*3.2.1 Idiopathic*

In majority of cases with bilateral vocal fold palsy, no aetiological factors can be found. However, 50% these patients tend to recover completely or partially within a period of 1–2 years. The improvement is thought to be a result of delayed maturation of vagal nuclei [8].

#### *3.2.2 Traumatic*

Trauma either to the vocal cords and cricoarytenoid joint or to the vagus nerve itself can present with bilateral abductor palsy in neonates. Commonest causes are birth trauma from instrumental delivery, cardiac surgeries, mediastinal surgeries, for example, PDA ligation, etc.

#### *3.2.3 Perinatal encephalopathy*

This is another recognized cause for bilateral abductor palsy in neonatal period. It can result from various causes like perinatal hypoxia or ischaemia, birth trauma or infection.

#### *3.2.4 Neurological disorders*

Various neurological disorders like Myasthenia Gravis, Charcot-Marie tooth Disease and multiple sclerosis can present with bilateral vocal cord paralysis; however, there are features of other neurological dysfunctions as well. These conditions to present neonatally are also exceedingly rare.

#### *3.2.5 Inflammatory*

Neuritis of recurrent laryngeal nerve resulting from bacterial or viral infections can cause bilateral abductor palsy. In the pre-antibiotic era, Syphilis was considered one of the common causes, which now has become very rare. Viruses such as Influenza and Herpes Simplex virus are also reported of causing bilateral abductor palsy [9].
