1. Jawad us Salam 2. Akhtar Ali Baloch 3. Munir Hussain Siddiqui 4. Babar Bashir 

5. Qamar un Nisa 6. Afzal Qasim 7. Muhammad Masroor

1. Asstt. Prof. of Neurology, DIMC, 2. Assoc. Prof. of Medicine, DIMC, 3. Asstt. Prof. of Medicine, DIMC, 

4. Asstt. Prof. of Medicine, DIMC, 5. Asstt. Prof. of Neurology, DIMC, 6. Asstt. Prof. of Cardiology, DIMC, 

7. Prof. of Medicine, DIMC, DUHS, Karachi

ABSTRACT

Objective: To assess the effectiveness of Repetitive Nerve Stimulation Test in the diagnosis of Seronegative Myasthenia Gravis.

Study Design: Descriptive Observational.

Place and Duration of Study: This study was conducted at Dow University of Health Sciences and Jinnah Postgraduate Medical Centre during the period of three years from 2010 to 2013.

Materials and Methods: A total 129 cases, both out patients as well as inpatients, who were diagnosed as a case of Myasthenia Gravis clinically and by other investigations including, Edrophonium Test, Chest Radiology, and Acetylcholine Receptor antibodies were studied. 

Results:  Out of 129 cases, of Myasthenia Gravis, who were admitted or came in outpatient department, 55 subjects are male. On Repetitive Nerve Stimulation study at 3Hz, significant decrement was found in trapezius in 16 (88%) patients who are seronegative and in 90 (81%) seropositive patients.  

Conclusion: Repetitive Nerve Stimulation Test is a promising tool in the diagnosis of Myasthenia Gravis and should be a part of investigations used to diagnose this neuromuscular junction disorder especially in seronegative cases, for confirming the diagnosis. 

Key Words: Nerve Stimulation Test, Seronegative Myasthenia Gravis, neuromuscular junction