**4. Clinical evaluation**

A detailed history and a thorough clinical examination will most of the times lead to the inciting cause. Clinical history should focus on any significant perinatal events like maternal infection, maternal drug use, time and mode of delivery, instrumentation during labour, birth weight and neonatal infection. A family history should be taken as there are reported cases of this entity being inherited within the family members.

A complete head to toe examination of the affected child should always be done as there may be signs that can guide towards the aetiological cause. Neurological examination should include motor and sensory evaluation along with examination of cranial nerves specially 9th, 10th and 11th which exit commonly through the jugular foramen. Features of raised ICP such as bulged fontanelle, papilloedema should be sought. Chest and heart should be examined thoroughly. ENT examination should focus on palatal mobility, tongue mobility and presence of gag reflex.

The child may have a wide range of presentations. Most of the cases are asymptomatic until they present with sudden onset stridor preceded by upper respiratory tract infections. Other cases might present with stridor immediately following birth or few days after birth. Stridor is usually during the inspiratory phase and tends to worsen on crying where it is not unusual for a child to become cyanotic. Since the vocal folds are in adducted position change in voice is usually not encountered. Other clinical features may be difficulty in feeding, recurrent pneumonia, O2 dependence and repeated failure to extubate. Although nonspecific, these clinical features always warrant a laryngeal evaluation.
