Spinal Cord Injury

Location & Type

• 50% in C-spine
• Mean age: 19 years old
• Men > Women
• Incomplete quadriplegia most common
• Incomplete paraplegia least common
• Only 1% of SCIs have complete recovery in hospital

Emergency Management

• Above C5 – likely to need intubation

Neurogenic Shock

• Loss of sympathetic – vasodilation; decreased SVR; bradycardia
• Need accurate fluid monitoring – Swan-Ganz on ICU

Spinal Shock

• Flaccid areflexia
• Occurs with cord injury – not cauda equina injury
• Resolves within 48 hours usually
• No assessment regarding injury can be made till spinal shock resolves
• Heralded by return of Bulbocavernosus reflex (spinal reflex arc S1, 2, 3)
  • Absence occurs in spinal shock but not complete cord injury
  • May be absent in cauda equina, conus, or sacral injury

Classification of SCI

• Incomplete or Complete
• Any sensation or motor power below the affected level = incomplete
• Sacral sparing often present in absence of motor power
• Level of injury described as the lowest normally functioning level
• ASIA scoring system classifies SCI (below)

ASIA Classification

Injury	Features
A	Complete – No sensory or motor function below level
B	Incomplete – Sensory but no motor function below level
C	Incomplete – Motor and sensory function below level; At least 50% key muscles below level have grade 2 or less power
D	Incomplete – At least 50% key muscles below level have grade 3 or more power
E	Normal Motor and Sensory function

Spinal Cord Injury Syndromes – Incomplete Patterns

Central Cord Syndrome

• Most common (10%)
• Good prognosis for recovery
• Associated with hyperextension of a stenotic C-spine
• Predominantly upper limb motor weakness
  • Distal limb affected more than proximal (hands)
• Because upper limb neurons more central in corticospinal tracts
• Sensory involvement variable but usually minimal

Brown-Sequard Syndrome

• 4% incidence
• Best prognosis – 75% ambulate independently
• Penetrating injury
• Effectively a cord hemisection
• Ipsilateral motor loss (corticospinal tracts)
• Ipsilateral proprioception, deep sensation & vibration loss (dorsal column)
• Contralateral pain, temperature, and light touch loss (spinothalamic tracts)

Anterior Cord Syndrome

• 2% of SCI
• Due to injury of anterior spinal artery:
  • Traumatic – flexion axial load: artery pinched by bone/disc
  • Ischaemic – vascular occlusion in arteriopath
• Affects anterior 2/3 of cord
• Quadra or paraplegic with loss of pain & temperature sensation
  • Dorsal columns (proprioception, vibration, deep sensation) spared
• Appears very similar to a complete injury
• Poor prognosis – 10% are able to ambulate independently

Posterior Cord Syndrome

• Rare – 1% of SCI
• Hyperextension injury
• Dorsal columns only (proprioception, vibration, deep sensation)

Conus Medullaris Syndrome

• Conus is the termination of the cord
• Variable – T12-L2 (usually L1)
• Conus contains all the cell bodies of the lumbar & sacral roots
• Injury causes a mixed picture of upper and lower motor neuron symptoms
• Unusual pattern of motor and sensory loss is seen
• Affects all lumbar & sacral roots to some degree
• Bulbocavernosus reflex is absent

Cauda Equina Syndrome

• Injury to the nerve roots outside the cord
• Lower motor neuron injury
• Bladder, bowel, and sexual dysfunction are typical
• Sacral/saddle anaesthesia
• Bilateral symptoms

Acute Management of SCI

• Prevent secondary injury to cord
  • Immobilise spine
  • Maintain oxygenation
  • Maintain normovolaemia
    • Aim for MAP 85mmHg
• Intubate and use invasive monitoring if necessary
• Diagnose & treat neurogenic shock

Treatment of SCI

Surgical Decompression & Stabilisation

• Traditional evidence says no difference in clinical results if decompression within 72 hours or within 5 days
• Non-clinical studies suggest decompression before 24 hours will give favourable outcome
• More recent RCT early results suggest decompression within 24 hours gives best results
• (Surgical Treatment for Acute Spinal Cord Injury Study – STASCIS)

Hypothermia

• Managing patient at 33 degrees reduces secondary cord injury
• Retrospective studies only – weak evidence
• No prospective or randomized trials

Methylprednisolone

• Evidence stems from National Acute Spinal Cord Injury Study (NASCIS)
• Initially no difference with use of MP in terms of motor/sensory scores
• Post-hoc analysis showed:
  • MP (30mg/kg) within 8 hours of injury for 48 hours gave better neurologic function at 6 weeks and 6 months
  • No difference at 1 year
  • Also showed that rate of pneumonia, death, and sepsis higher in those given MP for 48 rather than 24 hours
• Current Guidelines in US
  • Recommends use of MP for 23 hours if given at under 8hrs from injury, as a possible treatment as long as care giver aware that evidence for complications is greater than evidence for its benefit

Other Medical Therapies

• Several are in trial but results of high-quality studies are pending
• EPO; Anti-Nogo antibodies; Rho Antagonists etc.

Spinal Cord Injury Rehabilitation

• 85% who survive first 24 hrs after SCI are alive at 10 years
• Leading causes of mid to long-term death
  1. Sepsis – usually pulmonary
  2. Non-ischaemic heart disease
  3. Suicide

Classification & Definitions of SCI

• ASIA System is universally accepted
• Most reliable 72 hours after injury when spinal shock should have resolved
• A is worst and E is best

ASIA A | Complete SCI – no sensory or motor function & no sacral sparing |
ASIA B | Incomplete – Complete motor loss but sensory sparing at some level |
ASIA C | Incomplete - <50% muscles below the injury level have MRC power <3 |
ASIA D | Incomplete - >50% muscles below level have MRC power >3 |
ASIA E | Normal |

• Sensory level: Defined as the most cephalad level with normal pin prick and light touch
• Motor level: The most caudal level with MRC power 3 bilaterally as long as level immediately proximal is grade 5
• Skeletal level: Level at which the major bony injury exists
• Neurologic level: Most cephalic level with normal neurology bilaterally

Acute Management of SCI

• Prevent secondary injury
• Maintain MAP 80
• Good Oxygenation
• Steroids – may be of benefit if within first 8 hours
• C-spine Protection

Medical Complications in SCI

Pulmonary

• Problems occur because of:
  • Shallow breathing
  • Inability to clear secretions
  • Atelectasis

Cardiac

• Loss of sympathetic tone
• Bradycardia, flushing, sweating

Thromboembolism

• 15-80% DVT
• PE 2-12%
• Usually before 3 weeks
• Prophylaxis required

Bladder

• UMN causes spastic bladder – increased tone with retention or frequent emptying
• LMN causes loss of tone and retention with obstructive hydronephrosis
• Can cause recurrent UTI, pyelonephritis, renal stones, and kidney failure
• Intermittent or permanent catheterisation

Bowel

• LMN causes incontinence – difficult to control
• UMN causes high tone bowel – need regular manual evacuations etc.

Depression

• Frequent problem
• High suicide rate

Skin

• Pressure sores are a constant problem
• Special mattresses and high vigilance required

Musculoskeletal

• Osteoporosis from disuse
  • Fracture risk is high – difficult to fix – poor bone, deforming forces
  • Conservative management often appropriate
• Heterotopic Ossification
  • Most common around hip
  • Some degree in 50%, ankylosis in 5%

Functional Outcomes in SCI

• Some motor recovery documented up to 2 years after injury
• Prognosis determined by degree of initial neurologic injury
• Best prognosis in <30 year olds (most patients <30yrs)
• Worst prognosis is with cord haemorrhage seen on MRI
• 90% of tetraplegics will recover one root level of function
• Complete paraplegics generally do not recover function
• 80% of incomplete SCI regain to MRC 3 or more in hip flexion & knee extension by 1 year
• Quicker recovery (<3 months) indicates better outcome
• Upper limbs tend to recover better than lower

Outcome by Level of Injury

• C6 is the level where function and independence vastly improves

C1-3 | If survive require respiratory assistance |
C4 | Respiratory support early but may not require in long term; Need help with transfers & mobility; Need wheelchair with chin and head support |
C5 Quad | Shoulder function intact; Can feed with special instruments; Need a powered wheelchair (can’t ambulate or transfer independently) |
C6 Quad | Can transfer and dress independently; Can use a manual wheelchair; Can feed independently |
C7-8 Quad | Manual Wheelchair; Independent feeding, dressing, manual wheelchair; Personal bowel and bladder care; Can drive a specialised van |

Ambulation after SCI

• 90% with ASIA B will be able to ambulate at time of discharge
• Motor incomplete better prognosis than sensory complete

Tendon Transfer Surgery & Arthrodesis

• Priorities are to restore elbow flexion and wrist extension
• Allows hand to mouth and transfers plus self-propulsion of wheelchair
• Wrist Fusion