QuestionSBA
QuestionChoice
This would suggest an S1 radiculopathy, which would involve loss of plantarflexion, weakness of leg extension and knee flexion and loss of the ankle jerk reflex. Sensation would be reduced on the posterior aspect of the leg and the lateral edge of the foot
32097
e
Loss of sensation on the lateral edge of the foot
QuestionChoice
This would suggest a saphenous nerve lesion or L4 level lesion. The saphenous nerve is the largest branch of the femoral nerve, and entrapment may result in deep thigh ache, knee pain and paraesthesia of the anteromedial aspect of the leg
32095
c
Loss of sensation on the medial aspect of the leg
QuestionChoice
This would be present in a common peroneal nerve or L5 level lesion. The patient has suffered a common peroneal nerve lesion, the most common aetiologies of which are compression and trauma. Patients present with a loss of eversion and dorsiflexion (supplied by the common peroneal nerve), with intact inversion and plantarflexion (supplied by the tibial nerve). The common peroneal nerve also provides sensation to the anterolateral surface of the leg and dorsal aspect of the foot. Both the common peroneal and tibial nerve branches arise from the sciatic nerve
32093
a
Loss of sensation on the dorsum of the foot
QuestionChoice
This would suggest a sciatic nerve lesion or S1 level lesion. Peripheral neuropathy and cauda equina syndrome may also result in a loss of the ankle jerk reflex; however, this is more likely to present with bilateral foot drop. In common peroneal nerve lesions, the ankle deep tendon reflex is intact
32094
b
Absent ankle jerk
QuestionChoice
This would suggest an L5 radiculopathy or anterior horn cell dysfunction, which would also present with loss of dorsiflexion and eversion, but would also affect foot inversion, internal rotation and abduction of the hip. Patients typically present with back pain radiating down the lateral aspect of the leg
32096
d
Inability to internally rotate the hip
QuestionComment
S1 is sole and shin (weak plantar flex can dorsiflex)
60399
User
subscriber
Malignant Syndrome
Concept
Chapter
# Summary

Foot drop is a condition characterized by weakness or paralysis of the foot dorsiflexion and eversion. It can associated with systemic conditions, trauma, or focal neurological lesions. 

# Definition

Foot drop, also known as drop foot, is a gait abnormality characterized by the inability or difficulty in lifting the front part of the foot, resulting in dragging of the foot or a high-stepping gait. This condition is typically a symptom of an underlying neurological, muscular, or anatomical pathology.

# Aetiology

Foot drop may be caused by several factors:

- Common peroneal nerve lesions: The most common cause of foot drop is disease or trauma affecting the common peroneal nerve, particularly where it loops over the fibula's head on the knee joint's lateral aspect.
- L5 root lesion (radiculopathy): Foot drop can be a symptom of this condition, characterized by loss of **inversion** and sensory loss over the L5 dermatome. Lumbosacral disc herniation is the most common cause of this type of foot drop.
- Distal motor neuropathy: This condition is often associated with foot drop, accompanied by glove and stocking sensory disturbance and loss of all movements of the foot.
- Small cortical lesions: Foot drop can be associated with small cortical lesions, often presenting with other upper motor neuron features.
- Other causes: Intrinsic cord disease, partial sciatic nerve disease, and myopathy may also mimic foot drop, although these are less common.

# Signs and Symptoms

Key motor findings in foot drop include:

- Weakness or paralysis of dorsiflexion and eversion of the foot
- Difficulty in lifting the front part of the foot
- A high-stepping gait or foot dragging

In specific aetiologies, additional symptoms may be present:

- In L5 root lesions, loss of **inversion** (a tibial nerve function not lost in common peroneal nerve lesions), sensory loss over the L5 dermatome, and sciatica-type shooting leg pain.
- In distal motor neuropathy, glove and stocking sensory disturbance, and loss of all foot movements.


# Investigations

Investigations for foot drop typically involve:

- Neurological examination: To assess the strength, sensation, and reflexes in the lower limbs.
- Electromyography (EMG) and Nerve Conduction Studies (NCS): To evaluate the electrical activity in the muscles and nerves.
- Imaging studies: MRI or CT scans of the spine or brain may be ordered to identify potential causes such as disc herniations, spinal cord injuries, or small cortical lesions.
- Blood tests: To identify potential underlying conditions such as diabetes or other systemic diseases.

# Management

In most cases of common peroneal nerve palsy, the condition resolves spontaneously with lifestyle modifications avoiding the underlying cause of pressure or damage to the nerve.

Other menaagement options include:

- Physiotherapy: To strengthen the foot and leg muscles and improve gait.
- Orthotic devices: Such as braces or ankle-foot orthoses (AFOs) to support the foot and ankle.
- Medication: For underlying conditions that may cause foot drop such as diabetes
- Surgery: In some cases, decompression surgery or nerve grafts may be necessary.
218
216
Foot drop
Topic
34
Neurology
Video
Concept
216
Foot drop
304
XBigS3j
images/videos/neurology.png
Quesmed Tutorial: Advanced Neurology
Video
Concept
216
Foot drop
141
gGnLrDJ
images/videos/neurology.png
Foot drop
6419
A common peroneal nerve lesion causes foot drop, loss of dorsiflexion, eversion, and sensory loss over the dorsum of the foot.
A 25-year-old football player presents to Accident & Emergency with a sudden onset right-sided foot drop. X-rays of the right lower limb do not show any fractures. On examination, he cannot dorsiflex or evert his foot, but can plantarflex and invert his foot.

In view of the underlying diagnosis, which of the following examination findings will most likely be present in his right leg?
a