QuestionSBA
QuestionChoice
The lateral femoral cutaneous nerve provides sensory innervation to the skin of the lateral thigh. It does not control motor function. Injury to this nerve could cause sensory disturbances such as such as numbness and tingling. 'Cutaneous' in the name of a nerve suggests that it provides nerve supply to the skin and has sensory functions only.
10025249
e
Lateral femoral cutaneous nerve injury
QuestionChoice
This is the correct answer. This vignette describes an isolated right foot drop. The common fibular nerve, a branch of the sciatic nerve, is particularly susceptible to injury at the fibular head and is more commonly associated with isolated foot drop due to its role in dorsiflexion of the foot. Causes of common fibular nerve damage include fractures of the fibula and the use of a tight plaster cast.
10025245
a
Common fibular nerve injury
QuestionChoice
The femoral nerve primarily innervates the muscles of the anterior thigh, such as the quadriceps muscles, and is not directly responsible for dorsiflexion of the foot. As all other lower limb examinations are normal, it is unlikely femoral nerve. Injury to the femoral nerve would lead to other motor deficits such as weakness in knee extension (due to innervation of quadriceps), but not isolated foot drop.
10025247
c
Femoral nerve injury
QuestionChoice
The sciatic nerve is a major nerve that provides both sensory and motor innervation to the lower limbs, including the muscles responsible for leg and foot movement. A proximal lesion of the sciatic nerve could potentially affect the common fibular nerve and lead to foot drop, however, a direct injury to the sciatic nerve itself is less common and typically causes more widespread neurological deficits than just an isolated foot drop.
10025246
b
Sciatic nerve injury
QuestionChoice
The tibial nerve primarily innervates the posterior leg muscles and is responsible for plantarflexion of the foot, not dorsiflexion. The tibial nerve also supplies the muscles involved in flexing the toes, such as the flexor digitorum longus and the flexor hallucis longus. Injury to the tibial nerve could affect toe flexion.
10025248
d
Tibial nerve injury
Concept
Chapter
2693
3856
Foot drop
Topic
141
Neurology
17447
A 24 year old man attends his GP surgery with difficulty walking. He broke his left leg in a skiing accident several months ago. Although the fracture has healed well, he has noted ongoing difficulty in lifting his left foot from the floor.

On examination, he is unable to dorsiflex the right foot and therefore has difficulty in lifting the toes while walking. Sensation is reduced on the dorsum of the left foot and lateral aspect of the left leg. Both feet are peripherally warm and well perfused. All other lower limb examinations are normal.

Which of the following is the most likely underlying diagnosis?
a