A 52-year-old man presents with progressive hoarseness and dysphagia for 3 weeks. On laryngoscopy, the left vocal cord is seen in the paramedian position with reduced mobility. He has no history of thyroid surgery or intubation. What is the most appropriate next step in management?

## Clinical Context This patient presents with unilateral vocal cord paralysis (UVCP) in the paramedian position with no clear iatrogenic cause (no prior thyroid or cardiac surgery, no intubation history). The key clinical feature is the **unknown etiology** — this mandates imaging to identify the underlying cause along the RLN pathway. ## Management Algorithm for UVCP ```mermaid flowchart TD A[Unilateral VCP diagnosed]:::outcome --> B{Known cause?}:::decision B -->|Yes: post-thyroid/cardiac surgery| C[Observe 3-6 months for spontaneous recovery]:::action B -->|No: idiopathic/unknown| D[Imaging: CT chest with contrast]:::action D --> E{Lesion found?}:::decision E -->|Yes: malignancy, aneurysm, etc.| F[Treat underlying pathology]:::action E -->|No: idiopathic RLN palsy| G[Observe 3-6 months]:::action G --> H{Recovery at 6 months?}:::decision H -->|Yes| I[Continue observation]:::outcome H -->|No| J[Voice rehabilitation/injection laryngoplasty]:::action ``` ## Why CT Chest with Contrast? **Key Point:** In idiopathic or unknown-cause UVCP, the RLN must be traced from the larynx down through the thorax. CT with contrast evaluates: - Lung apex masses (Pancoast tumour) - Mediastinal masses - Aortic aneurysm or arch abnormalities - Lymphadenopathy - Thyroid pathology **High-Yield:** The left RLN has a longer course (loops around the aortic arch) and is more commonly affected by thoracic pathology than the right RLN. ## Timing of Investigations | Investigation | Timing | Purpose | |---|---|---| | **Imaging (CT/CXR)** | **Immediate** (at diagnosis) | Rule out serious underlying cause | | **EMG/NLG** | 3–4 weeks post-onset | Confirm denervation; prognostic value | | **Voice therapy** | After 3–6 months if no recovery | Functional rehabilitation | | **Injection/thyroplasty** | 6–12 months if no recovery | Permanent voice improvement | **Clinical Pearl:** EMG is useful *after* 3 weeks (to allow denervation changes to develop) and helps predict recovery potential, but it does NOT replace imaging to identify the cause. ## Why Observation Alone Is Inadequate **Warning:** Observing for 3 months without imaging in an idiopathic case risks missing a treatable malignancy or vascular lesion. This is appropriate only *after* imaging has ruled out serious pathology. [cite:Scott-Brown's Otorhinolaryngology Ch 35]