New Diagnosis of Myasthenia Gravis Following Magnesium Replacement

Tyler Kemnic^1, , James Choi¹, Samanjit Kandola¹ and Khader Herzallah¹

¹Michigan State University, United States

Cite this paper:
Tyler Kemnic, James Choi, Samanjit Kandola and Khader Herzallah. New Diagnosis of Myasthenia Gravis Following Magnesium Replacement. American Journal of Medical Case Reports. 2020; 8(6):148-149. doi: 10.12691/ajmcr-8-6-3

Abstract

A 29-year-old female G2P2 with a past medical history of hyperthyroidism and depression was admitted for 2-months of progressively worsening weakness of her bilateral upper and lower extremities. Initial investigations were unremarkable, and the patient’s weakness improve the next morning. The patient was thought to have a Somatoform Disorder and was planned for home discharge, however on the day of discharge her magnesium was 1.2 mg/dL. After repletion, she developed seizure-like activity and respiratory failure, requiring mechanical ventilation and transfer to the ICU. In ICU, patient received another dose of replacement magnesium that caused another seizure, code blue and re-intubation. Subsequent lab work revealed reactive Acetylcholine receptor antibodies and subsequent chest imaging demonstrated thymoma, confirming a diagnosis of Myasthenia Gravis in Crisis. The patient improved following plasma exchange and was discharged home with outpatient follow up.

Keywords:
myasthenia gravis magnesium seizure

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]	https://rarediseases.info.nih.gov/diseases/7122/myasthenia-gravi Accessed 8/3/2019.
[2]	Wendell LC, Levine JM. Myasthenic crisis. Neurohospitalist. 2011; 1(1): 16-22.
[3]	Baretić, M., Balić, S., & Gudelj, G. (2010). Myasthenic crisis as a side effect of methimazole therapy: case report. Acta clinica Croatica, 49 1, 67-71.
[4]	Fawcett WJ, Haxby EJ, Male DA. Magnesium: physiology and pharmacology. Br J Anaesth. 1999; 83(2): 302-20.
[5]	Singh P, Idowu O, Malik I, Nates JL. Acute Respiratory Failure Induced by Magnesium Replacement in a 62-Year-Old Woman with Myasthenia Gravis. Tex Heart Inst J. 2015; 42(5): 495-497.