MYASTHENIA GRAVIS

SUMMARY

1. Myasthenia gravis (MG) is an autoimmune disorder of the NMJ characterized by fatigability (weakness worsens with use & recovers with rest); affects brushing hair, climbing stairs.
2. Normal reflexes, sensation; proximal muscle weakness, inducible ptosis (with ice) & bulbar signs.

3. Most patients have auto-antibodies to either the post-syn­aptic acetylcholine receptor or muscle-specific tyrosine kinase receptor (MuSK).

4. An even smaller group of MG patients has neither anti-acetylcholine receptor nor anti­-MuSK antibodies (termed "seronegative MG").
5. MG is associated with thymomas (15% of patients) and thymic hyperplasia (60%), hence, do a CT chest to investigate.

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].