In a child with OCD, MRI will reveal reduced volume / atrophy in :
**Core Concept**
The question is testing the association between Obsessive-Compulsive Disorder (OCD) and structural brain abnormalities. OCD is a neuropsychiatric disorder characterized by recurring, intrusive thoughts and compulsions to perform specific rituals or behaviors. Research has linked OCD to alterations in brain regions involved in emotion regulation, habit formation, and motor control.
**Why the Correct Answer is Right**
Studies have consistently shown that individuals with OCD exhibit reduced volume in the orbitofrontal cortex (OFC), a region critical for executive function, decision-making, and impulse control. The OFC is also involved in the regulation of emotional responses, which is often impaired in OCD patients. This reduced volume is thought to contribute to the development of OCD symptoms, such as repetitive behaviors and intrusive thoughts.
**Why Each Wrong Option is Incorrect**
* **Option A:** The basal ganglia are involved in motor control and habit formation, but are not directly implicated in the pathophysiology of OCD.
* **Option B:** The amygdala is a key structure in fear processing and emotional regulation, but is not specifically linked to OCD.
* **Option C:** The hippocampus is involved in memory formation and spatial navigation, but is not directly related to the pathophysiology of OCD.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that OCD is a neurodevelopmental disorder, and structural brain abnormalities, such as reduced OFC volume, are thought to contribute to the development of symptoms. This knowledge is crucial for understanding the underlying pathophysiology of OCD and developing effective treatment strategies.
**Correct Answer: C. Striatum.**