EMQs in Clinical Medicine.pdf - Peshawar Medical College

94 Neurology
demyelinating disease of the central nervous system (CNS) that has a
progressive course. There is an increased prevalence further away
from the equator but the aetiology is still unknown. More women are
affected (1.5–2:1).
Diagnosis is made clinically but magnetic resonance imaging (MRI)
is the imaging of choice to detect demyelinating plaques. CSF examination
usually shows oligoclonal bands of IgG on electrophoresis.
Electrophysiological tests reveal delays in the propagation of potentials
(e.g. visual, somatosensory, auditory evoked potentials).
Intravenous methylprednisolone can reduce the severity of relapses
but does not improve long-term prognosis. Interferon- has been
shown to reduce the relapse rate in patients suffering from the relapsing–
remitting form of the illness but its use is limited because of its
high cost.
32 Nerve lesions
Answers: B J D F I
B
J
D
F
I
Inability to dorsiflex foot after blow to the side of knee.
The blow to the leg compresses the common peroneal nerve against the
head of the fibula. There is a weakness in eversion and the presence of foot
drop. There may be some numbness on the anterolateral aspect of the shin.
Sensory loss over medial one and a half fingers.
The median nerve supplies sensation to the palmar surface of the first
three and a half fingers. In ulnar nerve palsy there may be features of a
‘claw hand’, i.e. hyperextension at the metacarpophalangeal joints and
flexion at the interphalangeal joints of the fourth and fifth fingers.
A 25-year-old man presents with a winged scapula and the inability
to raise his arm above the horizontal.
The long thoracic nerve supplies serratus anterior which allows the lateral
and forward movement of the scapula.
Sensory loss bilaterally below the level of the umbilicus.
T10 is the level of the umbilicus
Right-sided ptosis, miosis and wasting of small muscles of the
right hand.
This is often called a Klumpke’s paralysis (C8–T1 lesion) with paralysis
of the small muscles of the hand, arm held in adduction and lack of
sensation over the ulnar side of the arm. The presence of a Horner’s
syndrome results from an avulsion of T1 (the preganglionic sympathetic
fibres leave the spinal nerve soon after it emerges from the intervertebral
foramen).