Tics may be classified according to degree of complexity (simple, complex), their quality (motor, vocal), and their Duration (Transient, Chronic). Both motor and vocal tics may be classified as either simple or complex, although the boundaries are not well-defined sudden movements.

1. Motor tics
2. Simple motor tics: Sudden movements such as eye-blinking, neck-jerking, shoulder-shrugging, and facial grimacing.
3. Complex motor tics: hitting oneself in the head, jumping, crouching down, hopping, abdominal twitching, twitching of the torso and pelvis, movement of the hands and arms, movement of the feet and legs, obscene gestures (copropraxia) e.g., pulling trousers down, repetition of a movement observed in another person (echopraxia).
4. Vocal or Phonic Tics: These are involuntary utterances of sounds, noises, sentences or words.
5. Simple vocal tics: throat-clearing, barking, sniffing, hissing, slight coughing, clearing of throat, wheezing, squeaking or loud shouting.
6. Complex vocal tics involves syllables, words or sentences, repetition of particular words, the use of socially unacceptable (often obscene), utterance of obscene or aggressive words or sentences (coprolalia), and the repetition of one's own sounds or words (palilalia).

The other classification (ICD-10) of tic disorders include: i) Transient tic disorder ii) Chronic motor or vocal tic disorder iii) Combined vocal and motor tic disorder (Tourette’s Syndrome) iv) Other tic disorder v) Tic disorder, unspecified.

Tic disorders are divided into 3 categories (based on the DSM-5): i) Provisional tic disorder, ii) Persistent tic disorder, and iii) Tourette syndrome (Gilles de LaTourette syndrome)

The prevalence of Tourette syndrome is about 1% worldwide. 4% - 12 % of all children suffer from tics at some time during their development. Approximately 3%-4% are afflicted by a chronic tic disorder and 1% with Tourette’s syndrome. Boys are afflicted three to four times more often than girls; and a family history of tics is common.

Tics onsets start around ages 2 - 15 years with peak age of onset- 6-8years. The first symptom simple motor tic in the face, such as eye blinking or grimacing. - spread to shoulders, extremities and torso. Often vocal tics appear 2-4 years after the start of the motor tics. Also, tics can commence in childhood and stop in young adulthood while some persons may have persistent symptoms throughout their lives.

The causes unknown and widely assumed – due to an interaction of genetic, neurobiological and psychological factors as well as environmental influences. A dysregulation within cortico-striato-thalamo-cortical circuits with deviations within the dopaminergic and serotonergic systems is believed to be responsible for the occurrence of tics. A familial predisposition is as a risk factor. Heritability has been estimated to be around 50%. Medical imaging techniques have determined that, on a neuroanatomical level, patients with tics show a reduced volume of the basal ganglia and the corpus callosum, but heterogeneity of study samples in terms of several confounders (e.g., long-term use of medication, tic performance and suppression over years) prevents firm conclusions.

1. Transient tic disorder (Provisional tic disorders): Meets the general criteria for a tic disorder, but tics do not persist for longer than 12 months. This is the commonest form of tic and is most frequent about the age of 4 or 5 years; the tics usually take the form of eye-blinking, facial grimacing, or head-jerking. In some cases the tics occur as a single episode but in other cases there are remissions and relapses over a period of months.
2. Chronic motor or vocal tic disorder (Persistent tic disorder): Meets the general criteria for a tic disorder, in which there are motor or vocal tics (but not both); tics may be single or multiple (but usually multiple), and last for more than a year.
3. Combined vocal and multiple motor tic disorder [Gilles de la Tourette syndrome]: A form of tic disorder in which there are, or have been, multiple motor tics and one or more vocal tics for more than a year, although these need not have occurred concurrently. Onset is almost always in childhood or adolescence (before age 18). A history of motor tics before development of vocal tics is common; the symptoms frequently worsen during adolescence, and it is common for the disorder to persist into adult life.

The major features distinguishing tics from other motor disorders are the sudden, rapid, transient, and circumscribed nature of the movements, together with the lack of evidence of underlying neurological disorder; their repetitiveness; (usually) their disappearance during sleep; and the ease with which they may be voluntarily reproduced or suppressed. Tics often occur as an isolated phenomenon but not infrequently they are associated with a wide variety of emotional disturbances, especially, perhaps, obsessional and hypochondriacal phenomena. However, specific developmental delays are also associated with tics. The lack of rhythmicity differentiates tics from the stereotyped repetitive movements seen in some cases of autism or of mental retardation. Manneristic motor activities seen in the same disorders tend to comprise more complex and variable movements than those usually seen with tics. Obsessive-compulsive activities resemble complex tics but differ in that their form tends to be defined by their purpose (such as touching some object or turning a number of times) rather than by muscle groups involved; however, the differentiation is sometimes difficult.

Children with tics may have one or more of the following co-morbidities:

1. Obsessive-compulsive disorder (in about 30-40% of the cases)
2. ADHD (in approximately 50% of the cases)
3. Autistic spectrum disorder (ASD) and Social communication difficulties (5-10% of cases)
4. Learning difficulties
5. Aggressive outbursts (close to 70%)
6. Anxiety disorders

Adolescents (and adults) with tics may have one or more of the following comorbidities: depression, bipolar disorder and substance use disorder

The differentials of Tourette’s syndrome are chorea in adult, complex partial seizures, frontal lobe syndrome, hemifacial spasm, intellectual disability, periodic limb movement disorder and neurologic effects of cocaine among others.

Before initiating pharmacological treatment, the following investigations should be carried out: blood and liver function tests, prolactin levels, ECG, EEG, as well as physical and neurological examinations (to establish a baseline, exclude cardiac contraindications, including long QT syndromes, other physical illnesses or potential contraindications for the use of medication).

The goal of management is to improve symptoms and quality of life. It involves a multidisciplinary approach comprising neurologists, psychiatrists, and social works who work together and develop best individualized treatment plans for the patients. Diagnosis is clinical and effective treatment starts with making right diagnosis.

1. Psychoeducation: Information should be provided regarding the disorder, its course, investigations and options for treatment.
2. Psychotherapy: Effective psychotherapeutic modalities are Cognitive behavioural therapy, habit reversal training, Exposure and response prevention, Relaxation training, Contingency management.
3. Pharmacotherapy: It is important to assess if the tic or another comorbid disorder is causing the worst impairment, to determine which of the disorders should be primarily treated. The examples include alpha adrenergic agonists (such as clonidine and guanfacine) and oral antipsychotics (risperidone, haloperidol, olanzapine,and pimozide)
4. Treatment of comorbidities is essential
5. Psychosurgery (in recalcitrant case though extremely rare)