What is Tourette Syndrome?
Tourette Syndrome is a neuro-developmental 'spectrum' disorder. Tics (motor and vocal) are the defining symptom domain of Tourette syndrome but their apparent severity is not always directly representational of the overall severity of all combined TS symptom domains in an individual and not an accurate measure of overall disability. Although often also referred to as 'Tic spectrum disorder', do not always expect to see overt tics. Some motor tics can be in muscle groups that are not easily observed. Motor and vocal tics, although involuntary, can often be suppressed or 'hidden'. Not all individuals are able to suppress tics and other TS behaviours and may find this incurs increased stress. Many older people are better able to hide their symptoms, an ability that can help in negotiating 'social opposition' and prejudice. Inhibitory dysfunction (or dysregulation) has a 'central' role in TS and many TS-related behaviours have an impulsive quality.
A small percentage (approx. 10%) of people with TS appear not to have other symptoms in addition to tics, known as uncomplicated TS. Around 90% have other symptom domains - this form of TS is commonly referred to as TS+. Tourette syndrome shows variation between individuals and no two are quite alike in terms of the importance or prominence of particular symptom groups, although specific variations of TS are beginning to be identified - these are known as phenotypes.
Defining the clinical meaning of symptoms and signs can be of value as they have an important bearing on the diagnostic process: symptoms are what a person experiences themselves (and conveys to a healthcare professional during history-taking which traditionally accounts for the greater part of diagnosis), signs are what are observed or elicited on examination. Often there is an over-dependence on signs (e.g. tics/OCBs etc) but this can be unreliable in TS. At medical school the history is usually said to provide the principal means by which diagnosis is achieved however it is frequently (and unfortunately), observed signs in TS, and other neurodevelopmental 'disorders' that are sought (sometimes exclusively) for this purpose.
The syndrome is named after Gilles de la Tourette a 19th Century French neurologist: History of TS.
Tic Behaviours
Tics are defining symptoms of Tourette syndrome. Tic behaviours and other TS symptoms can be confused with other disorders - Differential diagnosis of TS.
Vocal tics: throat-clearing/coughing, words/phrases/grunts/squeals and indrawing/expelling air via mouth/nostrils, tongue clicks. Sniffing, throat-clearing and coughing are often some of the earliest vocal tics in children. Vocal tics tend to develop after initial motor tic onset.
Motor tics: twitching, tightening/relaxing of any skeletal muscle group including the face/neck/limbs/abdomen/back/gluteal muscles and also the diaphragm. Common early motor tics in children tend to start at the 'head' end and often develop towards the lower body (cephalo-caudal direction) subsequently, and may include raising eyebrows, frowning, eye-rolling, blinking, facial/nose twitches (e.g nose-scrunching), grimacing, mouth/lip movements, neck twisting, head-nodding, shoulder shrugs and hair-flicking. Touching and finger tics may occur.
Complex tics: sequential movements or behaviours. 'Complex tics are distinct, coordinated patterns of sequential movements. They may appear purposeful, as if voluntary' .... TSA. Complex tics may mimic meaningful actions or gestures. Some individuals are able to disguise or hide tics by incorporating them into behaviours that appear 'normal.' Complex tics may include twirling, hopping, touching, complex arm, leg or neck movements and also vocalisations.
Tics of all types can appear suddenly or develop over time and become elaborated. They can just as easily disappear with time and be replaced by other tics. Vocal tics especially are noticeable for their coming and going or evolution. Some particular tics may persist over time or disappear or 'resurface' at a later time. Some can be lifelong 'companions'. Vocal tics (and echopraxia tics) may have an origin in something experienced that is of significance although there is frequently no conscious awareness of their origin. Complex tics often give the appearance of being a part of 'normal' routine and some individuals successfully 'hide' them by incorporating them into 'normal' activities. They can therefore appear meaningful and in context with usual, practical every-day behaviours. There is a complex interplay between what are termed obsessive-compulsive rituals and many complex tic behaviours. Although traditionally there is a tendency to try to allocate them to one or the other, they may appear as part of a continuum with little discernable distinction.
Enshrinement: fragmentary phrases, words, sounds, music, thoughts or movements that 'stick' in the mind and reiterate or become 'enshrined' as vocal or motor tics
Palilalia: Repeating one's own words or parts of phrases. Often repetition of the ending of a phrase
Echolalia: The repetition of other's or heard words, phrases or sounds
Palipraxia: Repetitive movements. An action may be performed over and over again before before compulsion/tic is completed
Echopraxia: Copying/mimicking the movements and gestures of others
Thought-blocking, sensory/attention interference and "Inner voice" distractions. Often referred to as "tics of the mind"
Obsessive thinking and unwanted thoughts
Obsessive, compulsive/impulsive thoughts and behaviours.
Traditionally OCD has been considered as a common 'co-morbidity' of Tourette syndrome however evidence suggests that the TS-related obsessive and compulsive behaviours, that affect more than 60% of individuals with TS, differ somewhat in character (and often treatment-responsiveness) to 'classic' OCD. Recent research suggests that obssessive-compulsive behaviours/symptoms (OCB/OCS) that occur in TS are more closely related to TS than OCD. Commonly, in TS-related OCB, there is an emphasis on perfectionism, evening-up, getting things 'just right', spatial and numerical symmetry and counting. Counting rituals may involve even or odd numbers or other 'preferred' numbers. OCBs (and usually tics) will usually be associated with a 'just right' feeling - the carrying out of the behaviour giving expression and fulfillment to an urge or 'itch'. Compulsions are seen as the need to carry-out actions that help resolve these inner-tensions. In OCBs there may be a deep need to carry through a ritual, such as touching an object, a person or switching a light switch a certain number of times or other ritual, which if not completed correctly may result in an unwanted consequence or even threat to the well-being of the individual or other person. Not quite as common in TS are behaviours related to avoiding contamination, cleaning and washing rituals, although these often occur. The full range of OCD behaviours are possible in TS-related OCB. It is necessary to refer to the literature on OCD for a comprehensive overview of the potential complexity of OCD symptomatology. OCB/OCD appears to fall into different phenotypes. People with TS invariably describe experiencing unwanted or intrusive thoughts, that can sometimes reiterate and persist over time, and many report that they can be one of the most challenging aspects of their 'disorder' with the potential to be very time-consuming and attention-diverting. These are sometimes referred to as 'thought-tics' or 'tics-of-the-mind'. Repeating or looping thought-tics can involve seemingly meaningless thoughts, meaningful thoughts, words or fragments of music or other cognitive entities. OCS in TS are an area that requires further understanding although the complex interplay with simple and complex tics poses challenges for their objective study.
Attention and concentration deficits Difficulty with focusing on a single specific task and poor concentration. Tendency to take on many separate tasks simultaneously (taking on too much at once) and tendency not to pursue tasks to an appropriate conclusion. Whether this results from intrinsic TS causes or from co-occurring ADD or ADHD is not easily determined. It is probable that these symptoms are often mis-diagnosed or mistakenly assigned to the latter conditions when the primary diagnosis and cause is actually TS.
Attention and concentration deficits Difficulty with focusing on a single specific task and poor concentration. Tendency to take on many separate tasks simultaneously (taking on too much at once) and tendency not to pursue tasks to an appropriate conclusion. Whether this results from intrinsic TS causes or from co-occurring ADD or ADHD is not easily determined. It is probable that these symptoms are often mis-diagnosed or mistakenly assigned to the latter conditions when the primary diagnosis and cause is actually TS.
Hyperactivity Both hyperactivity and attention deficit are often the earliest symptoms or, more correctly, signs 'seen' in young children and may be evident before tics. Hyperactivity is often regarded as intrinsic to TS but as with attention deficit, may be assigned as a component of ADHD although it's clinical/neuro-developmental origin may be ambiguous.
Sensory processing difficulties as seen in sensory processing disorder (sensory integration disorder). Sensory hypersensitivity, cross-modality interference and sensory defensiveness. Common issues in TS include auditory and visual processing difficulties and tactile (touch) sensitivity however all sensory modalities are potentially involved. Difficulties with sensory processing can have a negative impact on speech, social and educational development and should be evaluated in children and older students with TS. Sensory issues in TS >>
Low mood (a depressive symptom) is very common in TS. Clinical depression may be worsened by 'reactive' low-mood. The seeming 'exuberance' and (hyper)activity that often characterise TS in combination with low mood has lead to erroneous 'diagnoses' of bipolar disorder rather than TS - these may also mask the extent of 'underlying' depression. Self-harming thoughts can be significant in some and should always be taken seriously especially if they have at any time been acted-upon. Risk taking and impulsive behaviours that can occur in TS must also be considered. In many cases it is difficult to determine whether low-mood is a clinically-integral aspect of TS itself (low central-nervous system serotonin and nor-epinephrine levels have been measured in TS patients) or whether of environmental or 'psychological' origin resulting from the adverse challenges of TS and negative social reactions of others.
Low mood (a depressive symptom) is very common in TS. Clinical depression may be worsened by 'reactive' low-mood. The seeming 'exuberance' and (hyper)activity that often characterise TS in combination with low mood has lead to erroneous 'diagnoses' of bipolar disorder rather than TS - these may also mask the extent of 'underlying' depression. Self-harming thoughts can be significant in some and should always be taken seriously especially if they have at any time been acted-upon. Risk taking and impulsive behaviours that can occur in TS must also be considered. In many cases it is difficult to determine whether low-mood is a clinically-integral aspect of TS itself (low central-nervous system serotonin and nor-epinephrine levels have been measured in TS patients) or whether of environmental or 'psychological' origin resulting from the adverse challenges of TS and negative social reactions of others.
Speech difficulties: include stuttering, speaking loudly (poor volume awareness), rapidly, indistinctly, broken speech-flow/dysfluency, poor intonation and vocal tics. Reiteration/repetition and perseveration during conversation are very common in TS (also a frequent characteristic with OCB/OCD and Autistic Spectrum Disorders). Poor reciprocity in conversation and inappropriate initiation/commencement/breaking-off. Socially inappropriate or non-intentional speech content. There are many potential social consequences of speech difficulties in TS. There can be a tendency to 'discourse' with reduced constraint and perseverate rather than freely reciprocate and exchange ideas during conversation or an inability to remain passive or understated. These difficulties are often a very major source of anxiety as they are often painfully apparent to the individual with TS and can impair self-esteem and cause immense frustration.
Speech difficulties: include stuttering, speaking loudly (poor volume awareness), rapidly, indistinctly, broken speech-flow/dysfluency, poor intonation and vocal tics. Reiteration/repetition and perseveration during conversation are very common in TS (also a frequent characteristic with OCB/OCD and Autistic Spectrum Disorders). Poor reciprocity in conversation and inappropriate initiation/commencement/breaking-off. Socially inappropriate or non-intentional speech content. There are many potential social consequences of speech difficulties in TS. There can be a tendency to 'discourse' with reduced constraint and perseverate rather than freely reciprocate and exchange ideas during conversation or an inability to remain passive or understated. These difficulties are often a very major source of anxiety as they are often painfully apparent to the individual with TS and can impair self-esteem and cause immense frustration.
Cursing or coprolalia, a type of vocal tic, although widely thought of as characteristic due to inaccurate media portrayal, affects only a minority of people with TS and is a relatively rare symptom (10-12% or less). A more common difficulty is with non-offensive socially-inappropriate comments (NOSI)
Social difficulties: Difficulties in understanding or 'reading' others intentions, actions/reactions and in detecting deception/ingenuousness. These are known as 'Theory of mind' difficulties. Sometimes giving rise to an appearance of being overly trusting or even of gullibility. Many with TS tend to be quite 'direct' (open) and detailed in their own expressions of their thoughts, feelings and intentions. This may be related to the 'ambiguities' experienced in relation to understanding other people but is also consistent with reduced inhibition (dysinhibition). It is very common in people with TS, to appear to 'miss' some of the subtleties of 'non-verbal' communication during social interaction.
Negative consequences from others' reactions to their TS symptoms can lead to 'closing-up' or wariness and, in some cases, avoidance of social situations that might present 'pitfalls'. There is evidence of a tendency towards literality in thinking and speech in some individuals with TS. An impaired understanding of 'non-literal' language can convey the unintended impression of being overly pedantic or even of being intentionally willful and critical. This, combined with any non-verbal communication deficits, may mean they are more prone to misinterpreting the meaning of what others are intending to convey.
Some tend to perseverate or discourse when speaking and will over-discuss a particular topic or repeat points unnecessarily and miss the cues others are giving regarding impatience, boredom, changing the subject or breaking off the conversation. Many aspects of TS seem to contribute to the risks of committing social 'faux pas', a source of considerable anxiety to many with TS.
People with TS can over-estimate other people's understanding and ability to 'see things' and make connections that appear obvious to them. Rapid and expansive/analytical thinking often appears characteristic of TS and when expressed in 'dysinhibited' speech can leave others exhausted or overwhelmed. Appropriate descriptions used by those with the condition with respect to the high level of cognitive activity, that seems common in TS, are 'restlessness' and 'relentless.' This may contribute to difficulties with relaxing, getting adequate sleep and inattention.
Also often characteristic of TS, is a constant exploring or mental analysis-of and testing of ideas and boundaries, a 'getting to the bottom' of things. This frequently extends to testing and sometimes transcending 'conventional' social norms and boundaries. A need or compulsion for tactile involvement with their environment is not uncommon and the difficulties that may arise from 'touching' others can have adverse social consequences if considered inappropriate or an invasion of personal space.
Recent research suggests that of the common symptom set (or symptom 'spectrum') experienced by post-adolescent individuals with TS, anxiety and panic attacks may be the most troublesome and represent the greater part of the disability-impact compared to other symptoms. Previously attention-deficit, hyperactivity and obsessive and compulsive symptoms have been considered the most disabling and may be so for children.
It is not unusual for there to be a high level of emotional reactivity or volatility in Tourette syndrome. Often situations that might be ignored or over-ridden by others, can stimulate seemingly disproportionate responses. Those with TS sometimes describe their emotional responses as being very intense or overwhelming. The stress response is seemingly increased or dysinhibited - neuroendocrine studies suggest some dysregulation may occur involving increased cortisol release and 'sympathetic' neural activation. 'Rage' is a relatively common aspect of TS - perhaps a further expression of emotional volatility but undoubtedly also a consequence of the frustrations experienced in negotiating social situations and conversing. Children with TS in particular are less able to moderate their emotional responses and rage may be more readily triggered especially with a build-up of frustration or stress, as at the end of a school day spent suppressing their TS symptoms. Like many aspect of TS, impaired inhibitory control/selectivity appears to play a role in this increased reactivity.
Empathic attunement (hyperempathy) - Many with TS experience intense feelings of concern and empathy for others (and for animals) which can provoke strong anxiety especially in regard to family and close friends. Such concern for their 'well-being' often extends to individuals who are unknown to them but whose plight has been reported. These behaviours may have a close association with obsessive-thinking. Despite popular misconceptions, empathic attunement also occurs in autistic spectrum disorders - it cannot be assumed that an individual lacks empathy because they do not express or are unable to articulate their feelings well verbally.
TS may change with time and age:
Many individuals experience a lessening in the severity of motor and vocal tics as they progress into adulthood. However the non-tic symptoms in TS can decline, persist or can even worsen with age. There is a tendency for greater adaptation and compensation with age and improved ability in suppressing/managing socially-relevant tics. This may give an impression of resolution which in some cases is misleading as symptoms may be hidden and therefore not readily apparent as clinical 'signs'. As the individual ages there is a strong social-imperative to learn and adopt compensatory 'survival-strategies' to make their condition less noticeable, although some are more able to do so than others. They may however incur considerable 'stress' due to symptom suppression and social-vigilance.
All symptom domains in TS have the potential to lessen or worsen with time and may 'wax and wane', often unpredictably, and do so independently although many may experience their whole spectrum of symptoms changing together especially in times of adversity or when their TS is less troublesome. Drug therapies can make the picture more complex by improving or exacerbating particular symptom domains (note: some professionals separate TS symptom domains into multiple discrete simultaneous 'disorders' or 'co-morbidities'). Often children that have an early diagnosis will have been on a (varying/or consistent) drug regime through much of their childhood and their 'untreated' developmental progress will have been obscured to some extent - it can be difficult to define clearly which aspects are a consequence of treatment success, support, intrinsic symptomatology, side-effects or development (including compensatory neuroanatomical/physiological adaptation and puberty). Sometimes after a change or reduction in medication a 'different' child can seem to emerge. Effective medication regimes can become less effective with time and may need reviewing or rationalising. Keeping a symptom journal can help quantify when and why any changes in symptoms occur.
Links:
Recommended clinical overviews of TS (readable for non-professionals):
The Behavioral Spectrum of GTS >>
Treatment Strategies for Tics in TS >>
Recommended clinical overviews of TS (readable for non-professionals):
The Behavioral Spectrum of GTS >>
Treatment Strategies for Tics in TS >>
