OSCEs revision

Question 1

MG Ix

Answer 1

Bloods: FBC, U&Es, TFTs, creatine kinase (myositis), anti-AChR, anti-MuSK, voltage-gated calcium channel (Lambert Eaton) antibodies

Imaging: CXR and CT chest (to detect thymoma)

Special tests: tensilon test (no longer performed), spirometry

Question 2

GBS Ix

Answer 2

Bloods: FBC, U&Es, B12/folate, TFTs (exclude other causes of neuropathy), anti-ganglioside antibodies

Special tests: nerve conduction studies, LP (elevated protein), spirometry

Question 3

MG Rx

Answer 3

Supportive therapy, e.g. physiotherapy

First-line: Pyrodistigmine

Prednisolone or DMARDs can be offered if the above doesn’t work

Thymectomy

Question 4

GBS Rx

Answer 4

Supprotive therapy, e.g. physiotherapy

IVIg or plasma exchange

Question 5

Optic neuritis Ix

Answer 5

Bedside: full upper limb, lower limb, cranial nerve, gait and ophthalmological examinations, with a full set of observations
Bloods:
FBC, CRP, ESR: rule out infectious cause of optic neuritis
VDRL: positive in syphilis (cause of optic neuritis)
ACE: sarcoid can cause optic neuritis
AQP-4 antibody: raised in neuromyeitis optica
B12 and folate level
Imaging:
MRI brain and spinal cord with contrast: demyelinating plaques
Special:
Lumbar puncture: oligoclonal bands
Visual evoked potentials: delayed velocity but a normal amplitude