In this Master Series episode, we explore the puzzling case of a seventeen-month-old boy who suddenly stops talking, avoids eye contact, and becomes increasingly irritable. His grandmother is concerned. His growth chart shows something unexpected, and his vital signs are subtly off.

What’s hiding behind the behavioral changes?
What does a sudden shift in head growth really mean?

We’ll walk you through the clinical reasoning from the first clue to the final insight—step by step. This episode is designed to sharpen your diagnostic thinking, especially when it comes to developmental regression and neurologic red flags in toddlers.

You’ll learn how to:

• Approach regression with a structured differential

• Interpret pediatric growth charts like a pro

• Identify the early signs of dangerous neurologic pressure

• Distinguish key features of conditions that mimic each other on the exam

Think you’ve got it figured out?

Let’s find out together—no spoilers here.

Keep mastering your craft, and let’s dive in.