top of page

Myasthenia Gravis

Practice this case based on how you are assessed in your OSCEs, and use the relevant sections for general revision. 🤓

 

Doctor Instruction:


You are a doctor working in family medicine. Your next patient is called Tom Holland – a 49-year-old male due to limb weakness. Please take a history and perform a relevant examination.


 

Patient History:


Your name is Tom Holland- a 49-year-old male – senior IT engineer.


You have been feeling weak lately e.g. getting up from a chair, chewing food, running. This usually occurs late at night and started a few months ago but has been slowly worsening. Taking rests generally improves weakness, and you do not experience these problems in the morning.


While reading a book before bed at night, you have noticed not only double vision, but you find it difficult to open your eyes sometimes. Sometimes, you have noticed your wife has to ask you to repeat what you have said as if she didn't understand what you have said – you are not sure why this is the case– maybe you will ask her later today what the problem was. You struggled to chew food during dinner, so you are now eating softer food. You do not have any swallowing difficulties. No breathlessness.


Ideas, Concerns, Expectations:

  • You think this might be due to work at first but now maybe due to old age. You are worried because despite taking breaks at work – you continuously have problems and struggle to do things at night. You simply do not have any energy to do things like cooking, laundry…etc. You think you might retire soon because of this. You hope you can have some energy pills to help you get going – ask if drinking energy drinks will help?


Past Medical History:

  • Previous thymoma (had surgery)

  • Hypertension

  • Type 1 diabetes


Family History:

  • Rheumatoid Arthritis


Drug History:

  • Propranolol, insulin

  • NKDA


Social History:

  • Smoker – 10 cigarettes/day for 20 years

  • Occasional alcohol drinker

  • Work in IT

  • Live alone

  • Independent at home


 

Examination Findings:


  • Thymectomy scar

  • Repeated movements exacerbate symptoms of weakness

  • Examination otherwise is normal


 

Differentials:

  1. Myasthenia Gravis

  2. Conditions that cause generalised muscles weakness: Lambert-Eaton Syndrome, multiple sclerosis, motor neurone disease, hyperthyroidism, acute Guillain- Barre

  3. Anaemia


 

Investigations:

  • Observations

  • Bloods to rule out anaemia/causes for weakness– iron studies, B12 + folate, FBC, Vit D, calcium, glucose, TFTs for hyper/hypothyroidism

  • Specific markers for MG – Ach-R/MuSK/ LRP4 antibodies – can be positive in MG

  • Edrophonium test

  • Serial pulmonary function test – low FVC + NIF in MG

  • Consider CT/MR Chest (those not diagnosed with thymoma (associated with MG)) – may show thymic enlargement

  • Consider repetitive nerve stimulation/ EMG/ MR Head


 

Management (Myasthenia Gravis):

    Want to read more?

    Subscribe to oscefinals.com to keep reading this exclusive post.

    bottom of page