**Question:** True about Guillain-Barré Syndrome (GBS) is A/E

A. GBS is a post-infectious autoimmune disorder
B. GBS is caused by a deficiency in the immune system
C. GBS affects only children
D. GBS has a uniformly predictable progression

**Correct Answer:** A. GBS is a post-infectious autoimmune disorder

**Core Concept:** Guillain-Barré Syndrome (GBS) is a rare neurological disorder that occurs when the body's immune system attacks the peripheral nervous system (PNS). This attack leads to inflammation and damage of the myelin sheath, which surrounds nerve fibers. GBS typically develops following a viral or bacterial infection, which triggers an immune response against the body's own tissues.

**Why the Correct Answer is Right:** GBS is considered a post-infectious autoimmune disorder because it is triggered by an infection and involves an autoimmune response targeting the PNS myelin sheath. The correct answer (A) highlights this key aspect, distinguishing GBS from other options.

**Why Each Wrong Option is Incorrect:**

B. GBS is not caused by a deficiency in the immune system but rather results from an excessive or misdirected immune response. This makes option B incorrect.

C. GBS affects people of all ages, including children and adults. Although children may be more susceptible to certain types of GBS, the statement that GBS affects only children is incorrect. This makes option C incorrect.

D. GBS has a uniformly predictable progression. While GBS can have a relatively consistent course, the severity and progression of symptoms can vary among patients. This makes option D incorrect.

**Clinical Pearl:** Understanding the autoimmune nature of GBS is crucial in guiding diagnosis and treatment. In clinical practice, recognizing potential triggers (e.g., prior infections) and considering GBS in the differential diagnosis of acute flaccid paralysis can lead to timely diagnosis and appropriate management.