Question

A 65-year-old suffered from a stroke 2 days ago. He now presents with involuntary, violent, and flinging movements of the limbs on one side. What is the likely site of lesion in this patient?

• A. Subthalamic nuclei
• B. Globus pallidus
• C. Putamen
• D. Caudate nucleus

Answer 1

The Correct Option is A

In the context of this clinical scenario, the 65-year-old patient exhibits involuntary, violent, and flinging limb movements on one side following a stroke. This description aligns with a condition known as hemiballismus.

Hemiballismus is characterized by sudden, involuntary, jerky movements, primarily affecting one side (i.e., unilateral). The typical site of the lesion causing hemiballismus is in the subthalamic nucleus of the brain. The subthalamic nucleus is part of the basal ganglia, which is integral in regulating movement.

Detailed Explanation:

• The subthalamic nuclei play a crucial role in modulating the activity of the basal ganglia circuitry.
• Damage to the subthalamic nucleus due to a stroke disrupts this regulation, which can lead to the manifestation of violent, dysregulated movements, a hallmark of hemiballismus.
• The subthalamic nucleus has connections with both the globus pallidus and the substantia nigra, influencing inhibitory pathways crucial for movement control.

Conclusion: Given the presentation of unilateral violent, flinging movements post-stroke, the lesion's likely site is the subthalamic nuclei.