The genetic relationship of ADHD to Tourette syndrome, however, has not been fully established. A genetic link between autism and Tourettes has not been established as of 2017. Mechanism
The exact mechanism affecting the inherited vulnerability to Tourettes is not well established. Tics are believed to result from dysfunction in cortical and subcortical brain regions: the thalamus, basal ganglia and frontal cortex. Neuroanatomic models suggest failures in circuits connecting the brains cortex and subcortex; imaging techniques implicate the frontal cortex and basal ganglia. In the 2010s, neuroimaging and postmortem brain studies, as well as animal and genetic studies, made progress towards better understanding the neurobiological mechanisms leading to Tourettes. These studies support the basal ganglia model, in which neurons in the striatum are activated and inhibit outputs from the basal ganglia.Cortico-striato-thalamo-cortical (CSTC) circuits, or neural pathways, provide inputs to the basal ganglia from the cortex. These circuits connect the basal ganglia with other areas of the brain to transfer information that regulates planning and control of movements, behavior, decision-making, and learning. Behavior is regulated by cross-connections that "allow the integration of information" from these circuits. Involuntary movements may result from impairments in these CSTC circuits, including the sensorimotor, limbic, language and decision making pathways. Abnormalities in these circuits may be responsible for tics and premonitory urges.The caudate nuclei may be smaller in subjects with tics compared to those without tics, supporting the hypothesis of pathology in CSTC circuits in Tourettes.
Millipede burns are a cutaneous condition caused by some millipedes that secrete a toxic liquid that causes a brownish pigmentation or burn when it comes into contact with the skin. Some millipedes produce quinones in their defensive secretions, which have been reported to cause brown staining of the skin. See also
Centipede bite
Skin lesion

References


== External links ==