Bilateral recurrent laryngeal nerve palsy is seen in -
Thyroidectomy
Carcinoma thyroid
Cancer cervical oesophagus
All of the above
Causes of bilateral recurrent laryngeal nerve palsy are: 

Idiopathic
Post thyroid surgery
Thyroid malignancy
Carcinoma of cervical part of esophagus
Cervical Lymphadenopathy.

NOTE:
Peripheral neuritis causes high vagal palsy which leads to both superior as well as recurrent laryngeal nerve palsy i.e. bilateral complete palsy.