Chronic motor tic disorder

Essential (Required) Features:

• The persistent presence of motor tic(s).
• Motor tics are defined as sudden, rapid, non-rhythmic, and recurrent movements.
• Motor tics have been present for at least 1 year with onset during the developmental period.

Additional Clinical Features:

• Motor tics may be voluntarily suppressed for short periods of time, may be exacerbated by stress, and may diminish during sleep or during periods of focused enjoyable activity.
• Tics are often highly suggestible, for example such that when an individual with Chronic Motor Tic Disorder is asked about specific symptoms, old tics that have been absent for some time may transiently reappear.

Boundary with Normality (Threshold):

• Transient motor tics (e.g., eye blinking) are common during childhood and are differentiated from Chronic Motor Tic Disorder by their transient nature.

Developmental Presentations:

• The prevalence of Chronic Motor Tic Disorder is estimated between 0.3 – 0.8% of school-aged children.

Culture-Related Features:

• If movements have a specific function or meaning in the context of an individual’s culture and are used in ways that are consistent with that cultural function or meaning, they should not be considered evidence of Chronic Motor Tic Disorder.

Sex- and/or Gender-Related Features:

• Women with persistent tic disorders may be more likely to experience co-occurring Anxiety or Fear-Related Disorders and Depressive Disorders.

Boundaries with Other Disorders and Conditions (Differential Diagnosis):

• Boundary with Autism Spectrum Disorder and Stereotyped Movement Disorder: Repetitive and stereotyped motor movements such as whole body movements (e.g., rocking) and unusual hand or finger movements can be a characteristic feature of Autism Spectrum Disorder and of Stereotyped Movement Disorder. These behaviours can appear similar to tics but are differentiated because they tend to be more stereotyped, last longer than the duration of a typical tic, tend to emerge at a younger age, are not characterized by premonitory sensory urges, are often experienced by the individual as soothing or rewarding, and can generally be interrupted with distraction.
• Boundary with Obsessive-Compulsive Disorder: Repetitive, recurrent movements can also be symptomatic of Obsessive-Compulsive Disorder. Tics can be differentiated from Obsessive-Compulsive Disorder because they appear unintentional in nature and clearly utilize a discreet muscle group. However, it can be difficult to distinguish between complex tics and compulsions associated with Obsessive-Compulsive Disorder. Although tics (both complex and simple) are preceded by premonitory sensory urges, which may diminish over time, tics are not aimed at neutralizing antecedent cognitions (e.g., obsessions) or reducing physiological arousal (e.g., anxiety). Many individuals exhibit symptoms of both Obsessive-Compulsive Disorder and Chronic Motor Tic Disorder, and both diagnoses may be assigned if the diagnostic requirements for each are met.
• Boundary with self-injurious and self-mutilating behaviours: With enough force and repetition, motor tics may lead to self-injury. However, unlike self-injurious and self-mutilating behaviour, Chronic Motor Tic Disorder is not associated with an intention to cause self-injury.