Box 1.

Secondary causes of tics

Neurodevelopmental disorders
> Mental retardation
> Autistic spectrum disorders (including Asperger syndrome)
> Rett syndrome
> Genetic and chromosomal abnormalities
> X-linked mental retardation ( MRX23)
> Albright hereditary osteodystrophy
> Duchenne muscular dystrophy
> Factor VIII hemophilia
> Fragile X syndrome
> Lesch-Nyhan syndrome
> Triple X and 9p mosaicism
> 47 XXY karyotype
> Partial trisomy 16
> 9p monosomy
> Beckwith-Wiedemann syndrome
> Tuberous sclerosis
> Congenital adrenal hyperplasia due to 21-hydroxylase deficiency
> Phenylketonuria
> Corpus callosum dysgenesis
> Craniosynostosis
> Klinefelter syndrome
> Neurofibromatosis
> Developmental stuttering
Acute brain lesions
> Post-traumatic
> Vascular
> Infectious
> Varicella-zoster virus
> Herpes simplex encephalitis
>  Mycoplasma pneumoniae
> Lyme disease
Post-infectious
> Sydenham’s chorea
> Pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS)
Neurodegenerative diseases
> Huntington disease
> Neuroacanthocytosis syndromes
> Neurodegeneration with brain iron accumulation
Other systemic diseases
> Behçet’s syndrome
> Antiphospholipid syndrome
Peripheral trauma
Medications and toxins
> Amphetamines, cocaine, heroin, methylphenidate, pemoline, antipsychotics (tardive tics), antidepressants, antiepileptics (carbamazepine, phenytoin, phenobarbital, lamotrigine), L-dopa
Functional tic-like jerks