ICD10 diagnosis codes are:

- F95.0 Transient tic disorder

- F95.1 Chronic motor or vocal tic disorder

- F95.2 Combined vocal and multiple motor tic disorder [Gilles de la Tourette]

- F95.8 Other tic disorders

- F95.9 Tic disorder, unspecified

In the fourth revision of the DSM (DSM-IV-TR), tic disorders were classified as follows:

- Transient tic disorder consisted of multiple motor and/or phonic tics with duration of at least 4 weeks, but less than 12 months.

- Chronic tic disorder was either single or multiple motor or phonic tics, but not both, which were present for more than a year.

- Tourette syndrome was diagnosed when both motor and phonic tics were present for more than a year.

- Tic disorder NOS was diagnosed when tics were present, but did not meet the criteria for any specific tic disorder.

Tics are movements or sounds "that occur intermittently and unpredictably out of a background of normal motor activity", having the appearance of "normal behaviors gone wrong". The tics associated with Tourette's change in number, frequency, severity and anatomical location. Waxing and waning—the ongoing increase and decrease in severity and frequency of tics—occurs differently in each individual. Tics may also occur in "bouts of bouts", which vary for each person.

Coprolalia (the spontaneous utterance of socially objectionable or taboo words or phrases) is the most publicized symptom of Tourette's, but it is not required for a diagnosis of Tourette's and only about 10% of Tourette's patients exhibit it. Echolalia (repeating the words of others) and palilalia (repeating one's own words) occur in a minority of cases, while the most common initial motor and vocal tics are, respectively, eye blinking and throat clearing.

In contrast to the abnormal movements of other movement disorders (for example, choreas, dystonias, myoclonus, and dyskinesias), the tics of Tourette's are temporarily suppressible, nonrhythmic, and often preceded by an unwanted premonitory urge. Immediately preceding tic onset, most individuals with Tourette's are aware of an urge, similar to the need to sneeze or scratch an itch. Individuals describe the need to tic as a buildup of tension, pressure, or energy which they consciously choose to release, as if they "had to do it" to relieve the sensation or until it feels "just right". Examples of the 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. These urges and sensations, preceding the expression of the movement or vocalization as a tic, are referred to as "premonitory sensory phenomena" or premonitory urges. Because of the urges that precede them, tics are described as semi-voluntary or ""unvoluntary"", rather than specifically "involuntary"; they may be experienced as a "voluntary", suppressible response to the unwanted premonitory urge. Published descriptions of the tics of Tourette's identify sensory phenomena as the core symptom of the syndrome, even though they are not included in the diagnostic criteria.

While individuals with tics are sometimes able to suppress their tics for limited periods of time, doing so often results in tension or mental exhaustion. People with Tourette's may seek a secluded spot to release their symptoms, or there may be a marked increase in tics after a period of suppression at school or at work. Some people with Tourette's 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. They may have tics for several years before becoming aware of premonitory urges. Children may suppress tics while in the doctor's office, so they may need to be observed while they are not aware they are being watched. The ability to suppress tics varies among individuals, and may be more developed in adults than children.

Although there is no such thing as a "typical" case of Tourette syndrome, the condition follows a fairly reliable course in terms of the age of onset and the history of the severity of symptoms. Tics may appear up to the age of eighteen, but the most typical age of onset is from five to seven. A 1998 study published by Leckman and colleagues from the Yale Child Study Center showed that the ages of highest tic severity are eight to twelve (average ten), with tics steadily declining for most patients as they pass through adolescence. The most common, first-presenting tics are eye blinking, facial movements, sniffing and throat clearing. Initial tics present most frequently in midline body regions where there are many muscles, usually the head, neck and facial region. This can be contrasted with the stereotyped movements of other disorders (such as stims and stereotypies of the autism spectrum disorders), which typically have an earlier age of onset, are more symmetrical, rhythmical and bilateral, and involve the extremities (e.g., flapping the hands). Tics that appear early in the course of the condition are frequently confused with other conditions, such as allergies, asthma, and vision problems: pediatricians, allergists and ophthalmologists are typically the first to see a child with tics.

Most cases of Tourette's in older individuals are mild and almost unrecognizable. When symptoms are severe enough to warrant referral to clinics, obsessive–compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD) are often associated with Tourette's. In children with tics, the additional presence of ADHD is associated with functional impairment, disruptive behavior, and tic severity. Compulsions resembling tics are present in some individuals with OCD; "tic-related OCD" is hypothesized to be a subgroup of OCD, distinguished from non-tic related OCD by the type and nature of obsessions and compulsions. Not all persons with Tourette's have ADHD or OCD or other comorbid conditions, although in clinical populations, a high percentage of patients presenting for care do have ADHD. One author reports that a ten-year overview of patient records revealed about 40% of patients with Tourette's have "TS-only" or "pure TS", referring to Tourette syndrome in the absence of ADHD, OCD and other disorders. Another author reports that 57% of 656 patients presenting with tic disorders had uncomplicated tics, while 43% had tics plus comorbid conditions. People with "full-blown Tourette's" have significant comorbid conditions in addition to tics.

Tics are sudden, repetitive, nonrhythmic movements (motor tics) and utterances (phonic tics) that involve discrete muscle groups. Motor tics are movement-based tics, while phonic tics are involuntary sounds produced by moving air through the nose, mouth, or throat.

Tourette's was classified by the fourth version of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-IV-TR) as one of several tic disorders "usually first diagnosed in infancy, childhood, or adolescence" according to type (motor or phonic tics) and duration (transient or chronic). Transient tic disorders consisted of multiple motor tics, phonic tics or both, with a duration between four weeks and twelve months. Chronic tic disorder was either single or multiple, motor or phonic tics (but not both), which were present for more than a year. Tourette's is diagnosed when multiple motor tics, and at least one phonic tic, are present for more than a year. The fifth version of the DSM (DSM-5), published in May 2013, reclassified Tourette's and tic disorders as motor disorders listed in the neurodevelopmental disorder category, and replaced transient tic disorder with provisional tic disorder, but made few other significant changes.

Tic disorders are defined only slightly differently by the World Health Organization International Statistical Classification of Diseases and Related Health Problems, ICD-10; code F95.2 is for combined vocal and multiple motor tic disorder [de la Tourette].

Although Tourette's is the more severe expression of the spectrum of tic disorders, most cases are mild. The severity of symptoms varies widely among people with Tourette's, and mild cases may be undetected.

Other conditions which feature repetitive behaviors in the differential diagnosis include autism spectrum disorders, obsessive–compulsive disorder, tic disorders (e.g., Tourette syndrome), and other conditions including dyskinesias.

Stereotypic movement disorder is often misdiagnosed as tics or Tourette syndrome (TS). Unlike the tics of TS, which tend to appear around age six or seven, repetitive movements typically start before age three, are more bilateral than tics, and consist of intense patterns of movement for longer runs than tics. Tics are less likely to be stimulated by excitement. Children with stereotypic movement disorder do not always report being bothered by the movements as a child with tics might.

Stereotyped movements are common in infants and young children; if the child is not distressed by movements and daily activities are not impaired, diagnosis is not warranted. When stereotyped behaviors cause significant impairment in functioning, an evaluation for stereotypic movement disorder is warranted. There are no specific tests for diagnosing this disorder, although some tests may be ordered to rule out other conditions. SMD may occur with Lesch-Nyhan syndrome, intellectual disability, and fetal alcohol exposure or as a result of amphetamine intoxication.

When diagnosing stereotypic movement disorder, DSM-5 calls for specification of:

- with or without self-injurious behavior;

- association with another known medical condition or environmental factor;

- severity (mild, moderate or severe).

Because these are frequently found in cases of autistic disorders, criteria could be met for multiple neurological disorders, or cause severe symptoms.

Some examples include:

1. Learning difficulties symptoms such as dyslexia, dysgraphia, dyscalcula, NVLD, slow learning, poor memory, etc.

2. AD/HD symptoms such as poor concentration, poor decision making, poor judgement, impulsiveness, difficulty sitting still, etc.

3. Synesthesia.

4. Neurological sleep disorders such as narcolepsy, insomnia, circadian rhythm disorder, etc.

5. Conditions affecting perceptions and/or cognition, such as agnosia, aphasia, etc.

6. Tourette syndrome or Tic disorder.

7. Epilepsy or Seizure disorder.

8. Parkinsonian syndrome features such as tremors, stiff movements, etc.

Only about 10% of Tourette's patients exhibit coprolalia, but it tends to attract more attention than any other symptom. There is a paucity of epidemiological studies of Tourette syndrome; ascertainment bias affects clinical studies. Studies on people with Tourette's often "came from tertiary referral samples, the sickest of the sick". Further, the criteria for a diagnosis of Tourette's were changed in 2000, when the impairment criterion was removed from the DSM-IV-TR for all tic disorders, resulting in increased diagnoses of milder cases. Further, many clinical studies suffer from small sample size. These factors combine to render older estimates of coprolalia—biased towards clinical populations of the more severe cases—outdated. An international, multi-site database of 3,500 individuals with Tourette syndrome drawn from clinical samples found 14% of patients with Tourette's accompanied by comorbid conditions had coprolalia, while only 6% of those with uncomplicated ("pure") Tourette's had coprolalia. The same study found that the chance of having coprolalia increased linearly with the number of comorbid conditions: patients with four or five other conditions—in addition to tics—were four to six times more likely to have coprolalia than persons with only Tourette's. One study of a general pediatric practice found an 8% rate of coprolalia in children with Tourette syndrome, while another study found 60% in a tertiary referral center (where typically more severe cases are referred). A more recent Brazilian study of 44 patients with Tourette syndrome found a 14% rate of coprolalia; a Costa Rican study of 85 subjects found 20% had coprolalia; a Chilean study of 70 patients found an 8.5% rate of coprolalia; older studies in Japan reported a 4% incidence of coprolalia; and a still older clinical study in Brazil found 28% of 32 patients had coprolalia. Considering the methodological issues affecting all of these reports, the consensus of the Tourette Syndrome Association is that the actual number is below 15 percent.

The current diagnostic criteria for MCDD are a matter of debate due to it not being in the DSM-IV or ICD-10. Various websites contain various diagnostic criteria. At least three of the following categories should be present. Co-occurring clusters of symptoms must also not be better explained by being symptoms of another disorder such as experiencing mood swings due to autism, cognitive difficulties due to schizophrenia, and so on. The exact diagnostic criteria for MCDD remain unclear but may be a useful diagnosis for people who do not fall into any specific category. It could also be argued that MCDD is a vague and unhelpful term for these patients.

Coprolalia encompasses words and phrases that are culturally taboo or generally unsuitable for acceptable social use, when used out of context. The term is not used to describe contextual swearing. It is usually expressed out of social or emotional context, and may be spoken in a louder tone or different cadence or pitch than normal conversation. It can be a single word, or complex phrases. A person with coprolalia may repeat the word mentally rather than saying it out loud; these subvocalizations can be very distressing.

Coprolalia is an occasional characteristic of Tourette syndrome, although it is not required for a diagnosis of Tourette's. In Tourette syndrome, compulsive swearing can be uncontrollable and undesired by the person uttering the phrases. Involuntary outbursts, such as racial or ethnic slurs in the company of those most offended by such remarks, can be particularly embarrassing. The phrases uttered by a person with coprolalia do not necessarily reflect the thoughts or opinions of the person.

Cases of deaf Tourette patients swearing in sign language have been described, showing that coprolalia is not just a consequence of the short and sudden sound pattern of many swear words.

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) is a hypothesis that there exists a subset of children with rapid onset of obsessive-compulsive disorder (OCD) or tic disorders and these symptoms are caused by group A beta-hemolytic streptococcal (GABHS) infections. The proposed link between infection and these disorders is that an initial autoimmune reaction to a GABHS infection produces antibodies that interfere with basal ganglia function, causing symptom exacerbations. It has been proposed that this autoimmune response can result in a broad range of neuropsychiatric symptoms.

The PANDAS hypothesis was based on observations in clinical case studies at the US National Institutes of Health and in subsequent clinical trials where children appeared to have dramatic and sudden OCD exacerbations and tic disorders following infections. There is supportive evidence for the link between "streptococcus" infection and onset in some cases of OCD and tics, but proof of causality has remained elusive. The PANDAS hypothesis is controversial; whether it is a distinct entity differing from other cases of Tourette syndrome (TS)/OCD is debated.

PANDAS has not been validated as a disease entity; it is not listed as a diagnosis by the International Statistical Classification of Diseases and Related Health Problems (ICD) or the "Diagnostic and Statistical Manual of Mental Disorders" (DSM).

Tourette’s syndrome is a neurological disorder characterized by recurrent involuntary movements (motor tics) and involuntary noises (vocal tics). The reason Tourette’s syndrome and other tic disorders are being considered for placement in the obsessive compulsive spectrum is because of the phenomenology and co-morbidity of the disorders with obsessive compulsive disorder. Within the population of patients with OCD up to 40% have a history of a tic disorder and 60% of people with Tourette’s syndrome have obsessions and/or compulsions. Plus 30% of people with Tourette’s syndrome have full-scale OCD. Course of illness is another factor that suggests correlation because it has been found that tics displayed in childhood are a predictor of obsessive and compulsive symptoms in late adolescence and early adulthood. However, the association of Tourette’s and tic disorders with OCD is challenged by neuropsychology and pharmaceutical treatment. Whereas OCD is treated with SSRI’s, tics are treated with dopamine blockers and alpha-2 agonists.

Separation anxiety disorder

- excessive stress when separated from home or family

- fear of being alone

- refusal to sleep alone

- clinginess

- excessive worry about safety

- excessive worry about getting lost

- frequent medical complaints with no cause

- refusal to go to school

Selective mutism

- unable to speak in certain social situations, even though they are comfortable speaking at home or with friends

- difficulty maintaining eye contact

- may have blank facial expressions

- stiff body movements

- may have a worrisome personality

- may be incredibly sensitive to sound

- difficulty with verbal and non-verbal expression

- may appear shy, when in reality, they have a fear of people.

Reactive attachment disorder of infancy or early childhood

- withdrawing from others

- aggressive attitude towards peers

- awkwardness or discomfort

- watching others but not engaging in social interaction

Stereotypic movement disorder

- head banging

- nail biting

- hitting or biting oneself

- hand waving or shaking

- rocking back and forth

In addition to an OCD or tic disorder diagnosis, children may have other symptoms associated with exacerbations such as emotional lability, enuresis, anxiety, and deterioration in handwriting. In the PANDAS model, this abrupt onset is thought to be preceded by a strep throat infection. As the clinical spectrum of PANDAS appears to resemble that of Tourette's syndrome, some researchers hypothesized that PANDAS and Tourette's may be associated; this idea is controversial and a focus for current research.

Various areas of development can be affected by developmental coordination disorder and these will persist into adulthood, as DCD has no cure. Often various coping strategies are developed, and these can be enhanced through occupational therapy, psychomotor therapy, physiotherapy, speech therapy, or psychological training.

In addition to the physical impairments, developmental coordination disorder is associated with problems with memory, especially working memory. This typically results in difficulty remembering instructions, difficulty organizing one's time and remembering deadlines, increased propensity to lose things or problems carrying out tasks which require remembering several steps in sequence (such as cooking). Whilst most of the general population experience these problems to some extent, they have a much more significant impact on the lives of dyspraxic people. However, many dyspraxics have excellent long-term memories, despite poor short-term memory. Many dyspraxics benefit from working in a structured environment, as repeating the same routine minimises difficulty with time-management and allows them to commit procedures to long-term memory.

People with developmental coordination disorder sometimes have difficulty moderating the amount of sensory information that their body is constantly sending them, so as a result dyspraxics are prone to sensory overload and panic attacks.

Many dyspraxics struggle to distinguish left from right, even as adults, and have extremely poor sense of direction generally.

Moderate to extreme difficulty doing physical tasks is experienced by some dyspraxics, and fatigue is common because so much extra energy is expended while trying to execute physical movements correctly. Some (but not all) dyspraxics suffer from hypotonia, low muscle tone, which like DCD can detrimentally affect balance.

Developmental coordination disorder is classified (by doctors) in the fifth revision of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-5) as a motor disorder, in the category of neurodevelopmental disorders.

Hypochondriasis is excessive preoccupancy or worry about having a serious illness. These thoughts cause a person a great deal of anxiety and stress. The prevalence of this disorder is the same for men and women. Hypochondriasis is normally recognized in early adult age. Those that suffer with hypochondriasis are constantly thinking of their body functions, minor bumps and bruises as well as body images. Hypochondriacs go to numerous outpatient facilities for confirmation of their own diagnosis. Hypochondriasis is the belief that something is wrong but it is not known to be a delusion.

Patients with PANS may present with a new onset or acute flare and follow a relapsing-remitting course, chronic-static course, or a chronic-progressive course.

PANS Criteria include the following:

I. Abrupt, dramatic onset of obsessive-compulsive disorder or severely restricted food intake

II. Concurrent presence of additional neuropsychiatric symptoms, (with similarly severe and acute onset), from at least two of the following seven categories:

1. Anxiety

2. Emotional lability and/or depression

3. Irritability, aggression, and/or severely oppositional behaviors

4. Behavioral (developmental) regression

5. Deterioration in school performance (related to attention deficit/hyperactivity disorder ADHD-like symptoms, memory deficits, cognitive changes)

6. Sensory or motor abnormalities

7. Somatic signs and symptoms, including sleep disturbances, enuresis, or urinary frequency.

According to the 2017 "Survey of Pediatric Acute-Onset Neuropsychiatric Syndrome Characteristics and Course" these symptoms may occur in PANS patients:

A tic can be defined as a repeated, individually recognizable, intermittent movement or movement fragments that are almost always briefly suppressible and are usually associated with awareness of an urge to perform the movement. These abnormal movements occur with intervening periods of normal movement. These movements are predictable, often triggered by stress, excitement, suggestion, or brief voluntary suppressibility. Many children say that the onset of tics can stem from the strong urge to move. 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 suffers from tics, but at least 20% of boys will have developed tics at some point in their lifetimes.

Stereotypies are repetitive, rhythmic, simple movements that can be voluntarily suppressed. Like tremors, they are typically back and forth movements, and most commonly occur bilaterally. They often involve fingers, wrists, or proximal portions of the upper extremities. Although, like tics, they can stem from stress and excitement, there is no underlying urge to move associated with stereotypies and these movements can be stopped with distraction. When aware of the movements, the child can also suppress them voluntarily. Stereotypies are often associated with developmental syndromes, including the autism spectrum disorders. Stereotypies are quite common in preschool-aged children and for this reason are not necessarily indicative of neurological pathology on their own.

Motor disorders are malfunctions of the nervous system that cause involuntary or uncontrollable movements or actions of the body (Stone). These disorders can cause lack of intended movement or an excess of involuntary movement (Mandal). Symptoms of motor disorders include tremors, jerks, twitches, spasms, contractions, or gait problems.

Tardive dyskinesia is characterized by repetitive, involuntary movements. Some examples of these types of involuntary movements include:

- Grimacing

- Tongue movements

- Lip smacking

- Lip puckering

- Pursing of the lips

- Excessive eye blinking

Rapid, involuntary movements of the limbs, torso, and fingers may also occur. In some cases, an individual's legs can be so affected that walking becomes difficult or impossible. These symptoms are the opposite of patients who are diagnosed with Parkinson's disease. Parkinson's patients have difficulty moving, whereas tardive dyskinesia patients have difficulty not moving.

Respiratory irregularity, such as grunting and difficulty breathing, is another symptom associated with tardive dyskinesia, although studies have shown that the prevalence rate is relatively low.

Tardive dyskinesia is often misdiagnosed as a mental illness rather than a neurological disorder, and as a result patients are prescribed neuroleptic drugs, which increase the probability that the patient will develop a severe and disabling case, and shortening the typical survival period.

Other closely related neurological disorders have been recognized as variants of tardive dyskinesia. Tardive dystonia is similar to standard dystonia but permanent. Tardive akathisia involves painful feelings of inner tension and anxiety and a compulsive drive to move the body. In some extreme cases, afflicted individuals experience so much internal torture that they lose their ability to sit still. Tardive tourettism is a tic disorder featuring the same symptoms as Tourette syndrome. The two disorders are extremely close in nature and often can only be differentiated by the details of their respective onsets. Tardive myoclonus, a rare disorder, presents as brief jerks of muscles in the face, neck, trunk, and extremities.

"AIMS Examination": This test is used when psychotropic medications have been prescribed because patients sometimes develop tardive dyskinesia due to prolonged use of antipsychotic medications. The Abnormal Involuntary Movement Scale (AIMS) examination is a test used to identify the symptoms of tardive dyskinesia (TD). The test is not meant to tell whether there is an absence or presence of tardive dyskinesia. It just scales to level of symptoms indicated by the actions observed. The levels range from none to severe. The AIMS examination was constructed in the 1970s to measure involuntary facial, trunk, and limb movements. It is best to do this test before and after the administration of the psychotropic drugs. Taking the AIMS consistently can help to track severity of TD over time.

Children with a tic disorder may exhibit the following symptoms:

- overwhelming urge to make movement

- jerking of arms

- clenching of fists

- excessive eye blinking

- shrugging of shoulders

- kicking

- raising eyebrows

- flaring of nostrils

- production of repetitive noises such as grunting, clicking, moaning, snorting, squealing, or throat clearing

George Miller Beard recorded individuals who would obey any command given suddenly, even if it meant striking a loved one; the Jumping Frenchmen seemed to react abnormally to sudden stimuli. The more common and less intense symptoms consisted of jumping, yelling, and hitting. These individuals exhibited outrageous bursts, and many described themselves as ticklish and shy. Other cases involved echolalia (repeating vocalizations made by another person) and echopraxia (repeating movements made by another person). Beard noted that the men were "suggestible" and that they "could not help repeating the word or sounds that came from the person that ordered them any more than they could help striking, dropping, throwing, jumping, or starting".