CRCM  Vol.3 No.11 , November 2014
Severe Weight Loss and Dropped Head Syndrome in MuSK Myasthenia Gravis
Muscle Specific Receptor Thyrosine Kinase (MuSK) Myasthenia Gravis (MG) is a rare auto-immune disorder of the neuromuscular junction. The clinical presentation of MG is dominated by fluctuating weakness of the extra-ocular, orofacial and limb muscles. The clinical presentation of MuSK MG can vary, which may delay diagnostic procedures. We present a patient who initially presented with severe weight loss and slowly progressive developing neck extensor weakness and diplopia. A single fiber EMG led to the diagnosis MG and antibodies directed towards MuSK were detected. He was treated with prednisone and the steroid sparing agent azathioprine after which he made full recovery.

Cite this paper
Bing Tan, D. , Linssen, W. and Liberov, B. (2014) Severe Weight Loss and Dropped Head Syndrome in MuSK Myasthenia Gravis. Case Reports in Clinical Medicine, 3, 587-591. doi: 10.4236/crcm.2014.311127.
[1]   Benatar, M. (2006) A Systematic Review of Diagnostic Studies in Myasthenia Gravis. Neuromuscular Disorders, 16, 459-467.

[2]   Patrick, J. and Lindstrom, J. (1973) Autoimmune Response to Acetylcholine Receptors. Science, 180, 871-872.

[3]   Hoch, W., McConville, J., Helms, S., Newsome-Davis, J., Melms, A. and Vincent, A. (2001) Auto-Antibodies to the Receptor Tyrosine Kinase MuSK in Patients with Myasthenia Gravis without Acetylcholine Receptor Antibodies. Nature Medicine, 7, 365-368.

[4]   McConville, J., Farrugia, M.E., Beeson, D., Kishore, U., Metcalfe, R., Newsome-Davis, J. and Vincent, A. (2004) Detection and Characterisation of MuSK Antibodies in Seronegative Myasthenia Gravis. Annals of Neurology, 55, 580-584.

[5]   Pevzner, A., Schoser, B., Peters, K., Cosma, N., Karakatsani, A., Schalke, B., et al. (2012) Anti-LRP4 Autoantibodies in AChR- and MuSK-Antibody-Negative Myasthenia Gravis. Journal of Neurology, 259, 427-435.

[6]   Gasperi, C., Melms, A., Schoser, B., Zhang, Y., Meltoranta, J., Risson, V., et al. (2014) Anti-Agrin Autoantibodies in Myasthenia Gravis. Neurology, 82, 1976-1983.

[7]   Deymeer, F., Gungor-Tuncer, O., Yilmaz, V., Parman, Y., Serdaroglu, P., Ozdemir, C., Vincent, A. and Saruhan-Direskeneli, G. (2007) Clinical Comparison of Anti-MuSK- vs Anti AChR-Positive and Seronegative Myasthenia Gravis. Neurology, 68, 609-611.

[8]   Wirtz, P.W., Nijnuis, M.G., Sotodeh, M., Willems, L.N.A., Brahim, J.J., Putter, H., Wintzen, A.R. and Verschuuren, J.J. (2003) The Epidemiology of Myasthenia Gravis, Lambert-Eaton Myasthenic Syndrome and Their Associated Tumours in the Northern Part of the Province of South Holland. Journal of Neurology, 250, 698-701.

[9]   Niks, E.H., Kuks, J.B.M. and Verschuuren, J.J.G.M. (2007) Epidemiology of Myasthenia Gravis with Anti-Muscle Specific Kinase Antibodies in the Netherlands. Journal of Neurology, Neurosurgery and Psychiatry, 78, 417-418.

[10]   Grob, D., Brunner, N., Namba, T. and Pagala, M. (2008) Life-time Course of Myasthenia Gravis. Muscle Nerve, 37, 141-149.

[11]   Evoli, A., Tonali, P.A., Padua, L., Lo Monaco, M., Scuderi, F., Batocchi, A.P., Marino, M. and Bartoccioni, E. (2003) Clinical Correlates with Anti-MuSK Antibodies in Generalized Seronegative Myasthenia Gravis. Brain, 126, 2304-2311.

[12]   Stickler, D.E., Massey, J.M. and Sanders, D.B. (2005) MuSK-Antibody Positive Myasthenia Gravis: Clinical and Electrodiagnostic Patterns. Clinical Neurophysiology, 116, 2065-2068.

[13]   Zhou, L., McConville, J., Chaudhry, V., Adams, R.N., Skolasky, R.L., Vincent, A. and Drachman, D.B. (2004) Clinical Comparison of Muscle-Specific Tyrosine Kinase (MuSK) Antibody-Positive and -Negative Myasthenic Patients. Muscle & Nerve, 30, 55-60.

[14]   Sanders, D.B., El-Salem, K., Massey, J.M., McConville, J. and Vincent, A. (2003) Clinical Aspects of MuSK Antibody Positive Seronegative MG. Neurology, 60, 1978-1980.

[15]   Pasnoor, M., Wolfe, G.I., Nations, S., Trivedi, J., Barohn, R.J., Herbelin, L., et al. (2010) Clinical Findings in MuSK-Antobody Positive Myasthenia Gravis: A U.S. Experience. Muscle & Nerve, 41, 370-374.

[16]   Meriggioli, M.N. and Sanders, D.B. (2009) Autoimmune Myasthenia Gravis: Emerging Clinical and Biological Heterogeneity. Lancet Neurology, 8, 475-490.

[17]   Hatanaka, Y., Hemmi, S., Morgan, M.B., Scheufele, M.L., Claussen, G.C., Wolfe, G.I. and Oh, S.J. (2005) Nonresponsiveness to Anticholinesterase Agents in Patients with MuSK-Antibody-Positive MG. Neurology, 65, 1508-1509.

[18]   Evoli, A. and Padua, L. (2013) Diagnosis and Therapy of Myasthenia Gravis with Antibodies to Muscle-Specific Kinase. Autoimmunity Reviews, 12, 931-935.

[19]   Gajdos, P., Chevret, S., Clair, B., Tranchant, C. and Chastang, C. (1997) Clinical Trial of Plasma Exchange and High Dose Intravenous Immunoglobulin in Myasthenia Gravis. Annals of Neurology, 41, 789-796.

[20]   Qureshi, A.L., Chaundry, M.A., Akbar, M.S., Mohammad, Y., Chua, H.C., Yahia, A.M., et al. (1999) Plasma Exchange versus Intravenous Immunoglobulin Treatment in Myasthenic Crisis. Neurology, 52, 629-632.

[21]   Gronseth, G.S. and Barohn, R.J. (2000) Practice Parameter: Thymectomy for Autoimmune Myasthenia Gravis (an Evidence-Based Review): Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology, 55, 7-15.

[22]   Leite, M.I., Ströbel, P., Jones, M., Micklem, K., Moritz, R., Gold, R., et al. (2005) Fewer Thymic Changes in MuSK Antibody-Positive than in MuSK Antibody-Negative MG. Annals of Neurology, 57, 444-448.