Which one of the following lesion is dangerous to life?

As bilateral abductor paralysis can cause sudden dyspnoea and severe stridor, it is dangerous and hence should be managed immediately by tracheostomy. ABDUCTOR DYSPHONIA It is due to spasms of posterior cricoarytenoid muscle (the only abductor) and thus keeping the glottis open. Patient gets a breathy voice or breathy breaks in voice. The condition is gradually progressive and the symptoms get aggravated during periods of stress or when patient uses telephone.Like adductor spasm dysphonia, cause of abductor spasmodic dysphonia is not known. Treatment is injection of botulinum toxin in posterior cricoarytenoid muscles. It can be done by percutaneous or endoscopic route. The former being used with EMG guidance. Results of injection are not as good as in adductor spasmodic dysphonia. Only about 50% of patients improve and the duration of improvement is also less. Disadvantages of injection treatment are that it may compromise vocal cord movements with respiration leading to airway obstruction. Patients who do not respond to toxin injection can be treated by thyroplasty type I or fat injection. A prior gelfoam injection can be used to judge the effectiveness of the above procedure. Speech therapy should be combined with injection treatment as speech therapy alone may not be effective. Ref: ENT textbook by Dhingra 6th edition Pgno : 314,315