Violent abnormal flinging movements which are irregular and affecting one side are called as –
**Core Concept**
Hemiballismus is a rare movement disorder characterized by violent, irregular, and involuntary flinging movements that predominantly affect one side of the body. It is caused by damage to the subthalamic nucleus, a structure in the basal ganglia.
**Why the Correct Answer is Right**
Hemiballismus is typically seen in patients with lesions in the subthalamic nucleus, which disrupts the normal functioning of the basal ganglia circuitry. This leads to an overactivity of the motor pathways, resulting in the characteristic flinging movements. The subthalamic nucleus is a key component of the basal ganglia, and damage to this area can cause a range of movement disorders.
**Why Each Wrong Option is Incorrect**
**Option A:** None provided, skipping to next option.
**Option B:** This option is likely referring to athetosis, a movement disorder characterized by slow, involuntary movements, often seen in patients with cerebral palsy or other neurodegenerative disorders. Athetosis is distinct from hemiballismus in its slower and more writhing nature.
**Option C:** This option is likely referring to hemiparesis, a condition characterized by weakness on one side of the body, often due to stroke or brain injury. Hemiparesis is not the same as hemiballismus, which involves involuntary flinging movements.
**Clinical Pearl / High-Yield Fact**
Hemiballismus is a rare but important movement disorder to recognize, as it can be a sign of underlying brain pathology. In clinical practice, it is essential to differentiate hemiballismus from other movement disorders, such as athetosis or hemiparesis.
**Correct Answer:** B. Athetosis.