Diseases of the Spinal Cord

Question 1

What is the difference difference between Myelopathy/Myelitis and Radiculopathy/Radiculititis?

Answer 1

• Myelopathy = anything that caused damage to the spinal cord = UMN
• Radiculopathy = anything that causes damage to the nerve roots of the spinal cord = LMN
• “-itis” = inflammation

Question 2

What are the signs of a Spinal cord pathology? (Myelopathy/Myelitis)

Answer 2

• Motor signs:
• > UMN signs: no wasting, increased tone, increased reflexes, extensor plantar, pyramidal pattern of weakness (flexors, pronators, invertors prominant)
• > Below the level of any lesion
• > Often bilateral (cervical = spastic tetraparesis, thoracic = spastic paraparesis)
• Sensory signs
• > bilateral
• > hemicord lesion = Brown-Séquard syndrome (loss of JPS + vib on the same side, loss of pain + temp on the contralateral side)
• Autonomic
• > bladder/bowel ie. urinary retention, irritable bowel w frequency + incontinence

Question 3

What is Dorsal column responsible for?

Answer 3

• Fine touch
• 2-point discrimination
• Proprioception
• Vibration sense

Question 4

What is (Anterior) Corticospinal tract responsible for?

Answer 4

• Controls motor activity

Question 5

What is (Anterolateral) Spinothalamic tract responsible for?

Answer 5

• Pain

- Temp

Question 6

What are the causes of Myelopathy?

Answer 6

Intrinsic vs. Extrinsic

Surgical:

• Tumour
• Vascular abnormalities
• Degenerative (spine) = most common
• Trauma

Medical:

• Congenital/genetic: Hereditary paraparesis, spinocerebellar ataxias
• Acquired: (inflammation): MS, autoimmune, sarcoid
• Vascular: ischaemic vs. haemorrhage
• Infective: HSV, VZV, EBV, CMV, Measles, HIV
• Metabolic: B12-deficiency
• Malignant: infiltrative/paraneoplastic
• Idiopathic

Question 7

What is the first-line imaging of Myelopathy?

Answer 7

• Imaging: MRI (!!!)

- Investigate cause: bloods (?B-12), CSF (?spinal inflammation)

Question 8

What are the clinical features of Spinal Cord Infarction/Stroke?

Answer 8

• May have vascular risk factors (ie. hypercholesterolaemia, HT, smoking)
• Onset may be sudden (usually) or over several hours
• Pain
• > back pain, radicular
• Weakness
• > usually mid-thoracic
• > usually paraparesis rather than quadraparesis due to susceptibility of thoracic cord to flow-related ischaemia (watershed area!)
• Numbness and paraesthesia
• > damage to sensory tracts
• > usually anterior spinal artery: DORSAL COLUMNS SPARED (therefore, only loss of pain and temp, but not vib and JPS)
• if central sulcal artery: Brown-Séquard syndrome
• Urinary symptoms
• > autonomic features
• > retention followed by bladder and bowel incontinence as spinal shock settles
• may be Spinal Shock:
• > rapid shut-down of the spinal cord
• > UMN takes a little while to develop, may be initially flaccid limbs and no extensor plantars originally

Question 9

What are the investigations of Spinal Cord Infarction/Stroke?

Answer 9

• MRI!!
• • bloods!!
• > (look for evidence of diabetes, vasculitis (polycythaemia, high ESR or CRP)

Question 10

What is the treatment of Spinal Cord Infarction/Stroke?

Answer 10

• Reduce the risk of recurrence:
• > maintain adequate BP
• > reverse hypovolaemia/arrhythmia
• > anti-platelet therapy (ie. Aspirin or clopidogrel)
• OT and physio
• Manage vascular risk factors (HT, diabetes, smoking, etc)

Question 11

What are the clues to a diagnosis of Spinal cord infarction/stroke?

Answer 11

• Sudden onset
• Weakness and sensory features below the level of the lesion
• > (even if no clear UMN signs yet due to spinal shock)
• Vascular risk factors

Question 12

What is the prognosis of Spinal cord infarction/stroke?

Answer 12

• Unless significant motor recovery in first 24hrs, chances of major recovery is low
• Pain may be persistent -> contributes to disability
• 20% mortality -> only 35-40% have more than minimal recovery (about 60% have significant disability)

Question 13

What causes B12 deficiency?

Answer 13

• requires intake of meat, fish and animal by-product, parietal cells to release intrinsic factor (to absorb B12), and terminal ileum (to absorb both IF and B12)*
• Diet (vegans)
• Pernicious anaemia
• > autoantibodies to IF prevent B12 absorption
• Total Gastrectomy
• > (no IF produced due to lack of gastric parietal cells)
• Crohn’s
• > damage to terminal ileum
• Tapeworms
• > they eat the nutrients coming in!

Question 14

What are the signs of B-12 Deficient Myelopathy?

Answer 14

• Paraesthesia of hands and feet -> areflexia
• First UMN sign -> extensor plantars
• Degeneration of corticospinal tracts (paraplegia), and dorsal columns (sensory ataxia)
• Painless urinary retention

Question 15

What investigations of would you do for suspected B-12 Deficient Myelopathy?

Answer 15

• FBC/ blood film:
• > Macrocytic anaemia
• > low B12, high B12 metabolites (homocysteine)

Question 16

What is the treatment for B-12 Deficient Myelopathy?

Answer 16

I/M B-12

the quicker the better -> if u get it early, u can get complete recovery and less likely to be left w residual damage