Which of the following conditions is included under extrapulmonary restrictive disorders?

• A. Pneumoconiosis
• B. Idiopathic pulmonary fibrosis
• C. Guillian Barre
• D. Asthma

Answer: (C)

Extrapulmonary restrictive disorders are conditions that limit lung expansion due to factors outside the lungs themselves. In this context, Guillain-Barre syndrome is particularly relevant as it is a neurological disorder that can affect the nerves controlling the respiratory muscles. This leads to a decreased ability to breathe effectively, resulting in restrictive lung disease.

The key distinction here is that extrapulmonary restrictive disorders arise from factors that are not directly related to lung tissue. Guillain-Barre alters muscle function, impacting the mechanics of breathing despite the lung parenchyma being healthy.

In contrast, pneumoconiosis and idiopathic pulmonary fibrosis specifically involve damage or scarring within lung tissue, making them examples of intrapulmonary restrictive disorders rather than extrapulmonary ones. Asthma, while it impacts airflow, primarily involves airway constriction rather than restriction in the same sense as extrapulmonary involvement. Thus, Guillain-Barre stands out as the correct choice because it aligns with the definition of extrapulmonary restrictive disorders due to its neurological etiology affecting respiratory muscle function.