A case of silent myasthenia gravis with bilateral vocal cord paralysis' onset after thyroidectomy

Vocal cord paralysis is one of the most fearsome complications following thyroidectomy surgery. It can be unilateral or bilateral and in this case it could cause a life threatening respiratory distress which requires an emergency tracheostomy (1). Literature demonstrates a spontaneous recovery of vocal cord motility is possible in 79-87,5 % of the patients. Huge multinodular goiter that overturn the normal anatomy or an excessive bleeding that obscure the surgical field can make the intraoperative identification on both laryngeal nerves difficult. The tumoral invasion of the nerves following thyroid carcinoma could be a factor as well. For this reason the intra-operative nerve monitoring (IONM) is a great resource in this type of surgery.

We report the case of patient with bilateral laryngeal nerves paralysis after thyroidectomy with two failed extubating attempts which required the transfer to the intensive care unit. Two days after the patient was extubated and taken under O2 therapy. After a more detailed interview with the patient he reported a well-known history of exertional dyspnea which led to the suspect of latent form of Myasthenia gravis started to rise.

The electromyography (EMG) resulted alternated so that the diagnosis of Myasthenia Gravis was confirmed. The patient started a therapy protocol with corticosteroids and Pyridostigmine with progressive improvements of the symptoms.

In the suspect of a MG patient a careful preoperative evaluation as well as an appropriate intra-operative setting is demanded.