette's Disorder), so that both diagnoses may be warranted.
Certain vocal or motor tics (e.g., barking, echolalia, palilalia) must be distinguished from disorganized or catatonic behavior in Schizophrenia.
Other Tic Disorders
The Tic Disorders can be distinguished from one another based on duration and variety of tics and age at onset. Transient Tic Disorder includes motor and/or vocal tics lasting for at least 4 weeks but for no longer than 12 consecutive months. Tourette's Disorder and Chronic Motor or Vocal Tic Disorder each have a duration of more than 12 months but are distinguished by the requirement for Tourette's Disorder that there be multiple motor tics and at least one vocal tic. Tic Disorder Not Otherwise Specified would be appropriate for clinically significant presentations lasting less than 4 weeks, for presentations with an age at onset above age 18 years, and for the unusual case of an individual with only one motor tic and only one vocal tic.
- Tourette's Disorder
- Persistent (Chronic) Motor or Vocal Tic Disorder
- Provisional Tic Disorder
- Other Specified Tic Disorder
- Unspecified Tic Disorder
Abnormal movements that may accompany other medical conditions and stereotypic movement disorder
Motor stereotypies are defined as involuntary rhythmic, repetitive, predictable movements that appear purposeful but serve no obvious adaptive function or purpose and stop with distraction. Examples include repetitive hand waving/rotating, arm flapping, and finger wiggling. Motor stereotypies can be differentiated from tics based on the former's earlier age at onset (younger than 3 years), prolonged duration (seconds to minutes), constant repetitive fixed form and location, exacerbation when engrossed in activities, lack of a premonitory urge, and cessation with distraction (e.g., name called or touched). Chorea represents rapid, random, continual, abrupt, irregular, unpredictable, nonstereotyped actions that are usually bilateral and affect all parts of the body (i.e., face, trunk, and limbs). The timing, direction, and distribution of movements vary from moment to moment, and movements usually worsen during attempted voluntary action. Dystonia is the simultaneous sustained contracture of both agonist and antagonist muscles, resulting in a distorted posture or movement of parts of the body. Dystonic postures are often triggered by attempts at voluntary movements and are not seen during sleep.
Substance-induced and paroxysmal dyskinesias
Paroxysmal dyskinesias usually occur as dystonic or choreoathetoid movements that are precipitated by voluntary movement or exertion and less commonly arise from normal background activity.
Myoclonus is characterized by a sudden unidirectional movement that is often nonrhythmic. It may be worsened by movement and occur during sleep. Myoclonus is differentiated from tics by its rapidity, lack of suppressibility, and absence of a premonitory urge.
Differentiating obsessive-compulsive behaviors from tics may be difficult. Clues favoring an obsessive-compulsive behavior include a cognitive-based drive (e.g., fear of contamination) and the need to perform the action in a particular fashion a certain number of times, equally on both sides of the body, or until a "just right" feeling is achieved. Impulse-control problems and other repetitive behaviors, including persisten hair pulling, skin picking, and nail biting, appear more goal directed and complex than tics.