A 68-year-old woman presents with progressive hoarseness over 3 weeks, weak cough, and difficulty swallowing liquids more than solids. On examination, the right vocal cord is in the paramedian position and does not move on phonation. The gag reflex is intact bilaterally. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis **Key Point:** Unilateral vocal cord paralysis in the paramedian position with hoarseness and weak cough indicates **recurrent laryngeal nerve (RLN) palsy**, a branch of the vagus nerve (CN X). ## Anatomy of RLN Injury | Feature | Left RLN | Right RLN | |---------|----------|----------| | Course | Loops under aortic arch | Loops under right subclavian artery | | Vulnerable sites | Thorax (aortic arch, lung apex, mediastinum) | Neck (thyroid, carotid) | | Common causes | Lung cancer, TB, aortic aneurysm | Thyroid surgery, thyroid cancer | **Clinical Pearl:** The **paramedian position** of the vocal cord (neither fully abducted nor adducted) is characteristic of RLN paralysis. This contrasts with superior laryngeal nerve (SLN) injury, which causes voice fatigue and loss of high pitch. ## Why Imaging Is the Next Step ```mermaid flowchart TD A[Unilateral RLN palsy]:::outcome --> B{Cause?}:::decision B -->|Iatrogenic| C[Known thyroid/cardiac surgery]:::outcome B -->|Idiopathic or progressive| D[Imaging required]:::action D --> E[Chest X-ray + CT thorax]:::action E --> F{Lesion found?}:::decision F -->|Yes| G[Treat underlying cause]:::action F -->|No| H[Idiopathic RLN palsy]:::outcome H --> I[Voice therapy + observation]:::action ``` **High-Yield:** - RLN palsy is **not idiopathic** until malignancy and other structural lesions are excluded - Lung cancer (especially left-sided) is the most common **non-iatrogenic** cause of RLN paralysis - Progressive hoarseness over 3 weeks suggests an expanding lesion (malignancy, aneurysm, mediastinal mass) - Chest X-ray is the initial screening tool; CT thorax provides detailed imaging of mediastinum and lung apices ## Why Other Options Are Incorrect - **Laryngoscopy/biopsy:** Used to visualize the vocal cord (confirms diagnosis) but does not identify the cause of RLN compression - **Voice rest + PPI:** Treats symptoms, not the underlying pathology; delays diagnosis of potentially life-threatening conditions - **EMG:** Confirms denervation but does not identify the structural cause [cite:Harrison 21e Ch 379; Robbins 10e Ch 27]