Neurological disease in a child: Tic disorder Flashcards
Define tics.
Stereotyped movements of muscle groups that have no useful function.
Define Tourette’s Syndrome.
Chronic idiopathic syndrome with both motor and vocal tics beginning before adulthood.
Explain the aetiology/risk factors of tic disorders.
Genetic: Suggested by significantly higher concordance in monozygotic twins compared to dizygotic twins, and significantly higher incidence in first-degree relatives of sufferers.
Acquired: There is a possible subgroup that have antibodies to beta-haemolytic streptococci that cross-react with neurons.
Associations: ADHD in > 30%, OCD in > 20%
What is the pathophysiology of tic disorders?
Unknown. Theories include a reduction in the basal ganglia’s inhibition of undesired motor programmes.
Summarise the epidemiology of tics.
3-15% of children according to different studies, declining to 2-3% by adolescence. Usual onset 7-9 years.
Summarise the epidemiology of Tourette’s Syndrome.
0.5-1%
M:F = 2:1
What are the signs and symptoms of simple tics?
Brief movements involving a few muscle groups, e.g. eye blinking, shoulder shrugging, clearing the throat, humming. May be transient (> 4 weeks but < 1 year) or chronic (> 1 year).
What are the signs and symptoms of complex tics?
Co-ordinated patterns of successive movements involving several muscle groups, e.g. jumping, touching the nose, echolalia (reapeating another’s speech) and coprolalia (outbursts or obscenities). Tics are worsened by stress and suppressible for brief periods of time.
What are the signs and symptoms of Tourette syndrome?
Multiple motor and vocal tics occur (not necessarily concurrently). Tics occur many times a day, nearly every day for more than 1 year and frequently vary in nature, severity and location. Rage attacks consists of explosive, unpredictable outbursts out of proportion to stimuli, threatening destruction and self-injury, followed by immediate remorse.
What are appropriate investigations for tic disorder?
Usually none required. In specific cases investigations may be appropriate to exclude organic cause.
- Antistreptolysin titre (ASOT), especially if there was sudden onset of tics post impetigo, pharyngitis or otitis media.
- TFTs to exclude hyperthyroidism.
- Serum caeruloplasmin to exclude Wilson disease.
- EEG to assess for absence seizures.
Assess for co-morbid mental health problems: ADHD and OCD.
What is the MDT approach for tic disorders?
Supportive: Parental education and notify school of diagnosis.
Behavioural/psychotherapy: Reversal of habit.
Medical treatment: Only required if there is significant impairment of school and daily activities and distress. Treatment options include neuroleptic drugs (lower dose than for psychosis) and dopamine agonists.
What is the management for treating co-morbid psychiatric disease?
- OCD: SSRIs
- ADHD: Psychostimulant such as methylphenidate used in treating ADHD can cause/exacerbate tics. Recent studies show that children with co-morbid ADHD and tics may show improvement of both disorders with atomoexetine (selective noradrenaline reuptake inhibitor).
What are complications associated with tic disorder?
Stigma associated with outbursts may lead to social withdrawal. Interruption in thought and conversation affects education. Self-injurious behaviour may arise from depression.
What is the prognosis of tic disorders?
Tics may progressively worsen in childhood but abate or diminish markedly by the age of 18 in 90% of cases. There is significant morbidity associated with co-morbid psychiatric disease.
