Myasthenia gravis is an acquired autoimmune disorder characterised by fatigable weakness, typically of the periocular, facial, bulbar, and girdle muscles.
Immune disorders associated with myasthenia gravis:
- rheumatoid arthritis
- systemic lupus erythematosus
- pernicious anaemia
- Sjogren's syndrome
Diagnosis usually confirmed by detection of Acetyl Choline receptor antibodies (90% in generalised 50% in ocular)
Tensilon tests are rarely used because of cardiac risks.
Electromyography testing for the classical decrement on repetitive stimulation is reserved for antibody negative or emergency diagnosis.
Referral: Neurology if suspect.