title: Isolated laryngeal myasthenia gravis for 26 years.
abstract: Laryngeal myasthenia gravis is a relatively rare variant of myasthenia gravis. A vast portion of patients with initial laryngeal myasthenia gravis develop involvement of ocular and/or extra-ocular muscles during the years after symptom onset although a minority of laryngeal myasthenia gravis patients continues to have isolated laryngeal muscle involvement for several years. We present a 58-year-old woman with recurrent episodic isolated dysphonia (associated with diffuse bilateral vocal cord paresis on laryngoscopy) since the age of 32. Dysphonia became permanent since 6 months. A diagnosis of laryngeal myasthenia gravis was made based on abnormal single-fiber electromyography and spectacular response to pyridostigmine treatment. Repetitive nerve stimulation was normal and anti-acetylcholine receptor and anti-muscle specific tyrosine kinase antibodies were absent. This case shows that laryngeal myasthenia gravis can be isolated during 26 years of follow-up. We propose that even when myasthenia gravis seems unlikely as underlying mechanism of isolated dysphonia (because of lack of antibodies, normal repetitive nerve stimulation, and absence of extra-laryngeal involvement after years of follow-up), single-fiber electromyography should be performed and myasthenia gravis treatment should be tried.
authors.affiliation: Department of Neurology, CHU Nîmes, Hôpital Caremeau, Place du Pr Debré, Nîmes Cedex 4 30029, France. Electronic address: dimitrirenard@hotmail.com.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Renard
authors.affiliation: Department of Otorhinolaryngology, CHU Nîmes, Hôpital Caremeau, Place du Pr Debré, Nîmes Cedex 4 30029, France.
authors.forename: Amir
authors.initials: A
authors.lastname: Hedayat
authors.affiliation: Department of Electrophysiology, CHU Nîmes, Hôpital Caremeau, Place du Pr Debré, Nîmes Cedex 4 30029, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Gagnard
mesh_terms: D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000473:pathology*; D008137:Longitudinal Studies; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000473:pathology*
keywords: Laryngeal; Myasthenia gravis