A 35-year-old woman presents with sudden hearing loss in the left ear for 3 days. Audiometry shows unilateral low-frequency SNHL (bone conduction thresholds elevated at 250–500 Hz). Weber test lateralizes to the right ear. Tinnitus and mild vertigo are present. What is the most appropriate next step in management?

Explanation

## Clinical Presentation Analysis This patient presents with **sudden unilateral low-frequency SNHL** — a classic presentation of sudden sensorineural hearing loss (SSHL). The low-frequency pattern with tinnitus and vertigo suggests **cochlear hydrops or immune-mediated SNHL**, not retrocochlear pathology. ## Audiogram Pattern Recognition | Audiogram Pattern | Typical Cause | Management | |-------------------|---------------|-------------| | Sudden unilateral low-frequency SNHL | Cochlear hydrops, immune SNHL, viral labyrinthitis | **Corticosteroids** (urgent) | | Sudden unilateral high-frequency SNHL | Retrocochlear (acoustic neuroma) | MRI to rule out tumor | | Sudden unilateral flat SNHL | Viral labyrinthitis, sudden SNHL | Corticosteroids ± MRI | | Bilateral symmetric SNHL | Presbycusis, ototoxicity, genetic | Hearing aids, monitor | **Key Point:** Low-frequency SNHL in the context of sudden onset + tinnitus + vertigo is **cochlear**, not retrocochlear. Retrocochlear lesions (acoustic neuroma) typically cause high-frequency loss or asymmetric loss with progressive course. ## Management Algorithm for Sudden SNHL ```mermaid flowchart TD A[Sudden unilateral SNHL]:::outcome --> B{Onset within 2 weeks?}:::decision B -->|Yes| C[Start oral corticosteroids immediately]:::action C --> D[Repeat audiometry at 1–2 weeks]:::action D --> E{Response to steroids?}:::decision E -->|Good response| F[Continue steroids, taper]:::action E -->|Poor response| G[Consider MRI to exclude retrocochlear cause]:::action B -->|No| H[Observe, hearing aids if chronic]:::action ``` **High-Yield:** **Sudden SNHL is a medical emergency.** Corticosteroids must be started within 2 weeks of onset (ideally within 72 hours) to maximize recovery. Delaying steroids for imaging reduces efficacy. MRI is reserved for cases that do not respond to steroids or have high suspicion for retrocochlear pathology (progressive unilateral loss, asymmetric loss, or neurologic signs). **Clinical Pearl:** Low-frequency SNHL with vertigo and tinnitus suggests **cochlear** origin (hydrops, viral labyrinthitis, or immune SNHL). High-frequency SNHL suggests **retrocochlear** origin (acoustic neuroma). This patient's low-frequency pattern argues against acoustic neuroma.