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Examples of motor tics
Specialty Psychiatry, neurology

A tic is a sudden and repetitive motor movement or vocalization that is not rhythmic and involves discrete muscle groups. [1] [2] [3] It is typically brief, and may resemble a normal behavioral characteristic or gesture. [4]


Tics can be invisible to the observer, such as abdominal tensing or toe crunching. Common motor and phonic tics are, respectively, eye blinking and throat clearing. [5]

Tics must be distinguished from movements of disorders such as chorea, dystonia and myoclonus; the compulsions of obsessive–compulsive disorder (OCD) and seizure activity; [6] and movements exhibited in stereotypic movement disorder or among autistic people (also known as stimming). [7] [8] [9]


Tics are classified as either motor or phonic, and simple or complex. [4]

Motor or phonic

Motor tics are movement-based tics affecting discrete muscle groups. [4]

Phonic tics are involuntary sounds produced by moving air through the nose, mouth, or throat. They may be alternately referred to as verbal tics or vocal tics, but most diagnosticians prefer the term phonic tics to reflect the notion that the vocal cords are not involved in all tics that produce sound. [4]

Simple or complex

Simple motor tics are typically sudden, brief, meaningless movements that usually involve only one group of muscles, such as eye blinking, head jerking, or shoulder shrugging. [10] Motor tics can be of an endless variety and may include such movements as hand clapping, neck stretching, mouth movements, head, arm or leg jerks, and facial grimacing.

A simple phonic tic can be almost any sound or noise, with common phonic tics being throat clearing, sniffing, or grunting. [10]

Complex motor tics are typically more purposeful-appearing and of a longer nature. They may involve a cluster of movements and appear coordinated. [10] Examples of complex motor tics are pulling at clothes, touching people, touching objects, echopraxia (repeating or imitating another person's actions) and copropraxia (involuntarily performing obscene or forbidden gestures).

Complex phonic tics include echolalia (repeating words just spoken by someone else), palilalia (repeating one's own previously spoken words), lexilalia (repeating words after reading them), and coprolalia (the spontaneous utterance of socially objectionable or taboo words or phrases). Coprolalia is a highly publicized symptom of Tourette syndrome; however, only about 10% of TS patients exhibit coprolalia. [10]

Martino, et al have argued that tics may be considered physiological, or developmentally typical. [11]


Tics are described as semi-voluntary or unvoluntary, [12] because they are not strictly involuntary—they may be experienced as a voluntary response to a premonitory urge (a sensory phenomenon that is an inner sensation of mounting tension). A unique aspect of tics, relative to other movement disorders, is that they are suppressible yet irresistible; [13] they are experienced as an irresistible urge that must eventually be expressed. [12]

Tics may increase as a result of stress, fatigue, boredom, or high-energy emotions, which can include negative emotions, such as anxiety, as well as positive emotions, such as excitement or anticipation. Relaxation may result in a tic increase (for instance, watching television or using a computer), while concentration on an absorbing activity often leads to a decrease in tics. [14] [15] Neurologist and writer Oliver Sacks described a physician with severe Tourette syndrome (Canadian Mort Doran, M.D., a pilot and surgeon in real life, although a pseudonym was used in the book), whose tics remitted almost completely while he was performing surgery. [16] [17]

Immediately preceding tic onset, most individuals are aware of an urge [18] that is similar to the need to yawn, sneeze, blink, or scratch an itch. Individuals describe the need to tic as a buildup of tension [19] that they consciously choose to release, as if they "had to do it". [20] Examples of this premonitory urge are the feeling of having something in one's throat or a localized discomfort in the shoulders, leading to the need to clear one's throat or shrug the shoulders. The actual tic may be felt as relieving this tension or sensation, similar to scratching an itch. Another example is blinking to relieve an uncomfortable sensation in the eye. Some people with tics may not be aware of the premonitory urge. Children may be less aware of the premonitory urge associated with tics than are adults, but their awareness tends to increase with maturity. [12]

Complex tics are rarely seen in the absence of simple tics. Tics "may be challenging to differentiate from compulsions", [21] as in the case of klazomania (compulsive shouting).


Tic disorders occur along a spectrum, ranging from mild (transient or chronic tics) to more severe; Tourette syndrome is the more severe expression of a spectrum of tic disorders, which are thought to be due to the same genetic vulnerability. [22] Nevertheless, most cases of Tourette syndrome are not severe. [22] Management for the spectrum of tic disorders is similar to the management of Tourette syndrome.

Tic disorders are defined based on symptoms and duration. [23] The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published in May 2013, reclassified Tourette's and tic disorders as motor disorders listed in the neurodevelopmental disorder category, removed the word "stereotyped" from the definition of tic to better distinguish between stereotypies and tics, replaced transient tic disorder with provisional tic disorder, removed the criterion that tics must occur nearly every day, and removed the criterion that previously had excluded long tic-free periods (months) from counting towards the year needed to diagnose Tourette's or Persistent (Chronic) tic disorders. [23] [24] [25] [26]

Differential diagnosis

Dystonias, paroxysmal dyskinesias, chorea, other genetic conditions, and secondary causes of tics should be ruled out in the differential diagnosis. [27] Conditions besides Tourette syndrome that may manifest tics or stereotyped movements include developmental disorders, autism spectrum disorders, [28] and stereotypic movement disorder; [29] [30] Sydenham's chorea; idiopathic dystonia; and genetic conditions such as Huntington's disease, neuroacanthocytosis, pantothenate kinase-associated neurodegeneration, Duchenne muscular dystrophy, Wilson's disease, and tuberous sclerosis. Other possibilities include chromosomal disorders such as Down syndrome, Klinefelter syndrome, XYY syndrome, and fragile X syndrome. Acquired causes of tics include drug-induced tics, head trauma, encephalitis, stroke, and carbon monoxide poisoning. [27] [31] Most of these conditions are rarer than tic disorders, and a thorough history and examination may be enough to rule them out, without medical or screening tests. [22]

Although tic disorders are commonly considered to be childhood syndromes, tics occasionally develop during adulthood; adult-onset tics often have a secondary cause. [32] Tics that begin after the age of 18 are not diagnosed as Tourette's syndrome, but may be diagnosed as an "other specified" or "unspecified" tic disorder. [23]

Tests may be ordered as necessary to rule out other conditions: For example, when diagnostic confusion between tics and seizure activity exists, an EEG may be ordered, or symptoms may indicate that an MRI is needed to rule out brain abnormalities. [33] TSH levels can be measured to rule out hypothyroidism, which can be a cause of tics. Brain imaging studies are not usually warranted. [33] In teenagers and adults presenting with a sudden onset of tics and other behavioral symptoms, a urine drug screen for cocaine and stimulants might be necessary. If a family history of liver disease is present, serum copper and ceruloplasmin levels can rule out Wilson's disease. [27]

Individuals with obsessive–compulsive disorder (OCD) may present with features typically associated with a tic disorder, such as compulsions that may resemble motor tics. "Tic-related OCD" is hypothesized to be a subgroup of OCD, distinguished from non-tic-related OCD by the content and type of obsessions and compulsions; individuals with tic-related OCD have more intrusive thoughts, and exhibit more hoarding and counting rituals than individuals with non-tic-related OCD. [34]

Tics must also be distinguished from fasciculations. Small twitches of the upper or lower eyelid, for example, are not tics, because they do not involve a whole muscle, rather are twitches of a few muscle fibre bundles, that are not suppressible. [35]

See also


  1. Szejko N, Robinson S, Hartmann A, et al. (October 2021). "European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part I: assessment". Eur Child Adolesc Psychiatry. 31 (3): 383–402. doi:10.1007/s00787-021-01842-2. PMC   8521086 . PMID   34661764.
  2. Leckman JF, Bloch MH, King RA, Scahill L (2006). "Phenomenology of tics and natural history of tic disorders". Adv Neurol. 99: 1–16. PMID   16536348.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. American Psychiatric Association (2000). DSM-IV-TR: Tourette's Disorder. Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text revision (DSM-IV-TR), ISBN   0-89042-025-4. Available at BehaveNet.com Retrieved on August 10, 2009.
  4. 1 2 3 4 Jankovic, Joseph; Lang, Anthony E. (2022). "24. Diagnosis and assessment of Parkinson Disease and other movement disorders; Tics". In Jankovic, Joseph; Mazziotta, John C.; Pomeroy, Scott L. (eds.). Bradley and Daroff's Neurology in Clinical Practice. Vol. I. Principles of diagnosis (8th ed.). Edinburgh: Elsevier. pp. 325–326. ISBN   978-0-323-64261-3.
  5. Malone DA Jr, Pandya MM (2006). "Behavioral neurosurgery". Adv Neurol. 99: 241–47. PMID   16536372.
  6. Mineka S, Watson D, Clark LA (1998). "Comorbidity of anxiety and unipolar mood disorders". Annual Review of Psychology . 49: 377–412. doi:10.1146/annurev.psych.49.1.377. PMID   9496627. S2CID   14546782.
  7. Singer HS (2009). "Motor stereotypies" (PDF). Semin Pediatr Neurol. 16 (2): 77–81. doi:10.1016/j.spen.2009.03.008. PMID   19501335. Archived from the original (PDF) on 2014-05-13. Retrieved 2020-06-23.
  8. Nind M, Kellett M (2002). "Responding to individuals with severe learning difficulties and stereotyped behaviour: challenges for an inclusive era". Eur J Spec Needs Educ. 17 (3): 265–82. doi:10.1080/08856250210162167. S2CID   142836660.
  9. Muthugovindan D, Singer H (2009). "Motor stereotypy disorders". Current Opinion in Neurology. 22 (2): 131–6. doi: 10.1097/WCO.0b013e328326f6c8 . PMID   19532036. S2CID   23006424.
  10. 1 2 3 4 Singer HS (Mar 2005). "Tourette's syndrome: from behaviour to biology". Lancet Neurol. 4 (3): 149–59. doi:10.1016/S1474-4422(05)01012-4. PMID   15721825. S2CID   20181150.
  11. Martino D, Espay AJ, Fasano A, Morgante F. Unvoluntary motor behaviors. In: Martino D, Espay AJ, Fasano A, Morgante F, eds. Disorders of Movement: A Guide to Diagnosis and Treatment. 1 ed. Berlin: Springer-Verlag; 2016:97-153, p. 107.
  12. 1 2 3 "Definitions and classification of tic disorders". Arch Neurol. 50 (10): 1013–16. Oct 1993. doi:10.1001/archneur.1993.00540100012008. PMID   8215958.
  13. Dure LS, DeWolfe J (2006). "Treatment of tics". Adv Neurol. 99: 191–96. PMID   16536366.
  14. National Institutes of Health (NIH). Tourette Syndrome Fact Sheet. Retrieved on March 23, 2005.
  15. Packer, L. Tourette Syndrome "Plus" [ dead link ]. Retrieved on February 12, 2006.
  16. Doran, Morton L. The Tourette Syndrome Association, Inc., Connecticut Chapter 1998 Educators' Conference; 1998 Nov 6; Danbury, CT.
  17. Sacks O. An Anthropologist on Mars . Knopf, New York, 1995.
  18. Cohen AJ, Leckman JF (Sep 1992). "Sensory phenomena associated with Gilles de la Tourette's syndrome". J Clin Psychiatry. 53 (9): 319–23. PMID   1517194.
  19. Bliss J (Dec 1980). "Sensory experiences of Gilles de la Tourette syndrome". Arch Gen Psychiatry. 37 (12): 1343–47. doi:10.1001/archpsyc.1980.01780250029002. PMID   6934713.
  20. Kwak C, Dat Vuong K, Jankovic J (Dec 2003). "Premonitory sensory phenomenon in Tourette's syndrome". Mov Disord. 18 (12): 1530–33. doi:10.1002/mds.10618. PMID   14673893. S2CID   8152205.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  21. Scamvougeras, Anton. "Challenging Phenomenology in Tourette Syndrome and Obsessive–Compulsive Disorder: The Benefits of Reductionism". Canadian Psychiatric Association (February 2002). Retrieved on June 5, 2007.
  22. 1 2 3 Zinner SH (November 2000). "Tourette disorder". Pediatr Rev. 21 (11): 372–83. doi:10.1542/pir.21-11-372. PMID   11077021. S2CID   7774922.
  23. 1 2 3 American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders, 5th ed., pp. 81–85 ISBN   978-0-89042-555-8 Archived 2017-06-30 at the Wayback Machine
  24. Neurodevelopmental disorders. American Psychiatric Association. Retrieved on December 29, 2011.
  25. Moran M (2013). "DSM-5 provides new take on neurodevelopment disorders". Psychiatric News. 48 (2): 6–23. doi:10.1176/appi.pn.2013.1b11.
  26. "Highlights of changes from DSM-IV-TR to DSM-5" (PDF). American Psychiatric Association. 2013. Retrieved on June 5, 2013. Archived February 3, 2013, at the Wayback Machine
  27. 1 2 3 Bagheri, Kerbeshian & Burd (1999).
  28. Ringman JM, Jankovic J (Jun 2000). "Occurrence of tics in Asperger's syndrome and autistic disorder". J Child Neurol. 15 (6): 394–400. doi:10.1177/088307380001500608. PMID   10868783. S2CID   8596251.
  29. Jankovic J, Mejia NI (2006). "Tics associated with other disorders". Adv Neurol. 99: 61–8. PMID   16536352.
  30. Freeman, RD. Tourette's Syndrome: minimizing confusion. Roger Freeman, MD, blog. Retrieved on February 8, 2006.
  31. Mejia NI, Jankovic J (2005). "Secondary tics and tourettism". Rev Bras Psiquiatr. 27 (1): 11–17. doi: 10.1590/s1516-44462005000100006 . PMID   15867978.
  32. "Adult-onset tic disorder, motor stereotypies, and behavioural disturbance associated with antibasal ganglia antibodies". Archived from the original on 2009-01-13. Retrieved 2008-06-05.
  33. 1 2 Scahill L, Erenberg G, Berlin CM Jr, Budman C, Coffey BJ, Jankovic J, Kiessling L, King RA, Kurlan R, Lang A, Mink J, Murphy T, Zinner S, Walkup J, Tourette (Apr 2006). "Contemporary assessment and pharmacotherapy of Tourette syndrome". NeuroRx. 3 (2): 192–206. doi:10.1016/j.nurx.2006.01.009. PMC   3593444 . PMID   16554257.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  34. Hounie AG, do Rosario-Campos MC, Diniz JB; et al. (2006). "Obsessive-compulsive disorder in Tourette syndrome". Adv Neurol. 99: 22–38. PMID   16536350.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  35. Perrotta G (2019). "Tic disorder: definition, clinical contexts, differential diagnosis, neural correlates and therapeutic approaches" (PDF). Journal of Neuroscience and Rehabilitation. MeDOA Publications. 2019 (1). Archived from the original (PDF) on 2020-07-15. Tics must also be distinguished from fasciculations. Small contractions of the upper or lower eyelid, for example, are not tics, because they do not involve an entire muscle. They are contractions of some bundles of muscle fibres, which can be felt but just seen. These contractions of the eyelids also differ from tics in that they are not suppressible, are strictly involuntary and tend to fade after a day or two.

Further reading

Related Research Articles

<span class="mw-page-title-main">Tourette syndrome</span> Neurodevelopmental disorder involving motor and vocal tics

Tourette syndrome or Tourette's syndrome is a common neurodevelopmental disorder that begins in childhood or adolescence. It is characterized by multiple movement (motor) tics and at least one vocal (phonic) tic. Common tics are blinking, coughing, throat clearing, sniffing, and facial movements. These are typically preceded by an unwanted urge or sensation in the affected muscles known as a premonitory urge, can sometimes be suppressed temporarily, and characteristically change in location, strength, and frequency. Tourette's is at the more severe end of a spectrum of tic disorders. The tics often go unnoticed by casual observers.

Coprolalia is involuntary swearing or the involuntary utterance of obscene words or socially inappropriate and derogatory remarks. The word comes from the Greek κόπρος, meaning "dung, feces", and λαλιά "speech", from λαλεῖν "to talk".

A stereotypy is a repetitive or ritualistic movement, posture, or utterance. Stereotypies may be simple movements such as body rocking, or complex, such as self-caressing, crossing and uncrossing of legs, and marching in place. They are found especially in people with autism spectrum disorders and visually impaired children, and are also found in intellectual disabilities, tardive dyskinesia and stereotypic movement disorder, yet may also be encountered in neurotypical individuals as well. Studies have shown stereotypies associated with some types of schizophrenia. Frontotemporal dementia is also a common neurological cause of repetitive behaviors and stereotypies. Several causes have been hypothesized for stereotypy, and several treatment options are available.

<span class="mw-page-title-main">PANDAS</span> Hypothesis in pediatric medicine

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) is a controversial hypothetical diagnosis for a subset of children with rapid onset of obsessive-compulsive disorder (OCD) or tic disorders. Symptoms are proposed to be caused by group A streptococcal (GAS), and more specifically, group A beta-hemolytic streptococcal (GABHS) infections. OCD and tic disorders are hypothesized to arise in a subset of children as a result of a post-streptococcal autoimmune process. The proposed link between infection and these disorders is that an autoimmune reaction to infection produces antibodies that interfere with basal ganglia function, causing symptom exacerbations, and this autoimmune response results in a broad range of neuropsychiatric symptoms.

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Stereotypic movement disorder (SMD) is a motor disorder with onset in childhood involving restrictive and/or repetitive, nonfunctional motor behavior, that markedly interferes with normal activities or results in bodily injury. To be classified as SMD, the behavior in question must not be due to the direct effects of a substance, autism, or another medical condition. The cause of this disorder is not known.

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Tourette syndrome is an inherited neurodevelopmental disorder that begins in childhood or adolescence, characterized by the presence of motor and phonic tics. The management of Tourette syndrome has the goal of managing symptoms to achieve optimum functioning, rather than eliminating symptoms; not all persons with Tourette's require treatment, and there is no cure or universally effective medication. Explanation and reassurance alone are often sufficient treatment; education is an important part of any treatment plan.

Causes and origins of Tourette syndrome have not been fully elucidated. Tourette syndrome is an inherited neurodevelopmental disorder that begins in childhood or adolescence, characterized by the presence of multiple motor tics and at least one phonic tic, which characteristically wax and wane. Tourette's syndrome occurs along a spectrum of tic disorders, which includes transient tics and chronic tics.

Arthur K. Shapiro, M.D., was an American psychiatrist and expert on Tourette syndrome. His "contributions to the understanding of Tourette syndrome completely changed the prevailing view of this disorder"; he has been described as "the father of modern tic disorder research" and is "revered by his colleagues as the first dean of modern Tourette syndrome researchers".

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Sensory phenomena are general feelings, urges or bodily sensations. They are present in many conditions including autism spectrum disorders, epilepsy, neuropathy, obsessive–compulsive disorder, pain conditions, tardive syndromes, and tic disorders.

Habit reversal training (HRT) is a "multicomponent behavioral treatment package originally developed to address a wide variety of repetitive behavior disorders".

Klazomania refers to compulsive shouting; it has features resembling the complex tics such as echolalia, palilalia and coprolalia seen in tic disorders, but has been seen in people with encephalitis lethargica, alcohol use disorder, and carbon monoxide poisoning. It was first reported by L. Benedek in 1925 in a patient with postencephalitic parkinsonism. Little is known about the condition, and few cases have been reported.

The obsessive–compulsive spectrum is a model of medical classification where various psychiatric, neurological and/or medical conditions are described as existing on a spectrum of conditions related to obsessive–compulsive disorder (OCD). "The disorders are thought to lie on a spectrum from impulsive to compulsive where impulsivity is said to persist due to deficits in the ability to inhibit repetitive behavior with known negative consequences, while compulsivity persists as a consequence of deficits in recognizing completion of tasks." OCD is a mental disorder characterized by obsessions and/or compulsions. An obsession is defined as "a recurring thought, image, or urge that the individual cannot control". Compulsion can be described as a "ritualistic behavior that the person feels compelled to perform". The model suggests that many conditions overlap with OCD in symptomatic profile, demographics, family history, neurobiology, comorbidity, clinical course and response to various pharmacotherapies. Conditions described as being on the spectrum are sometimes referred to as obsessive–compulsive spectrum disorders.

<span class="mw-page-title-main">History of Tourette syndrome</span> Aspect of history

Tourette syndrome is an inherited neurological disorder that begins in childhood or adolescence, characterized by the presence of multiple physical (motor) tics and at least one vocal (phonic) tic.

<span class="mw-page-title-main">Obsessive–compulsive disorder</span> Mental and behavioral disorder

Obsessive–compulsive disorder (OCD) is a mental and behavioral disorder in which an individual has intrusive thoughts and feels the need to perform certain routines (compulsions) repeatedly to relieve the distress caused by the obsession, to the extent where it impairs general function.

The cause of obsessive–compulsive disorder is understood mainly through identifying biological risk factors that lead to obsessive–compulsive disorder (OCD) symptomology. The leading hypotheses propose the involvement of the orbitofrontal cortex, basal ganglia, and/or the limbic system, with discoveries being made in the fields of neuroanatomy, neurochemistry, neuroimmunology, neurogenetics, and neuroethology.

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A premonitory urge is a sensory phenomenon associated with Tourette syndrome and other tic disorders. Premonitory urges are "uncomfortable feelings or sensations preceding tics that usually are relieved by [a particular] movement".