Pathogenesis (development of the disease)
The origin of the neurological disorder is the corpus striatum (“striate body”), which is a part of the basal ganglia. The basal ganglia are a group of endbrain and diencephalic nuclei (nuclei basales) that are of great importance for motor, as well as cognitive and limbic, regulation. The corpus striatum, in turn, is an important switch point in the extrapyramidal motor system (EPS) with the main task of inhibiting movement processes. The striatum contains the caudate nucleus (curved nucleus) and the putamen (shell body). In Tourette syndrome sufferers, both nucleus areas are reduced in size. Degeneration in this area results in hyperkineses (lightning-like movements). In addition, Tourette syndrome appears to be associated with dysfunction of dopaminergic signaling in the striatum.
Etiology (Causes)
Biographic Causes
- Genetic burden from parents: 1st-degree relatives have a 5-15% risk of developing Tourette syndrome; causative gene abnormalities have not yet been found.
- Intrauterine growth retardation – pathological (abnormal) delay in the growth of a fetus in the uterus (womb).
- Perinatal hypoxia – oxygen deficiency of the unborn during birth.
- Premature birth
- Low birth weight
Behavioral causes
- Consumption of stimulants
- Psycho-social situation
- Stress during gravidity
Causes related to disease
- Postnatal infections (after birth) – mainly with group A ß-hemolytic streptococci (GABHS) with PANDAS (pediatric autoimmune neuropsychiatric disorders associates with streptococcal infections).
- Secondary tics in the setting of the following underlying diseases (rare):
- Huntington’s chorea (synonyms: Huntington’s chorea or Huntington’s disease; older name: St. Vitus’ dance) – genetic disorder with autosomal dominant inheritance characterized by involuntary, uncoordinated movements accompanied by flaccid muscle tone; as a result, there are problems with eating, among other things.
- Chorea minor (Chorea Sydenham) – late manifestation of rheumatic fever (weeks to months) with involvement of the corpus striatum (part of the basal ganglia, which belong to the cerebrum); occurring almost exclusively in children; leads to hyperkineses (lightning-like movements), muscle hypotonia and mental changes
- Fragile X syndrome (Martin-Bell syndrome) – X-linked inherited syndrome in which the following malformations are most common: large auricles, large genitalia, sterility (infertility), and mental retardation
- Wilson’s disease (copper storage disease) – autosomal recessive inherited disease in which one or more gene mutations disrupt copper metabolism in the liver.
- Neuroacanthocytoses (Huntington disease like 2, autosomal recessive chorea-acanthocytosis, McLeod syndrome).
