Overview
Definition:
Tourette syndrome (TS) is a neurodevelopmental disorder characterized by sudden, rapid, recurrent, non-rhythmic, stereotyped motor movements or vocalizations called tics
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by persistent patterns of inattention and/or hyperactivity-impulsivity that interfere with functioning or development.
Epidemiology:
Tourette syndrome affects an estimated 0.5-1.5% of the school-aged population
ADHD is much more common, affecting 5-10% of children
A significant comorbidity exists, with ADHD present in 50-70% of individuals with TS
Boys are more frequently diagnosed with both conditions.
Clinical Significance:
The co-occurrence of Tourette syndrome and ADHD presents complex challenges in diagnosis and management
Effective treatment requires a comprehensive approach that addresses both conditions to improve a child's academic performance, social functioning, and overall quality of life
This dual comorbidity is a common scenario in pediatric practice and crucial for board examinations.
Clinical Presentation
Symptoms:
Tourette Syndrome: Presence of multiple motor tics and at least one vocal tic, occurring many times a day, nearly every day, for more than 1 year
Tics often wax and wane in frequency and type
Tics may be simple (e.g., eye blinking, throat clearing) or complex (e.g., jumping, uttering words)
ADHD: Inattention symptoms include difficulty sustaining attention, careless mistakes, not seeming to listen, trouble following instructions, difficulty organizing, losing things, being easily distracted, forgetfulness
Hyperactivity/Impulsivity symptoms include fidgeting, leaving seat, running/climbing inappropriately, difficulty playing quietly, being "on the go," talking excessively, blurting out answers, difficulty waiting turn, interrupting others.
Signs:
Physical examination may reveal observable tics
Neurological examination is typically normal
Behavioral observations during assessment can highlight inattention, distractibility, impulsivity, and motor restlessness
Signs of social difficulties or academic underachievement may also be evident.
Diagnostic Criteria:
Diagnosis of Tourette Syndrome is based on DSM-5 criteria: presence of multiple motor tics and at least one vocal tic for more than 1 year, onset before age 18, and not attributable to substance use or another medical condition
Diagnosis of ADHD is based on DSM-5 criteria for inattention and/or hyperactivity-impulsivity, with symptoms present before age 12, occurring in two or more settings, and interfering with functioning.
Diagnostic Approach
History Taking:
Detailed history of tic onset, types, frequency, and severity
Explore premonitory urges
Assess impact of tics on daily life
Inquire about symptoms of inattention, hyperactivity, and impulsivity
Assess academic performance, social interactions, and family history of TS, ADHD, or other neurodevelopmental disorders
Rule out other causes of tics (e.g., Sydenham's chorea, drug-induced tics).
Physical Examination:
A thorough general physical and neurological examination is essential to rule out other medical conditions
Focus on observing for any motor or vocal tics
Assess for signs of other comorbid conditions
A mental status examination can help evaluate cognitive function and behavior.
Investigations:
Generally, no specific laboratory tests or imaging studies are required to diagnose Tourette syndrome or ADHD
Investigations may be considered to rule out other conditions if the clinical presentation is atypical or if there are red flags suggesting an underlying medical cause (e.g., MRI brain if neurological deficits are present, thyroid function tests if tremor is prominent).
Differential Diagnosis:
Differential diagnoses for tics include other hyperkinetic disorders (e.g., Huntington's disease, Sydenham's chorea), stereotypies, Tourette's-like disorders (e.g., post-infectious autoimmune encephalitis), drug-induced tics, and habit disorders
Differential diagnoses for ADHD include learning disabilities, anxiety disorders, mood disorders, oppositional defiant disorder, and intellectual disability.
Management
Initial Management:
The cornerstone of initial management is education for the child and family about TS and ADHD, emphasizing that these are neurodevelopmental conditions and not the child's fault
Psychoeducation on symptom management and strategies for coping is vital
Establish a strong therapeutic alliance.
Medical Management:
For TS: Alpha-2 adrenergic agonists (e.g., clonidine, guanfacine) are often first-line for reducing tics, especially when comorbid with ADHD
Dopamine-receptor blocking agents (e.g., haloperidol, pimozide, risperidone, aripiprazole) are more potent but have higher risks of side effects and are typically reserved for severe, disabling tics
For ADHD: Stimulant medications (e.g., methylphenidate, amphetamines) are highly effective
Non-stimulants (e.g., atomoxetine, guanfacine, clonidine) are alternatives, particularly if stimulants are contraindicated or ineffective
Sequencing is key: often, ADHD is treated first if it is the primary driver of functional impairment, as stimulants may sometimes exacerbate tics, though this is not universal
Conversely, treating tics first may improve focus
Guanfacine and clonidine can be effective for both ADHD and tics simultaneously
Careful titration and monitoring are essential.
Behavioral Therapy:
Behavioral therapies are crucial for both TS and ADHD
For TS, Comprehensive Behavioral Intervention for Tics (CBIT) is highly effective, involving habit reversal training and functional analysis
Exposure and Response Prevention (ERP) can also be helpful
For ADHD, behavioral therapy focuses on developing organizational skills, time management, and impulse control
Parent training in behavior management is also a vital component.
Educational Support:
Collaboration with the child's school is essential
Accommodations such as extended time for assignments, preferential seating, and reduced homework load can significantly improve academic outcomes
Individualized Education Programs (IEPs) or 504 plans may be necessary
Social skills training can help children with TS and ADHD navigate peer interactions.
Treatment Sequencing
General Principle:
Treatment sequencing is individualized and depends on which condition causes the most significant impairment
If ADHD is the primary cause of functional impairment (e.g., severe academic failure, significant behavioral issues), treating ADHD first may be considered, especially with non-stimulant medications or cautiously with stimulants while monitoring tics.
Adhd First Approach:
When ADHD symptoms significantly disrupt learning and behavior, initiating ADHD treatment with atomoxetine, guanfacine, or clonidine is often preferred
If stimulants are used, close monitoring for tic exacerbation is mandatory
If tics worsen, consider switching to a non-stimulant or adding an anti-tic medication.
Tics First Approach:
If severe, disabling tics significantly interfere with schooling or social life, initiating treatment with an alpha-2 adrenergic agonist (clonidine, guanfacine) may be beneficial for both tics and ADHD symptoms
If tics are refractory and disabling, a dopamine blocker might be considered, but this can sometimes worsen ADHD symptoms, requiring careful adjustment.
Combined Approach:
Often, a combined approach is necessary, using medications that target both conditions
For example, guanfacine and clonidine can improve both ADHD and tics
Behavioral therapies for both TS (CBIT) and ADHD (organizational skills) should be integrated into the treatment plan regardless of the medication strategy.
Complications
Early Complications:
Social stigma and peer rejection
Academic underachievement due to inattention and disruptive tics
Frustration and low self-esteem
Potential for medication side effects.
Late Complications:
Chronic academic difficulties
Persistent social isolation
Increased risk of comorbid mood and anxiety disorders
Substance abuse
Difficulty with employment and independent living if not managed effectively.
Prevention Strategies:
Early diagnosis and comprehensive management
Consistent use of behavioral therapies
School-based accommodations and support
Psychoeducation for family, peers, and educators
Regular follow-up with a multidisciplinary team.
Prognosis
Factors Affecting Prognosis:
Severity of TS and ADHD symptoms at onset
Presence and severity of comorbidities (e.g., OCD, anxiety)
Responsiveness to treatment
Family support
Access to comprehensive care
Early intervention significantly improves outcomes.
Outcomes:
With appropriate and integrated treatment, most individuals with co-occurring TS and ADHD can achieve significant improvements in tic control, attention, and impulse regulation
This leads to better academic performance, improved social functioning, and a higher quality of life
Many adults learn to manage their symptoms effectively.
Follow Up:
Long-term follow-up is essential
Regular appointments with a pediatrician, neurologist, or child psychiatrist are recommended
Monitoring for symptom changes, medication efficacy and side effects, and the emergence of new comorbidities is crucial
Transition planning for adult care is also important.
Key Points
Exam Focus:
The comorbidity rate of ADHD in TS is high (50-70%)
Alpha-2 adrenergic agonists (clonidine, guanfacine) are often first-line for both conditions or can be used to treat tics when stimulants are used for ADHD
CBIT is the gold standard behavioral therapy for tics
Sequencing treatment depends on which condition is more impairing.
Clinical Pearls:
Always ask about premonitory urges for tics
Be aware that stimulants can sometimes exacerbate tics, but do not withhold them if ADHD is severely impairing without careful consideration and monitoring
Combining behavioral therapies with pharmacotherapy provides the best outcomes
Educate parents extensively.
Common Mistakes:
Underestimating the impact of ADHD on tic severity or vice versa
Focusing solely on medication without incorporating behavioral and educational strategies
Failing to screen for comorbid conditions like OCD or anxiety
Incorrectly sequencing treatment without considering the primary source of impairment.