Beneficial effects of albuterol in congenital endplate acetylcholinesterase deficiency and Dok-7 myasthenia

Abstract

Introduction: Congenital myasthenic syndromes (CMS) are disabling but treatable disorders. Anticholinesterase therapy is effective in most of them, but is contraindicated in endplate (EP) acetylcholinesterase (AChE) deficiency, the slow-channel syndrome, Dok-7 myasthenia, and β(2) -laminin deficiency, and is not useful in CMS due to defects in muscle-specific kinase (MuSK), agrin, and plectin. EP AChE, Dok-7, and β(2)-laminin deficiencies respond favorably to ephedrine, but ephedrine can no longer be prescribed in the USA.

Methods: We used albuterol, another sympathomimetic agent, to treat 3 patients with EP AChE deficiency and 15 with Dok-7 myasthenia. Response to therapy was evaluated by a 9-point questionnaire pertaining to activities of daily life.

Results: Comparison of the pre- and posttreatment responses indicated a beneficial response to albuterol (P < 0.001) in both patient groups. The adverse effects of therapy were like those of ephedrine.

Conclusion: Our observations should spur controlled, prospective clinical trials of albuterol in these as well as other CMS.

Figure 1

Distance walked (A) and steps climbed (B) without having to rest before and after albuterol therapy. Asterisks indicate patients who were unable to climb steps before therapy and have not tried to do so after therapy. (C) Effect of 3,4-DAP, and of 3,4-DAP plus albuterol, on walking distance and steps climbed by Patient 14. (D) Walking distance and steps climbed by Patient 15 before and at 1, 2, 5, and 10 months after the treatment with albuterol.