BOF: 26
You are called to see a patient
in the surgical ward. He is recovering from surgery. He has had emergency
surgery for dissecting aneurysm of the descending aorta. The postoperative
period was complicated by pneumonia and pseudomembranous colitis. He has been
transferred from the ITU to the surgical wards two days prior to you been called
to see him. The patient is not moving his right lower limb normally and the
surgical registrar thinks he may have had a stroke.
On examination, the patient is
conscious and alert and has no abnormality in relation to speech. His cranial
nerves are intact and there is no neurological deficit in the upper limbs. On
examination of his lower limbs there is weakness of dorsiflexion and eversion of
his right foot and there is weakness of toe extension. Sensation is impaired
over the lateral aspect of the right lower leg and over the dorsum of the right
foot.
The lesion in this patient is:
a)
Anterior spinal artery thrombosis
b)
Lacunar infarction of the left internal capsule
c)
Femoral nerve palsy
d)
Tibial nerve palsy
e)
Common peroneal nerve palsy
Answer:
e)
A compression neuropathy of the
common peroneal nerve may occur after prolonged bed rest. Associated loss of
weight with reduction in the size of the protective fat pad may also contribute.
Anterior spinal artery
thrombosis would result in paraparesis and a characteristic pattern of sensory
loss, bilateral loss of pain and temperature sensation with preserved joint
position sense and vibration sense (See ACES for
PACES page 452, 453)
Lesions of the internal capsule
would result in hemiparesis or hemiplegia (See ACES
for PACES page 451)
Revise the features of femoral
nerve palsy and tibial nerve palsy (See ACES for
PACES page 518,519)
Last updated: 15/04/06
