Spastic legs

Question 1

Spastic legs presentation

Answer 1

This man had difficulty in walking Examine his lower limbs neurologically.

Question 2

Clinical signs in Spastic legs

Answer 2

1. Inspection: Wheelchair and walking sticks (disuse atrophy and contractures may be present if chronic)
2. Tone: Increased tone and ankle clonus
3. Power: Generalized weakness
4. Reflexes: Hyper‐reflexia and extensor plantars
5. Gait: ‘scissoring’

Question 3

Additional signs in Spastic legs

Answer 3

1. Examine for a sensory level suggestive of a spinal lesion
2. Look at the back for scars or spinal deformity
3. Search for features of multiple sclerosis, e.g. cerebellar signs, fundoscopy for optic atrophy
4. Ask about bladder symptoms and note the presence or absence of urinary catheter.
5. Offer to test anal tone

Question 4

Common causes of Spastic legs

Answer 4

1. Multiple sclerosis
2. Spinal cord compression/cervical myelopathy
3. Trauma
4. Motor neurone disease (no sensory signs)

Question 5

Other causes of Spastic legs

Answer 5

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

Question 6

Cord compression

Answer 6

• Medical emergency

Question 7

Causes of Cord compression

Answer 7

1. Trauma: # vertebra
2. Tumour: Malignancy
3. Infection: abscess or TB
4. Disc prolapse (above L1/2)

Question 8

Investigation of choice for cord compression

Answer 8

Spinal MRI

Question 9

Treatment of cord compression

Answer 9

1. Urgent surgical decompression
2. Consider steroids and radiotherapy (for a malignant cause)

Question 10

Lumbo‐sacral root levels

Answer 10

• L 2/3 Hip flexion
• L 3/4 Knee extension => Knee jerk L 3/4
• L 4/5 Foot dorsi‐flexion
• L 5/S1 Knee flexion & Hip extension
• S 1/2 Foot plantar‐flexion => Ankle jerk S 1/2

Question 11

Lower limb dermatomes

Answer 11

Hints:
L3 (L three to the knee)
L4 (L four to the floor medially)
S2, 3, 4 (keeps the faeces off the floor!)