INTERNAL MEDICINE SHORT CASE QUESTION WITH ANSWERS.

INTERNAL MEDICINE CASE QUESTION

SET AND COMPILED BY: SULEIMAN NDORO JNR (DR AUDI)

Mr. Kwangaru, a 55 year old man comes to your clinic with complaints of difficulty in chewing and facial weakness when attempting to smile. He also complains of general body weakness and easy fatigability for the past 2 weeks. The weakness which started in the upper limbs and is associated with double vision and ptosis increases with exercise and is relieved by rest. Mr. Kwangaru  has no other neurological deficits.

a)    Classify the disease

b)    What is your diagnosis?

c)    Outline the etiology of Mr. Kwangaru’s condition

d)    Outline the various laboratory testing methods of the condition above

e)    How is Mr. Kwangaru’s disease treated?

f)     Which other disease is in the same category as Mr. Kwangaru’s disease?

g)    What causes the disease in (f)?

ANSWERS

a)    A neuromuscular junction disease

b)    Myasthenia gravis

c)  Myasthenia gravis is an autoimmune disease in which patients produce antibodies that destroy the acetylcholine receptors on muscle. Acetylcholine is the neurotransmitter that makes muscles contract.

d)    –Anti-AChR radioimmunoassay

-Repetitive nerve stimulation

-Single fiber electromyography

-Edrophonium chloride (Tensilon test)

e) Treatment consists of acetyl cholinesterase inhibitors which block the enzymatic breakdown of acetylcholine, thus following greater concentrations of acetylcholine at the receptor. Pyridostigmine is the drug of choice.

However, immunosuppressive drugs, including prednisone, azathioprine and cyclosporine are necessary to attack the autoimmune process.

Plasmapheresis and IVIG have also been shown to help.

Surgical thymectomy is also beneficial.

f)     Lambert-Eaton myasthenic syndrome (LEMS)

g) Like Myasthenia gravis, LEMS is an autoimmune condition although its target is the presynaptic voltage-gated calcium channel involved in acetylcholine release, not the receptor.