Tics and Tourettes Flashcards
Describe and give examples of the different types of tics
Motor tics: sudden, rapid, non-rythmic motor movements. They can be simple ( eye blinking, mouth twitching) or complex (repetitive or compulsive nature such as certain ways of touching an object or elaborate sequences of movements copropraxia).
Phonic/vocal tics: flow of air through vocal cords, nose or mouth (throat clearing, grunts, coprolalia and echolalia)
What are compulsions and what is their link to tics and tourettes
Movements or ritualistic behaviours used to reduce stress (hand washing, counting). Fear of impending doom if not carried out (obsessive).
Unlike tics, movements are purposeful and not stereotyped.
Family history of obsessive/compulsive behaviour linked to childhood motor sstereotypies and tics…
Outline childhood motor stereotypies
DSM-IV-TR it is a repetitive, non functional motor disorder which interferes with normal activities or results in injury. However, in clinical setting children are not aware of actions.
Common: hand flapping, head banging, face or mouth stretching.
25% of children have affected relative and family history of obsessive tendencies.
Aetiology: not understood.
Lesions of basal ganglia, excess dopamine in ascending pathways. NB: seems to be genetic predisposition likely, combo.
Treatment:
Usually behavioural strat unless self injury or severe = drugs, SSRIs.
Co-morbidities are common in 80% of childhood motor stereotypies. What are these?
Autism, sensory impairment, social isolation, learning disability.
What is the difference between primary and secondary motor stereotypies?
Primary: observed in neurotypical children. Remain stable or regress with age as children become more aware of social surroundings.
Secondary: additional developmental delay or neurological disorder, may persist over time (characteristic hand movements in Rett’s)
State the difference between tourettes and chronic tic disorder
Chronic must have phonic or motor.
Tourettes must have both.
To be diagnosed both must have persisted for over a year and patient must have multiple tics per day.
How many children are affected by tics?
10%
Outline progression of tics
Begin as simple motor, progress to complex motor and phonic tics over 1-2 year period.
Most difficult period with maximum tic severity is 8-12 years.
18+ tics often wane and impairments due to tics documented to reduce with either no or mild tics in adulthood. For small % will go into adulthood with debilitating tics and associated mood disorders.
State key features of a tic
Ability to suppress tics temporarily
Suppression may lead to discomfort or urge may precede the tic
Active participation is required in performing the tic
Often highly suggestible (depend on environment, tic at home vs not).
Define Tourettes Syndrome
Multiple tics per day, both phonic and motor that must have first presented under the age of 18 and lasted over a year, not be related to a medical condition or substance use.
More males than females diagnosed, 3:1.
Known to be underdiagnosed so there is inadequate care. Average 5 yrs from onset to diagnosis.
Outline management of tic disorders.
Aim to diminish tic severity and frequency. Education and reassurance followed by watchful waiting.
Behavioural: habit reversal training, exposure and response prevention as well as relaxation training.
Pharmacological: reserved for severe cases, used for symptomatic control (lack of long term data to address side effects).
*Clonidine: most common and useful in coexisting behaviours such as sleep probs and ADHD.
*Risperidone alongside SSRI also used.
Surgery: Deep Brain Stimulation, evidence is limited. Only recommended for adult, treatment resistant, severly impacted patients where tics present for 5+ yrs.
What makes tics severe?
1) Causing pain or discomfort: musculoskeletal or neuropathic, can lead to injuries.
2) Social stimga: social isolation, bullying.
3) Psychological probs: negative peer interation can lead to reactive depression, anxiety and social phobia.
4) Functional impairment: can impact concentration as tic suppression is tiring. Phonic tics can impair pronounciation and ability to interact in the classroom.
Define stereotypie
Rhythmic, fixed movements that do not seem to have a purpose, but are predictable in pattern and location on the body.
Give some examples of differential diagnosis of motor disorders
Tic diorder, Tourette Syndrome, compulsions, dystonia, seizures…
State differences between tics and stereotypies
Onset: 5-7yrs for tics, over 2 years for stereo.
Patterns: t-variable, s-foreseeable, identical, fixed.
Movement: t-quick and sudden, s-rhythmic and prolonged.
Pre-movement: t- sensorimotor phenomena, s-nothing.
Supress: t-self directed and uncomfortable, s-external distraction, no conscious effort.
Treatment: t responsive to neuroleptics and s rarely are.
Define copropraxia:
Obscene movements or gestures
Define echopraxia
mimicking actions or gestures of others.
Coprolalia
Vocalisation of expletives or insults.
Palilalia
Repeating what oneself has just said
Echolalia
Repeating what another person has just said
Akathisia
Restlessness, compulsion to move ore walk around to alleviate perceived discomfort
Hyperekplexia
excessive startle resulting from hypertonicity. Thought to be hereditary and due to mutation of glycine receptor.
PANDAS?
PAEDIATRIC AUTOIMMUNE NEUROPSYCHIATRIC DISORDER ASSOCIATED WITH STREPTOCOCCAL INFECTION
Evidence that disorders are autoimmune and mediated by antibodies that bind to and cause dysfunction within CNS (esp basal ganglia).
These antibodies are universal in acute Sydenham’s chorea and post-streptococcal dystonia. The hypothesis is that an antecedent group A Haemolytic streptococcal infection could lead to molecular mimicry at the basal ganglia and then produce a neuropsychiatric manifestation.
Recent large cohort found no link.
What are paroxysmal dyskinesias?
Hyperkinetic movement disorders; abnormal repetitive involuntary movements. Episodic where abnormal only present at certain times and between attacks people are well. Can be inherited.
Encompasses tics, chorea, dystonia.
Phenotypically linked by excess of unwanted movements and thought to share common neural pathways (basal ganglia, thalamus and cerebellum).
State the difference between kinesiogenic and non kinesiogenic paroxymal dyskinesias.
Kinesiogenic: action induced, specific movement or startle. Can occur up to 100 times per day and short, often occur in one limb.
Non-kinesiogenic: less frequent occuring only twice or three times a year. Certain triggers - caffeine, alcohol, stress. Can last hours, often begin in one limb and spread to face. Often cannot communicate but remain conscious.
Are all brief motor episodes tics?
No can be stereotypies for examples
Name of disorder where motor and phonic tics are present, age of onset is below 18 and has lasted over 4 weeks but not as long as a year
Provisional Transient tic disorder
What pathway is implicated in organic tic and associated disorders and how does this explain how medication works?
cortico-striato-thalamo-cortical circuit (CTSC) is hyperactive (excess excitation)
1) hyper of excitatory neurons in somatosensory and efferent motor that elicit tics.
2) hypo of motor suppressing executive control circuits
Meds:
1) D2 antagonists excite inhibitory neurons
2) clonidine reduces excitatory NA input to glutamatergic
The more you do a certain tic, the more embedded it gets, why?
Due to plasticity circuits.
Parallels between tic disorders and epilepsy
Both thought to be caused by imbalance of E/I.
Both have an aura: can feel urge before manifestation of a seizure or a tic.
What are functional tic disorders and how do they differ from organic?
Acute severe onset of tics that only occur in social situations
Are not responsive to pharmacological invention.
Cannot be suppressed, no urge and therefore no relief.
More prevalent in females, onset in teenage years.
Predisposition: low socioeconomic status, psychosocial stress, brain maladaptation.
How are females and males affected by Tourettes differently?
Females: later onset, later severity peak, lower likelihood of remission.
Proposed that phenotype is markedly different.
What is mass functional illness?
It is the rapid spread of illness signs and symptoms affecting members of a cohesive group, originating from a nervous system disturbance involving excitation, loss, or alteration of function, whereby physical complaints that are exhibited unconsciously have no corresponding organic causes.
Link between Mass functional illness, social media and tics?
recent meta-analysis of gender differences showed 2.4:1 female predominance of MFI in children and adolescent. Normal needs to be cohesive group but social media breaks this barrier.
A recent meta-analysis of gender differences showed 2.4:1 female predominance of MFI in children and adolescent.
Increase in covid thought to be due to increased stress and possibly social isolation.
Case study: Jan Zimmerman. The channel gained rapid popularity
and has more than 2.2 million subscribers and 312 million
views. Zimmerman has a similarly large presence across multiple
platforms. Individuals presented with near identical complex
movements, vocalizations, and unique words or phrases often
seen in Zimmerman’s videos. Given the specific role of social
media, a more specific term was suggested - mass social
media-induced illness.
Outline the issue of animal models for tics.
Pharmacological: hallucinogens, dopamine modulators etc used cause rodents to develop symptoms but can be argued causes type epilepsy, cause is not taken into account.
Genetic: often type of epilepsy generated.
What does injection of GABA A antagonist Bicucullin into the Nacc and sensorimotor putamen produce?
NAcc: Macaques developed grunting vocalisations hypothesised to be like human complex vocal tics.
Sensorimotor: motor tics.
Radiolabelled water showed: in motor tics, ipsilateral side changes but in vocal bilateral in hippo and amygdala.
In motor tics: LFP in M1 at same time motor tics occur.
Vocal: LFP in Nacc and acc but did occur without LFP spikes…
McCairn Labs
Outline evidence that Cannabinoids can be used for Tourettes
Cochrane review: 2 trials found positive effect of delta-9-THC (most abundant and psychoactive) in tic frequency and severity. However both small trials and only detected in some of outcome measures.
Current medicine Risperidone improves tics for up to 60% of patients and Clonidone used for ADHD.
Anecdotal evidence: Muller Vahl found beneficial effect on premonitory urges and obsessive compulsive behaviours after interviewing TS patients who used cannabis.
BoNT A for tics?
Injection into affected muscle:
1) inhib of acetylcholine weakens hyperactive muscles
2) reduction of premonitory sensation and pain associated with tics
BOTOX INHIBITS RELEASE OF ACETYLCHOLINE AT THE NEUROMUSCULAR JUNCTION
DBS for tics?
Only for adults with treatment resistant:
High freq stim in thalamus (cstc) to stop transmission.
40% reduction in tic severity scales
