Periventricular heterotopia is characterized by neurons failing to migrate away from which region?

Periventricular heterotopia is characterized by neurons failing to migrate away from which region?

• A. To the cortex and forming excessive cortical columns
• B. From the thalamic nuclei to the cortex
• C. From the spinal cord to the brain
• D. From the ventricles, forming nodules along ventricular walls

Answer: (D)

Neurons migrate from the ventricular zone outward to form the cerebral cortex during brain development. In periventricular heterotopia, these neurons fail to migrate away from the ventricles and instead stay near the ventricular walls, creating nodules along those walls. That pattern—originating from the ventricles and forming nodules along the ventricular lining—is the hallmark of this condition. The other scenarios don’t fit: migrating neurons toward the cortex would build cortical structure differently, thalamic-to-cortical projections describe normal connectivity rather than a migration block, and neurons moving from the spinal cord to the brain aren’t the issue here.

Neurons migrate from the ventricular zone outward to form the cerebral cortex during brain development. In periventricular heterotopia, these neurons fail to migrate away from the ventricles and instead stay near the ventricular walls, creating nodules along those walls. That pattern—originating from the ventricles and forming nodules along the ventricular lining—is the hallmark of this condition.

The other scenarios don’t fit: migrating neurons toward the cortex would build cortical structure differently, thalamic-to-cortical projections describe normal connectivity rather than a migration block, and neurons moving from the spinal cord to the brain aren’t the issue here.