EMQs in Clinical Medicine.pdf - Peshawar Medical College

98 Neurology
A test dose of an anticholinesterase, e.g. edrophonium, improves muscle
power and can also be used to aid diagnosis.
Myasthenia gravis can be treated with the use of anticholinesterases (oral
pyridostigmine is a popular drug) and oral corticosteroids (for immunosuppression).
Be aware of Eaton–Lambert syndrome (a manifestation of bronchial
small cell carcinoma) where there is defective release of acetylcholine at
neuromuscular junctions giving rise to a myasthenic syndrome. In myasthenic
syndrome the muscle strength increases and reflexes return with
repeated contraction, unlike MG where repeated contraction gives rise to
more weakness and a reduction of reflexes.
D
A 15-year-old boy is found to have several coffee-coloured patches on
his body. Slit-lamp examination reveals the presence of Lisch nodules.
This is a presentation of type I neurofibromatosis (also known as von
Recklinghausen’s disease). It is an autosomal dominant condition characterized
by decreased production of neurofibromin.
Diagnosis requires two of seven diagnostic criteria.
(i) six or more café-au-lait spots 5 mm (in children 10) or 15 mm
in adults
(ii) axillary/inguinal freckling
(iii) two or more neurofibromas or even one plexiform neurofibroma
(iv) optic glioma
(v) two or more Lisch nodules (iris hamartoma detected with slit-lamp
examination)
(vi) osseous lesion such as sphenoid dysplasia/pseudoarthrosis
(vii) family history in first-degree relative.
36 Gait
Answers: F D L G B
F
D
A 65-year-old man with a festinant, shuffling gait.
There is a characteristic fixed stoop with reduced arm swing while walking.
As a result of the impairment of righting reflexes, sufferers are
sometimes observed to fall stiffly ‘like a tree’ without putting their arms
out to break the fall.
A 60-year-old woman walks with a drop foot and high-stepping gait
shortly after hip replacement.
Sciatic nerve is derived from the anterior primary rami of L4, L5, S1, S2
and S3, and divides into the common peroneal and tibial nerves about
two-thirds of the way down the thigh.
Sciatic nerve injury is an important postoperative complication of hip
replacement and can result from direct trauma or traction on the nerve.