**5.1 Endoscopic evaluation**

An in-office flexible laryngoscopy can be done as an initial diagnostic procedure to evaluate the mobility of bilateral vocal folds, adequacy of glottic chink and to rule out other associated laryngeal anomalies such as laryngomalacia, laryngeal cleft, anterior or posterior glottic stenosis, etc. In addition, it is also important to look for velopharyngeal closure. Functional endoscopic evaluation of swallowing should be done in those who have recurrent aspiration. A rigid endoscopic evaluation under intravenous anaesthesia will also be required to assess the subglottis, trachea and bronchi as it is not uncommon to encounter second laryngeal pathology such as subglottic stenosis and tracheobronchomalacia. Cricoarytenoid joint should also be assessed for its mobility and to rule out any traumatic dislocation.

### **5.2 Imaging**

## *5.2.1 Ultrasonography*

Ultrasound can detect the neurological abnormalities like meningomyelocele, Arnold Chiari malformation, hydrocephalus prenatally which can have associated bilateral abductor palsy. In neonates with significant morbidity, laryngeal ultrasound can also be done to detect vocal fold palsy and any associated pathologies in the neck [10].

#### *5.2.2 Magnetic resonance imaging*

MRI scan of brain, brainstem, neck and mediastinum should be done routinely as pathologies like Arnold Chiari malformation, intraventricular hemorrhage, meningomyelocele, brainstem dysgenesis, neck or mediastinal masses can be identified easily.

#### *5.2.3 X-ray*

Chest x-ray can give the evidence of aspiration if present as well as any associated cardiac, lungs or mediastinal pathologies.

### **5.3 Serology**

Cases where there are features of viral infection, viral serology should always be done specially for Herpes Simplex and Influenza virus. Anti-viral drugs if started early have good outcome in these cases. Also, serological tests for syphilis may be warranted if there are features of congenital syphilis.
