A misdiagnosed myasthenia gravis with anti-muscle-specific tyrosine kinase antibodies with possible childhood onset

Ana V Nikolić; Dragana V Lavrnić; Ivana Z Basta; Dimitrije M Nikolić; Slobodan A Apostolski

doi:10.2298/4862

Ana V Nikolić Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
Dragana V Lavrnić Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
Ivana Z Basta Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
Dimitrije M Nikolić Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Neurology Department, University Children’s Hospital, Belgrade, Serbia
Slobodan A Apostolski Private Neurological Practice “Apostolski”, Belgrade, Serbia

DOI: https://doi.org/10.2298/4862

Keywords: myasthenia gravis, child, diagnosis, differential, antibodies, protein-tyrosine kinases,

Abstract

Introduction. Childhood onset myasthenia gravis associated with anti-muscle-specific tyrosine kinase antibodies is very rare and atypical in presentation. Case report. As a baby, the presented patient was choking and sleeping with open eyes. She had weak cry and breathing difficulties. In childhood, there were frequent falls and fluctuating swallowing difficulties. At the age of 19 she was misdiagnosed with Miller Fisher syndrome due to the presence of diplopia, ataxia and hyporeflexia with spontaneous recovery. Repetitive nerve stimulation test was normal. Four years later, after several relapses, there was significant decrement on facial muscles. Neostigmine test was negative, provoking muscle fasciculations. Serum anti-muscle-specific tyrosine kinase antibodies were positive. With cyclosporine therapy she achieved the minimal manifestations status. Conclusion. The presented case confirms that childhood onset myasthenia gravis associated with anti-muscle-specific tyrosine kinase antibodies is often with atypical presentation and spontaneous remissions, so it could be easily misdiagnosed.

References

Guptill JT, Sanders DB. Update on muscle-specific tyrosine ki-nase antibody positive myasthenia gravis. Curr Opin Neurol 2010; 23(5): 530−5.

Skjei KL, Lennon VA, Kuntz NL. Muscle specific kinase auto-immune myasthenia gravis in children: a case series. Neuro-muscul Disord 2013; 23(11): 874−82.

Takahashi Y, Sugiyama M, Ueda Y, Itoh T, Yagyu K, Shiraishi H, et al. Childhood-onset anti-MuSK antibody positive myasthenia gravis demonstrates a distinct clinical course. Brain Dev 2012; 34(9): 784−6.

Anlar B, Yilmaz V, Saruhan-Direskeneli G. Long remission in muscle-specific kinase antibody-positive juvenile myasthenia. Pediatr Neurol 2009; 40(6): 455−6.

Gungor-Tuncer O, Orhan EK, Yilmaz V, Parman Y, Oflazer P, Sar-uhan-Direskeneli G, et al. . Prepubertal Anti-Musk Positive My-asthenia Gravis With Long Remission. Neuromuscul Disord 2014; 24(1): 36−9.