EMQs in Clinical Medicine.pdf - Peshawar Medical College

Neurological problems – answers 97
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A 62-year-old woman presents with a stiff spastic tongue and ‘Donald
Duck’-like speech. On examination she had a brisk jaw jerk and was
prone to laughing inappropriately.
Pseudobulbar palsy is an upper motor neuron lesion caused by bilateral
lesions of the lower cranial nuclei and can be associated with emotional
lability. It is known to occur in multiple sclerosis, motor neuron disease
and after bilateral strokes affecting the corticobulbar pathways.
A 27-year-old woman presents with wasting and weakness of the small
muscles of the hand. Examination reveals loss of pain and temperature
sensation over the trunk and arms with intact vibration sense.
Syringomyelia is the term used to describe the development of a fluidfilled
cavity (syrinx) within the spinal cord. The condition may be associated
with an Arnold–Chiari malformation.
The expansion of the syrinx compresses surrounding tracts, giving rise to
a particular pattern of symptoms/signs that relates to the position of the
tracts within the spinal cord.
The pain and temperature modalities are characteristically affected first
as a result of compression of decussating spinothalamic fibres anteriorly
in the ventral horns. This loss of pain and temperature sensation is often
described as occurring in a ‘cape’ distribution (over trunk and arms).
Wasting and weakness of hands and arms reflects involvement of
cervical anterior horn cells.
Sensory loss can result in Charcot’s joints (neuropathic joints damaged
through loss of sensation). Involvement of the sympathetic trunk can
give rise to Horner’s syndrome.
The condition is gradually progressive and there is no known curative
treatment. Patients with an Arnold–Chiari malformation may be treated
with decompression at the foramen magnum to slow progression.
A 34-year-old woman complains of generalized weakness in her
muscles, diplopia and weakening of her voice if talking for longer
than half a minute. Examination reveals bilateral ptosis.
Myasthenia gravis (MG) is an acquired autoimmune disease characterized
by muscle weakness and fatiguability resulting from the presence of
anti-acetylcholine receptor antibodies.
MG is associated with other autoimmune disease, e.g. thyroid disease.
The patient usually presents as a young adult with extraocular and
bulbar muscle weakness. Weakness of the facial muscles is very
common. Indeed bilateral facial weakness gives rise to the classic
horizontal smile called a ‘myasthenic snarl’. Neck weakness leads to the
head drooping. Limb weakness is usually much more pronounced
proximally.
Detection of anti-acetylcholine receptor antibodies is a reliable test for
diagnosis of MG.