Athetosis is caused by lesions in several brain areas such as the hippocampus and the motor thalamus, as well as the corpus striatum; therefore children during the developmental age could possibly suffer from severe communication deficits such as speech impairment, hearing loss, and failed or delayed acquirement of sitting balance, although most people with athetosis have normal or near-normal intelligence. Causes
Athetosis is a symptom primarily caused by the marbling, or degeneration of the basal ganglia. This degeneration is most commonly caused by complications at birth or by Huntingtons disease, in addition to rare cases in which the damage may also arise later in life due to stroke or trauma. The two complications of particular interest are intranatal asphyxia and neonatal jaundice. Asphyxia
Asphyxia directly causes basal ganglia damage due to lack of oxygen and therefore, insufficient nutrient supply. The lesions caused by asphyxia are most prominent on the caudate nucleus and the putamen. However, a less-studied consequence of the resulting hypoxia is its effect on the concentrations of the neurotransmitter dopamine within the synapses of neurons in the basal ganglia. Hypoxia leads to an increase in the extracellular dopamine levels and therefore, an increase in the activity of the dopaminergic neurons. Furthermore, this increase in extracellular concentration is not caused by an increase in the neurotransmitter synthesis, but instead on inhibiting its reuptake back into the neurons and glial cells. Therefore, there is an increased dopaminergic effect as dopamine remains in the synapse at higher concentrations leading to additional post-synaptic response.
By doing so it frees the thalamus from pallidal inhibition allowing the thalamus to send excitatory outputs to the cortex. Therefore, the lesions to the thalamus or any other part of this feedback loop can result in movement disorders as they can alter the reactivity of one towards the other. Also, in a case of people with thalamic stroke, a majority suffered severe sensory deficits and ataxia. It is proposed that this loss of proprioception and the ensuing loss of synergic stabilization may also lead to abnormal movements, such as those dealt with in athetosis. Fahrs syndrome
Treatments
There are several different treatment approaches to dealing with athetosis. The most common methods are the use of drugs, surgical intervention, and retraining movements of the afflicted person. It is suggested that training a person to relearn movements can be helpful in select situations. Though, generally, this type of treatment will not work, in certain cases it can be found to be very helpful in treating the symptom of athetosis.Drugs can also be used in the treatment of athetosis, however their collective effectiveness is not very convincing. There is not a single drug that is a standard among treatment. Many different medicines can be used, including:

Artane
Cogentin
Curare, though not practical due to respiratory paralysis
Tetrabenazine
Haloperidol
Thiopropazate
DiazepamMost instances of drug use where the symptoms seem to be lessened tend to be in more mild cases of athetosis.Treatment by surgical intervention can obviously have the most immediate impact, again however, it is not a cure-all.