Spinal cord disorders

Question 1

Blood supply of spinal cord

Answer 1

Three longitudinal arteries

Two posterior spinal arteries

One anterior spinal artery

Question 2

External causes of spinal-cord injury

Answer 2

Spinal trauma, compression, blockage of blood supply

Question 3

internal causes of spinal-cord injury

Answer 3

• Syrinxes - cysts
• Spinal stroke
• Inflammation e.g. transverse myelitis
• Tumours
• Abscesses
• Vitamin B12 deficiency
• Copper deficiency
• Infection
• MS
• Syphilis

Question 4

Best form of imaging for spinal-cord disorders?

Answer 4

MRI

Question 5

What is myelography?

Answer 5

X-rays of spinal cord are taken after radiopaque contrast injected into subarachnoid space

Question 6

What is the term for a pathology that affects the spinal-cord?

Answer 6

Myelopathy

Question 7

What are the potential abnormal findings following lumbar puncture

Answer 7

• Increased WCC suggesting infection
• Cloudy fluid due to increased WCCs indicates infection e.g. meningitis or encephalitis
• High protein levels due to injury to CNS or spina nerve root
• Abnormal antibodies suggesting MS or infection
• Low glucose: meningitis or cancer because both consume a lot of glucose
• Blood: brain haemorrhage
• Increased opening pressure: space occupying lesion, meningitis

Question 8

Why do we not do a lumbar puncture when there is a raised ICP?

Answer 8

The removal of fluid may suddenly cause brain to herniate

Question 9

Where does CSF run?

Answer 9

Subarachnoid space

Question 10

Brown Sequard syndrome

Answer 10

Damage to hemisection of spinal-cord

Consequences: loss of pain and temperature sensation on the opposite side (because the spinothalamic tract crosses in the spinal-cord)

Spastic paralysis and loss of proprioception and fine touch on the same side

Causes: trauma is the most common cause, tumours, ischaemia, infection or inflammation

Investigations: only really performed in non-traumatic cases, imaging via a spinal x-ray to look for bony trauma, MRI to determine the extent of spinal-cord injury or CT Milagra 30 if the use of MRI is contra indicated

Management: Careful cervical spine or dorsal spine immobilisation and clarification of the level affected, important to identify cases of spinal-cord herniation were surgical intervention may improve prognosis however there is no real treatment

Question 11

Tract loss in Brown-Séquard syndrome

Answer 11

1. Damage to dorsal columns: ipsilateral loss of fine touch, proprioception and vibration
2. Damage to corticospinal tract: loss of motor function ipsilaterally/ UMN symptoms
3. Damage to spinothalamic tract: loss of pain and temperature 1-2 segments below the level of the lesion contralaterally because the tract enters the cord and ascends 1-2 segments before crossing over
4. Damage to anterior grey horn: ipsilateral LMN signs at the level of the lesion

Question 12

Central cord syndrome

Answer 12

Injury to the central region of the spinal-cord, this is the most common incomplete spinal cord syndrome

Causes motor loss in the upper limbs more than the lower

Common in the elderly with degeneration in the cervical spine

Question 13

What causes central cord syndrome?

Answer 13

Most common mechanism is patients who have cervical spondylosis who have an acute hyper extension injury – can occur during car crash or falls

• These injuries cause the ligamentum flavum to squash the spinal-cord, mashing occurs on both sides and the central portion is damaged

Syringomyelia - dilation or expansion of the central cord

Can occur due to Arnold-Chiari malformation type one where the cerebellar tonsils squeeze through the foramen magnum and squashed a portion of the spinal-cord causing dilation on either side

Also due to development of cystic fluid cavity within spinal canal

Question 14

Clinical features of central cord syndrome

Answer 14

The lateral corticospinal tracts are comprised of UMN so we would get UMN signs

• Spastic paralysis
• Hyperreflexia
• Hypertonia
• Arms affected more because it is the portions of the corticospinal tract that control upper limb movement
• Anterior grey horn also affected: LMN lesion at the level of the lesion only (doesn’t affected fibres still descending as they are descending outside of central region)
• The spinothalamic tract’s decussation occurs over the anterior white commissure before entering the anterior or lateral spinothalamic tracts - this is also affected bilaterally so sensation of pain, temperature, crude touch and pressure will be lost at the level of the lesion and below

Most commonly occurs in cervical and thoracic region - said to be like a cape

Question 15

What is anterior cord syndrome?

Answer 15

• Damage to the anterior 2/3 of the spinal cord
• Usually due to anterior artery occlusion/ damage
• Tends to occur lower in the spinal cord

Question 16

Features of anterior cord syndrome

Answer 16

• Wipes out spinothalamic, corticospinal and autonomic pathways
• Faecal and urinary incontinence due to autonomic loss
• Loss of corticospinal tract = UMN lesion so bilateral spastic paralysis
• Loss of spinothalamic tract = loss of pain, crude touch, temperature and pressure
• Damage to anterior grey horn leading to bilateral LMN lesion at the level of the lesion - causing LMN signs AT the level of the lesion
• The sensation of fine touch is maintained

Question 17

What are the consequences of anterior horn lesions?

Answer 17

Anterior horn contains lower motor neurons - the neurons exit and innervate the skeletal muscles

• Damage therefore causes LMN signs
• Hyporeflexia
• Loss of tone
• Flaccid paralysis

Question 18

What causes anterior horn syndrome?

Answer 18

• Anterior spinal artery ischaemia, polio, spinal muscular atrophy
• Viruses: poliomyelitis
• Hx of no vaccinations?
• SMA: genetic condition - seen in young patients
• ALS: causes LMN and UMN lesions

Question 19

Causes of posterior cord syndrome

Answer 19

• Can be caused by tertiary syphilis: tabes dorsalis
• Trauma to the neck: hyperflexion injuries
• B12 deficiency
• Tumours
• Friedrich’s ataxia

Question 20

Supportive management for patients with spinal cord injuries

Answer 20

• Pressure sores: keep skin clean, turn patient frequently, use of special beds
• Urinary difficulty: catheter?
• Pneumonia: teach patient deep breathing exercises and position them at an angle to help drain secretions
• VTE: anticoagulation
• Rehab
• PT/ OT

Question 21

What is radiculopathy?

Answer 21

AKA spinal nerve root dysfunction

• Compression or impingement of spinal nerve root causing pain, numbness, weakness in the distribution of the affected spinal nerve root
• Radicular pain – sharp, burning, shooting
• Compression of the root causes friction, pressure and demyelination and ischaemia
• Cervical radiculopathy: neck pain radiating down arms
• Lumbar radiculopathy: lower back pain, sciatica
• Straight leg raise
• If this occurs below L1 and the cause is a large disc herniation it can cause cauda equina

Question 22

What is the most common cause of radiculopathy?

Answer 22

Herniated disc - most common in lumbar spine

Question 23

Symptoms of radiculopathy?

Answer 23

• Symptoms will affect the myotome and dermatome supplied by that spinal nerve root
• To find the spinal nerve root affected we can test sensation to elicit the dermatome affected and test power in muscles to assess myotome affected
• This is classically seen due to disc prolapse which usually affects either the cervical or the lumbar spine

Question 24

How is radiculopathy diagnosed?

Answer 24

Spinal MRI

If no lesion visible on MRI: Neurophysiology

Question 25

Management of radiculopathy

Answer 25

* 75% of patients with disc herniation will recover spontaneously * Physio to improve spinal alignment * Medication: NSAIDs e.g. diclofenac and neuropathic medication e.g. gabapentin * Treatment of specific infection if appropriate * Surgery: early decompression indicated if: pain unresponsive to medical management, compression with cauda equina, severe motor deficit e.g. foot drop

Question 26

What is cervical spondylosis?

Answer 26

* Degenerative changes in cervical discs * Non-specific term for osteo arthritis or degenerative change * Very common * Degenerative

Question 27

Epidemiology of cervical spondylosis

Answer 27

* F\>M * Highest prevalence in patients in 50s * Affects over 50% of people aged 50+ * Symptomatic in less than 20%

Question 28

What causes cervical spondylosis?

Answer 28

Ageing and cumulative stress leads to degeneration of intervertebral discs thus reducing their ability to act as a shock absorber, the consequences are: * Disc rupture and prolapse into spinal canal * Osteophyte formation * Bone sclerosis * Hypertrophy of spinal ligaments Overall the changes cause narrowing of the spinal canal which can compress the cord Disc rupture can also occur and cause compression of spinal nerve roots

Question 29

How does cervical spondylosis present?

Answer 29

* Cervical pain worse on movement * Referred pain: back of head, shoulder blades, arms * Cervical stiffness * Vague numbness and tingling * Poor balance * Limited ROM * Postural asymmetry: patient can hold head in a position to decompress nerve root

Question 30

How is cervical spondylosis diagnosed and managed?

Answer 30

* Conservative + analgesia if there is no significant motor deficit – worsening neurological deficit warrants surgery * Surgery: decompression although high risk of complications including paralysis, CSF leakage and spinal instability for this reason surgery is reserved for those who have progressive deficits and those in significant pain

Question 31

What is myelopathy?

Answer 31

Compression of the spinal cord through a variety of mechanisms

Question 32

How can we begin to understand what has caused myelopathy?

Answer 32

**Timing can give a clue as to what is causing the pathology the spinal cord** **Acute: mins-hrs** * Trauma (bone injury or disc prolapse) or vascular (haemorrhage into spinal cord causing compression or spinal stroke) * Subacute (days-weeks) * Inflammation (demyelination due to MS or infection), infection (viral, TB, abscess) **Chronic (weeks-months)** * Cervical spondylosis, tumours, syringomyelia, congenital, b12 deficiency

Question 33

Why is the spinal cord prone to infarction?

Answer 33

Zones of the spinal cord have poor blood supply and ischaemia/ infarction can occur rapidly

Question 34

Causes of spinal infarction

Answer 34

* Spinal vascular disease (risk factors same as for stroke) * Iatrogenic e.g. vascular damage during surgery * Arterial dissection or aneurysm * Trauma

Question 35

Presentation of spinal infarction

Answer 35

* Onset is rapid * 80% have back pain that is sudden and severe along with acute neurological signs * Anterior infarction: spares dorsal columns * Posterior infarction: posterior cord syndrome , posterior 1/3 (dorsal columns) affected

Question 36

Diagnosis and investigation of spinal infarction

Answer 36

**Diagnosis** * Usually presents with quadriplegia or paraplegia * Differentials: Guillain-Barre and transverse myelitis but these are slower in onset **Investigation** * Urgent MRI * Coagulation screen: thrombophilia * Angiography * Immune markers for vasculitis

Question 37

Management of spinal infarction

Answer 37

* Secondary prophylaxis may be considered * Supportive: preventing pressure sores, VTE prophylaxis, bowel and bladder care