Life-threatening misdiagnosis of bulbar onset myasthenia gravis as a motor neuron disease: How much can one rely on exaggerated deep tendon reflexes

Authors

Department of Neurology, Isfahan Neurosciences Research Center, Alzahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

The autoimmune disease myasthenia gravis (MG), can mimic a variety of neurological disorders leading to a delay in diagnosis and treatment. On occasions, misdiagnosis of MG could lead to unnecessary therapeutic interventions. We report the case of a 50 year-old man, in whom MG was mistaken for motor neuron disease (MND). Subsequently, correct diagnosis and optimal management resulted in saving his life and significant improvement in his functional status. We discuss the importance of considering MG as one of the potential differential diagnoses among cases of new onset or recurrent unexplained bulbar symptoms, despite exaggerated deep tendon reflexes. Also, a literature review on the misdiagnosis of MG and the potential pitfalls in MG diagnosis are discussed.

Keywords

1.
Drachman DB. Myasthenia gravis. N Engl J Med 1994;330:1797-810.  Back to cited text no. 1
    
2.
Keesey JC. Clinical evaluation and management of myasthenia gravis. Muscle Nerve 2004;29:484-505.  Back to cited text no. 2
    
3.
Grob D, Brunner N, Namba T, Pagala M. Lifetime course of myasthenia gravis. Muscle Nerve 2008;37:141-9.  Back to cited text no. 3
    
4.
Grob D, Arsura EL, Brunner NG, Namba T. The course of myasthenia gravis and therapies affecting outcome. Ann N Y Acad Sci 1987;505:472-99.  Back to cited text no. 4
    
5.
Oosterhuis HJ. The natural course of myasthenia gravis: A long term follow up study. J Neurol Neurosurg Psychiatry 1989;52:1121-7.  Back to cited text no. 5
    
6.
Weinberg DH, Rizzo JF 3 rd , Hayes MT, Kneeland MD, Kelly JJ Jr. Ocular myasthenia gravis: Predictive value of single-fiber electromyography. Muscle Nerve 1999;22:1222-7.  Back to cited text no. 6
    
7.
Akhawajah NM, Oger J. Late-onset myasthenia gravis: A review when incidence in older adults keeps increasing. Muscle Nerve 2013;48:705-10.  Back to cited text no. 7
    
8.
Mitsumoto H, Chad DA, Pioro EP. Amyotrophic Lateral Sclerosis. Contemporary Neurology. Philadelphia: FA Davis Company; 1998.  Back to cited text no. 8
    
9.
Aragonès JM, Bolíbar I, Bonfill X, Bufill E, Mummany A, Alonso F, Illa I et al. Myasthenia gravis: A higher than expected incidence in the elderly. Neurology 2003;60:1024-6.  Back to cited text no. 9
    
10.
Andrews PI. Autoimmune myasthenia gravis in childhood. Semin Neurol 2004;24:101-10.  Back to cited text no. 10
    
11.
Khanna S, Liao K, Kaminski HJ, Tomsak RL, Joshi A, Leigh RJ. Ocular myasthenia revisited: Insights from pseudo--internuclear ophthalmoplegia. J Neurol 2007; 254:1569-74.  Back to cited text no. 11
    
12.
Kleiner-Fisman G, Kott HS. Myasthenia gravis mimicking stroke in elderly patients. Mayo Clin Proc 1998;73:1077-8.  Back to cited text no. 12
    
13.
Wheeler SD. Misdiagnosis of myasthenia gravis. J Natl Med Assoc 1987;79:425-9.  Back to cited text no. 13
[PUBMED]    
14.
Libman R, Benson R, Einberg K. Myasthenia mimicking vertebrobasilar stroke. J Neurol 2002;249:1512-4.  Back to cited text no. 14
    
15.
Kutz I, Garb R, Kuritzky A. Diagnosis of misdiagnosis: On some of the origins and functions of psychophysical misdiagnosis. Gen Hosp Psychiatry 1983;5:197-202.  Back to cited text no. 15
    
16.
Lloyd JM, Mitchell RG. Myasthenia gravis as a cause of facial pain. Oral Surg Oral Med Oral Pathol 1988;66:45-6.  Back to cited text no. 16
    
17.
Roberts ME, Steiger MJ, Hart IK. Presentation of myasthenia gravis mimicking blepharospasm. Neurology 2002;58:150-1.  Back to cited text no. 17
    
18.
Pasnoor M, Wolfe GI, Nations S, Trivedi J, Barohn RJ, Herbelin L, et al. Clinical findings in MuSK-antibody positive myasthenia gravis: A U.S. experience. Muscle Nerve 2010;41:370-4.  Back to cited text no. 18