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 Foundation Year Doctor working in GP Surgery. 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:
Myasthenia Gravis
Conditions that cause generalised muscles weakness: Lambert-Eaton Syndrome, multiple sclerosis, motor neurone disease, hyperthyroidism, acute Guillain- Barre
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):