Motor Paralysis:

1) Cortical paralysis:
These lesions are rare as the larynx has bilateral motor innervation. May be seen in case of :

• Congenital cerebral palsy
• Encephalitis
• Kernicterus
• Diffuse cerebral arteriosclerosis

2) Corticobulbar paralysis:
These are extremely rare due to paralysis of the corticobulbar tracts.

• Vascular insufficiencies such as vertebral or posteroinferior cerebellar arteries
• Multiple sclerosis
• Intramedullary tumors like gliomas.

3) Peripheral causes:
They are responsible for 90 percent of the vocal cord paralysis. The lesion involves the fibres of the laryngeal nerves from the surface of the medulla up to the larynx. Usually combines with multiple cranial nerves.

Peripheral paralysis of the vocal cords is divided into two groups:

• High vagal paralysis: Lesions near the ganglion with only recurrent laryngeal nerve damage
• Low vagal paralysis: Nerve intact up to ganglion