Neurology - Lower Limb

Question 0

Unilateral leg weakness Ddx - LMN

Answer 0

1. Root lesion

2. Nerve lesion

Question 1

Unilateral leg weakness Ddx - UMN

Answer 1

1. Stroke
2. Tumour
3. MS

Question 2

B12/folate deficiency - subacute combined degeneration of the cord (SCDC) signs

Answer 2

1. Spastic paraparesis
2. Up going plantar
3. Reduced lower limb reflexes
4. Dorsal column loss including Romberg

Question 3

Amyotrophic lateral sclerosis (ALS) signs

Answer 3

Type of MND

1. Weakness
2. Wasting
3. Fasiculation
4. Spasticity
5. Brisk reflexes

Question 4

Foot drop Ddx

Answer 4

1. Common peroneal nerve palsy
2. Stroke
3. L4/5 root lesion
4. MND
5. Charcot-Marie-Tooth syndrome

Question 5

Bilateral leg weakness Ddx - acute/progressive (unlikely in OSCE)

Answer 5

1. Acute spinal cord compression (UMN)
2. Cauda equina syndrome (LMN)
3. Guillain Barre syndrome (LMN)

Question 6

Bilateral leg weakness Ddx - UMN

Answer 6

1. Sagittal sinus lesion (exclusively motor signs)
2. Bilateral strokes
3. Syringomyelia (with upper limb signs)
4. Cord trauma
5. Cord compression (extramural tumour, disc prolapse, spondylosis)
6. Intrinsic cord disease (tumour, vascular myelopathy, MS)
   Check sensory level for 4-6
   LMN at level of 5

Question 7

Bilateral leg weakness Ddx - LMN

Answer 7

1. Polio
2. Mostly motor peripheral neuropathy (GB, lead poisoning, Charcot Marie tooth)
3. Mixed peripheral neuropathy (diabetic, uraemic, vitamin def., paraneoplastic, alcoholic)

Question 8

Peripheral sensory neuropathy Ddx

Answer 8

1. Mononeuropathies - I.e. Compression neuropathy e.g carpel tunnel
2. Diabetic peripheral neuropathy
3. Demyelinating neuropathy
4. Neuritis - B12 deficiency, shingles

Question 9

Guillain barre - cause, observation

Answer 9

Cause - cross reactivity (anti-ganglioside antibodies)
Observation - progressive, idiopathic, symmetrical weakness, and loss of deep tendon reflexes. Maximal intensity at 4 weeks

Question 10

Charcot Marie Tooth - cause, observation

Answer 10

Cause: Genetic disease
Observation: gradual loss of muscle bulk and sensation.
1. Foot drop
2. Loss of sensation
3. Neuropathic pain

Question 11

Charcot Marie Tooth - Ix

Answer 11

1. Nerve conduction studies
2. Nerve biopsy
3. Genetic testing