**Core Concept**
The **Globus pallidus** is a structure in the **basal ganglia** that plays a crucial role in movement control and cognition. Lesions in this area can lead to various motor and cognitive disturbances. The **basal ganglia** are a group of nuclei linked to the **thalamus** and **subthalamic nucleus**, facilitating the regulation of voluntary motor movements.

**Why the Correct Answer is Right**
A lesion in the **Globus pallidus** can cause **hemiballismus**, characterized by involuntary, violent, and large-amplitude movements of the proximal part of the limbs. This is due to the disruption of the **indirect pathway** of motor control, which normally inhibits unnecessary movements. The **Globus pallidus** is part of this pathway, and its dysfunction leads to an imbalance in **dopamine** and **GABA** regulation.

**Why Each Wrong Option is Incorrect**
**Option A:**
**Option B:**
**Option C:**
**Option D:**

**Clinical Pearl / High-Yield Fact**
A key point to remember is that lesions in different parts of the **basal ganglia** can lead to distinct movement disorders, such as **Parkinson's disease** associated with **substantia nigra** damage.

**Correct Answer:** D. Hemiballismus