QuestionSBA
QuestionChoice
This answer is incorrect. Whilst a common peroneal nerve lesion can give rise to foot drop, sensory loss and pain, this patient's presentation is not wholly in keeping with a common peroneal nerve lesion. The impairment of inversion (a tibial nerve function), is indicative of an L5 radiculopathy rather than a common peroneal nerve lesion.
10025808
d
L3
QuestionChoice
This is incorrect. The dermatome of L4 supplies the anterior aspect of the knee and medial malleolus, rather than the dorsum of the foot. Furthermore, the patella reflex is commonly disrupted in L4 lesions, whereas this patient demonstrated normal reflexes. L4 is therefore not the most likely location of the lesion in this case.
10025807
c
L4
QuestionChoice
This answer is incorrect. Whilst a common peroneal nerve lesion can give rise to foot drop, sensory loss and pain, this patient's presentation is not wholly in keeping with a common peroneal nerve lesion. The impairment of inversion (a tibial nerve function), is indicative of an L5 radiculopathy rather than a common peroneal nerve lesion.
10025806
b
Common peroneal nerve
QuestionChoice
This is correct. This vignette is characteristic of an L5 radiculopathy. The patient demonstrates clinical signs of foot drop, including a loss of dorsiflexion and a high stepping gate. The back pain and history of heavy lifting is suggestive of a disc herniation causing sciatica-like shooting pain, while the dermatomal loss of sensation on the dorsum of the foot makes an L5 lesion most likely. Limb reflexes are intact in L5 lesions.
10025805
a
L5
QuestionChoice
This is incorrect. Tibial nerve damage is characterised by weakness of foot plantarflexion and sensory loss over the plantar surface of the foot, rather than the dorsum. The tibial nerve is therefore not the most likely location of the lesion in this case. Another point to note is that the tibial nerve is a deep structure and is therefore not often injured through mechanical trauma.
10025809
e
Tibial nerve
Concept
Chapter
2693
3856
Foot drop
Topic
141
Neurology
L5
17559
A 39 year old male presents to the GP surgery after a back injury sustained by picking up a heavy box at work. He experienced sudden, severe pain in his lower back with shooting pains down the back of his legs. Since the incident he has been unsteady on his feet tripping over multiple times. 
The patient enters the consultation room with a high-stepping gait. On examination there is sensory loss over the dorsum of his left foot. Dorsiflexion, inversion and eversion of the foot are significantly weaker on the left compared to the right side, however, all reflexes of the upper and lower limbs are intact.
Which of the following structures is most likely implicated in the patient's presentation
a