Station 3.18: Spastic legs

Question 1

Clinical

What are the clinical signs of Spastic legs?
What are the additional signs of Spastic legs?

Spastic legs

Examine this man’s lower limbs neurologically. He has had difficulty in walking.

Answer 1

• Wheelchair and walking sticks (disuse atrophy and contractures may be present if chronic)
• Increased tone and ankle clonus
• Generalized weakness
• Hyper‐reflexia and extensor plantars
• Gait: ‘scissoring’

Additional signs
* Examine for a sensory level suggestive of a spinal lesion
* Look at the back for scars or spinal deformity
* Search for features of multiple sclerosis, e.g. cerebellar signs, fundoscopy for optic atrophy
* Ask about bladder symptoms and note the presence or absence of urinary catheter.

Offer to test anal tone

Question 2

Discussion - common causes

What are the common causes of Spastic legs?

Spastic legs

Examine this man’s lower limbs neurologically. He has had difficulty in walking.

Answer 2

• Multiple sclerosis
• Spinal cord compression/cervical myelopathy
• Trauma
• Motor neurone disease (no sensory signs)

Question 3

Discussion - other causes

What are the other causes of Spastic legs?

Spastic legs

Examine this man’s lower limbs neurologically. He has had difficulty in walking.

Answer 3

• Anterior spinal artery thrombosis: dissociated sensory loss with preservation of dorsal columns
• Syringomyelia: with typical upper limb signs
• Hereditary spastic paraplegia: stiffness exceeds weakness, positive family history
• Subacute combined degeneration of the cord: absent reflexes with upgoing plantars
• Friedreich’s ataxia
• Parasagittal falx meningioma

Question 4

Discussion - Cord compression

What Cord compression in Spastic legs?

Spastic legs

Examine this man’s lower limbs neurologically. He has had difficulty in walking.

Answer 4

• Medical emergency
• Causes:
  ⚬ Disc prolapse (above L1/2)
  ⚬ Malignancy
  ⚬ Infection: abscess or TB
  ⚬ Trauma: # vertebra
• Investigation of choice: spinal MRI
• Treatment:
  ⚬ Urgent surgical decompression
  ⚬ Consider steroids and radiotherapy (for a malignant cause

Question 5

Discussion - Lumbo‐sacral root levels

What Lumbo‐sacral root levels in Spastic legs?

Spastic legs

Examine this man’s lower limbs neurologically. He has had difficulty in walking.

Answer 5

L 2/3 ——— Hip flexion
L 3/4 ——— Knee extension ——- Knee jerk L 3/4
L 4/5 ——— Foot dorsi‐flexion
L 5/S 1 —— Knee flexion
—————— Hip extension
S 1/2 ——– Foot plantar‐flexion —- Ankle jerk S 1/2

Question 6

Discussion - Lower limb dermatomes

What Lower limb dermatomes in Spastic legs?

Spastic legs

Examine this man’s lower limbs neurologically. He has had difficulty in walking.

Answer 6

Lower limb dermatomes