Putamen
The putamen is also part of the basal ganglia and can be involved in hemiballismus due to the fact that it projects to the premotor cortex through the globus pallidus. As a result, damage to this area can also cause hemiballistic movements to be seen as it is also part of the chain in movement. Caudate nucleus
The caudate nucleus is the portion of the basal ganglia that helps control voluntary movement. Damage to this area can also result in hemiballismus as it is directly related to voluntary movement. Cortical structures
While the majority of damage that causes hemiballismus occurs within the basal ganglia, there are still cases that have been documented on which damage to cortical structures has caused hemiballistic movements. Diagnosis
Diagnosis of hemiballismus is a clinical one, made with observation during clinical examination. Hemiballismus is a clinical sign with a number of different causes. Therefore, a diagnosis underlying this clinical sign should be sought. The observer should note sudden, flinging movements of a limb(s) and occasionally the face. This is commonly unilateral ("Hemiballismus"). The movements must be distinguished from other hyperkinetic movement disorders such as tremor (generally more rhythmic, and smaller amplitude) and chorea, akathisia and athetosis (all are often of lower amplitude and less violent). Treatments
When treating hemiballismus, it is first important to treat whatever may be causing the manifestation of this disorder. This could be hyperglycemia, infections, or neoplastic lesions. Some patients may not even need treatment because the disorder is not severe and can be self-limited.
The removal of the ear canal wall results in: 

a space, the "mastoid cavity", which is less likely than the original ear canal to resist infection;
exposure of the ossicles, which may allow the subsequent formation of a new cholesteatoma deep to the ossicles. To prevent this, these ossicles must be removed, which may diminish the patients hearing.The formation of a mastoid cavity by removal of the canal wall is the simplest and most effective procedure for facilitating the removal of cholesteatoma, but may bestow the most lasting infirmity due to loss of ear function upon the patient treated in this way. The following strategies are employed to mitigate the effects of canal wall removal:

Careful design and construction of the mastoid cavity. This is essential for the health and integrity of the protective sheet of migrating, keratising epithelium which lines the distorted ear canal. This requires the surgeon to saucerise the cavity. A high facial ridge and an inappropriately small cartilaginous meatus are obstructions to epithelial migration and are particularly high risk factors for failure of the self-cleaning mechanism of the external ear. Partial obliteration of the mastoid cavity. This can be performed using a wide range of materials. Many of these resorb in time, which means that the long-term results of such surgery are poorer than the short-term results. Reconstruction of the ear canal wall. Canal wall reconstruction has been performed using ear canal skin alone, fascia, cartilage, titanium as well as by replacing the original intact wall.